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Monday, February 24, 2025

Ireland

From Wikipedia, the free encyclopedia
Éire (Irish)
Airlann (Ulster Scots)
Satellite image of Ireland
Satellite image, October 2010
 
Location of Ireland (dark green) in Europe (dark grey)

Geography
LocationNorthwestern Europe
Coordinates53°N 8°W
ArchipelagoBritish Isles
Adjacent toAtlantic Ocean
Area84,421 km2 (32,595 sq mi)
Area rank20th
Coastline7,527 km (4677.1 mi)
Highest elevation1,041 m (3415 ft)
Highest pointCarrauntoohil
Administration
Largest cityDublin, pop. 1,458,154 Metropolitan Area (2022)
CountryNorthern Ireland
Largest cityBelfast, pop. 671,559 Metropolitan Area (2011)
Demographics
DemonymIrish
Population7,185,600 (2023 estimate)
Population rank19th
Pop. density82.2/km2 (212.9/sq mi)
Languages
Ethnic groups
Additional information
Time zone
 • Summer (DST)

Ireland (/ˈaɪərlənd/ , IRE-lənd; Irish: Éire [ˈeːɾʲə] ; Ulster-Scots: Airlann [ˈɑːrlən]) is an island in the North Atlantic Ocean, in Northwestern Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the second-largest island of the British Isles, the third-largest in Europe, and the twentieth-largest in the world. Geopolitically, the island is divided between the Republic of Ireland (officially named Ireland), a sovereign state covering five-sixths of the island, and Northern Ireland, which is part of the United Kingdom. As of 2022, the population of the entire island is just over 7 million, with 5.1 million in the Republic of Ireland and 1.9 million in Northern Ireland, ranking it the second-most populous island in Europe after Great Britain.

The geography of Ireland comprises relatively low-lying mountains surrounding a central plain, with several navigable rivers extending inland. Its lush vegetation is a product of its mild but changeable climate which is free of extremes in temperature. Much of Ireland was woodland until the end of the Middle Ages. Today, woodland makes up about 10% of the island, compared with a European average of over 33%, with most of it being non-native conifer plantations. The Irish climate is influenced by the Atlantic Ocean and thus very moderate, and winters are milder than expected for such a northerly area, although summers are cooler than those in continental Europe. Rainfall and cloud cover are abundant.

Gaelic Ireland had emerged by the 1st century AD. The island was Christianised from the 5th century onwards. During this period Ireland was divided into many petty kingships under provincial kingships (Cúige "fifth" of the traditional provinces) vying for dominance and the title of High King of Ireland. In the late 8th to early 11th century AD, Viking raids and settlements took place culminating in the Battle of Clontarf on 23 April 1014 which resulted in the ending of Viking power in Ireland. Following the 12th-century Anglo-Norman invasion, England claimed sovereignty. However, English rule did not extend over the whole island until the 16th–17th century Tudor conquest, which led to colonisation by settlers from Britain. In the 1690s, a system of Protestant English rule was designed to materially disadvantage the Catholic majority and Protestant dissenters, and was extended during the 18th century. With the Acts of Union in 1801, Ireland became a part of the United Kingdom. A war of independence in the early 20th century was followed by the partition of the island, leading to the creation of the Irish Free State, which became increasingly sovereign over the following decades until it declared a republic in 1948 (Republic of Ireland Act, 1948) and Northern Ireland, which remained a part of the United Kingdom. Northern Ireland saw much civil unrest from the late 1960s until the 1990s. This subsided following the Good Friday Agreement in 1998. In 1973, both the Republic of Ireland and the United Kingdom, with Northern Ireland as part of it, joined the European Economic Community. Following a referendum vote in 2016, the United Kingdom, Northern Ireland included, left the European Union (EU) in 2020. Northern Ireland was granted a limited special status and allowed to operate within the EU single market for goods without being in the European Union.

Irish culture has had a significant influence on other cultures, especially in the field of literature. Alongside mainstream Western culture, a strong indigenous culture exists, as expressed through Gaelic games, Irish music, Irish language, and Irish dance. The island's culture shares many features with that of Great Britain, including the English language, and sports such as association football, rugby, horse racing, golf, and boxing.

Name

The names Ireland and Éire derive from Old Irish Ériu, a goddess in Irish mythology first recorded in the ninth century. The etymology of Ériu is disputed but may derive from the Proto-Indo-European root *h2uer, referring to flowing water.

History

Prehistoric Ireland

During the last glacial period, and until about 16,000 BC, much of Ireland was periodically covered in ice. The relative sea level was less than 50m lower resulting in an ice bridge (but not a land bridge) forming between Ireland and Great Britain. By 14,000 BC this ice bridge existed only between Northern Ireland and Scotland and by 12,000 BC Ireland was completely separated from Great Britain. Later, around 6,100 BC, Great Britain became separated from continental Europe. Until recently, the earliest evidence of human activity in Ireland was dated at 12,500 years ago, demonstrated by a butchered bear bone found in a cave in County Clare. Since 2021, the earliest evidence of human activity in Ireland is dated to 33,000 years ago.

By about 8,000 BC, more sustained occupation of the island has been shown, with evidence for Mesolithic communities around the island.

Some time before 4,000 BC, Neolithic settlers introduced cereal cultivars, domesticated animals such as cattle and sheep, built large timber buildings, and stone monuments. The earliest evidence for farming in Ireland or Great Britain is from Ferriter's Cove, County Kerry, where a flint knife, cattle bones and a sheep's tooth were carbon-dated to c. 4,350 BC. Field systems were developed in different parts of Ireland, including at the Céide Fields, that has been preserved beneath a blanket of peat in present-day Tyrawley. An extensive field system, arguably the oldest in the world, consisted of small divisions separated by dry-stone walls. The fields were farmed for several centuries between 3,500 BC and 3,000 BC. Wheat and barley were the principal crops.

The Bronze Age began around 2,500 BC, with technology changing people's everyday lives during this period through innovations such as the wheel, harnessing oxen, weaving textiles, brewing alcohol and metalworking, which produced new weapons and tools, along with fine gold decoration and jewellery, such as brooches and torcs.

Emergence of Celtic Ireland

How and when the island became Celtic has been debated for close to a century, with the migrations of the Celts being one of the more enduring themes of archaeological and linguistic studies. The most recent genetic research strongly associates the spread of Indo-European languages (including Celtic) through Western Europe with a people bringing a composite Beaker culture, with its arrival in Britain and Ireland dated to around the middle of the third millennium BC. According to John T. Koch and others, Ireland in the Late Bronze Age was part of a maritime trading-network culture called the Atlantic Bronze Age that also included Britain, western France and Iberia, and that this is where Celtic languages developed. This contrasts with the traditional view that their origin lies in mainland Europe with the Hallstatt culture.

The Uragh Stone Circle, a Neolithic stone circle in Tuosist, close to Gleninchaquin Park, County Kerry

The long-standing traditional view is that the Celtic language, Ogham script and culture were brought to Ireland by waves of invading or migrating Celts from mainland Europe. This theory draws on the Lebor Gabála Érenn, a medieval Christian pseudo-history of Ireland, along with the presence of Celtic culture, language and artefacts found in Ireland such as Celtic bronze spears, shields, torcs and other finely crafted Celtic associated possessions. The theory holds that there were four separate Celtic invasions of Ireland. The Priteni were said to be the first, followed by the Belgae from northern Gaul and Britain. Later, Laighin tribes from Armorica (present-day Brittany) were said to have invaded Ireland and Britain more or less simultaneously. Lastly, the Milesians (Gaels) were said to have reached Ireland from either northern Iberia or southern Gaul. It was claimed that a second wave named the Euerni, belonging to the Belgae people of northern Gaul, began arriving about the sixth century BC. They were said to have given their name to the island.

The theory was advanced in part because of the lack of archaeological evidence for large-scale Celtic immigration, though it is accepted that such movements are notoriously difficult to identify. Historical linguists are skeptical that this method alone could account for the absorption of Celtic language, with some saying that an assumed processual view of Celtic linguistic formation is 'an especially hazardous exercise'. Genetic lineage investigation into the area of Celtic migration to Ireland has led to findings that showed no significant differences in mitochondrial DNA between Ireland and large areas of continental Europe, in contrast to parts of the Y-chromosome pattern. When taking both into account, a study concluded that modern Celtic speakers in Ireland could be thought of as European "Atlantic Celts" showing a shared ancestry throughout the Atlantic zone from northern Iberia to western Scandinavia rather than substantially central European. In 2012, research showed that the occurrence of genetic markers for the earliest farmers was almost eliminated by Beaker-culture immigrants: they carried what was then a new Y-chromosome R1b marker, believed to have originated in Iberia about 2,500 BC. The prevalence amongst modern Irish men of this mutation is a remarkable 84%, the highest in the world, and closely matched in other populations along the Atlantic fringes down to Spain. A similar genetic replacement happened with lineages in mitochondrial DNA. This conclusion is supported by recent research carried out by the geneticist David Reich, who says: "British and Irish skeletons from the Bronze Age that followed the Beaker period had at most 10 per cent ancestry from the first farmers of these islands, with other 90 per cent from people like those associated with the Bell Beaker culture in the Netherlands." He suggests that it was Beaker users who introduced an Indo-European language, represented here by Celtic (i.e. a new language and culture introduced directly by migration and genetic replacement).

Late antiquity and early medieval times

The Scoti were Gaelic-speaking people from Ireland who settled in western Scotland in the 6th century or before.

The earliest written records of Ireland come from classical Greco-Roman geographers. Ptolemy in his Almagest refers to Ireland as Mikra Brettania ("Little Britain"), in contrast to the larger island, which he called Megale Brettania ("Great Britain"). In his map of Ireland in his later work, Geography, Ptolemy refers to Ireland as Iouernia and to Great Britain as Albion. These 'new' names were likely to have been the local names for the islands at the time. The earlier names, in contrast, were likely to have been coined before direct contact with local peoples was made.

The Romans referred to Ireland by this name too in its Latinised form, Hibernia, or Scotia. Ptolemy records 16 nations inhabiting every part of Ireland in 100 AD. The relationship between the Roman Empire and the kingdoms of ancient Ireland is unclear. However, a number of finds of Roman coins have been made, for example at the Iron Age settlement of Freestone Hill near Gowran and Newgrange.

Ireland continued as a patchwork of rival kingdoms; however, beginning in the 7th century, a concept of national kingship gradually became articulated through the concept of a High King of Ireland. Medieval Irish literature portrays an almost unbroken sequence of high kings stretching back thousands of years, but some modern historians believe the scheme was constructed in the 8th century to justify the status of powerful political groupings by projecting the origins of their rule into the remote past.

All of the Irish kingdoms had their own kings but were nominally subject to the high king. The high king was drawn from the ranks of the provincial kings and ruled also the royal kingdom of Meath, with a ceremonial capital at the Hill of Tara. The concept did not become a political reality until the Viking Age and even then was not a consistent one. Ireland did have a culturally unifying rule of law: the early written judicial system, the Brehon Laws, administered by a professional class of jurists known as the brehons.

The Chronicle of Ireland records that in 431, Bishop Palladius arrived in Ireland on a mission from Pope Celestine I to minister to the Irish "already believing in Christ". The same chronicle records that Saint Patrick, Ireland's best known patron saint, arrived the following year. There is continued debate over the missions of Palladius and Patrick, but the consensus is that they both took place and that the older druid tradition collapsed in the face of the new religion. Irish Christian scholars excelled in the study of Latin and Greek learning and Christian theology. In the monastic culture that followed the Christianisation of Ireland, Latin and Greek learning was preserved in Ireland during the Early Middle Ages in contrast to elsewhere in Western Europe, where the Dark Ages followed the Fall of the Western Roman Empire.

A folio of the Book of Kells showing Christ enthroned

The arts of manuscript illumination, metalworking and sculpture flourished and produced treasures such as the Book of Kells, ornate jewellery and the many carved stone crosses that still dot the island today. A mission founded in 563 on Iona by the Irish monk Saint Columba began a tradition of Irish missionary work that spread Celtic Christianity and learning to Scotland, England and the Frankish Empire on continental Europe after the fall of Rome. These missions continued until the late Middle Ages, establishing monasteries and centres of learning, producing scholars such as Sedulius Scottus and Johannes Eriugena and exerting much influence in Europe.

From the 9th century, waves of Viking raiders plundered Irish monasteries and towns. These raids added to a pattern of raiding and endemic warfare that was already deep-seated in Ireland. The Vikings were involved in establishing most of the major coastal settlements in Ireland: Dublin, Limerick, Cork, Wexford, Waterford, as well as other smaller settlements.

Norman and English invasions

Remains of the 12th-century Trim Castle in County Meath, the largest Norman castle in Ireland

On 1 May 1169, an expedition of Cambro-Norman knights, with an army of about 600 men, landed at Bannow Strand in present-day County Wexford. It was led by Richard de Clare, known as 'Strongbow' owing to his prowess as an archer. The invasion, which coincided with a period of renewed Norman expansion, was at the invitation of Dermot Mac Murrough, King of Leinster.

In 1166, Mac Murrough had fled to Anjou, France, following a war involving Tighearnán Ua Ruairc, of Breifne, and sought the assistance of the Angevin King Henry II, in recapturing his kingdom. In 1171, Henry arrived in Ireland in order to review the general progress of the expedition. He wanted to re-exert royal authority over the invasion which was expanding beyond his control. Henry successfully re-imposed his authority over Strongbow and the Cambro-Norman warlords and persuaded many of the Irish kings to accept him as their overlord, an arrangement confirmed in the 1175 Treaty of Windsor.

The invasion was legitimised by reference to provisions of the alleged Papal Bull Laudabiliter, issued by an Englishman, Adrian IV, in 1155. The document apparently encouraged Henry to take control in Ireland in order to oversee the financial and administrative reorganisation of the Irish Church and its integration into the Roman Church system. Some restructuring had already begun at the ecclesiastical level following the Synod of Kells in 1152. There has been significant controversy regarding the authenticity of Laudabiliter, and there is no general agreement as to whether the bull was genuine or a forgery. Further, it had no standing in the Irish legal system.

Political boundaries in Ireland in 1450, before the plantations

In 1172, Pope Alexander III further encouraged Henry to advance the integration of the Irish Church with Rome. Henry was authorised to impose a tithe of one penny per hearth as an annual contribution. This church levy, called Peter's Pence, is extant in Ireland as a voluntary donation. In turn, Henry assumed the title of Lord of Ireland which Henry conferred on his younger son, John Lackland, in 1185. This defined the Anglo-Norman administration in Ireland as the Lordship of Ireland. When Henry's successor died unexpectedly in 1199, John inherited the crown of England and retained the Lordship of Ireland. Over the century that followed, Norman feudal law gradually replaced the Gaelic Brehon Law across large areas, so that by the late 13th century the Norman-Irish had established a feudal system throughout much of Ireland. Norman settlements were characterised by the establishment of baronies, manors, towns and the seeds of the modern county system. A version of Magna Carta (the Great Charter of Ireland), substituting Dublin for London and the Irish Church for, the English church at the time, the Catholic Church, was published in 1216 and the Parliament of Ireland was founded in 1297.

Gaelicisation

From the mid-14th century, after the Black Death, Norman settlements in Ireland went into a period of decline. The Norman rulers and the Gaelic Irish elites intermarried and the areas under Norman rule became Gaelicised. In some parts, a hybrid Hiberno-Norman culture emerged. In response, the Irish parliament passed the Statutes of Kilkenny in 1367. These were a set of laws designed to prevent the assimilation of the Normans into Irish society by requiring English subjects in Ireland to speak English, follow English customs and abide by English law.

By the end of the 15th century, central English authority in Ireland had all but disappeared, and a renewed Irish culture and language, albeit with Norman influences, was again dominant. English Crown control remained relatively unshaken in an amorphous foothold around Dublin known as The Pale, and under the provisions of Poynings' Law of 1494, Irish Parliamentary legislation was subject to the approval of the English Privy Council.

The Kingdom of Ireland

A 16th-century perception of Irish women and girls, illustrated in the manuscript "Théâtre de tous les peuples et nations de la terre avec leurs habits et ornemens divers, tant anciens que modernes, diligemment depeints au naturel". Painted by Lucas d'Heere in the 2nd half of the 16th century. Preserved in the Ghent University Library.

The title of King of Ireland was re-created in 1542 by Henry VIII, the then King of England, of the Tudor dynasty. English rule was reinforced and expanded in Ireland during the latter part of the 16th century, leading to the Tudor conquest of Ireland. A near-complete conquest was achieved by the turn of the 17th century, following the Nine Years' War and the Flight of the Earls.

This control was consolidated during the wars and conflicts of the 17th century, including the English and Scottish colonisation in the Plantations of Ireland, the Wars of the Three Kingdoms and the Williamite War. Irish losses during the Wars of the Three Kingdoms (which, in Ireland, included the Irish Confederacy and the Cromwellian conquest of Ireland) are estimated to include 20,000 battlefield casualties. 200,000 civilians are estimated to have died as a result of a combination of war-related famine, displacement, guerrilla activity and pestilence throughout the war. A further 50,000 were sent into indentured servitude in the West Indies. Physician-general William Petty estimated that 504,000 Catholic Irish and 112,000 Protestant settlers died, and 100,000 people were transported, as a result of the war. If a prewar population of 1.5 million is assumed, this would mean that the population was reduced by almost half.

The religious struggles of the 17th century left a deep sectarian division in Ireland. Religious allegiance now determined the perception in law of loyalty to the Irish King and Parliament. After the passing of the Test Act 1672, and the victory of the forces of the dual monarchy of William and Mary over the Jacobites, Roman Catholics and nonconforming Protestant Dissenters were barred from sitting as members in the Irish Parliament. Under the emerging Penal Laws, Irish Roman Catholics and Dissenters were increasingly deprived of various civil rights, even the ownership of hereditary property. Additional regressive punitive legislation followed in 1703, 1709 and 1728. This completed a comprehensive systemic effort to materially disadvantage Roman Catholics and Protestant Dissenters while enriching a new ruling class of Anglican conformists. The new Anglo-Irish ruling class became known as the Protestant Ascendancy.

Half-hanging of suspected United Irishmen

The "Great Frost" struck Ireland and the rest of Europe between December 1739 and September 1741, after a decade of relatively mild winters. The winters destroyed stored crops of potatoes and other staples, and the poor summers severely damaged harvests. This resulted in the famine of 1740. An estimated 250,000 people (about one in eight of the population) died from the ensuing pestilence and disease. The Irish government halted export of corn and kept the army in quarters but did little more. Local gentry and charitable organisations provided relief but could do little to prevent the ensuing mortality.

In the aftermath of the famine, an increase in industrial production and a surge in trade brought a succession of construction booms. The population soared in the latter part of this century and the architectural legacy of Georgian Ireland was built. In 1782, Poynings' Law was repealed, giving Ireland legislative independence from Great Britain for the first time since 1495. The British government, however, still retained the right to nominate the government of Ireland without the consent of the Irish parliament.

1798 Rebellion

"The Camp on Vinegar Hill" - an illustration by George Cruikshank to accompany William Hamilton Maxwell's 1845 work History of the Irish rebellion in 1798

In 1798, members of the Protestant Dissenter tradition (mainly Presbyterian) made common cause with Roman Catholics in a republican rebellion inspired and led by the Society of United Irishmen, with the aim of creating an independent Ireland. Despite assistance from France the rebellion was put down by British and Irish government and yeomanry forces. The rebellion lasted from the 24th of May to the 12th of October that year and saw the establishment of the short lived Irish Republic (1798) in the province of Connacht. It saw numerous battles across the island with an estimated 30,000 people dead.

Union with Great Britain

As a direct result of the 1798 rebellion in its aftermath in 1800, the British and Irish parliaments both passed Acts of Union that, with effect from 1 January 1801, merged the Kingdom of Ireland and the Kingdom of Great Britain to create a United Kingdom of Great Britain and Ireland.

The passage of the Act in the Irish Parliament was ultimately achieved with substantial majorities, having failed on the first attempt in 1799. According to contemporary documents and historical analysis, this was achieved through a considerable degree of bribery, with funding provided by the British Secret Service Office, and the awarding of peerages, places and honours to secure votes. Thus, the parliament in Ireland was abolished and replaced by a united parliament at Westminster in London, though resistance remained, as evidenced by Robert Emmet's failed Irish Rebellion of 1803.

Aside from the development of the linen industry, Ireland was largely passed over by the Industrial Revolution, partly because it lacked coal and iron resources and partly because of the impact of the sudden union with the structurally superior economy of England, which saw Ireland as a source of agricultural produce and capital.

A depiction of the Great Famine from Our Boys in Ireland by Henry Willard French (1891)

The Great Famine of 1845–1851 devastated Ireland, as in those years Ireland's population fell by one-third. More than one million people died from starvation and disease, with an additional million people emigrating during the famine, mostly to the United States and Canada. In the century that followed, an economic depression caused by the famine resulted in a further million people emigrating. By the end of the decade, half of all immigration to the United States was from Ireland. The period of civil unrest that followed until the end of the 19th century is referred to as the Land War. Mass emigration became deeply entrenched and the population continued to decline until the mid-20th century. Immediately prior to the famine the population was recorded as 8.2 million by the 1841 census. The population has never returned to this level since. The population continued to fall until 1961; County Leitrim was the final Irish county to record a population increase post-famine, in 2006.

The 19th and early 20th centuries saw the rise of modern Irish nationalism, primarily among the Roman Catholic population. The pre-eminent Irish political figure after the Union was Daniel O'Connell. He was elected as Member of Parliament for Ennis in a surprise result and despite being unable to take his seat as a Roman Catholic. O'Connell spearheaded a vigorous campaign that was taken up by the Prime Minister, the Irish-born soldier and statesman, the Duke of Wellington. Steering the Catholic Relief Bill through Parliament, aided by future prime minister Robert Peel, Wellington prevailed upon a reluctant George IV to sign the Bill and proclaim it into law. George's father had opposed the plan of the earlier Prime Minister, Pitt the Younger, to introduce such a bill following the Union of 1801, fearing Catholic Emancipation to be in conflict with the Act of Settlement 1701.

Daniel O'Connell led a subsequent campaign, for the repeal of the Act of Union, which failed. Later in the century, Charles Stewart Parnell and others campaigned for autonomy within the Union, or "Home Rule". Unionists, especially those located in Ulster, were strongly opposed to Home Rule, which they thought would be dominated by Catholic interests. After several attempts to pass a Home Rule bill through parliament, it looked certain that one would finally pass in 1914. To prevent this from happening, the Ulster Volunteers were formed in 1913 under the leadership of Edward Carson.

Their formation was followed in 1914 by the establishment of the Irish Volunteers, whose aim was to ensure that the Home Rule Bill was passed. The Act was passed but with the "temporary" exclusion of the six counties of Ulster, which later became Northern Ireland. Before it could be implemented, however, the Act was suspended for the duration of the First World War. The Irish Volunteers split into two groups. The majority, approximately 175,000 in number, under John Redmond, took the name National Volunteers and supported Irish involvement in the war. A minority, approximately 13,000, retained the Irish Volunteers' name and opposed Ireland's involvement in the war.

Sackville Street (now O'Connell Street), Dublin, after the 1916 Easter Rising

The Easter Rising of 1916 was carried out by the latter group together with a smaller socialist militia, the Irish Citizen Army. The British response, executing 15 leaders of the Rising over a period of ten days and imprisoning or interning more than a thousand people, turned the mood of the country in favour of the rebels. Support for Irish republicanism increased further due to the ongoing war in Europe, as well as the Conscription Crisis of 1918.

The pro-independence republican party, Sinn Féin, received overwhelming endorsement in the general election of 1918, and in 1919 proclaimed an Irish Republic, setting up its own parliament (Dáil Éireann) and government. Simultaneously the Volunteers, which became known as the Irish Republican Army (IRA), launched a three-year guerrilla war, which ended in a truce in July 1921 (although violence continued until June 1922, mostly in Northern Ireland).

Partition

In December 1921, the Anglo-Irish Treaty was concluded between the British government and representatives of the Second Dáil. It gave Ireland complete independence in its home affairs and practical independence for foreign policy, but an opt-out clause allowed Northern Ireland to remain within the United Kingdom, which it immediately exercised. Additionally, Members of the Free State Parliament were required to swear an oath of allegiance to the Constitution of the Irish Free State and make a statement of faithfulness to the king. Disagreements over these provisions led to a split in the nationalist movement and a subsequent Irish Civil War between the new government of the Irish Free State and those opposed to the treaty, led by Éamon de Valera. The civil war officially ended in May 1923 when de Valera issued a cease-fire order.

Independence

Annotated page from the Anglo-Irish Treaty that established the Irish Free State and independence for 26 out of 32 Irish counties

During its first decade, the newly formed Irish Free State was governed by the victors of the civil war. When de Valera achieved power, he took advantage of the Statute of Westminster and political circumstances to build upon inroads to greater sovereignty made by the previous government. The oath was abolished and in 1937 a new constitution was adopted. This completed a process of gradual separation from the British Empire that governments had pursued since independence. However, it was not until 1949 that the state was declared, officially, to be the Republic of Ireland.

The state was neutral during World War II, but offered clandestine assistance to the Allies, particularly in the potential defence of Northern Ireland. Despite their country's neutrality, approximately 50,000 volunteers from independent Ireland joined the British forces during the war, four being awarded Victoria Crosses.

The German intelligence was also active in Ireland. Its operations ended in September 1941 when police made arrests based on surveillance carried out on the key diplomatic legations in Dublin. To the authorities, counterintelligence was a fundamental line of defence. With a regular army of only slightly over seven thousand men at the start of the war, and with limited supplies of modern weapons, the state would have had great difficulty in defending itself from invasion from either side in the conflict.

Large-scale emigration marked most of the post-WWII period (particularly during the 1950s and 1980s), but beginning in 1987 the economy improved, and the 1990s saw the beginning of substantial economic growth. This period of growth became known as the Celtic Tiger. The Republic's real GDP grew by an average of 9.6% per annum between 1995 and 1999, in which year the Republic joined the euro. In 2000, it was the sixth-richest country in the world in terms of GDP per capita. Historian R. F. Foster argues the cause was a combination of a new sense of initiative and the entry of American corporations. He concludes the chief factors were low taxation, pro-business regulatory policies, and a young, tech-savvy workforce. For many multinationals, the decision to do business in Ireland was made easier still by generous incentives from the Industrial Development Authority. In addition European Union membership was helpful, giving the country lucrative access to markets that it had previously reached only through the United Kingdom, and pumping huge subsidies and investment capital into the Irish economy.

Modernisation brought secularisation in its wake. The traditionally high levels of religiosity have sharply declined. Foster points to three factors: First, Irish feminism, largely imported from America with liberal stances on contraception, abortion and divorce, undermined the authority of bishops and priests. Second, the mishandling of the paedophile scandals humiliated the Church, whose bishops seemed less concerned with the victims and more concerned with covering up for errant priests. Third, prosperity brought hedonism and materialism that undercut the ideals of saintly poverty.

The financial crisis that began in 2008 dramatically ended this period of boom. GDP fell by 3% in 2008 and by 7.1% in 2009, the worst year since records began (although earnings by foreign-owned businesses continued to grow). The state has since experienced deep recession, with unemployment, which doubled during 2009, remaining above 14% in 2012.

Northern Ireland

Northern Ireland resulted from the division of the United Kingdom by the Government of Ireland Act 1920, and until 1972 was a self-governing jurisdiction within the United Kingdom with its own parliament and prime minister. Northern Ireland, as part of the United Kingdom, was not neutral during the Second World War, and Belfast suffered four bombing raids in 1941. Conscription was not extended to Northern Ireland, and roughly an equal number volunteered from Northern Ireland as volunteered from the Republic of Ireland.

Edward Carson signing the Solemn League and Covenant in 1912, declaring opposition to Home Rule "using all means which may be found necessary"

Although Northern Ireland was largely spared the strife of the civil war, in the decades that followed partition there were sporadic episodes of inter-communal violence. Nationalists, mainly Roman Catholic, wanted to unite Ireland as an independent republic, whereas unionists, mainly Protestant, wanted Northern Ireland to remain in the United Kingdom. The Protestant and Catholic communities in Northern Ireland voted largely along sectarian lines, meaning that the government of Northern Ireland (elected by "first-past-the-post" from 1929) was controlled by the Ulster Unionist Party. Over time, the minority Catholic community felt increasingly alienated with further disaffection fuelled by practices such as gerrymandering and discrimination in housing and employment.

In the late 1960s, nationalist grievances were aired publicly in mass civil rights protests, which were often confronted by loyalist counter-protests. The government's reaction to confrontations was seen to be one-sided and heavy-handed in favour of unionists. Law and order broke down as unrest and inter-communal violence increased.[104] The Northern Ireland government requested the British Army to aid the police and protect the Irish Nationalist population. In 1969, the paramilitary Provisional IRA, which favoured the creation of a united Ireland, emerged from a split in the Irish Republican Army and began a campaign against what it called the "British occupation of the six counties".

Other groups, both the unionist and nationalist participated in violence, and a period known as "the Troubles" began. More than 3,600 deaths resulted over the subsequent three decades of conflict. Owing to the civil unrest during the Troubles, the British government suspended home rule in 1972 and imposed direct rule. There were several unsuccessful attempts to end the Troubles politically, such as the Sunningdale Agreement of 1973. In 1998, following a ceasefire by the Provisional IRA and multi-party talks, the Good Friday Agreement was concluded as a treaty between the British and Irish governments, annexing the text agreed in the multi-party talks.

The substance of the Agreement (formally referred to as the Belfast Agreement) was later endorsed by referendums in both parts of Ireland. The Agreement restored self-government to Northern Ireland on the basis of power-sharing in a regional Executive drawn from the major parties in a new Northern Ireland Assembly, with entrenched protections for the two main communities. The Executive is jointly headed by a First Minister and deputy First Minister drawn from the unionist and nationalist parties. Violence had decreased greatly after the Provisional IRA and loyalist ceasefires in 1994, and in 2005, the Provisional IRA announced the end of its armed campaign and an independent commission supervised its disarmament and that of other nationalist and unionist paramilitary organisations.

The Assembly and power-sharing Executive were suspended several times but were restored again in 2007. In that year the British government officially ended its military support of the police in Northern Ireland (Operation Banner) and began withdrawing troops. On 27 June 2012, Northern Ireland's deputy first minister and former IRA commander, Martin McGuinness, shook hands with Queen Elizabeth II in Belfast, symbolising reconciliation between the two sides.

Politics

Political entities on the island of Ireland

The island is divided between the Republic of Ireland, an independent state, and Northern Ireland, a constituent country of the United Kingdom. They share an open border and both are part of the Common Travel Area and as a consequence, there is free movement of people, goods, services and capital across the border.

The Republic of Ireland is a member state of the European Union while the United Kingdom is a former member state, having both acceded to its precursor entity, the European Economic Community (EEC), in 1973 but the UK left the European Union in 2020 after a referendum on EU membership was held in 2016 which resulted in 51.9% of UK voters choosing to leave the bloc.

Republic of Ireland

Áras an Uachtaráin, the official residence of the President of Ireland

The Republic of Ireland is a parliamentary democracy based on the Westminster system, with a written constitution and a popularly elected president whose role is mostly ceremonial. The Oireachtas is a bicameral parliament, composed of Dáil Éireann (the Dáil), a house of representatives, and Seanad Éireann (the Seanad), an upper house. The government is headed by a prime minister, the Taoiseach, who is appointed by the president on the nomination of the Dáil. Its capital is Dublin.

The Republic of Ireland today ranks among the wealthiest countries in the world in terms of GDP per capita and in 2015 was ranked the sixth most developed nation in the world by the United Nations' Human Development Index. A period of rapid economic expansion from 1995 onwards became known as the Celtic Tiger period, was brought to an end in 2008 with an unprecedented financial crisis and an economic depression in 2009. According to the 2024 Global Peace Index, Ireland is the second most peaceful country in the world.

Northern Ireland

Parliament Buildings, in Stormont Estate, seat of the Northern Ireland Assembly

Northern Ireland is a part of the United Kingdom with a local executive and assembly which exercise devolved powers. The executive is jointly headed by the first and deputy first minister, with the ministries being allocated in proportion to each party's representation in the assembly. Its capital is Belfast.

Ultimately political power is held by the UK government, from which Northern Ireland has gone through intermittent periods of direct rule during which devolved powers have been suspended. Northern Ireland elects 18 of the UK House of Commons' 650 MPs. The Northern Ireland Secretary is a cabinet-level post in the British government.

Along with England and Wales and with Scotland, Northern Ireland forms one of the three separate legal jurisdictions of the UK, all of which share the Supreme Court of the United Kingdom as their court of final appeal.

All-island institutions

As part of the Good Friday Agreement, the British and Irish governments agreed on the creation of all-island institutions and areas of cooperation. The North/South Ministerial Council is an institution through which ministers from the Government of Ireland and the Northern Ireland Executive agree all-island policies. At least six of these policy areas must have an associated all-island "implementation body", and at least six others must be implemented separately in each jurisdiction. The implementation bodies are: Waterways Ireland, the Food Safety Promotion Board, InterTradeIreland, the Special European Union Programmes Body, the North/South Language Body and the Foyle, Carlingford and Irish Lights Commission.

The British–Irish Intergovernmental Conference provides for co-operation between the Government of Ireland and the Government of the United Kingdom on all matters of mutual interest, especially Northern Ireland. In light of the Republic's particular interest in the governance of Northern Ireland, "regular and frequent" meetings co-chaired by the Irish Minister for Foreign Affairs and the British Secretary of State for Northern Ireland, dealing with non-devolved matters to do with Northern Ireland and non-devolved all-Ireland issues, are required to take place under the establishing treaty.

The North/South Inter-Parliamentary Association is a joint parliamentary forum for the island of Ireland. It has no formal powers but operates as a forum for discussing matters of common concern between the respective legislatures.

Geography

Physical features of Ireland

Ireland is located in the north-west of Europe, between latitudes 51° and 56° N, and longitudes 11° and 5° W. It is separated from Great Britain by the Irish Sea and the North Channel, which has a width of 23 kilometres (14 mi) at its narrowest point. To the west is the northern Atlantic Ocean and to the south is the Celtic Sea, which lies between Ireland and Brittany, in France. Ireland has a total area of 84,421 km2 (32,595 sq mi), of which the Republic of Ireland occupies 83 percent. Ireland and Great Britain, together with many nearby smaller islands, are known collectively as the British Isles. As the term British Isles can be controversial in relation to Ireland, the alternate term Britain and Ireland is sometimes used as a neutral term for the islands.

A ring of coastal mountains surrounds low plains at the centre of the island. The highest of these is Carrauntoohil (Irish: Corrán Tuathail) in County Kerry, which rises to 1,039 m (3,409 ft) above sea level. The most arable land lies in the province of Leinster. Western areas are mainly mountainous and rocky with green panoramic vistas. River Shannon, the island's longest river at 360.5 km (224 mi) long, rises in County Cavan in the north-west and flows through Limerick in the midwest.

Geology

Topography of Ireland

The island consists of varied geological provinces. In the west, around County Galway and County Donegal, is a medium- to high-grade metamorphic and igneous complex of Caledonide affinity, similar to the Scottish Highlands. Across southeast Ulster and extending southwest to Longford and south to Navan is a province of Ordovician and Silurian rocks, with similarities to the Southern Uplands province of Scotland. Further south, along the County Wexford coastline, is an area of granite intrusives into more Ordovician and Silurian rocks, like that found in Wales.

In the southwest, around Bantry Bay and the mountains of MacGillycuddy's Reeks, is an area of substantially deformed, lightly metamorphosed Devonian-aged rocks. This partial ring of "hard rock" geology is covered by a blanket of Carboniferous limestone over the centre of the country, giving rise to a comparatively fertile and lush landscape. The west-coast district of the Burren around Lisdoonvarna has well-developed karst features. Significant stratiform lead-zinc mineralisation is found in the limestones around Silvermines and Tynagh.

Hydrocarbon exploration is ongoing following the first major find at the Kinsale Head gas field off Cork in the mid-1970s. In 1999, economically significant finds of natural gas were made in the Corrib Gas Field off the County Mayo coast. This has increased activity off the west coast in parallel with the "West of Shetland" step-out development from the North Sea hydrocarbon province. In 2000, the Helvick oil field was discovered, which was estimated to contain over 28 million barrels (4,500,000 m3) of oil.

Climate

The island's lush vegetation, a product of its mild climate and frequent rainfall, earns it the sobriquet the Emerald Isle. Overall, Ireland has a mild but changeable oceanic climate with few extremes. The climate is typically insular and temperate, avoiding the extremes in temperature of many other areas in the world at similar latitudes. This is a result of the moist winds which ordinarily prevail from the southwestern Atlantic.

Precipitation falls throughout the year but is light overall, particularly in the east. The west tends to be wetter on average and prone to Atlantic storms, especially in the late autumn and winter months. These occasionally bring destructive winds and higher total rainfall to these areas, as well as sometimes snow and hail. The regions of north County Galway and east County Mayo have the highest incidents of recorded lightning annually for the island, with lightning occurring approximately five to ten days per year in these areas. Munster, in the south, records the least snow whereas Ulster, in the north, records the most.

Inland areas are warmer in summer and colder in winter. Usually around 40 days of the year are below freezing 0 °C (32 °F) at inland weather stations, compared to 10 days at coastal stations. Ireland is sometimes affected by heat waves, most recently in 1995, 2003, 2006, 2013 and 2018. In common with the rest of Europe, Ireland experienced unusually cold weather during the winter of 2010–11. Temperatures fell as low as −17.2 °C (1 °F) in County Mayo on 20 December and up to a metre (3 ft) of snow fell in mountainous areas.


Climate data for Ireland
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 18.5
(65.3)
18.1
(64.6)
23.6
(74.5)
25.8
(78.4)
28.4
(83.1)
33.3
(91.9)
33.0
(91.4)
32.1
(89.8)
29.1
(84.4)
25.2
(77.4)
20.1
(68.2)
18.1
(64.6)
33.3
(91.9)
Record low °C (°F) −19.1
(−2.4)
−17.8
(0.0)
−17.2
(1.0)
−7.7
(18.1)
−5.6
(21.9)
−3.3
(26.1)
−0.3
(31.5)
−2.7
(27.1)
−3
(27)
−8.3
(17.1)
−11.5
(11.3)
−17.5
(0.5)
−19.1
(−2.4)
Source 1: Met Éireann
Source 2: The Irish Times (November record high)

Flora and fauna

The red fox is common in Ireland.
Two red foxes (Vulpes vulpes) in Gubbeen, County Cork

Unlike Great Britain which had a land bridge with mainland Europe, Ireland only had an ice bridge ending around 14,000 years ago at the end of the last ice age and as a result, it has fewer land animal and plant species than Great Britain or mainland Europe. There are 55 mammal species in Ireland, and of them, only 26 land mammal species are considered native to Ireland. Some species, such as, the red fox, hedgehog and badger, are very common, whereas others, like the Irish hare, red deer and pine marten are less so. Aquatic wildlife, such as species of sea turtle, shark, seal, whale, and dolphin, are common off the coast. About 400 species of birds have been recorded in Ireland. Many of these are migratory, including the barn swallow.

Red deer (Cervus elaphus) in Killarney National Park

Several different habitat types are found in Ireland, including farmland, open woodland, temperate broadleaf and mixed forests, conifer plantations, peat bogs and a variety of coastal habitats. However, agriculture drives current land use patterns in Ireland, limiting natural habitat preserves, particularly for larger wild mammals with greater territorial needs. With no large apex predators in Ireland other than humans and dogs, such populations of animals as semi-wild deer that cannot be controlled by smaller predators, such as the fox, are controlled by annual culling.

There are no snakes in Ireland, and only one species of reptile (the common lizard) is native to the island. Extinct species include the Irish elk, the great auk, brown bear and the wolf. Some previously extinct birds, such as the golden eagle, have been reintroduced after decades of extirpation.

Ireland is now one of the least forested countries in Europe. Until the end of the Middle Ages, Ireland was heavily forested. Native species include deciduous trees such as oak, ash, hazel, birch, alder, willow, aspen, rowan and hawthorn, as well as evergreen trees such Scots pine, yew, holly and strawberry trees. Only about 10% of Ireland today is woodland; most of this is non-native conifer plantations, and only 2% is native woodland. The average woodland cover of European countries is over 33%. In the Republic, about 389,356 hectares (3,893.56 km2) is owned by the state, mainly by the forestry service Coillte. Remnants of native forest can be found scattered around the island, in particular in the Killarney National Park.

Furze (Ulex europaeus)

Much of the land is now covered with pasture and there are many species of wild-flower. Gorse (Ulex europaeus), a wild furze, is commonly found growing in the uplands and ferns are plentiful in the more moist regions, especially in the western parts. It is home to hundreds of plant species, some of them unique to the island, and has been "invaded" by some grasses, such as Spartina anglica.

The algal and seaweed flora is that of the cold-temperate variety. The total number of species is 574 The island has been invaded by some algae, some of which are now well established.

Because of its mild climate, many species, including sub-tropical species such as palm trees, are grown in Ireland. Phytogeographically, Ireland belongs to the Atlantic European province of the Circumboreal Region within the Boreal Kingdom. The island can be subdivided into two ecoregions: the Celtic broadleaf forests and North Atlantic moist mixed forests.

Impact of agriculture

Silage harvesting in Clonard, County Meath

The long history of agricultural production, coupled with modern intensive agricultural methods such as pesticide and fertiliser use and runoff from contaminants into streams, rivers and lakes, has placed pressure on biodiversity in Ireland. A land of green fields for crop cultivation and cattle rearing limits the space available for the establishment of native wild species. Hedgerows, however, traditionally used for maintaining and demarcating land boundaries, act as a refuge for native wild flora. This ecosystem stretches across the countryside and acts as a network of connections to preserve remnants of the ecosystem that once covered the island. Subsidies under the Common Agricultural Policy, which supported agricultural practices that preserved hedgerow environments, are undergoing reforms. The Common Agricultural Policy had in the past subsidised potentially destructive agricultural practices, for example by emphasising production without placing limits on indiscriminate use of fertilisers and pesticides; but reforms have gradually decoupled subsidies from production levels and introduced environmental and other requirements. 32% of Ireland's greenhouse gas emissions are correlated to agriculture. Forested areas typically consist of monoculture plantations of non-native species, which may result in habitats that are not suitable for supporting native species of invertebrates. Natural areas require fencing to prevent over-grazing by deer and sheep that roam over uncultivated areas. Grazing in this manner is one of the main factors preventing the natural regeneration of forests across many regions of the country.

Demographics

Proportion of respondents to the Ireland census 2011 or the Northern Ireland census 2011 who stated they were Catholic. Areas in which Catholics are in the majority are blue. Areas in which Catholics are in a minority are red.

The population of Ireland is just over 7 million, of which approximately 5.1 million reside in the Republic of Ireland and 1.9 million reside in Northern Ireland.

People have lived in Ireland for over 9,000 years. Early historical and genealogical records note the existence of major groups such as the Cruthin, Corcu Loígde, Dál Riata, Dáirine, Deirgtine, Delbhna, Érainn, Laigin, Ulaid. Later major groups included the Connachta, Ciannachta, Eóganachta. Smaller groups included the aithechthúatha (see Attacotti), Cálraighe, Cíarraige, Conmaicne, Dartraighe, Déisi, Éile, Fir Bolg, Fortuatha, Gailenga, Gamanraige, Mairtine, Múscraige, Partraige, Soghain, Uaithni, Uí Maine, Uí Liatháin. Many survived into late medieval times, others vanished as they became politically unimportant. Over the past 1,200 years, Vikings, Normans, Welsh, Flemings, Scots, English, Africans and Eastern Europeans have all added to the population and have had significant influences on Irish culture.

The population of Ireland rose rapidly from the 16th century until the mid-19th century, interrupted briefly by the Famine of 1740–41, which killed roughly two-fifths of the island's population. The population rebounded and multiplied over the next century, but the Great Famine of the 1840s caused one million deaths and forced over one million more to emigrate in its immediate wake. Over the following century, the population was reduced by over half, at a time when the general trend in European countries was for populations to rise by an average of three-fold.

Ireland's largest religious group is Christianity. The largest denomination is Roman Catholicism, representing over 73% of the island (and about 87% of the Republic of Ireland). Most of the rest of the population adhere to one of the various Protestant denominations (about 48% of Northern Ireland). The largest is the Anglican Church of Ireland. The Muslim community is growing in Ireland, mostly through increased immigration, with a 50% increase in the republic between the 2006 and 2011 census. The island has a small Jewish community. About 4% of the Republic's population and about 14% of the Northern Ireland population describe themselves as of no religion. In a 2010 survey conducted on behalf of the Irish Times, 32% of respondents said they went to a religious service more than once per week.

Divisions and settlements

Traditionally, Ireland is subdivided into four provinces: Connacht (west), Leinster (east), Munster (south), and Ulster (north). In a system that developed between the 13th and 17th centuries, Ireland has 32 traditional counties. Twenty-six of these counties are in the Republic of Ireland, and six are in Northern Ireland. The six counties that constitute Northern Ireland are all in the province of Ulster (which has nine counties in total). As such, Ulster is often used as a synonym for Northern Ireland, although the two are not coterminous. In the Republic of Ireland, counties form the basis of the system of local government. Counties Dublin, Cork, Limerick, Galway, Waterford and Tipperary have been broken up into smaller administrative areas. However, they are still treated as counties for cultural and some official purposes, for example, postal addresses and by the Ordnance Survey Ireland. Counties in Northern Ireland are no longer used for local governmental purposes, but, as in the Republic, their traditional boundaries are still used for informal purposes such as sports leagues and in cultural or tourism contexts.

City status in Ireland is decided by legislative or royal charter. Dublin, with over one million residents in the Greater Dublin Area, is the largest city on the island. Belfast, with 579,726 residents, is the largest city in Northern Ireland. City status does not directly equate with population size. For example, Armagh, with 14,590 is the seat of the Church of Ireland and the Roman Catholic Primate of All Ireland and was re-granted city status by Queen Elizabeth II in 1994 (having lost that status in local government reforms of 1840). In the Republic of Ireland, Kilkenny, the seat of the Butler dynasty, while no longer a city for administrative purposes (since the 2001 Local Government Act), is entitled by law to continue to use the description.

Cities and towns by population

Dublin


Belfast
# Settlement City
Popu­lation
Urban
popu­lation
Metro
popu­lation

Cork


Limerick
1 Dublin 592,713 1,263,219 1,458,154
2 Belfast 293,298
639,000
3 Cork 222,333
305,222
4 Limerick 102,287

5 Galway 85,910

6 Derry 85,279

7 Greater Craigavon 72,301

8 Newtownabbey 67,599

9 Bangor 64,596

10 Waterford 60,079

Migration

The population of Ireland collapsed dramatically during the second half of the 19th century. A population of over eight million in 1841 was reduced to slightly over four million by 1921. In part, the fall in population was caused by death from the Great Famine of 1845 to 1852, which took roughly one million lives. The remaining decline of around three million was due to the entrenched culture of emigration caused by the dire economic state of the country, lasting until the late 20th century.

Emigration from Ireland in the 19th century contributed to the populations of England, the United States, Canada and Australia, in all of which a large Irish diaspora lives. As of 2006, 4.3 million Canadians, or 14% of the population, were of Irish descent, while around one-third of the Australian population had an element of Irish descent. As of 2013, there were 40 million Irish-Americans and 33 million Americans who claimed Irish ancestry.

With growing prosperity since the last decade of the 20th century, Ireland became a destination for immigrants. Since the European Union expanded to include Poland in 2004, Polish people have comprised the largest number of immigrants (over 150,000) from Central Europe. There has also been significant immigration from Lithuania, Czech Republic and Latvia.

The Republic of Ireland in particular has seen large-scale immigration, with 420,000 foreign nationals as of 2006, about 10% of the population. Nearly a quarter of births (24 percent) in 2009 were to mothers born outside of Ireland. Up to 50,000 eastern and central European migrant workers left Ireland in response to the Irish financial crisis.

Languages

Proportion of respondents who said they could speak Irish in the Ireland census in 2011 or the Northern Ireland census in 2011

The two official languages of the Republic of Ireland are Irish and English. Each language has produced noteworthy literature. Irish, though now only the language of a minority, was the vernacular of the Irish people for thousands of years and was possibly introduced during the Iron Age. It began to be written down after Christianisation in the 5th century and spread to Scotland and the Isle of Man, where it evolved into the Scottish Gaelic and Manx languages, respectively.

The Irish language has a vast treasury of written texts from many centuries and is divided by linguists into Old Irish from the 6th to 10th century, Middle Irish from the 10th to 13th century, Early Modern Irish until the 17th century, and the Modern Irish spoken today. It remained the dominant language of Ireland for most of those periods, having influences from Latin, Old Norse, French and English. It declined under British rule but remained the majority tongue until the early 19th century, and since then has been a minority language.

The Gaelic Revival of the late 19th and early 20th centuries had a long-term influence. Irish is taught in mainstream Irish schools as a compulsory subject, but teaching methods have been criticised for their ineffectiveness, with most students showing little evidence of fluency even after 14 years of instruction.

There is now a growing population of urban Irish speakers in both the Republic and Northern Ireland, especially in Dublin and Belfast, with the children of such Irish speakers sometimes attending Irish-medium schools (Gaelscoil or Gaelscoileanna). It has been argued that they tend to be more highly educated than monolingual English speakers. Recent research suggests that urban Irish is developing in a direction of its own, both in pronunciation and grammar.

Traditional rural Irish-speaking areas, known collectively as the Gaeltacht, are in linguistic decline. The main Gaeltacht areas are in the west, south-west and north-west, in Galway, Mayo, Donegal, western Cork and Kerry with smaller Gaeltacht areas near Dungarvan in Waterford and in Meath.

English in Ireland was first introduced during the Norman invasion. It was spoken by a few peasants and merchants brought over from England and was largely replaced by Irish before the Tudor conquest of Ireland. It was introduced as the official language during the Tudor and Cromwellian conquests. The Ulster plantations gave it a permanent foothold in Ulster, and it remained the official and upper-class language elsewhere, the Irish-speaking chieftains and nobility having been deposed. Language shift during the 19th century replaced Irish with English as the first language for a vast majority of the population.

Fewer than 2% of the population of the Republic of Ireland today speak Irish on a daily basis, and under 10% regularly, outside of the education system and 38% of those over 15 years are classified as "Irish speakers". In Northern Ireland, English is the de facto official language, but official recognition is afforded to Irish, including specific protective measures under Part III of the European Charter for Regional or Minority Languages. A lesser status (including recognition under Part II of the Charter) is given to Ulster Scots dialects, which are spoken by roughly 2% of Northern Ireland residents, and also spoken by some in the Republic of Ireland. Since the 1960s with the increase in immigration, many more languages have been introduced, particularly deriving from Asia and Eastern Europe.

Also native to Ireland are Shelta, the language of the nomadic Irish Travellers, Irish Sign Language, and Northern Ireland Sign Language.

Culture

Tall stone cross, with intricate carved patterns, protected by metal railings surrounded by short cut grass. Trees are to either side, cows in open countryside are in the middle distance.
Ardboe High Cross, County Tyrone

Ireland's culture comprises elements of the culture of ancient peoples, later immigrant and broadcast cultural influences (chiefly Gaelic culture, Anglicisation, Americanisation and aspects of broader European culture). In broad terms, Ireland is regarded as one of the Celtic nations of Europe, alongside Scotland, Wales, Cornwall, Isle of Man and Brittany. This combination of cultural influences is visible in the intricate designs termed Irish interlace or Celtic knotwork. These can be seen in the ornamentation of medieval religious and secular works. The style is still popular today in jewellery and graphic art, as is the distinctive style of traditional Irish music and dance, and has become indicative of modern "Celtic" culture in general.

Religion has played a significant role in the cultural life of the island since ancient times (and since the 17th century plantations, has been the focus of political identity and divisions on the island). Ireland's pre-Christian heritage fused with the Celtic Church following the missions of Saint Patrick in the fifth century. The Hiberno-Scottish missions, begun by the Irish monk Saint Columba, spread the Irish vision of Christianity to pagan England and the Frankish Empire. These missions brought written language to an illiterate population of Europe during the Dark Ages that followed the fall of Rome, earning Ireland the sobriquet, "the island of saints and scholars".

Since the 20th century Irish pubs worldwide have become outposts of Irish culture, especially those with a full range of cultural and gastronomic offerings.

Arts

Illuminated page from Book of Kells

Literature

Ireland has made a substantial contribution to world literature in all its branches, both in Irish and English. Poetry in Irish is among the oldest vernacular poetry in Europe, with the earliest examples dating from the 6th century. Irish remained the dominant literary language down to the 19th century, despite the spread of English from the 17th century on. Prominent names from the medieval period and later include Gofraidh Fionn Ó Dálaigh (14th century), Dáibhí Ó Bruadair (17th century) and Aogán Ó Rathaille (18th century). Eibhlín Dubh Ní Chonaill (c. 1743 – c. 1800) was an outstanding poet in the oral tradition. The latter part of the 19th century saw a rapid replacement of Irish by English. By 1900, however, cultural nationalists had begun the Gaelic revival, which saw the beginnings of modern literature in Irish. This was to produce a number of notable writers, including Máirtín Ó Cadhain, Máire Mhac an tSaoi and others. Irish-language publishers such as Coiscéim and Cló Iar-Chonnacht continue to produce scores of titles every year.

In English, Jonathan Swift, often called the foremost satirist in the English language, gained fame for works such as Gulliver's Travels and A Modest Proposal. Other notable 18th-century writers of Irish origin included Oliver Goldsmith and Richard Brinsley Sheridan, though they spent most of their lives in England. The Anglo-Irish novel came to the fore in the 19th century, featuring such writers as Charles Kickham, William Carleton, and (in collaboration) Edith Somerville and Violet Florence Martin. The playwright and poet Oscar Wilde, noted for his epigrams, was born in Ireland.

In the 20th century, Ireland produced four winners of the Nobel Prize for Literature: George Bernard Shaw, William Butler Yeats, Samuel Beckett and Seamus Heaney. Although not a Nobel Prize winner, James Joyce is widely considered to be one of the most significant writers of the 20th century. Joyce's 1922 novel Ulysses is considered one of the most important works of Modernist literature and his life is celebrated annually on 16 June in Dublin as "Bloomsday". A comparable writer in Irish is Máirtín Ó Cadhain, whose 1949 novel Cré na Cille is regarded as a modernist masterpiece and has been translated into several languages.

Modern Irish literature is often connected with its rural heritage through English-language writers such as John McGahern and Seamus Heaney and Irish-language writers such as Máirtín Ó Direáin and others from the Gaeltacht.

James Joyce, one of the most significant writers of the 20th century

Music and dance

Music has been in evidence in Ireland since prehistoric times. Although in the early Middle Ages the church was "quite unlike its counterpart in continental Europe", there was a considerable interchange between monastic settlements in Ireland and the rest of Europe that contributed to what is known as Gregorian chant. Outside religious establishments, musical genres in early Gaelic Ireland are referred to as a triad of weeping music (goltraige), laughing music (geantraige) and sleeping music (suantraige). Vocal and instrumental music (e.g. for the harp, pipes, and various string instruments) was transmitted orally, but the Irish harp, in particular, was of such significance that it became Ireland's national symbol. Classical music following European models first developed in urban areas, in establishments of Anglo-Irish rule such as Dublin Castle, St Patrick's Cathedral and Christ Church as well as the country houses of the Anglo-Irish ascendancy, with the first performance of Handel's Messiah (1742) being among the highlights of the baroque era. In the 19th century, public concerts provided access to classical music to all classes of society. Yet, for political and financial reasons Ireland has been too small to provide a living to many musicians, so the names of the better-known Irish composers of this time belong to emigrants.

Irish traditional music and dance have seen a surge in popularity and global coverage since the 1960s. In the middle years of the 20th century, as Irish society was modernising, traditional music had fallen out of favour, especially in urban areas. However during the 1960s, there was a revival of interest in Irish traditional music led by groups such as the Dubliners, the Chieftains, the Wolfe Tones, the Clancy Brothers, Sweeney's Men and individuals like Seán Ó Riada and Christy Moore. Groups and musicians including Horslips, Van Morrison and Thin Lizzy incorporated elements of Irish traditional music into contemporary rock music and, during the 1970s and 1980s, the distinction between traditional and rock musicians became blurred, with many individuals regularly crossing over between these styles of playing. This trend can be seen more recently in the work of artists like Enya, the Saw Doctors, the Corrs, Sinéad O'Connor, Clannad, the Cranberries and the Pogues among others.

Art

The earliest known Irish graphic art and sculpture are Neolithic carvings found at sites such as Newgrange and is traced through Bronze Age artefacts and the religious carvings and illuminated manuscripts of the medieval period. During the course of the 19th and 20th centuries, a strong tradition of painting emerged, including such figures as John Butler Yeats, William Orpen, Jack Yeats and Louis le Brocquy. Contemporary Irish visual artists of note include Sean Scully, Kevin Abosch, and Alice Maher.

Drama and theatre

The Republic of Ireland's national theatre is the Abbey Theatre, which was founded in 1904, and the national Irish-language theatre is An Taibhdhearc, which was established in 1928 in Galway. Playwrights such as Seán O'Casey, Brian Friel, Sebastian Barry, Conor McPherson and Billy Roche are internationally renowned.

Science

Robert Boyle formulated Boyle's Law.

The Irish philosopher and theologian Johannes Scotus Eriugena was considered one of the leading intellectuals of the early Middle Ages. Sir Ernest Henry Shackleton, an Irish explorer, was one of the principal figures of Antarctic exploration. He, along with his expedition, made the first ascent of Mount Erebus and the discovery of the approximate location of the South Magnetic Pole. Robert Boyle was a 17th-century natural philosopher, chemist, physicist, inventor and early gentleman scientist. He is largely regarded as one of the founders of modern chemistry and is best known for the formulation of Boyle's law.

19th-century physicist, John Tyndall, discovered the Tyndall effect. Father Nicholas Joseph Callan, professor of natural philosophy in Maynooth College, is best known for his invention of the induction coil, transformer and he discovered an early method of galvanisation in the 19th century.

Other notable Irish physicists include Ernest Walton, winner of the 1951 Nobel Prize in Physics. With Sir John Douglas Cockcroft, he was the first to split the nucleus of the atom by artificial means and made contributions to the development of a new theory of wave equation. William Thomson, or Lord Kelvin, is the person whom the absolute temperature unit, the kelvin, is named after. Sir Joseph Larmor, a physicist and mathematician, made innovations in the understanding of electricity, dynamics, thermodynamics and the electron theory of matter. His most influential work was Aether and Matter, a book on theoretical physics published in 1900.

George Johnstone Stoney introduced the term electron in 1891. John Stewart Bell was the originator of Bell's Theorem and a paper concerning the discovery of the Bell-Jackiw-Adler anomaly and was nominated for a Nobel prize. The astronomer Jocelyn Bell Burnell, from Lurgan, County Armagh, discovered pulsars in 1967. Notable mathematicians include Sir William Rowan Hamilton, famous for work in classical mechanics and the invention of quaternions. Francis Ysidro Edgeworth's contribution, the Edgeworth Box. remains influential in neo-classical microeconomic theory to this day; while Richard Cantillon inspired Adam Smith, among others. John B. Cosgrave was a specialist in number theory and discovered a 2000-digit prime number in 1999 and a record composite Fermat number in 2003. John Lighton Synge made progress in different fields of science, including mechanics and geometrical methods in general relativity. He had mathematician John Nash as one of his students. Kathleen Lonsdale, born in Ireland and most known for her work with crystallography, became the first female president of the British Association for the Advancement of Science.

Ireland has nine universities, seven in the Republic of Ireland and two in Northern Ireland, including Trinity College Dublin and the University College Dublin, as well as numerous third-level colleges and institutes and a branch of the Open University, the Open University in Ireland. Ireland was ranked 19th in the Global Innovation Index in 2024.

Sports

Gaelic football is the most popular sport in Ireland in terms of match attendance and community involvement, with about 2,600 clubs on the island. In 2003 it represented 34% of total sports attendances at events in Ireland and abroad, followed by hurling at 23%, soccer at 16% and rugby at 8%. The All-Ireland Football Final is the most watched event in the sporting calendar. Soccer is the most widely played team game on the island and the most popular in Northern Ireland.

Other sporting activities with the highest levels of playing participation include swimming, golf, aerobics, cycling, and billiards/snooker. Many other sports are also played and followed, including boxing, cricket, fishing, greyhound racing, handball, hockey, horse racing, motor sport, show jumping and tennis.

The island fields a single international team in most sports. One notable exception to this is association football, although both associations continued to field international teams under the name "Ireland" until the 1950s. The sport is also the most notable exception where the Republic of Ireland and Northern Ireland field separate international teams. Northern Ireland has produced two World Snooker Champions.

Field sports

Tyrone v Kerry in the 2005 All-Ireland Senior Football Championship Final

Gaelic football, hurling and Gaelic handball are the best-known Irish traditional sports, collectively known as Gaelic games. Gaelic games are governed by the Gaelic Athletic Association (GAA), with the exception of women's Gaelic football and camogie (women's variant of hurling), which are governed by separate organisations. The headquarters of the GAA (and the main stadium) is located at Croke Park in north Dublin and has a capacity of 82,500. Many major GAA games are played there, including the semi-finals and finals of the All-Ireland Senior Football Championship and All-Ireland Senior Hurling Championship. During the redevelopment of the Lansdowne Road stadium in 2007–2010, international rugby and soccer were played there. All GAA players, even at the highest level, are amateurs, receiving no wages, although they are permitted to receive a limited amount of sport-related income from commercial sponsorship.

The Irish Football Association (IFA) was originally the governing body for soccer across the island. The game has been played in an organised fashion in Ireland since the 1870s, with Cliftonville F.C. in Belfast being Ireland's oldest club. It was most popular, especially in its first decades, around Belfast and in Ulster. However, some clubs based outside Belfast thought that the IFA largely favoured Ulster-based clubs in such matters as selection for the national team. In 1921, following an incident in which, despite an earlier promise, the IFA moved an Irish Cup semi-final replay from Dublin to Belfast, Dublin-based clubs broke away to form the Football Association of the Irish Free State. Today the southern association is known as the Football Association of Ireland (FAI). Despite being initially blacklisted by the Home Nations' associations, the FAI was recognised by FIFA in 1923 and organised its first international fixture in 1926 (against Italy). However, both the IFA and FAI continued to select their teams from the whole of Ireland, with some players earning international caps for matches with both teams. Both also referred to their respective teams as Ireland.

Paul O'Connell reaching for the ball during a line out against Argentina in 2007

In 1950, FIFA directed the associations only to select players from within their respective territories and, in 1953, directed that the FAI's team be known only as "Republic of Ireland" and that the IFA's team be known as "Northern Ireland" (with certain exceptions). Northern Ireland qualified for the World Cup finals in 1958 (reaching the quarter-finals), 1982 and 1986 and the European Championship in 2016. The Republic qualified for the World Cup finals in 1990 (reaching the quarter-finals), 1994, 2002 and the European Championship in 1988, 2012 and 2016. Across Ireland, there is significant interest in the English and, to a lesser extent, Scottish soccer leagues.

Ireland fields a single national rugby team and a single association, the Irish Rugby Football Union, governs the sport across the island. The Irish rugby team have played in every Rugby World Cup, making the quarter-finals in eight of them. Ireland also hosted games during the 1991 and the 1999 Rugby World Cups (including a quarter-final). There are four professional Irish teams; all four play in the Pro14 and at least three compete for the Heineken Cup. Irish rugby has become increasingly competitive at both the international and provincial levels since the sport went professional in 1994. During that time, Ulster (1999), Munster (2006 and 2008) and Leinster (2009, 2011 and 2012) have won the Heineken Cup. In addition to this, the Irish International side has had increased success in the Six Nations Championship against the other European elite sides. This success, including Triple Crowns in 2004, 2006 and 2007, culminated with a clean sweep of victories, known as a Grand Slam, in 2009 and 2018.

Boxing

Amateur boxing on the island of Ireland is governed by the Irish Athletic Boxing Association. Ireland has won more medals in boxing than in any other Olympic sport. Michael Carruth won a gold medal and Wayne McCullough won a silver medal in the Barcelona Olympic Games. In 2008 Kenneth Egan won a silver medal in the Beijing Games. Paddy Barnes secured bronze in those games and gold in the 2010 European Amateur Boxing Championships (where Ireland came 2nd in the overall medal table) and 2010 Commonwealth Games. Katie Taylor has won gold in every European and World championship since 2005. In August 2012 at the Olympic Games in London, Taylor created history by becoming the first Irish woman to win a gold medal in boxing in the 60 kg lightweight. More recently, Kellie Harrington won a gold medal at the 2020 Tokyo Olympics.

Other sports

Horse racing in Sligo

Horse racing and greyhound racing are both popular in Ireland. There are frequent horse race meetings and greyhound stadiums are well-attended. The island is noted for the breeding and training of race horses and is also a large exporter of racing dogs. The horse racing sector is largely concentrated in the County Kildare.

Irish athletics is an all-Ireland sport governed by Athletics Ireland. Sonia O'Sullivan won two medals at 5,000 metres on the track; gold at the 1995 World Championships and silver at the 2000 Sydney Olympics. Gillian O'Sullivan won silver in the 20k walk at the 2003 World Championships, while sprint hurdler Derval O'Rourke won gold at the 2006 World Indoor Championship in Moscow. Olive Loughnane won a silver medal in the 20k walk at the World Athletics Championships in Berlin in 2009.

Golf is very popular, and golf tourism is a major industry attracting more than 240,000 golfing visitors annually. The 2006 Ryder Cup was held at The K Club in County Kildare. Pádraig Harrington became the first Irishman since Fred Daly in 1947 to win the British Open at Carnoustie in July 2007. He successfully defended his title in July 2008 before going on to win the PGA Championship in August. Harrington became the first European to win the PGA Championship in 78 years and was the first winner from Ireland. Three golfers from Northern Ireland have been particularly successful. In 2010, Graeme McDowell became the first Irish golfer to win the U.S. Open, and the first European to win that tournament since 1970. Rory McIlroy, at the age of 22, won the 2011 U.S. Open, while Darren Clarke's latest victory was the 2011 Open Championship at Royal St. George's. In August 2012, McIlroy won his 2nd major championship by winning the USPGA Championship by a record margin of 8 shots.

Recreation

The west coast of Ireland, Lahinch and Donegal Bay in particular, have popular surfing beaches, being fully exposed to the Atlantic Ocean. Donegal Bay is shaped like a funnel and catches west/south-west Atlantic winds, creating good surf, especially in winter. Since just before the year 2010, Bundoran has hosted European championship surfing. Scuba diving is increasingly popular in Ireland with clear waters and large populations of sea life, particularly along the western seaboard. There are also many shipwrecks along the coast of Ireland, with some of the best wreck dives being in Malin Head and off the County Cork coast.

With thousands of lakes, over 14,000 kilometres (8,700 mi) of fish-bearing rivers and over 7,500 kilometres (4,660 mi) of coastline, Ireland is a popular angling destination. The temperate Irish climate is suited to sport angling. While salmon and trout fishing remain popular with anglers, salmon fishing, in particular, received a boost in 2006 with the closing of the salmon driftnet fishery. Coarse fishing continues to increase its profile. Sea angling is developed with many beaches mapped and signposted, and the range of sea angling species is around 80.

Food and drink

Gubbeen cheese, an example of the resurgence in Irish cheese making

Food and cuisine in Ireland take their influence from the crops grown and animals farmed in the island's temperate climate and from the social and political circumstances of Irish history. For example, whilst from the Middle Ages until the arrival of the potato in the 16th century the dominant feature of the Irish economy was the herding of cattle, the number of cattle a person owned was equated to their social standing. Thus herders would avoid slaughtering a milk-producing cow.

For this reason, pork and white meat were more common than beef, and thick fatty strips of salted bacon (known as rashers) and the eating of salted butter (i.e. a dairy product rather than beef itself) have been a central feature of the diet in Ireland since the Middle Ages. The practice of bleeding cattle and mixing the blood with milk and butter (not unlike the practice of the Maasai) was common and black pudding, made from blood, grain (usually barley) and seasoning, remains a breakfast staple in Ireland. All of these influences can be seen today in the phenomenon of the "breakfast roll".

The introduction of the potato in the second half of the 16th century heavily influenced cuisine thereafter. Great poverty encouraged a subsistence approach to food, and by the mid-19th century, the vast majority of the population sufficed with a diet of potatoes and milk. A typical family, consisting of a man, a woman and four children, would eat 18 stone (110 kg) of potatoes per week. Consequently, dishes that are considered as national dishes represent a fundamental simplicity to cooking, such as the Irish stew, bacon and cabbage, boxty, a type of potato pancake, or colcannon, a dish of mashed potatoes and kale or cabbage.

Since the last quarter of the 20th century, with a re-emergence of wealth in Ireland, a "New Irish Cuisine" based on traditional ingredients incorporating international influences has emerged. This cuisine is based on fresh vegetables, fish (especially salmon, trout, oysters, mussels and other shellfish), as well as traditional soda breads and the wide range of hand-made cheeses that are now being produced across the country. An example of this new cuisine is "Dublin Lawyer": lobster cooked in whiskey and cream. The potato remains however a fundamental feature of this cuisine and the Irish remain the highest per capita consumers of potatoes in Europe. Traditional regional foods can be found throughout the country, for example coddle in Dublin or drisheen in Cork, both a type of sausage, or blaa, a doughy white bread particular to Waterford.

The Old Bushmills Distillery in County Antrim

Ireland once dominated the world's market for whiskey, producing 90% of the world's whiskey at the start of the 20th century. However, as a consequence of bootleggers during the prohibition in the United States (who sold poor-quality whiskey bearing Irish-sounding names thus eroding the pre-prohibition popularity for Irish brands) and tariffs on Irish whiskey across the British Empire during the Anglo-Irish Trade War of the 1930s, sales of Irish whiskey worldwide fell to a mere 2% by the mid-20th century. In 1953, an Irish government survey, found that 50% of whiskey drinkers in the United States had never heard of Irish whiskey.

Irish whiskey, as researched in 2009 by the CNBC American broadcaster, remains popular domestically and has grown in international sales steadily over a few decades. Typically CNBC states Irish whiskey is not as smoky as a Scotch whisky, but not as sweet as American or Canadian whiskies. Whiskey forms the basis of cream liqueurs, such as Baileys, and the "Irish coffee" (a cocktail of coffee and whiskey reputedly invented at Foynes flying-boat station) is probably the best-known Irish cocktail.

Stout, a kind of porter beer, particularly Guinness, is typically associated with Ireland, although historically it was more closely associated with London. Porter remains very popular, although it has lost sales since the mid-20th century to lager. Cider, particularly Magners (marketed in the Republic of Ireland as Bulmers), is also a popular drink. Red lemonade, a soft-drink, is consumed on its own and as a mixer, particularly with whiskey.

Economy

The GDP of the Republic of Ireland as of 2021 was €423.5 billion (nominal), and in Northern Ireland in 2021, it was £52 billion (GVA Balanced). The GDP per capita in the Republic of Ireland was €84,049.9 (nominal) as of 2021, and in Northern Ireland 2021 was £27,154 (GVA Balanced). The Republic of Ireland and the United Kingdom measure these numbers differently.

Despite the two jurisdictions using two distinct currencies (the euro and pound sterling), a growing amount of commercial activity is carried out on an all-Ireland basis. This has been facilitated by the two jurisdictions' former shared membership of the European Union, and there have been calls from members of the business community and policymakers for the creation of an "all-Ireland economy" to take advantage of economies of scale and boost competitiveness.

Regional economics

Below is a comparison of the regional GDP on the island of Ireland.

Republic of Ireland: Northern and Western Republic of Ireland: Eastern and Midland Republic of Ireland: Southern United Kingdom: Northern Ireland
GDP (2018): €22 bn GDP (2018): €175 bn GDP (2018): €127 bn GDP (2021): £52 bn
€24,926 per person €74,824 per person €77,794 per person £27,154 per person

Northern Ireland trade comparison

Below is a comparison of the goods being sold and purchased between Northern Ireland and the United Kingdom, compared with the goods being exported and imported between Northern Ireland and the Republic of Ireland:

Northern Ireland Sales/Exports

United Kingdom Republic of Ireland
2020 £11.3 billion £4.2 billion
2021 £12.8 billion £5.2 billion

Northern Ireland Purchases/Imports

United Kingdom Republic of Ireland
2020 £13.4 billion £2.5 billion
2021 £14.4 billion £3.1 billion

Cost of living comparison

Below is a comparison of the monthly cost of living and average wage after tax in Northern Ireland versus those in the Republic of Ireland in 2023:

Monthly Cost of Living Comparison

Northern Ireland Republic of Ireland
Cost of living (1 person) $1459 $2198
Average wage after tax $2393 $3010

Economic history

Prior to partition in 1921, Ireland had a long history as an economic colony – first, partially, of the Norse, via their cities (9th to 10th centuries CE), and later, to varying extents, of polities related to England. Though the climate and soil favoured certain forms of agriculture, trade barriers frequently hobbled its development. Repeated invasions and plantations disrupted land-ownership, and multiple failed uprisings also contributed to repeated phases of deportation and of emigration.

Salient events in the economic history of Ireland include:

  • 16th and 17th centuries: confiscation and redistribution of land in the Plantations of Ireland
  • 1845–1849: The Great Famine occasioned depopulation and mass emigration
  • 1846: Westminster's repeal of the Corn Laws disrupted Irish agriculture

Major industries

Tourism

There are two World Heritage Sites on the island: the Brú na Bóinne complex and the Giant's Causeway. Several other places are on the tentative list, for example the Burren, the Ceide Fields and Mount Stewart.

Some of the most visited sites in Ireland include Bunratty Castle, the Rock of Cashel, the Cliffs of Moher, Holy Cross Abbey and Blarney Castle. Historically important monastic sites include Glendalough and Clonmacnoise, which are maintained as national monuments in the Republic of Ireland.

The Dublin region receives the most tourists and is home to several of the most popular attractions such as the Guinness Storehouse and Book of Kells. The west and south west, which includes the Lakes of Killarney and the Dingle peninsula in County Kerry and Connemara and the Aran Islands in County Galway, are also popular tourist destinations.

Stately homes, built during the 17th, 18th and 19th centuries in Palladian, Neoclassical and neo-Gothic styles, such as Castle Ward, Castletown House, Bantry House, Strokestown Park and Glenveagh Castle are also of interest to tourists. Some have been converted into hotels, such as Ashford Castle, Castle Leslie and Dromoland Castle.

Energy

Although for most of their existence electricity networks in the Republic of Ireland and Northern Ireland were entirely separate, the island has operated for some time as a single market for electricity. Both networks were designed and constructed independently post-partition but they are now connected with three interlinks and are also connected through Great Britain to mainland Europe. The situation in Northern Ireland is complicated by the issue of private companies not supplying Northern Ireland Electricity with enough power. In the Republic of Ireland, the ESB has failed to modernise its power stations, and the availability of power plants has recently averaged only 66%, one of the worst such rates in Western Europe. EirGrid has started building a HVDC transmission line between Ireland and Great Britain with a capacity of 500 MW, about 10% of Ireland's peak demand.

As with electricity, the natural gas distribution network is also now all-island, with a pipeline linking Gormanston, County Meath, and Ballyclare, County Antrim. Most of Ireland's gas comes through interconnectors between Twynholm in Scotland and Ballylumford, County Antrim and Loughshinny, County Dublin. Supplies come from the Corrib Gas Field, off the coast of County Mayo, with a supply previously also coming from the Kinsale gas field off the County Cork coast. The County Mayo field faces some localised opposition over a controversial decision to refine the gas onshore.

Turf-cutting near Maam Cross by the road to Leenane, County Galway

Ireland has an ancient industry based on peat (known locally as "turf") as a source of energy for home fires. A form of biomass energy, this source of heat is still widely used in rural areas. However, because of the ecological importance of peatlands in storing carbon and their rarity, the EU is attempting to protect this habitat by fining Ireland for digging up peat. In cities, heat is generally supplied by natural gas or heating oil, although some urban suppliers distribute sods of turf as "smokeless fuel" for domestic use.

The Republic has a strong commitment to renewable energy and ranks as one of the top 10 markets for clean-technology investment in the 2014 Global Green Economy Index. Research and development in renewable energy (such as wind power) has increased since 2004. Large wind farms have been constructed in Cork, Donegal, Mayo and Antrim. The construction of wind farms has in some cases been delayed by opposition from local communities, some of whom regard the wind turbines as unsightly. The Republic is hindered by an ageing network that was not designed to handle the varying availability of power that comes from wind farms. The ESB's Turlough Hill facility is the only power-storage facility in the state.

Anti-art

 


From Wikipedia, the free encyclopedia
Artist's Shit (Italian: Merda d'artista) is a 1961 artwork by the Italian artist Piero Manzoni, which consists of 90 tin cans, each reportedly filled with 30 grams (1.1 oz) of faeces. One of his friends, Enrico Baj, said that the cans were meant as "an act of defiant mockery of the art world, artists, and art criticism".

Anti-art is a loosely used term applied to an array of concepts and attitudes that reject prior definitions of art and question art in general. Somewhat paradoxically, anti-art tends to conduct this questioning and rejection from the vantage point of art. The term is associated with the Dada movement and is generally accepted as attributable  to Marcel Duchamp pre-World War I around 1914, when he began to use found objects as art. It was used to describe revolutionary forms of art. The term was used later by the Conceptual artists of the 1960s to describe the work of those who claimed to have retired altogether from the practice of art, from the production of works which could be sold.

An expression of anti-art may or may not take traditional form or meet the criteria for being defined as a work of art according to conventional standards. Works of anti-art may express an outright rejection of having conventionally defined criteria as a means of defining what art is, and what it is not. Anti-artworks may reject conventional artistic standards altogether, or focus criticism only on certain aspects of art, such as the art market and high art. Some anti-artworks may reject individualism in art,whereas some may reject "universality" as an accepted factor in art. Additionally, some forms of anti-art reject art entirely, or reject the idea that art is a separate realm or specialization. Anti-artworks may also reject art based upon a consideration of art as being oppressive of a segment of the population.

Anti-art artworks may articulate a disagreement with the generally supposed notion of there being a separation between art and life. Anti-art artworks may voice a question as to whether "art" really exists or not. "Anti-art" has been referred to as a "paradoxical neologism", in that its obvious opposition to art has been observed concurring with staples of twentieth-century art or "modern art", in particular art movements that have self-consciously sought to transgress traditions or institutions. Anti-art itself is not a distinct art movement, however. This would tend to be indicated by the time it spans—longer than that usually spanned by art movements. Some art movements though, are labeled "anti-art". The Dada movement is generally considered the first anti-art movement; the term anti-art itself is said to have been coined by Dadaist Marcel Duchamp around 1914, and his readymades have been cited as early examples of anti-art objects. Theodor W. Adorno in Aesthetic Theory (1970) stated that "...even the abolition of art is respectful of art because it takes the truth claim of art seriously".

Anti-art has become generally accepted by the artworld to be art, although some people still reject Duchamp's readymades as art, for instance the Stuckist group of artists, who are "anti-anti-art".

Forms

Marcel Duchamp, Fountain, 1917. Photograph by Alfred Stieglitz

Anti-art can take the form of art or not. It is posited that anti-art need not even take the form of art, in order to embody its function as anti-art. This point is disputed. Some of the forms of anti-art which are art strive to reveal the conventional limits of art by expanding its properties.

Some instances of anti-art are suggestive of a reduction to what might seem to be fundamental elements or building blocks of art. Examples of this sort of phenomenon might include monochrome paintings, empty frames, silence as music, chance art. Anti-art is also often seen to make use of highly innovative materials and techniques, and well beyond—to include hitherto unheard of elements in visual art. These types of anti-art can be readymades, found object art, détournement, combine paintings, appropriation (art), happenings, performance art, and body art.

Anti-art can involve the renouncement of making art entirely. This can be accomplished through an art strike and this can also be accomplished through revolutionary activism. An aim of anti-art can be to undermine or understate individual creativity. This may be accomplished through the utilization of readymades. Individual creativity can be further downplayed by the use of industrial processes in the making of art. Anti-artists may seek to undermine individual creativity by producing their artworks anonymously. They may refuse to show their artworks. They may refuse public recognition. Anti-artists may choose to work collectively, in order to place less emphasis on individual identity and individual creativity. This can be seen in the instance of happenings. This is sometimes the case with "supertemporal" artworks, which are by design impermanent. Anti-artists will sometimes destroy their works of art. Some artworks made by anti-artists are purposely created to be destroyed. This can be seen in auto-destructive art.

André Malraux has developed a concept of anti-art quite different from that outlined above. For Malraux, anti-art began with the 'Salon' or 'Academic' art of the nineteenth century which rejected the basic ambition of art in favour of a semi-photographic illusionism (often prettified). Of Academic painting, Malraux writes, 'All true painters, all those for whom painting is a value, were nauseated by these pictures – "Portrait of a Great Surgeon Operating" and the like – because they saw in them not a form of painting, but the negation of painting'. For Malraux, anti-art is still very much with us, though in a different form. Its descendants are commercial cinema and television, and popular music and fiction. The 'Salon', Malraux writes, 'has been expelled from painting, but elsewhere it reigns supreme'.

Theory

Anti-art is also a tendency in the theoretical understanding of art and fine art.

The philosopher Roger Taylor puts forward that art is a bourgeois ideology that has its origins with capitalism in "Art, an Enemy of the People". Holding a strong anti-essentialist position he states also that art has not always existed and is not universal but peculiar to Europe.

The Invention of Art: A Cultural History by Larry Shiner is an art history book which fundamentally questions our understanding of art. "The modern system of art is not an essence or a fate but something we have made. Art as we have generally understood it is a European invention barely two hundred years old." (Shiner 2003, p. 3) Shiner presents (fine) art as a social construction that has not always existed throughout human history and could also disappear in its turn.

History

Pre World War I

Jean-Jacques Rousseau rejected the separation between performer and spectator, life and theatre. Karl Marx posited that art was a consequence of the class system and therefore concluded that, in a communist society, there would only be people who engage in the making of art and no "artists".

Illustration of Le rire (1887). First shown 1883 at an "Incohérents" exhibition by Arthur Sapeck (Eugène Bataille).

Arguably the first movement that deliberately set itself in opposition to established art were the Incoherents in late 19th. century Paris. Founded by Jules Lévy in 1882, the Incoherents organized charitable art exhibitions intended to be satirical and humoristic, they presented "...drawings by people who can't draw..." and held masked balls with artistic themes, all in the greater tradition of Montmartre cabaret culture. While short lived – the last Incoherent show took place in 1896 – the movement was popular for its entertainment value. In their commitment to satire, irreverence and ridicule they produced a number of works that show remarkable formal similarities to creations of the avant-garde of the 20th century: ready-mades, monochromes, empty frames and silence as music.

Dada and constructivism

Beginning in Switzerland, during World War I, much of Dada, and some aspects of the art movements it inspired, such as Neo-Dada, Nouveau réalisme, and Fluxus, is considered anti-art. Dadaists rejected cultural and intellectual conformity in art and more broadly in society. For everything that art stood for, Dada was to represent the opposite.

Where art was concerned with traditional aesthetics, Dada ignored aesthetics completely. If art was to appeal to sensibilities, Dada was intended to offend. Through their rejection of traditional culture and aesthetics the Dadaists hoped to destroy traditional culture and aesthetics. Because they were more politicized, the Berlin dadas were the most radically anti-art within Dada. In 1919, in the Berlin group, the Dadaist revolutionary central council outlined the Dadaist ideals of radical communism.

Beginning in 1913 Marcel Duchamp's readymades challenged individual creativity and redefined art as a nominal rather than an intrinsic object.

Tristan Tzara indicated: "I am against systems; the most acceptable system is on principle to have none." In addition, Tzara, who once stated that "logic is always false", probably approved of Walter Serner's vision of a "final dissolution". A core concept in Tzara's thought was that "as long as we do things the way we think we once did them we will be unable to achieve any kind of livable society."

Originating in Russia in 1919, constructivism rejected art in its entirety and as a specific activity creating a universal aesthetic in favour of practices directed towards social purposes, "useful" to everyday life, such as graphic design, advertising and photography. In 1921, exhibiting at the 5x5=25 exhibition, Alexander Rodchenko created monochromes and proclaimed the end of painting. For artists of the Russian Revolution, Rodchenko's radical action was full of utopian possibility. It marked the end of art along with the end of bourgeois norms and practices. It cleared the way for the beginning of a new Russian life, a new mode of production, a new culture.

Surrealism

Beginning in the early 1920s, many Surrealist artists and writers regard their work as an expression of the philosophical movement first and foremost, with the works being an artifact. Surrealism as a political force developed unevenly around the world, in some places more emphasis being put on artistic practices, while in others political practises outweighed. In other places still, Surrealist praxis looked to overshadow both the arts and politics. Politically, Surrealism was ultra-leftist, communist, or anarchist. The split from Dada has been characterised as a split between anarchists and communists, with the Surrealists as communist. In 1925, the Bureau of Surrealist Research declared their affinity for revolutionary politics. By the 1930s many Surrealists had strongly identified themselves with communism. Breton and his comrades supported Leon Trotsky and his International Left Opposition for a while, though there was an openness to anarchism that manifested more fully after World War II.

Leader André Breton was explicit in his assertion that Surrealism was above all a revolutionary movement. Breton believed the tenets of Surrealism could be applied in any circumstance of life, and is not merely restricted to the artistic realm. Breton's followers, along with the Communist Party, were working for the "liberation of man." However, Breton's group refused to prioritize the proletarian struggle over radical creation such that their struggles with the Party made the late 1920s a turbulent time for both. Many individuals closely associated with Breton, notably Louis Aragon, left his group to work more closely with the Communists. In 1929, Breton asked Surrealists to assess their "degree of moral competence", and theoretical refinements included in the second manifeste du surréalisme excluded anyone reluctant to commit to collective action

By the end of World War II the surrealist group led by André Breton decided to explicitly embrace anarchism. In 1952 Breton wrote "It was in the black mirror of anarchism that surrealism first recognised itself."

Letterism and the Situationist International

In 1956, recalling the infinitesimals of Gottfried Wilhelm Leibniz, quantities which could not actually exist except conceptually, the founder of Lettrism, Isidore Isou, developed the notion of a work of art which, by its very nature, could never be created in reality, but which could nevertheless provide aesthetic rewards by being contemplated intellectually. Related to this, and arising out of it, is excoördism, the current incarnation of the Isouian movement, defined as the art of the infinitely large and the infinitely small.

In 1960, Isidore Isou created supertemporal art: a device for inviting and enabling an audience to participate in the creation of a work of art. In its simplest form, this might involve nothing more than the inclusion of several blank pages in a book, for the reader to add his or her own contributions.

In Japan in the late 1950s, Group Kyushu was an edgy, experimental and rambunctious art group. They ripped and burned canvasses, stapled corrugated cardboard, nails, nuts, springs, metal drill shavings, and burlap to their works, assembled many unwieldy junk assemblages, and were best known for covering much of their work in tar. They also occasionally covered their work in urine and excrement. They tried to bring art closer to everyday life, by incorporating objects from daily life into their work, and also by exhibiting and performing their work outside on the street for everyone to see.

Other similar anti-art groups included Neo-Dada (Neo-Dadaizumu Oganaizazu), Gutai (Gutai Bijutsu Kyokai), and Hi-Red-Center. Influenced in various ways by L'Art Informel, these groups and their members worked to foreground material in their work: rather than seeing the art work as representing some remote referent, the material itself and the artists' interaction with it became the main point. The freeing up of gesture was another legacy of L'Art Informel, and the members of Group Kyushu took to it with great verve, throwing, dripping, and breaking material, sometimes destroying the work in the process.

Beginning in the 1950s in France, the Letterist International and after the Situationist International developed a dialectical viewpoint, seeing their task as superseding art, abolishing the notion of art as a separate, specialized activity and transforming it so it became part of the fabric of everyday life. From the Situationist's viewpoint, art is revolutionary or it is nothing. In this way, the Situationists saw their efforts as completing the work of both Dada and surrealism while abolishing both. The situationists renounced the making of art entirely.

The members of the Situationist International liked to think they were probably the most radical, politicized, well organized, and theoretically productive anti-art movement, reaching their apex with the student protests and general strike of May 1968 in France, a view endorsed by others including the academic Martin Puchner.

In 1959 Giuseppe Pinot-Gallizio proposed Industrial Painting as an "industrial-inflationist art"

Neo-Dada and later

Similar to Dada, in the 1960s, Fluxus included a strong current of anti-commercialism and an anti-art sensibility, disparaging the conventional market-driven art world in favor of an artist-centered creative practice. Fluxus artists used their minimal performances to blur the distinction between life and art.

In 1962 Henry Flynt began to campaign for an anti-art position. Flynt wanted avant-garde art to become superseded by the terms of veramusement and brendneologisms meaning approximately pure recreation.

In 1963 George Maciunas advocated revolution, "living art, anti-art" and "non art reality to be grasped by all peoples". Maciunas strived to uphold his stated aims of demonstrating the artist's 'non-professional status...his dispensability and inclusiveness' and that 'anything can be art and anyone can do it.'

In the 1960s, the Dada-influenced art group Black Mask declared that revolutionary art should be "an integral part of life, as in primitive society, and not an appendage to wealth". Black Mask disrupted cultural events in New York by giving made up flyers of art events to the homeless with the lure of free drinks. Later, the Motherfuckers were to grow out of a combination of Black Mask and another group called Angry Arts.

The BBC aired an interview with Duchamp conducted by Joan Bakewell in 1966 which expressed some of Duchamps more explicit Anti-Art ideas. Duchamp compared art with religion, whereby he stated that he wished to do away with art the same way many have done away with religion. Duchamp goes on to explain to the interviewer that "the word art etymologically means to do", that art means activity of any kind, and that it is our society that creates "purely artificial" distinctions of being an artist.

During the 1970s, King Mob was responsible for various attacks on art galleries along with the art inside. According to the philosopher Roger Taylor the concept of art is not universal but is an invention of bourgeois ideology helping to promote this social order. He compares it to a cancer that colonises other forms of life so that it becomes difficult to distinguish one from the other.

Stewart Home called for an Art Strike between 1990 and 1993. Unlike earlier art-strike proposals such as that of Gustav Metzger in the 1970s, it was not intended as an opportunity for artists to seize control of the means of distributing their own work, but rather as an exercise in propaganda and psychic warfare aimed at smashing the entire art world rather than just the gallery system. As Black Mask had done in the 1960s, Stewart Home disrupted cultural events in London in the 1990s by giving made up flyers of literary events to the homeless with the lure of free drinks.

The K Foundation was an art foundation that published a series of Situationist-inspired press adverts and extravagant subversions in the art world. Most notoriously, when their plans to use banknotes as part of a work of art fell through, they burnt a million pounds in cash.

Punk has developed anti-art positions. Some "industrial music" bands describe their work as a form of "cultural terrorism" or as a form of "anti-art". The term is also used to describe other intentionally provocative art forms, such as nonsense verse.

As art

Paradoxically, most forms of anti-art have gradually been completely accepted by the art establishment as normal and conventional forms of art. Even the movements which rejected art with the most virulence are now collected by the most prestigious cultural institutions.

Duchamp's readymades are still regarded as anti-art by the Stuckists, who also say that anti-art has become conformist, and describe themselves as anti-anti-art.

Neural coding

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Neural_coding

Neural coding (or neural representation) is a neuroscience field concerned with characterising the hypothetical relationship between the stimulus and the neuronal responses, and the relationship among the electrical activities of the neurons in the ensemble. Based on the theory that sensory and other information is represented in the brain by networks of neurons, it is believed that neurons can encode both digital and analog information.

Overview

Neurons have an ability uncommon among the cells of the body to propagate signals rapidly over large distances by generating characteristic electrical pulses called action potentials: voltage spikes that can travel down axons. Sensory neurons change their activities by firing sequences of action potentials in various temporal patterns, with the presence of external sensory stimuli, such as light, sound, taste, smell and touch. Information about the stimulus is encoded in this pattern of action potentials and transmitted into and around the brain. Beyond this, specialized neurons, such as those of the retina, can communicate more information through graded potentials. These differ from action potentials because information about the strength of a stimulus directly correlates with the strength of the neurons' output. The signal decays much faster for graded potentials, necessitating short inter-neuron distances and high neuronal density. The advantage of graded potentials is higher information rates capable of encoding more states (i.e. higher fidelity) than spiking neurons.

Although action potentials can vary somewhat in duration, amplitude and shape, they are typically treated as identical stereotyped events in neural coding studies. If the brief duration of an action potential (about 1 ms) is ignored, an action potential sequence, or spike train, can be characterized simply by a series of all-or-none point events in time. The lengths of interspike intervals (ISIs) between two successive spikes in a spike train often vary, apparently randomly. The study of neural coding involves measuring and characterizing how stimulus attributes, such as light or sound intensity, or motor actions, such as the direction of an arm movement, are represented by neuron action potentials or spikes. In order to describe and analyze neuronal firing, statistical methods and methods of probability theory and stochastic point processes have been widely applied.

With the development of large-scale neural recording and decoding technologies, researchers have begun to crack the neural code and have already provided the first glimpse into the real-time neural code as memory is formed and recalled in the hippocampus, a brain region known to be central for memory formation. Neuroscientists have initiated several large-scale brain decoding projects.

Encoding and decoding

The link between stimulus and response can be studied from two opposite points of view. Neural encoding refers to the map from stimulus to response. The main focus is to understand how neurons respond to a wide variety of stimuli, and to construct models that attempt to predict responses to other stimuli. Neural decoding refers to the reverse map, from response to stimulus, and the challenge is to reconstruct a stimulus, or certain aspects of that stimulus, from the spike sequences it evokes.

Hypothesized coding schemes

A sequence, or 'train', of spikes may contain information based on different coding schemes. In some neurons the strength with which a postsynaptic partner responds may depend solely on the 'firing rate', the average number of spikes per unit time (a 'rate code'). At the other end, a complex 'temporal code' is based on the precise timing of single spikes. They may be locked to an external stimulus such as in the visual and auditory system or be generated intrinsically by the neural circuitry.

Whether neurons use rate coding or temporal coding is a topic of intense debate within the neuroscience community, even though there is no clear definition of what these terms mean.

Rate code

The rate coding model of neuronal firing communication states that as the intensity of a stimulus increases, the frequency or rate of action potentials, or "spike firing", increases. Rate coding is sometimes called frequency coding.

Rate coding is a traditional coding scheme, assuming that most, if not all, information about the stimulus is contained in the firing rate of the neuron. Because the sequence of action potentials generated by a given stimulus varies from trial to trial, neuronal responses are typically treated statistically or probabilistically. They may be characterized by firing rates, rather than as specific spike sequences. In most sensory systems, the firing rate increases, generally non-linearly, with increasing stimulus intensity. Under a rate coding assumption, any information possibly encoded in the temporal structure of the spike train is ignored. Consequently, rate coding is inefficient but highly robust with respect to the ISI 'noise'.

During rate coding, precisely calculating firing rate is very important. In fact, the term "firing rate" has a few different definitions, which refer to different averaging procedures, such as an average over time (rate as a single-neuron spike count) or an average over several repetitions (rate of PSTH) of experiment.

In rate coding, learning is based on activity-dependent synaptic weight modifications.

Rate coding was originally shown by Edgar Adrian and Yngve Zotterman in 1926. In this simple experiment different weights were hung from a muscle. As the weight of the stimulus increased, the number of spikes recorded from sensory nerves innervating the muscle also increased. From these original experiments, Adrian and Zotterman concluded that action potentials were unitary events, and that the frequency of events, and not individual event magnitude, was the basis for most inter-neuronal communication.

In the following decades, measurement of firing rates became a standard tool for describing the properties of all types of sensory or cortical neurons, partly due to the relative ease of measuring rates experimentally. However, this approach neglects all the information possibly contained in the exact timing of the spikes. During recent years, more and more experimental evidence has suggested that a straightforward firing rate concept based on temporal averaging may be too simplistic to describe brain activity.

Spike-count rate (average over time)

The spike-count rate, also referred to as temporal average, is obtained by counting the number of spikes that appear during a trial and dividing by the duration of trial. The length T of the time window is set by the experimenter and depends on the type of neuron recorded from and to the stimulus. In practice, to get sensible averages, several spikes should occur within the time window. Typical values are T = 100 ms or T = 500 ms, but the duration may also be longer or shorter (Chapter 1.5 in the textbook 'Spiking Neuron Models' ).

The spike-count rate can be determined from a single trial, but at the expense of losing all temporal resolution about variations in neural response during the course of the trial. Temporal averaging can work well in cases where the stimulus is constant or slowly varying and does not require a fast reaction of the organism — and this is the situation usually encountered in experimental protocols. Real-world input, however, is hardly stationary, but often changing on a fast time scale. For example, even when viewing a static image, humans perform saccades, rapid changes of the direction of gaze. The image projected onto the retinal photoreceptors changes therefore every few hundred milliseconds.

Despite its shortcomings, the concept of a spike-count rate code is widely used not only in experiments, but also in models of neural networks. It has led to the idea that a neuron transforms information about a single input variable (the stimulus strength) into a single continuous output variable (the firing rate).

There is a growing body of evidence that in Purkinje neurons, at least, information is not simply encoded in firing but also in the timing and duration of non-firing, quiescent periods. There is also evidence from retinal cells, that information is encoded not only in the firing rate but also in spike timing.[19] More generally, whenever a rapid response of an organism is required a firing rate defined as a spike-count over a few hundred milliseconds is simply too slow.

Time-dependent firing rate (averaging over several trials)

The time-dependent firing rate is defined as the average number of spikes (averaged over trials) appearing during a short interval between times t and t+Δt, divided by the duration of the interval. It works for stationary as well as for time-dependent stimuli. To experimentally measure the time-dependent firing rate, the experimenter records from a neuron while stimulating with some input sequence. The same stimulation sequence is repeated several times and the neuronal response is reported in a Peri-Stimulus-Time Histogram (PSTH). The time t is measured with respect to the start of the stimulation sequence. The Δt must be large enough (typically in the range of one or a few milliseconds) so that there is a sufficient number of spikes within the interval to obtain a reliable estimate of the average. The number of occurrences of spikes nK(t;t+Δt) summed over all repetitions of the experiment divided by the number K of repetitions is a measure of the typical activity of the neuron between time t and t+Δt. A further division by the interval length Δt yields time-dependent firing rate r(t) of the neuron, which is equivalent to the spike density of PSTH (Chapter 1.5 in.).

For sufficiently small Δt, r(t)Δt is the average number of spikes occurring between times t and t+Δt over multiple trials. If Δt is small, there will never be more than one spike within the interval between t and t+Δt on any given trial. This means that r(t)Δt is also the fraction of trials on which a spike occurred between those times. Equivalently, r(t)Δt is the probability that a spike occurs during this time interval.

As an experimental procedure, the time-dependent firing rate measure is a useful method to evaluate neuronal activity, in particular in the case of time-dependent stimuli. The obvious problem with this approach is that it can not be the coding scheme used by neurons in the brain. Neurons can not wait for the stimuli to repeatedly present in an exactly same manner before generating a response.

Nevertheless, the experimental time-dependent firing rate measure can make sense, if there are large populations of independent neurons that receive the same stimulus. Instead of recording from a population of N neurons in a single run, it is experimentally easier to record from a single neuron and average over N repeated runs. Thus, the time-dependent firing rate coding relies on the implicit assumption that there are always populations of neurons.

Temporal coding

When precise spike timing or high-frequency firing-rate fluctuations are found to carry information, the neural code is often identified as a temporal code. A number of studies have found that the temporal resolution of the neural code is on a millisecond time scale, indicating that precise spike timing is a significant element in neural coding. Such codes, that communicate via the time between spikes are also referred to as interpulse interval codes, and have been supported by recent studies.

Neurons exhibit high-frequency fluctuations of firing-rates which could be noise or could carry information. Rate coding models suggest that these irregularities are noise, while temporal coding models suggest that they encode information. If the nervous system only used rate codes to convey information, a more consistent, regular firing rate would have been evolutionarily advantageous, and neurons would have utilized this code over other less robust options. Temporal coding supplies an alternate explanation for the “noise," suggesting that it actually encodes information and affects neural processing. To model this idea, binary symbols can be used to mark the spikes: 1 for a spike, 0 for no spike. Temporal coding allows the sequence 000111000111 to mean something different from 001100110011, even though the mean firing rate is the same for both sequences, at 6 spikes/10 ms.

Until recently, scientists had put the most emphasis on rate encoding as an explanation for post-synaptic potential patterns. However, functions of the brain are more temporally precise than the use of only rate encoding seems to allow. In other words, essential information could be lost due to the inability of the rate code to capture all the available information of the spike train. In addition, responses are different enough between similar (but not identical) stimuli to suggest that the distinct patterns of spikes contain a higher volume of information than is possible to include in a rate code.

Temporal codes (also called spike codes), employ those features of the spiking activity that cannot be described by the firing rate. For example, time-to-first-spike after the stimulus onset, phase-of-firing with respect to background oscillations, characteristics based on the second and higher statistical moments of the ISI probability distribution, spike randomness, or precisely timed groups of spikes (temporal patterns) are candidates for temporal codes. As there is no absolute time reference in the nervous system, the information is carried either in terms of the relative timing of spikes in a population of neurons (temporal patterns) or with respect to an ongoing brain oscillation (phase of firing). One way in which temporal codes are decoded, in presence of neural oscillations, is that spikes occurring at specific phases of an oscillatory cycle are more effective in depolarizing the post-synaptic neuron.

The temporal structure of a spike train or firing rate evoked by a stimulus is determined both by the dynamics of the stimulus and by the nature of the neural encoding process. Stimuli that change rapidly tend to generate precisely timed spikes (and rapidly changing firing rates in PSTHs) no matter what neural coding strategy is being used. Temporal coding in the narrow sense refers to temporal precision in the response that does not arise solely from the dynamics of the stimulus, but that nevertheless relates to properties of the stimulus. The interplay between stimulus and encoding dynamics makes the identification of a temporal code difficult.

In temporal coding, learning can be explained by activity-dependent synaptic delay modifications. The modifications can themselves depend not only on spike rates (rate coding) but also on spike timing patterns (temporal coding), i.e., can be a special case of spike-timing-dependent plasticity.

The issue of temporal coding is distinct and independent from the issue of independent-spike coding. If each spike is independent of all the other spikes in the train, the temporal character of the neural code is determined by the behavior of time-dependent firing rate r(t). If r(t) varies slowly with time, the code is typically called a rate code, and if it varies rapidly, the code is called temporal.

Temporal coding in sensory systems

For very brief stimuli, a neuron's maximum firing rate may not be fast enough to produce more than a single spike. Due to the density of information about the abbreviated stimulus contained in this single spike, it would seem that the timing of the spike itself would have to convey more information than simply the average frequency of action potentials over a given period of time. This model is especially important for sound localization, which occurs within the brain on the order of milliseconds. The brain must obtain a large quantity of information based on a relatively short neural response. Additionally, if low firing rates on the order of ten spikes per second must be distinguished from arbitrarily close rate coding for different stimuli, then a neuron trying to discriminate these two stimuli may need to wait for a second or more to accumulate enough information. This is not consistent with numerous organisms which are able to discriminate between stimuli in the time frame of milliseconds, suggesting that a rate code is not the only model at work.

To account for the fast encoding of visual stimuli, it has been suggested that neurons of the retina encode visual information in the latency time between stimulus onset and first action potential, also called latency to first spike or time-to-first-spike. This type of temporal coding has been shown also in the auditory and somato-sensory system. The main drawback of such a coding scheme is its sensitivity to intrinsic neuronal fluctuations. In the primary visual cortex of macaques, the timing of the first spike relative to the start of the stimulus was found to provide more information than the interval between spikes. However, the interspike interval could be used to encode additional information, which is especially important when the spike rate reaches its limit, as in high-contrast situations. For this reason, temporal coding may play a part in coding defined edges rather than gradual transitions.

The mammalian gustatory system is useful for studying temporal coding because of its fairly distinct stimuli and the easily discernible responses of the organism. Temporally encoded information may help an organism discriminate between different tastants of the same category (sweet, bitter, sour, salty, umami) that elicit very similar responses in terms of spike count. The temporal component of the pattern elicited by each tastant may be used to determine its identity (e.g., the difference between two bitter tastants, such as quinine and denatonium). In this way, both rate coding and temporal coding may be used in the gustatory system – rate for basic tastant type, temporal for more specific differentiation.

Research on mammalian gustatory system has shown that there is an abundance of information present in temporal patterns across populations of neurons, and this information is different from that which is determined by rate coding schemes. Groups of neurons may synchronize in response to a stimulus. In studies dealing with the front cortical portion of the brain in primates, precise patterns with short time scales only a few milliseconds in length were found across small populations of neurons which correlated with certain information processing behaviors. However, little information could be determined from the patterns; one possible theory is they represented the higher-order processing taking place in the brain.

As with the visual system, in mitral/tufted cells in the olfactory bulb of mice, first-spike latency relative to the start of a sniffing action seemed to encode much of the information about an odor. This strategy of using spike latency allows for rapid identification of and reaction to an odorant. In addition, some mitral/tufted cells have specific firing patterns for given odorants. This type of extra information could help in recognizing a certain odor, but is not completely necessary, as average spike count over the course of the animal's sniffing was also a good identifier. Along the same lines, experiments done with the olfactory system of rabbits showed distinct patterns which correlated with different subsets of odorants, and a similar result was obtained in experiments with the locust olfactory system.

Temporal coding applications

The specificity of temporal coding requires highly refined technology to measure informative, reliable, experimental data. Advances made in optogenetics allow neurologists to control spikes in individual neurons, offering electrical and spatial single-cell resolution. For example, blue light causes the light-gated ion channel channelrhodopsin to open, depolarizing the cell and producing a spike. When blue light is not sensed by the cell, the channel closes, and the neuron ceases to spike. The pattern of the spikes matches the pattern of the blue light stimuli. By inserting channelrhodopsin gene sequences into mouse DNA, researchers can control spikes and therefore certain behaviors of the mouse (e.g., making the mouse turn left). Researchers, through optogenetics, have the tools to effect different temporal codes in a neuron while maintaining the same mean firing rate, and thereby can test whether or not temporal coding occurs in specific neural circuits.

Optogenetic technology also has the potential to enable the correction of spike abnormalities at the root of several neurological and psychological disorders. If neurons do encode information in individual spike timing patterns, key signals could be missed by attempting to crack the code while looking only at mean firing rates. Understanding any temporally encoded aspects of the neural code and replicating these sequences in neurons could allow for greater control and treatment of neurological disorders such as depression, schizophrenia, and Parkinson's disease. Regulation of spike intervals in single cells more precisely controls brain activity than the addition of pharmacological agents intravenously.

Phase-of-firing code

Phase-of-firing code is a neural coding scheme that combines the spike count code with a time reference based on oscillations. This type of code takes into account a time label for each spike according to a time reference based on phase of local ongoing oscillations at low or high frequencies.

It has been shown that neurons in some cortical sensory areas encode rich naturalistic stimuli in terms of their spike times relative to the phase of ongoing network oscillatory fluctuations, rather than only in terms of their spike count. The local field potential signals reflect population (network) oscillations. The phase-of-firing code is often categorized as a temporal code although the time label used for spikes (i.e. the network oscillation phase) is a low-resolution (coarse-grained) reference for time. As a result, often only four discrete values for the phase are enough to represent all the information content in this kind of code with respect to the phase of oscillations in low frequencies. Phase-of-firing code is loosely based on the phase precession phenomena observed in place cells of the hippocampus. Another feature of this code is that neurons adhere to a preferred order of spiking between a group of sensory neurons, resulting in firing sequence.

Phase code has been shown in visual cortex to involve also high-frequency oscillations. Within a cycle of gamma oscillation, each neuron has its own preferred relative firing time. As a result, an entire population of neurons generates a firing sequence that has a duration of up to about 15 ms.

Population coding

Population coding is a method to represent stimuli by using the joint activities of a number of neurons. In population coding, each neuron has a distribution of responses over some set of inputs, and the responses of many neurons may be combined to determine some value about the inputs. From the theoretical point of view, population coding is one of a few mathematically well-formulated problems in neuroscience. It grasps the essential features of neural coding and yet is simple enough for theoretic analysis. Experimental studies have revealed that this coding paradigm is widely used in the sensory and motor areas of the brain.

For example, in the visual area medial temporal (MT), neurons are tuned to the direction of object motion. In response to an object moving in a particular direction, many neurons in MT fire with a noise-corrupted and bell-shaped activity pattern across the population. The moving direction of the object is retrieved from the population activity, to be immune from the fluctuation existing in a single neuron's signal. When monkeys are trained to move a joystick towards a lit target, a single neuron will fire for multiple target directions. However it fires the fastest for one direction and more slowly depending on how close the target was to the neuron's "preferred" direction. If each neuron represents movement in its preferred direction, and the vector sum of all neurons is calculated (each neuron has a firing rate and a preferred direction), the sum points in the direction of motion. In this manner, the population of neurons codes the signal for the motion. This particular population code is referred to as population vector coding.

Place-time population codes, termed the averaged-localized-synchronized-response (ALSR) code, have been derived for neural representation of auditory acoustic stimuli. This exploits both the place or tuning within the auditory nerve, as well as the phase-locking within each nerve fiber auditory nerve. The first ALSR representation was for steady-state vowels; ALSR representations of pitch and formant frequencies in complex, non-steady state stimuli were later demonstrated for voiced-pitch, and formant representations in consonant-vowel syllables. The advantage of such representations is that global features such as pitch or formant transition profiles can be represented as global features across the entire nerve simultaneously via both rate and place coding.

Population coding has a number of other advantages as well, including reduction of uncertainty due to neuronal variability and the ability to represent a number of different stimulus attributes simultaneously. Population coding is also much faster than rate coding and can reflect changes in the stimulus conditions nearly instantaneously. Individual neurons in such a population typically have different but overlapping selectivities, so that many neurons, but not necessarily all, respond to a given stimulus.

Typically an encoding function has a peak value such that activity of the neuron is greatest if the perceptual value is close to the peak value, and becomes reduced accordingly for values less close to the peak value.  It follows that the actual perceived value can be reconstructed from the overall pattern of activity in the set of neurons. Vector coding is an example of simple averaging. A more sophisticated mathematical technique for performing such a reconstruction is the method of maximum likelihood based on a multivariate distribution of the neuronal responses. These models can assume independence, second order correlations,  or even more detailed dependencies such as higher order maximum entropy models, or copulas.

Correlation coding

The correlation coding model of neuronal firing claims that correlations between action potentials, or "spikes", within a spike train may carry additional information above and beyond the simple timing of the spikes. Early work suggested that correlation between spike trains can only reduce, and never increase, the total mutual information present in the two spike trains about a stimulus feature. However, this was later demonstrated to be incorrect. Correlation structure can increase information content if noise and signal correlations are of opposite sign. Correlations can also carry information not present in the average firing rate of two pairs of neurons. A good example of this exists in the pentobarbital-anesthetized marmoset auditory cortex, in which a pure tone causes an increase in the number of correlated spikes, but not an increase in the mean firing rate, of pairs of neurons.

Independent-spike coding

The independent-spike coding model of neuronal firing claims that each individual action potential, or "spike", is independent of each other spike within the spike train.

Position coding

Plot of typical position coding

A typical population code involves neurons with a Gaussian tuning curve whose means vary linearly with the stimulus intensity, meaning that the neuron responds most strongly (in terms of spikes per second) to a stimulus near the mean. The actual intensity could be recovered as the stimulus level corresponding to the mean of the neuron with the greatest response. However, the noise inherent in neural responses means that a maximum likelihood estimation function is more accurate.

Neural responses are noisy and unreliable.

This type of code is used to encode continuous variables such as joint position, eye position, color, or sound frequency. Any individual neuron is too noisy to faithfully encode the variable using rate coding, but an entire population ensures greater fidelity and precision. For a population of unimodal tuning curves, i.e. with a single peak, the precision typically scales linearly with the number of neurons. Hence, for half the precision, half as many neurons are required. In contrast, when the tuning curves have multiple peaks, as in grid cells that represent space, the precision of the population can scale exponentially with the number of neurons. This greatly reduces the number of neurons required for the same precision.

Sparse coding

The sparse code is when each item is encoded by the strong activation of a relatively small set of neurons. For each item to be encoded, this is a different subset of all available neurons. In contrast to sensor-sparse coding, sensor-dense coding implies that all information from possible sensor locations is known.

As a consequence, sparseness may be focused on temporal sparseness ("a relatively small number of time periods are active") or on the sparseness in an activated population of neurons. In this latter case, this may be defined in one time period as the number of activated neurons relative to the total number of neurons in the population. This seems to be a hallmark of neural computations since compared to traditional computers, information is massively distributed across neurons. Sparse coding of natural images produces wavelet-like oriented filters that resemble the receptive fields of simple cells in the visual cortex. The capacity of sparse codes may be increased by simultaneous use of temporal coding, as found in the locust olfactory system.

Given a potentially large set of input patterns, sparse coding algorithms (e.g. sparse autoencoder) attempt to automatically find a small number of representative patterns which, when combined in the right proportions, reproduce the original input patterns. The sparse coding for the input then consists of those representative patterns. For example, the very large set of English sentences can be encoded by a small number of symbols (i.e. letters, numbers, punctuation, and spaces) combined in a particular order for a particular sentence, and so a sparse coding for English would be those symbols.

Linear generative model

Most models of sparse coding are based on the linear generative model. In this model, the symbols are combined in a linear fashion to approximate the input.

More formally, given a k-dimensional set of real-numbered input vectors , the goal of sparse coding is to determine n k-dimensional basis vectors , corresponding to neuronal receptive fields, along with a sparse n-dimensional vector of weights or coefficients for each input vector, so that a linear combination of the basis vectors with proportions given by the coefficients results in a close approximation to the input vector: .

The codings generated by algorithms implementing a linear generative model can be classified into codings with soft sparseness and those with hard sparseness. These refer to the distribution of basis vector coefficients for typical inputs. A coding with soft sparseness has a smooth Gaussian-like distribution, but peakier than Gaussian, with many zero values, some small absolute values, fewer larger absolute values, and very few very large absolute values. Thus, many of the basis vectors are active. Hard sparseness, on the other hand, indicates that there are many zero values, no or hardly any small absolute values, fewer larger absolute values, and very few very large absolute values, and thus few of the basis vectors are active. This is appealing from a metabolic perspective: less energy is used when fewer neurons are firing.

Another measure of coding is whether it is critically complete or overcomplete. If the number of basis vectors n is equal to the dimensionality k of the input set, the coding is said to be critically complete. In this case, smooth changes in the input vector result in abrupt changes in the coefficients, and the coding is not able to gracefully handle small scalings, small translations, or noise in the inputs. If, however, the number of basis vectors is larger than the dimensionality of the input set, the coding is overcomplete. Overcomplete codings smoothly interpolate between input vectors and are robust under input noise. The human primary visual cortex is estimated to be overcomplete by a factor of 500, so that, for example, a 14 x 14 patch of input (a 196-dimensional space) is coded by roughly 100,000 neurons.

Other models are based on matching pursuit, a sparse approximation algorithm which finds the "best matching" projections of multidimensional data, and dictionary learning, a representation learning method which aims to find a sparse matrix representation of the input data in the form of a linear combination of basic elements as well as those basic elements themselves.

Biological evidence

Sparse coding may be a general strategy of neural systems to augment memory capacity. To adapt to their environments, animals must learn which stimuli are associated with rewards or punishments and distinguish these reinforced stimuli from similar but irrelevant ones. Such tasks require implementing stimulus-specific associative memories in which only a few neurons out of a population respond to any given stimulus and each neuron responds to only a few stimuli out of all possible stimuli.

Theoretical work on sparse distributed memory has suggested that sparse coding increases the capacity of associative memory by reducing overlap between representations. Experimentally, sparse representations of sensory information have been observed in many systems, including vision, audition, touch, and olfaction. However, despite the accumulating evidence for widespread sparse coding and theoretical arguments for its importance, a demonstration that sparse coding improves the stimulus-specificity of associative memory has been difficult to obtain.

In the Drosophila olfactory system, sparse odor coding by the Kenyon cells of the mushroom body is thought to generate a large number of precisely addressable locations for the storage of odor-specific memories. Sparseness is controlled by a negative feedback circuit between Kenyon cells and GABAergic anterior paired lateral (APL) neurons. Systematic activation and blockade of each leg of this feedback circuit shows that Kenyon cells activate APL neurons and APL neurons inhibit Kenyon cells. Disrupting the Kenyon cell–APL feedback loop decreases the sparseness of Kenyon cell odor responses, increases inter-odor correlations, and prevents flies from learning to discriminate similar, but not dissimilar, odors. These results suggest that feedback inhibition suppresses Kenyon cell activity to maintain sparse, decorrelated odor coding and thus the odor-specificity of memories.

Sterilization law in the United States

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