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Friday, May 13, 2022

Louis Farrakhan

From Wikipedia, the free encyclopedia
 
Minister

Louis Farrakhan
Louis Farrakhan 2018.jpg
Farrakhan in November 2018
Born
Louis Eugene Walcott

May 11, 1933
New York City, U.S.
EducationEnglish High School of Boston, Winston-Salem State University
OccupationLeader of the Nation of Islam
Former calypso music singer
PredecessorWarith Deen Mohammed
Spouse(s)
(m. 1953)
Children9; including Mustapha and Donna

Louis Farrakhan (/ˈfɑːrəkɑːn/; born Louis Eugene Walcott, May 11, 1933) is an American religious leader, black supremacist, anti-white conspiracy theorist, and former singer who heads the Nation of Islam (NOI). Prior to joining the NOI, he was a calypso music singer who went by the stage name Calypso Gene. Earlier in his career, he served as the minister of mosques in Boston and Harlem and was appointed National Representative of the Nation of Islam by former NOI leader Elijah Muhammad. He adopted the name Louis X, before being named Louis Farrakhan.

After Warith Deen Mohammed reorganized the original NOI into the orthodox Sunni Islamic group American Society of Muslims, Farrakhan began to rebuild the NOI as "Final Call". In 1981, he officially adopted the name "Nation of Islam", reviving the group and establishing its headquarters at Mosque Maryam. The Nation of Islam is an organization which the Southern Poverty Law Center (SPLC) describes as a hate group. Farrakhan’s antisemitic statements and views have been condemned by the SPLC, the Anti-Defamation League (ADL), and other monitoring organizations. According to the SPLC, the NOI promotes a "fundamentally anti-white theology" amounting to an "innate black superiority over whites". Farrakhan's views and remarks have also been called homophobic. He has disputed these assertions.

In October 1995, he organized and led the Million Man March in Washington, D.C. Due to health issues, he reduced his responsibilities with the NOI in 2007. However, Farrakhan has continued to deliver sermons and speak at NOI events. In 2015, he led the 20th Anniversary of the Million Man March: Justice or Else.

Farrakhan was banned from Facebook in 2019 along with other public figures considered to be extremists.

Early life and education

Farrakhan was born Louis Eugene Walcott on May 11, 1933, in The Bronx, New York City, the younger of two sons of Sarah Mae Manning (1900–1988) and Percival Clark, immigrants from the Anglo-Caribbean islands. His mother was born in Saint Kitts, while his father was Jamaican. The couple separated before their second son was born, and Farrakhan says he never knew his biological father.

In a 1996 interview with Henry Louis Gates Jr., he speculated that his father, "Gene", may have been Jewish.

After his stepfather died in 1936, the Walcott family moved to Boston, where they settled in the largely African-American neighborhood of Roxbury.

Walcott received his first violin at the age of five and by the time he was 12 years old, he had been on tour with the Boston College Orchestra. A year later, he participated in national competitions and won them. In 1946, he was one of the first black performers to appear on the Ted Mack Original Amateur Hour, where he also won an award. Walcott and his family were active members of the Episcopal St. Cyprian's Church in Roxbury.

Walcott attended the Boston Latin School, and later the English High School, from which he graduated. He completed three years at Winston-Salem Teachers College, where he had a track scholarship.

Louis and Khadijah Farrakhan

In 1953, Walcott married Betsy Ross (later known as Khadijah Farrakhan) while he was in college. Due to complications from his new wife's first pregnancy, Walcott dropped out after completing his junior year of college to devote time to his wife and their child. Farrakhan is the father of 9 children and grandfather of basketball player Mustapha Farrakhan Jr.

Career and activities (1953–1995)

In the 1950s, Walcott began his professional music career as a singer billed as "The Charmer". At this point, earning $500 a week, Walcott was touring the northeastern and midwestern United States, sometimes also using the nickname "Calypso Gene". In 1953–1954, preceding Harry Belafonte's success with his album Calypso (released in 1956), he recorded and released a dozen cheeky, funny tunes as "The Charmer" in a mixed mento/calypso style, including "Ugly Woman", "Stone Cold Man" and calypso standards like "Zombie Jamboree", "Hol 'Em Joe", "Mary Ann" and "Brown Skin Girl". Some were reissued: "Don’t Touch Me Nylon" has mild, explicit sexual lyrics as well as "Female Boxer", which contains some sexist overtones and "Is She Is, Or Is She Ain't" (inspired by Christine Jorgensen's sex change operation).

In February 1955, he was headlining a show in Chicago, Illinois, called Calypso Follies. There he first came in contact with the teachings of the Nation of Islam (NOI) through Rodney Smith, a friend and saxophonist from Boston. Walcott and his wife Betsy were invited to the Nation of Islam's annual Saviours' Day address by Elijah Muhammad. Prior to going to Saviours' Day, due to then-Minister Malcolm X's media presence, Walcott had never heard of Elijah Muhammad, and like many outside of the Nation of Islam, he thought that Malcolm X was the leader of the Nation of Islam.

In 1955, Walcott fulfilled the requirements to be a registered Muslim/registered believer/registered laborer. He memorized and recited verbatim the 10 questions and answers of the NOI's Student Enrollment. He then wrote a Saviour's Letter that must be sent to the NOI's headquarters in Chicago. The Saviour's Letter must be copied verbatim, and have the identical handwriting of the Nation of Islam's founder, Wallace Fard Muhammad.

After having the Saviour's Letter reviewed, and approved by the NOI's headquarters in Chicago in July 1955, Walcott received a letter of approval from the Nation of Islam acknowledging his official membership as a registered Muslim/registered believer/registered laborer in the NOI. As a result, he received his "X." The "X" was considered a placeholder, used to indicate that Nation of Islam members' original African family names had been lost. They acknowledged that European surnames were slave names, assigned by the slaveowners in order to mark their ownership. Members of the NOI used the "X" while they were waiting for their Islamic names, which some NOI members received later in their conversions.

Hence, Louis Walcott became Louis X. Elijah Muhammad then replaced his "X" with the "holy name" Farrakhan, which is a corruption of the Arabic word فرقان furqan, which means "The Criterion". On a very different tone from his calypso songs, he recorded two tunes as Louis X, criticizing racism in A White Man's Heaven Is a Black Man's Hell, a record album which was issued on Boston's A Moslem Sings label in 1960.

The summer after Farrakhan's conversion, Elijah Muhammad stated that all musicians in the NOI had to choose between music and the Nation of Islam.

After nine months of being a registered Muslim in the NOI and a member of Muhammad's Temple of Islam in Boston, where Malcolm X was the minister, the former calypso-singer turned Muslim became his assistant minister. Eventually he became the official minister after Elijah Muhammad transferred Malcolm X to Muhammad's Temple of Islam No. 7 on West 116th St. in Harlem, New York City. Louis X continued to be mentored by Malcolm X, until the latter's assassination in 1965.

The day that Malcolm X died in Harlem, Farrakhan happened to be in Newark, New Jersey on rotation, 45 minutes away from where Malcolm X was assassinated. After Malcolm X's death, Elijah Muhammad appointed Farrakhan to the two prominent positions that Malcolm held before being dismissed from the NOI. Farrakhan became the national spokesman/national representative of the NOI and was appointed minister of the influential Harlem Mosque (Temple), where he served until 1975.

Farrakhan made numerous incendiary statements about Malcolm X, contributing to what was called a "climate of vilification." Three men from a Newark, NOI mosque—Thomas Hagan, Muhammad Abdul Aziz (aka Norman 3X Butler) and Kahlil Islam (aka Thomas 15X Johnson)—were convicted of the killing and served prison sentences. Only Hagan ever admitted his role.

Leadership of the Nation of Islam

Warith Deen Mohammed, the seventh son of Elijah and Clara Muhammad, was declared the new leader of the Nation of Islam at the annual Saviours' Day Convention in February 1975, a day after his father died. He made substantial changes in the organization in the late 1970s, taking most of its members into a closer relationship with orthodox Islam, and renaming the group "World Community of Islam in the West", and eventually renaming it the American Society of Muslims, to indicate the apparent changes which had occurred in the group. He rejected the deification of the Nation of Islam's founder Wallace D. Fard as Allah in person, the Mahdi of the Holy Qur'an and the messiah of the Bible, welcomed white worshipers who were once considered devils and enemies in the NOI as equal brothers, sisters, and friends. At the beginning of these changes, Chief Min. Warith Deen Mohammed gave some Euro-Americans X's, and he extended efforts at inter-religious cooperation and outreach to Christians and Jews. He changed his position and title from Chief Minister Wallace Muhammad to Imam Warith Huddin Mohammad, and finally changed them to Imam Warith Al-Deen Mohammed.

Farrakhan joined Mohammed's movement and followed Imam Warith Al-Deen Mohammed, and eventually became a Sunni Imam under him for 3+12 years from 1975 to 1978. Imam Mohammed gave Imam Farrakhan the name Abdul-Haleem. In 1978, Imam Farrakhan distanced himself from Mohammed's movement. In a 1990 interview with Emerge magazine, Farrakhan said that he had become disillusioned with Mohammed's movement and decided to "quietly walk away" from it rather than cause a schism among its members. In 1978, Farrakhan and a small number of supporters decided to rebuild what they considered the original Nation of Islam upon the foundations established by Wallace Fard Muhammad, and Elijah Muhammad. This decision was made without public announcement.

In 1979, Farrakhan's group founded a weekly newspaper entitled The Final Call, which was intended to be similar to the original Muhammad Speaks newspaper that Malcolm X claimed to have started, Farrakhan had a weekly column in The Final Call. In 1981, Farrakhan and his supporters held their first Saviours' Day convention in Chicago, Illinois, and took back the name of the Nation of Islam. The event was similar to the earlier Nation's celebrations, last held in Chicago on February 26, 1975. At the convention's keynote address, Farrakhan announced his attempt to restore the Nation of Islam under Elijah Muhammad's teachings.

On October 24, 1989, at a press conference at the J.W. Marriott Hotel in Washington, DC, Minister Farrakhan described a vision which he had on September 17, 1985 in Tepoztlán, Mexico. In this 'Vision-like' experience he was carried up to "a Wheel, or what you call an unidentified flying object", as in the Bible's Book of Ezekiel. During this experience, he heard the voice of Elijah Muhammad, the leader of the Nation of Islam.

He said in the press conference that Elijah Muhammad "spoke in short cryptic sentences and as he spoke a scroll full of cursive writing rolled down in front of my eyes, but it was a projection of what was being written in my mind. As I attempted to read the cursive writing, which was in English, the scroll disappeared and the Honorable Elijah Muhammad began to speak to me." [Elijah Muhammad said], "President Reagan has met with the Joint Chiefs of Staff to plan a war. I want you to hold a press conference in Washington, D.C., and announce their plan and say to the world that you got the information from me, Elijah Muhammad, on the Wheel."

During that same press conference Farrakhan stated that he believed his "experience" was proven: "In 1987, in The New York Times' Sunday magazine and on the front page of The Atlanta Constitution, the truth of my vision was verified, for the headlines of The Atlanta Constitution read, 'President Reagan Planned War Against Libya.'" Farrakhan added "In the article which followed, the exact words that the Honorable Elijah Muhammad spoke to me on the Wheel were found; that the President had met with the Joint Chiefs of Staff and planned a war against Libya in the early part of September 1985."

Qubilah Shabazz, the daughter of Malcolm X and Betty Shabazz, was arrested on January 12, 1995 accused of conspiracy to assassinate Farrakhan in retaliation for the murder of her father, for which she believed he was responsible. According to Stanford University historian Clayborne Carson, "[her family] resented Farrakhan and had good reason to because he was one of those in the Nation responsible for the climate of vilification that resulted in Malcolm X's assassination". Some critics later alleged that the FBI had used paid informant Michael Fitzpatrick to frame Shabazz, who was four years old when her father was killed. Nearly four months later, on May 1, Shabazz accepted a plea agreement under which she maintained her innocence but accepted responsibility for her actions.

Farrakhan in 1997

Million Man March

That year in October, Farrakhan convened a broad coalition of what he and his supporters claimed was one million men in Washington, D.C., for the Million Man March. The count however fell far below the hoped-for numbers. The National Park Service estimated that approximately 440,000 were in attendance. Farrakhan threatened to sue the National Park Service because of the low estimate from the Park Police.

Farrakhan and other speakers called for black men to renew their commitments to their families and communities. In Farrakhan's 212 hours he quoted from spirituals as well as the Old and New Testaments and termed himself a prophet sent by God to show America its evil. The event was organized by many civil rights and religious organizations and drew men and their sons from across the United States of America. Many other distinguished African Americans addressed the throng, including: Maya Angelou; Rosa Parks; Martin Luther King III, Cornel West, Jesse Jackson and Benjamin Chavis. In 2005, together with other prominent African Americans such as the New Black Panther Party leader Malik Zulu Shabazz, the activist Al Sharpton, Addis Daniel and others, Farrakhan marked the 10th anniversary of the Million Man March by holding a second gathering, the Millions More Movement, October 14–17 in Washington D.C.

Views

Racism and black nationalism

The Anti-Defamation League classifies Farrakhan as a racist and the Southern Poverty Law Center considers the Nation of Islam (NOI) as a hate group and a black nationalist organization. According to the SPLC, the NOI's theology claims black superiority over whites. According to the NOI, whites were created 6,600 years ago as a "race of devils" by an evil scientist named Yakub, a story which originated with the founder of the NOI, Wallace D. Fard.

The split in the NOI into two factions after Eljiah Muhammad died in 1975, was caused in part because new leader Warith Mohammed wished to reject the Yakub myth, while national spokesman Farrakhan wanted to reaffirm it. At an event in Milwaukee in August 2015, Farrakhan said: "White people deserve to die, and they know, so they think it’s us coming to do it".

Antisemitism

Southern Poverty Law Center classifies Farrakhan as an "antisemite". He disputes this label. Farrakhan has made many comments that have been deemed antisemitic by the Anti-Defamation League. The Simon Wiesenthal Center included some of Farrakhan's comments on its list of the Top 10 antisemitic slurs in 2012.

"Gutter religion" remarks

In June 1984, after returning from a visit to Libya, Farrakhan delivered a sermon that was recorded by a Chicago Sun-Times reporter. A transcript from part of the sermon was published in The New York Times:

Toward the end of that portion of his speech that was recorded, Mr. Farrakhan said: "Now that nation called Israel never has had any peace in 40 years and she will never have any peace because there can be no peace structured on injustice, thievery, lying and deceit and using the name of God to shield your dirty religion under His holy and righteous name.

Farrakhan has repeatedly denied referring to Judaism as a "gutter religion" by explaining that he was instead referring to what he believed was the Israeli Government's use of Judaism as a political tool. In a June 18, 1997, letter to a former Wall Street Journal editor Jude Wanniski he stated:

Countless times over the years I have explained that I never referred to Judaism as a gutter religion, but, clearly referred to the machinations of those who hide behind the shield of Judaism while using unjust political means to achieve their objectives. This was distilled in the New York tabloids and other media saying, 'Farrakhan calls Judaism a gutter religion.'

As a Muslim, I revere Abraham, Moses, and all the Prophets whom Allah (God) sent to the children of Israel. I believe in the scriptures brought by these Prophets and the Laws of Allah (God) as expressed in the Torah. I would never refer to the Revealed Word of Allah (God)—the basis of Jewish Faith—as 'dirty' or 'gutter.' You know, Jude, as well as I, that the Revealed Word of Allah (God) comes as a Message from Allah (God) to purify us from our evil that has divided us and caused us to fall into the gutter.

Over the centuries, the evils of Christians, Jews and Muslims have dirtied their respective religions. True Faith in the laws and Teaching of Abraham, Jesus and Muhammad is not dirty, but, practices in the name of these religions can be unclean and can cause people to look upon the misrepresented religion as being unclean.

Adolf Hitler and the Holocaust

In response to Farrakhan's speech, Nathan Pearlmutter, then Chair of the Anti-Defamation League, referred to Farrakhan as the new "Black Hitler" and Village Voice journalist Nat Hentoff also characterized the NOI leader as a "Black Hitler" while he was a guest on a New York radio talk-show.

In response, Farrakhan announced during a March 11, 1984, speech which was broadcast on a Chicago radio station:

So I said to the members of the press, 'Why won't you go and look into what we are saying about the threats on Reverend Jackson's life?' Here the Jews don't like Farrakhan and so they call me 'Hitler'. Well that's a good name. Hitler was a very great man. He wasn't great for me as a Black man but he was a great German and he rose Germany up from the ashes of her defeat by the united force of all of Europe and America after the First World War. Yet Hitler took Germany from the ashes and rose her up and made her the greatest fighting machine of the twentieth century, brothers and sisters, and even though Europe and America had deciphered the code that Hitler was using to speak to his chiefs of staff, they still had trouble defeating Hitler even after knowing his plans in advance. Now I'm not proud of Hitler's evil toward Jewish people, but that's a matter of record. He rose Germany up from nothing. Well, in a sense you could say there is a similarity in that we are rising our people up from nothing, but don't compare me with your wicked killers.

At a later meeting of the Nation of Islam at Madison Square Garden in 1985, Farrakhan said of the Jews: "And don't you forget, when it's God who puts you in the ovens, it's forever!" He has also claimed that German Jews financed the Holocaust in a speech at the Mosque Maryam, Chicago in March 1995: "German Jews financed Hitler right here in America...International bankers financed Hitler and poor Jews died while big Jews were at the root of what you call the Holocaust". Almost three years later at a Saviors' Day gathering in the same city, he said: "The Jews have been so bad at politics they lost half their population in the Holocaust. They thought they could trust in Hitler, and they helped him get the Third Reich on the road."

Incidents and comments since 2002

On March 23, 2002, Farrakhan visited Kahal Kadosh Shaare Shalom in Kingston, Jamaica, which was his first visit to a synagogue, in an attempt to repair his relationship with the Jewish community. Farrakhan was accepted to speak at Shaare Shalom in the native country of his father, after being rejected to appear at American synagogues, many of whom had fear of sending the wrong signals to the Jewish community.

Farrakhan in Iran, 2018

Farrakhan made antisemitic comments during his May 16–17, 2013 visit to Detroit in which he accused President Obama of having “surrounded himself with Satan…members of the Jewish community". Jews, according to Farrakhan, "have mastered the civilization now, but they’ve mastered it in evil". In a weekly lecture series titled "The Time and What Must Be Done", which began during January 2013, he prophesied the downfall of the United States soon and said the country faced divine punishment if his warnings were rejected.

In March 2015, Farrakhan accused "Israelis and Zionist Jews" of being involved in the September 11 attacks. (In 2012 and 2017 speeches, he said the American government were behind 9/11.) In his Saviours' Day speech in February 2018, Farrakhan described "the powerful Jews" as his enemy and approvingly cited President Richard Nixon and the Reverend Billy Graham's derogatory comments about Jews "grip on the media", and claimed they are responsible for "all of this filth and degenerate behavior that Hollywood is putting out turning men into women and women into men".

A three-hour speech by Farrakhan on July 4, 2020 was carried by Revolt TV's YouTube channel, He claimed Jonathan Greenblatt, the head of the anti-bigotry nonprofit Anti-Defamation League, is Satan, and described Alan Dershowitz as "a skillful deceiver" and "Satan masquerading as a lawyer". Greenblatt responded in a tweet: "This is routine for Farrakhan—give him a platform, he never fails to espouse hatred." Farrakhan made the factually inaccurate claim that Jews are required by their religion to poison prophets and claimed Jews had "broken their covenant relationship with God" and were the "enemy of God". However, in his speech, Farrakhan also said: “If you really think I hate the Jewish people, you don’t know me at all,” adding “[I’ve never] uttered the words of death to the Jewish people.” As of July 15, 2020, Farrakhan's speech had been viewed more than 1.2 million times on YouTube.

Activities and statements since 2005

Hurricane Katrina

In comments in 2005, Farrakhan stated that there was a 25-foot (7.6 m) hole under one of the key levees that failed in New Orleans following Hurricane Katrina. He implied that the levee's destruction was a deliberate attempt to wipe out the population of the largely black sections within the city. Farrakhan later said that New Orleans Mayor Ray Nagin told him of the crater during a meeting in Dallas, Texas.

Farrakhan further claimed that the fact the levee broke the day after Hurricane Katrina is proof that the destruction of the levee was not a natural occurrence. Farrakhan has raised additional questions and has called for federal investigations into the source of the levee break. He also asserted that the hurricane was "God's way of punishing America for its warmongering and racism".

Experts including the Independent Levee Investigation Team (ILIT) from the University of California, Berkeley have countered his accusations. The report from the ILIT said "The findings of this panel are that the over-topping of the levees by flood waters, the often sub-standard materials used to shore up the levees, and the age of the levees contributed to these scour holes found at many of the sites of levee breaks after the hurricane."

Relations with Barack Obama

In 2008, Farrakhan publicly criticized the United States and supported then-Senator Barack Obama who was campaigning at the time to become the president of the United States of America. Farrakhan and Obama had met at least once before that time.

The Obama campaign quickly responded to convey his distance from the minister. "Senator Obama has been clear in his objections to Farrakhan's past pronouncements and has not solicited the minister's support," said Obama spokesman Bill Burton. Obama "rejected and denounced" Farrakhan's support during an NBC presidential candidate debate.

Following the 2008 presidential election, Farrakhan explained, during a BET television interview, that he was "careful" never to endorse Obama during his campaign. "I talked about him—but, in very beautiful and glowing terms, stopping short of endorsing him. And unfortunately, or fortunately, however we look at it, the media said I 'endorsed' him, so he renounced my so-called endorsement and support. But that didn't stop me from supporting him."

On May 28, 2011, Farrakhan, speaking at the American Clergy Leadership Conference, lambasted Obama over the wars in Iraq and Afghanistan and the intervention in Libya, calling him an "assassin" and a "murderer." "We voted for our brother Barack, a beautiful human being with a sweet heart," Farrakhan said, in a video that was widely shared on the Internet. "But he has turned into someone else," Farrakhan told the crowd. "Now he's an assassin."

Dianetics

A connection between the Church of Scientology and the Nation of Islam is reported to date from the late 1990s when Farrakhan was introduced to its teachings by the musician Isaac Hayes, who was the Church of Scientology's International spokesman for its World Literacy Crusade.

On May 8, 2010, Farrakhan publicly announced his embrace of Dianetics and has actively encouraged Nation of Islam members to undergo auditing from the Church. Although he has stressed that he is not a Scientologist, but only a believer in Dianetics and the theories related to it, the Church honored Farrakhan previously during its 2006 Ebony Awakening awards ceremony (which he did not attend). Farrakhan has also urged European Americans to join the Church of Scientology, stating in his 2011 Saviour's Day speech, "All white people should flock to [Scientology founder] L. Ron Hubbard." Reportedly, according to the SPLC, Hubbard was a racist who supported the apartheid regime in South Africa.

Since the announcement in 2010, the Nation of Islam has been hosting its own Dianetic courses and its own graduation ceremonies. At the third such ceremony, which was held on Saviours Day 2013, it was announced that nearly 8,500 members of the organisation had undergone Dianetic auditing. The Organisation announced it had graduated 1,055 auditors and had delivered 82,424 hours of auditing. The graduation ceremony was certified by the Church of Scientology, and the Nation of Islam members received official certification. The ceremony was attended by Shane Woodruff, vice-president of the Church of Scientology's Celebrity Centre International. He stated that "The unfolding story of the Nation of Islam and Dianetics is bold, it is determined and it is absolutely committed to restoring freedom and wiping hell from the face of this planet."

Praise for Donald Trump

During the 2016 Republican Party presidential primaries, Farrakhan praised Republican candidate Donald Trump as the only candidate "who has stood in front of the Jewish community and said 'I don’t want your money.'" While he declined to endorse Trump outright, he said of Trump "I like what I'm looking at." In 2018, Farrakhan again praised Trump for "destroying every enemy that was an enemy of our rise". He included the Department of Justice and the Federal Bureau of Investigation (FBI) in this group.

Conservative pundits Candace Owens and Glenn Beck both took note of Farrakhan's position, with Owens saying, while she did not "endorse Farrakhan’s views," it remained a "really big deal" that Farrakhan had "aligned himself with Trump's administration" and Beck declaring that "the enemy of my enemy is my friend" and urged "reconciliation" between conservatives and Farrakhan.

Controversies

Farrakhan's police escort in Memphis, Tennessee, 2015

Farrakhan has been the center of much controversy with critics saying that his political views and comments are antisemitic or racist. Farrakhan has categorically denied these charges and stated that much of America's perception of him has been shaped by the media.

Malcolm X's death

Many, including Malcolm X's family, have accused Farrakhan of being involved in the plot to assassinate Malcolm X. For many years, Betty Shabazz, the widow of Malcolm X, harbored resentment toward the Nation of Islam—and Farrakhan in particular—for what she felt was their role in the assassination of her husband. In a 1993 speech, Farrakhan seemed to confirm that the Nation of Islam was responsible for the assassination:

We don't give a damn about no white man law if you attack what we love. And frankly, it ain't none of your business. What do you got to say about it? Did you teach Malcolm? Did you make Malcolm? Did you clean up Malcolm? Did you put Malcolm out before the world? Was Malcolm your traitor or ours? And if we dealt with him like a nation deals with a traitor, what the hell business is it of yours? You just shut your mouth, and stay out of it. Because in the future, we gonna become a nation. And a nation gotta be able to deal with traitors and cutthroats and turncoats. The white man deals with his. The Jews deal with theirs.

During a 1994 interview, Gabe Pressman asked Shabazz whether Farrakhan "had anything to do" with Malcolm X's death. She replied: "Of course, yes. Nobody kept it a secret. It was a badge of honor. Everybody talked about it, yes."

In a 60 Minutes interview that aired during May 2000, Farrakhan stated that some of the things he said may have led to the assassination of Malcolm X. "I may have been complicit in words that I spoke", he said. "I acknowledge that and regret that any word that I have said caused the loss of life of a human being." A few days later Farrakhan denied that he "ordered the assassination" of Malcolm X, although he again acknowledged that he "created the atmosphere that ultimately led to Malcolm X's assassination."

Allegations of sexism

Farrakhan received sexual discrimination complaints filed with a New York state agency when he banned women from attending a speech he gave in a city-owned theater in 1993. The next year he gave a speech only women could attend. In his speech for women, as The New York Times reported,

Mr. Farrakhan urged the women to embrace his formula for a successful family. He encouraged them to put husbands and children ahead of their careers, shun tight, short skirts, stay off welfare and reject abortion. He also stressed the importance of cooking and cleaning and urged women not to abandon homemaking for careers. 'You're just not going to be happy unless there is happiness in the home,' Mr. Farrakhan said at the Mason Cathedral Church of God in Christ in the Dorchester section, not far from the Roxbury neighborhood where he was raised by a single mother. 'Your professional lives can't satisfy your soul like a good, loving man.'

Muammar Gaddafi

In 1985, Farrakhan obtained working capital in the amount of $5 million, in the form of an interest-free loan from Libya's Islamic Call Society to be repaid within 18 months which was to be used to create a toiletries firm with black employees. Libyan President Muammar Gaddafi had also offered Farrahkan guns to begin a black nation. Farrakhan said that he told Gaddafi that he preferred an economic investment in black America.

In January 1996, when Farrakhan visited Libya, Gaddafi pledged giving him a gift of $1 billion and a personal award of $250,000. As economic activity between the two countries had been restricted by the US government since 1986 following allegations of Libya's connection to terrorism, the financial transfer was blocked. It was unclear if Gaddafi would have been in a position to finance the money transfer.

At the time of the wider uprisings in the Arab world and the Tsunami in Japan in a Chicago press conference on March 31, 2011, Farrakhan said President Obama's action in supporting the rebels in Libya were going to advance the arrival of UFOs, or divine spaceships, as punishments for black sufferings. Depicting Obama as engulfed by the people surrounding him, he said: "The stupid mistake that we make is to think that the president is the supreme power. Never was. Money is the power in America. … All of you know what I’m talking about, Zionist control of the government of the United States of America." When Gaddafi was killed in October 2011, Farrakhan blamed Obama's advisors whom he called "wicked demons".

Social media

Farrakhan lost his verified status on his Twitter posts in June 2018, denying him full verification, after asserting the Harvey Weinstein scandal was about "Jewish power". A contributor to the Tablet website, Yair Rosenberg, objected to a potential suspension as "erasing hate from social media doesn’t make it go away, it just makes it easier to ignore" making them more difficult to dismiss as "inconsequential". The following October, Twitter said that it would not suspend Farrakhan's account after a tweet he posted compared Jews to termites as he had not broken the site's rules. After a Twitter rule change on hateful conduct in July 2019, the tweet ("I’m not an anti-Semite. I’m anti-Termite") was removed.

At the beginning of May 2019, Farrakhan was banned from Facebook, along with other prominent individuals considered by the company to be extremists, with antisemitism believed to be the reason for Farrakhan's removal.

During a speech at Saint Sabina Catholic Church in Chicago a week later, Farrakhan stated he had "never been arrested" for "drunken driving" and asked: "What have I done that you would hate me like that?" The Nation of Islam said his speech was Farrakhan's response to the "public outrage over the unprecedented and unwarranted lifetime ban" from Facebook. He insisted he was neither a misogynist nor a homophobe and that: "I do not hate Jewish people". Archbishop of Chicago Cardinal Blase J. Cupich condemned the decision of the church in allowing Farrakhan to speak there.

Other issues

Farrakhan's home in Kenwood, Chicago

Brief return to music

When Farrakhan first joined the NOI, he was asked by Elijah Muhammad to put aside his musical career as a calypso singer. After 42 years, Farrakhan decided to take up the violin once more primarily due to the urging of prominent classical musician Sylvia Olden Lee.

On April 17, 1993, Farrakhan made his return concert debut with performances of the Violin Concerto in E Minor by Felix Mendelssohn. Farrakhan intimated that his performance of a concerto by a Jewish composer was, in part, an effort to heal a rift between him and the Jewish community. (Mendelssohn's family converted to Christianity). The New York Times music critic Bernard Holland reported that Farrakhan's performance was somewhat flawed due to years of neglect, but "nonetheless Mr. Farrakhan's sound is that of the authentic player. It is wide, deep and full of the energy that makes the violin gleam."

Health

Farrakhan announced that he was seriously ill in a letter on September 11, 2006, that was directed to his staff, Nation of Islam members, and supporters. The letter, published in The Final Call newspaper, said that doctors in Cuba had discovered a peptic ulcer. According to the letter subsequent infections caused Farrakhan to lose 35 pounds (16 kg), and he urged the Nation of Islam leadership to carry on while he recovered.

Farrakhan was released from his five-week hospital stay on January 28, 2007, after major abdominal surgery. The operation was performed to correct damage caused by side effects of a radioactive "seed" implantation procedure that he received years earlier to successfully treat prostate cancer.

Following his hospital stay, Farrakhan released a "Message of Appreciation" to supporters and well-wishers and weeks later delivered the keynote address at the Nation of Islam's annual convention in Detroit.

In December 2013, Farrakhan announced that he had not appeared publicly for two months because he had suffered a heart attack in October.

Awards

Belief bias

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

Belief bias is the tendency to judge the strength of arguments based on the plausibility of their conclusion rather than how strongly they support that conclusion. A person is more likely to accept an argument that supports a conclusion that aligns with their values, beliefs and prior knowledge, while rejecting counter arguments to the conclusion. Belief bias is an extremely common and therefore significant form of error; we can easily be blinded by our beliefs and reach the wrong conclusion. Belief bias has been found to influence various reasoning tasks, including conditional reasoning, relation reasoning and transitive reasoning.

Syllogisms

A syllogism is a kind of logical argument in which one proposition (the conclusion) is inferred from two or more others (the premises) of a specific form. The classical example of a valid syllogism is:

All humans are mortal. (major premise)
Socrates is human. (minor premise)
Therefore, Socrates is mortal. (conclusion)

An example of an invalid syllogism is:

All teenage girls are ambitious.
Teenage girls study hard.
Therefore, girls study hard because they are ambitious.

Typically, a majority of test subjects in studies incorrectly identify this syllogism as one in which the conclusion follows from the premises. It might be true in the real world that a) girls study and b) this is because they are ambitious. However, this argument is a fallacy, because the conclusion is not supported by its premises. The validity of an argument is independent from the truth of its conclusion: there are valid arguments for false conclusions and invalid arguments for true conclusions. Hence, it is an error to judge the validity of an argument from the plausibility of its conclusion. This is the reasoning error known as belief bias.

When a person gives a response that is determined by the believability of the conclusion rather than logical validity, this is referred to as belief bias only when a syllogism is used. This phenomenon is so closely related to syllogistic reasoning that, when it does occur, in areas such as Wason's selection task or the THOG problem, it is called "memory cueing" or the "effects of content".

Dual-process theory of belief bias

Many researchers in thinking and reasoning have provided evidence for a dual-process cognitive approach to reasoning, judgment and decision making. They argue that these two mental processes (system 1 and system 2) engage in a constant battle for control over our brain to reason and make decisions. System 1 can be described as an automatic response system characterised by "unconscious", "intuitive" and "rapid" evaluation; whereas system 2 is said to be a controlled response system, characterised by “conscious”, “analytic” and “slow” evaluation; some researchers even claimed to have found a link between general intelligence and the effectiveness of decision making. It is important to note that the dual-process cognitive theory is different from the two minds hypothesis. Research done by Jonathan Evans in 2007 provided evidence for the view that System 1, which serves as a quick heuristic processor, fights for control over System 2's slower analytical approach. In the experiment, participants were asked to evaluate syllogisms that have valid arguments with unconvincing conclusions; valid arguments with convincing conclusions; invalid arguments with unconvincing conclusions; invalid arguments with convincing conclusions. The results show that when the conclusion is believable, people blindly accept invalid conclusions more so than invalid arguments are accepted.

Influencing factors of belief bias

Time

Various studies have proved that the time period for which a subject is allowed to think when evaluating arguments is related to the tendency for belief bias to take place. In a study done by Evans and Holmes in 2005, they recruited two different groups of people to answer a series of reasoning questions. One group of people were given only two seconds to answer the questions; whereas the other group of people were allowed to use as much time as they would like to answer the questions. The result obtained was that a higher percentage of incorrect answers were found in the time pressured group than the other; they concluded that this was a result of a shift in logical to belief-biased way of thinking.

Nature of content

The nature of the content presented can also affect belief bias of an individual as shown by a study done by Goel & Vartanian in 2011. In their experiment, 34 participants were presented with a syllogism upon each trial. Each trial were either neutral or carried some degree of negative content. Negative content involved in the experiment were politically incorrect social norm violations, such as the statement “Some wars are not unjustified, Some wars involve raping of women, therefore, Some raping of women is not unjustified”. For syllogisms where the content was neutral, the results were consistent with studies of belief bias; however, for syllogisms with negative emotional content, participants were more likely to reason logically on invalid syllogisms with believable conclusions instead of automatically judging them to be valid. In other words, the effect of belief bias is reduced when the content presented is of negative emotion. According to Goel and Vartanian, this is because negative emotions prompts us to reason in more careful and in more detail. This argument was supported by the observation that for questions with negative emotions, the reaction time taken was significantly longer than that of questions that a neutral.

Instructions given

In an experiment done by Evans, Newstead, Allen & Pollard in 1994, where subjects were given detailed instructions which lack specific reference to the notion of logical necessity when answering questions, it was shown that a larger proportion of answers actually rejected invalid arguments with convincing conclusions as opposed to when no further instructions were given when the subjects were asked to answer the questions. The results of the experiments reflects that when elaborated instructions were given to subjects to reason logically, the effects of belief bias is decreased.

Research

In a series of experiments by Evans, Barston and Pollard (1983), participants were presented with evaluation task paradigms, containing two premises and a conclusion. The participants were asked to make an evaluation of logical validity. The subjects, however, exhibited a belief bias, evidenced by their tendency to reject valid arguments with unbelievable conclusions, and endorse invalid arguments with believable conclusions. Instead of following directions and assessing logical validity, the subjects based their assessments on personal beliefs.

Consequently, these results demonstrated a greater acceptance of more believable (80%), than unbelievable (33%) conclusions. Participants also illustrated evidence of logical competences and the results determined an increase in acceptance of valid (73%) than invalid (41%). Additionally, there's a small difference between believable and valid (89%) in comparison to unbelievable and invalid (56%) (Evans, Barston & Pollard, 1983; Morley, Evans & Handley, 2004).

It has been argued that using more realistic content in syllogisms can facilitate more normative performance from participants. It has been suggested that the use of more abstract, artificial content will also have a biasing effect on performance. Therefore, more research is required to fully understand how and why belief bias occurs and if there are certain mechanisms that are responsible for such things. There is also evidence of clear individual differences in normative responding that are predicted by the response times of participants.

A 1989 study by Markovits and Nantel gave participants four reasoning tasks. The results indicated “a significant belief-bias effect” that existed “independently of the subjects' abstract reasoning ability.”

A 2010 study by Donna Torrens examined differences in belief bias among individuals. Torrens found that “the extent of an individual's belief bias effect was unrelated to a number of measures of reasoning competence” but was, instead, related to that person's ability “to generate alternative representations of premises: the more alternatives a person generated, the less likely they were to show a belief bias effect."

In a 2010 study, Chad Dube and Caren M. Rotello of the University of Massachusetts and Evan Heit of the University of California, Merced, showed that “the belief bias effect is simply a response bias effect.”

In a 2012 study, Adrian P. Banks of the University of Surrey explained that “belief bias is caused by the believability of a conclusion in working memory which influences its activation level, determining its likelihood of retrieval and therefore its effect on the reasoning process.”

Michelle Colleen and Elizabeth Hilscher of the University of Toronto showed in 2014 that belief bias can be affected by the difficulty level and placement of the syllogism in question.

Neural oscillation

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

Neural oscillations, or brainwaves, are rhythmic or repetitive patterns of neural activity in the central nervous system. Neural tissue can generate oscillatory activity in many ways, driven either by mechanisms within individual neurons or by interactions between neurons. In individual neurons, oscillations can appear either as oscillations in membrane potential or as rhythmic patterns of action potentials, which then produce oscillatory activation of post-synaptic neurons. At the level of neural ensembles, synchronized activity of large numbers of neurons can give rise to macroscopic oscillations, which can be observed in an electroencephalogram. Oscillatory activity in groups of neurons generally arises from feedback connections between the neurons that result in the synchronization of their firing patterns. The interaction between neurons can give rise to oscillations at a different frequency than the firing frequency of individual neurons. A well-known example of macroscopic neural oscillations is alpha activity.

Neural oscillations in humans were observed by researchers as early as 1924 (by Hans Berger). More than 50 years later, intrinsic oscillatory behavior was encountered in vertebrate neurons, but its functional role is still not fully understood. The possible roles of neural oscillations include feature binding, information transfer mechanisms and the generation of rhythmic motor output. Over the last decades more insight has been gained, especially with advances in brain imaging. A major area of research in neuroscience involves determining how oscillations are generated and what their roles are. Oscillatory activity in the brain is widely observed at different levels of organization and is thought to play a key role in processing neural information. Numerous experimental studies support a functional role of neural oscillations; a unified interpretation, however, is still lacking.

Simulation of neural oscillations at 10 Hz. Upper panel shows spiking of individual neurons (with each dot representing an individual action potential within the population of neurons), and the lower panel the local field potential reflecting their summed activity. Figure illustrates how synchronized patterns of action potentials may result in macroscopic oscillations that can be measured outside the scalp.

History

Richard Caton discovered electrical activity in the cerebral hemispheres of rabbits and monkeys and presented his findings in 1875. Adolf Beck published in 1890 his observations of spontaneous electrical activity of the brain of rabbits and dogs that included rhythmic oscillations altered by light detected with electrodes directly placed on the surface of the brain. Before Hans Berger, Vladimir Vladimirovich Pravdich-Neminsky published the first animal EEG and the evoked potential of a dog.

Overview

Neural oscillations are observed throughout the central nervous system at all levels, and include spike trains, local field potentials and large-scale oscillations which can be measured by electroencephalography (EEG). In general, oscillations can be characterized by their frequency, amplitude and phase. These signal properties can be extracted from neural recordings using time-frequency analysis. In large-scale oscillations, amplitude changes are considered to result from changes in synchronization within a neural ensemble, also referred to as local synchronization. In addition to local synchronization, oscillatory activity of distant neural structures (single neurons or neural ensembles) can synchronize. Neural oscillations and synchronization have been linked to many cognitive functions such as information transfer, perception, motor control and memory.

Five frequency bands of neural oscillation, as seen in ten seconds of EEG.

Neural oscillations have been most widely studied in neural activity generated by large groups of neurons. Large-scale activity can be measured by techniques such as EEG. In general, EEG signals have a broad spectral content similar to pink noise, but also reveal oscillatory activity in specific frequency bands. The first discovered and best-known frequency band is alpha activity (8–12 Hz) that can be detected from the occipital lobe during relaxed wakefulness and which increases when the eyes are closed. Other frequency bands are: delta (1–4 Hz), theta (4–8 Hz), beta (13–30 Hz), low gamma (30–70 Hz), and high gamma (70–150 Hz) frequency bands, where faster rhythms such as gamma activity have been linked to cognitive processing. Indeed, EEG signals change dramatically during sleep and show a transition from faster frequencies to increasingly slower frequencies such as alpha waves. In fact, different sleep stages are commonly characterized by their spectral content. Consequently, neural oscillations have been linked to cognitive states, such as awareness and consciousness.

Although neural oscillations in human brain activity are mostly investigated using EEG recordings, they are also observed using more invasive recording techniques such as single-unit recordings. Neurons can generate rhythmic patterns of action potentials or spikes. Some types of neurons have the tendency to fire at particular frequencies, so-called resonators. Bursting is another form of rhythmic spiking. Spiking patterns are considered fundamental for information coding in the brain. Oscillatory activity can also be observed in the form of subthreshold membrane potential oscillations (i.e. in the absence of action potentials). If numerous neurons spike in synchrony, they can give rise to oscillations in local field potentials. Quantitative models can estimate the strength of neural oscillations in recorded data.

Neural oscillations are commonly studied from a mathematical framework and belong to the field of "neurodynamics", an area of research in the cognitive sciences that places a strong focus upon the dynamic character of neural activity in describing brain function. It considers the brain a dynamical system and uses differential equations to describe how neural activity evolves over time. In particular, it aims to relate dynamic patterns of brain activity to cognitive functions such as perception and memory. In very abstract form, neural oscillations can be analyzed analytically. When studied in a more physiologically realistic setting, oscillatory activity is generally studied using computer simulations of a computational model.

The functions of neural oscillations are wide-ranging and vary for different types of oscillatory activity. Examples are the generation of rhythmic activity such as a heartbeat and the neural binding of sensory features in perception, such as the shape and color of an object. Neural oscillations also play an important role in many neurological disorders, such as excessive synchronization during seizure activity in epilepsy or tremor in patients with Parkinson's disease. Oscillatory activity can also be used to control external devices such as a brain–computer interface.

Physiology

Oscillatory activity is observed throughout the central nervous system at all levels of organization. Three different levels have been widely recognized: the micro-scale (activity of a single neuron), the meso-scale (activity of a local group of neurons) and the macro-scale (activity of different brain regions).

Tonic firing pattern of single neuron showing rhythmic spiking activity

Microscopic

Neurons generate action potentials resulting from changes in the electric membrane potential. Neurons can generate multiple action potentials in sequence forming so-called spike trains. These spike trains are the basis for neural coding and information transfer in the brain. Spike trains can form all kinds of patterns, such as rhythmic spiking and bursting, and often display oscillatory activity. Oscillatory activity in single neurons can also be observed in sub-threshold fluctuations in membrane potential. These rhythmic changes in membrane potential do not reach the critical threshold and therefore do not result in an action potential. They can result from postsynaptic potentials from synchronous inputs or from intrinsic properties of neurons.

Neuronal spiking can be classified by their activity patterns. The excitability of neurons can be subdivided in Class I and II. Class I neurons can generate action potentials with arbitrarily low frequency depending on the input strength, whereas Class II neurons generate action potentials in a certain frequency band, which is relatively insensitive to changes in input strength. Class II neurons are also more prone to display sub-threshold oscillations in membrane potential.

Mesoscopic

A group of neurons can also generate oscillatory activity. Through synaptic interactions, the firing patterns of different neurons may become synchronized and the rhythmic changes in electric potential caused by their action potentials will add up (constructive interference). That is, synchronized firing patterns result in synchronized input into other cortical areas, which gives rise to large-amplitude oscillations of the local field potential. These large-scale oscillations can also be measured outside the scalp using electroencephalography (EEG) and magnetoencephalography (MEG). The electric potentials generated by single neurons are far too small to be picked up outside the scalp, and EEG or MEG activity always reflects the summation of the synchronous activity of thousands or millions of neurons that have similar spatial orientation. Neurons in a neural ensemble rarely all fire at exactly the same moment, i.e. fully synchronized. Instead, the probability of firing is rhythmically modulated such that neurons are more likely to fire at the same time, which gives rise to oscillations in their mean activity (see figure at top of page). As such, the frequency of large-scale oscillations does not need to match the firing pattern of individual neurons. Isolated cortical neurons fire regularly under certain conditions, but in the intact brain cortical cells are bombarded by highly fluctuating synaptic inputs and typically fire seemingly at random. However, if the probability of a large group of neurons is rhythmically modulated at a common frequency, they will generate oscillations in the mean field (see also figure at top of page). Neural ensembles can generate oscillatory activity endogenously through local interactions between excitatory and inhibitory neurons. In particular, inhibitory interneurons play an important role in producing neural ensemble synchrony by generating a narrow window for effective excitation and rhythmically modulating the firing rate of excitatory neurons.

Macroscopic

Neural oscillation can also arise from interactions between different brain areas coupled through the structural connectome. Time delays play an important role here. Because all brain areas are bidirectionally coupled, these connections between brain areas form feedback loops. Positive feedback loops tend to cause oscillatory activity where frequency is inversely related to the delay time. An example of such a feedback loop is the connections between the thalamus and cortex – the thalamocortical radiations. This thalamocortical network is able to generate oscillatory activity known as recurrent thalamo-cortical resonance. The thalamocortical network plays an important role in the generation of alpha activity. In a whole-brain network model with realistic anatomical connectivity and propagation delays between brain areas, oscillations in the beta frequency range emerge from the partial synchronisation of subsets of brain areas oscillating in the gamma-band (generated at the mesoscopic level).

Mechanisms

Neuronal properties

Scientists have identified some intrinsic neuronal properties that play an important role in generating membrane potential oscillations. In particular, voltage-gated ion channels are critical in the generation of action potentials. The dynamics of these ion channels have been captured in the well-established Hodgkin–Huxley model that describes how action potentials are initiated and propagated by means of a set of differential equations. Using bifurcation analysis, different oscillatory varieties of these neuronal models can be determined, allowing for the classification of types of neuronal responses. The oscillatory dynamics of neuronal spiking as identified in the Hodgkin–Huxley model closely agree with empirical findings. In addition to periodic spiking, subthreshold membrane potential oscillations, i.e. resonance behavior that does not result in action potentials, may also contribute to oscillatory activity by facilitating synchronous activity of neighboring neurons. Like pacemaker neurons in central pattern generators, subtypes of cortical cells fire bursts of spikes (brief clusters of spikes) rhythmically at preferred frequencies. Bursting neurons have the potential to serve as pacemakers for synchronous network oscillations, and bursts of spikes may underlie or enhance neuronal resonance.

Network properties

Apart from intrinsic properties of neurons, biological neural network properties are also an important source of oscillatory activity. Neurons communicate with one another via synapses and affect the timing of spike trains in the post-synaptic neurons. Depending on the properties of the connection, such as the coupling strength, time delay and whether coupling is excitatory or inhibitory, the spike trains of the interacting neurons may become synchronized.[32] Neurons are locally connected, forming small clusters that are called neural ensembles. Certain network structures promote oscillatory activity at specific frequencies. For example, neuronal activity generated by two populations of interconnected inhibitory and excitatory cells can show spontaneous oscillations that are described by the Wilson-Cowan model.

If a group of neurons engages in synchronized oscillatory activity, the neural ensemble can be mathematically represented as a single oscillator. Different neural ensembles are coupled through long-range connections and form a network of weakly coupled oscillators at the next spatial scale. Weakly coupled oscillators can generate a range of dynamics including oscillatory activity. Long-range connections between different brain structures, such as the thalamus and the cortex (see thalamocortical oscillation), involve time-delays due to the finite conduction velocity of axons. Because most connections are reciprocal, they form feed-back loops that support oscillatory activity. Oscillations recorded from multiple cortical areas can become synchronized to form large scale brain networks, whose dynamics and functional connectivity can be studied by means of spectral analysis and Granger causality measures. Coherent activity of large-scale brain activity may form dynamic links between brain areas required for the integration of distributed information.

Neuromodulation

In addition to fast direct synaptic interactions between neurons forming a network, oscillatory activity is regulated by neuromodulators on a much slower time scale. That is, the concentration levels of certain neurotransmitters are known to regulate the amount of oscillatory activity. For instance, GABA concentration has been shown to be positively correlated with frequency of oscillations in induced stimuli. A number of nuclei in the brainstem have diffuse projections throughout the brain influencing concentration levels of neurotransmitters such as norepinephrine, acetylcholine and serotonin. These neurotransmitter systems affect the physiological state, e.g., wakefulness or arousal, and have a pronounced effect on amplitude of different brain waves, such as alpha activity.

Mathematical description

Oscillations can often be described and analyzed using mathematics. Mathematicians have identified several dynamical mechanisms that generate rhythmicity. Among the most important are harmonic (linear) oscillators, limit cycle oscillators, and delayed-feedback oscillators. Harmonic oscillations appear very frequently in nature—examples are sound waves, the motion of a pendulum, and vibrations of every sort. They generally arise when a physical system is perturbed by a small degree from a minimum-energy state, and are well understood mathematically. Noise-driven harmonic oscillators realistically simulate alpha rhythm in the waking EEG as well as slow waves and spindles in the sleep EEG. Successful EEG analysis algorithms were based on such models. Several other EEG components are better described by limit-cycle or delayed-feedback oscillations. Limit-cycle oscillations arise from physical systems that show large deviations from equilibrium, whereas delayed-feedback oscillations arise when components of a system affect each other after significant time delays. Limit-cycle oscillations can be complex but there are powerful mathematical tools for analyzing them; the mathematics of delayed-feedback oscillations is primitive in comparison. Linear oscillators and limit-cycle oscillators qualitatively differ in terms of how they respond to fluctuations in input. In a linear oscillator, the frequency is more or less constant but the amplitude can vary greatly. In a limit-cycle oscillator, the amplitude tends to be more or less constant but the frequency can vary greatly. A heartbeat is an example of a limit-cycle oscillation in that the frequency of beats varies widely, while each individual beat continues to pump about the same amount of blood.

Computational models adopt a variety of abstractions in order to describe complex oscillatory dynamics observed in brain activity. Many models are used in the field, each defined at a different level of abstraction and trying to model different aspects of neural systems. They range from models of the short-term behaviour of individual neurons, through models of how the dynamics of neural circuitry arise from interactions between individual neurons, to models of how behaviour can arise from abstract neural modules that represent complete subsystems.

Single neuron model

Simulation of a Hindmarsh–Rose neuron showing typical bursting behavior: a fast rhythm generated by individual spikes and a slower rhythm generated by the bursts.
 

A model of a biological neuron is a mathematical description of the properties of nerve cells, or neurons, that is designed to accurately describe and predict its biological processes. The most successful and widely used model of neurons, the Hodgkin–Huxley model, is based on data from the squid giant axon. It is a set of nonlinear ordinary differential equations that approximates the electrical characteristics of a neuron, in particular the generation and propagation of action potentials. The model is very accurate and detailed and Hodgkin and Huxley received the 1963 Nobel Prize in physiology or medicine for this work.

The mathematics of the Hodgkin–Huxley model are quite complicated and several simplifications have been proposed, such as the FitzHugh–Nagumo model, the Hindmarsh–Rose model or the capacitor-switch model as an extension of the integrate-and-fire model. Such models only capture the basic neuronal dynamics, such as rhythmic spiking and bursting, but are more computationally efficient. This allows the simulation of a large number of interconnected neurons that form a neural network.

Spiking model

A neural network model describes a population of physically interconnected neurons or a group of disparate neurons whose inputs or signalling targets define a recognizable circuit. These models aim to describe how the dynamics of neural circuitry arise from interactions between individual neurons. Local interactions between neurons can result in the synchronization of spiking activity and form the basis of oscillatory activity. In particular, models of interacting pyramidal cells and inhibitory interneurons have been shown to generate brain rhythms such as gamma activity. Similarly, it was shown that simulations of neural networks with a phenomenological model for neuronal response failures can predict spontaneous broadband neural oscillations.eural mass model

Simulation of a neural mass model showing network spiking during the onset of a seizure. As the gain A is increased the network starts to oscillate at 3Hz.
 

Neural field models are another important tool in studying neural oscillations and are a mathematical framework describing evolution of variables such as mean firing rate in space and time. In modeling the activity of large numbers of neurons, the central idea is to take the density of neurons to the continuum limit, resulting in spatially continuous neural networks. Instead of modelling individual neurons, this approach approximates a group of neurons by its average properties and interactions. It is based on the mean field approach, an area of statistical physics that deals with large-scale systems. Models based on these principles have been used to provide mathematical descriptions of neural oscillations and EEG rhythms. They have for instance been used to investigate visual hallucinations.

Kuramoto model

Simulation of Kuramoto model showing neural synchronization and oscillations in the mean field
 

The Kuramoto model of coupled phase oscillators is one of the most abstract and fundamental models used to investigate neural oscillations and synchronization. It captures the activity of a local system (e.g., a single neuron or neural ensemble) by its circular phase alone and hence ignores the amplitude of oscillations (amplitude is constant). Interactions amongst these oscillators are introduced by a simple algebraic form (such as a sine function) and collectively generate a dynamical pattern at the global scale. The Kuramoto model is widely used to study oscillatory brain activity and several extensions have been proposed that increase its neurobiological plausibility, for instance by incorporating topological properties of local cortical connectivity. In particular, it describes how the activity of a group of interacting neurons can become synchronized and generate large-scale oscillations. Simulations using the Kuramoto model with realistic long-range cortical connectivity and time-delayed interactions reveal the emergence of slow patterned fluctuations that reproduce resting-state BOLD functional maps, which can be measured using fMRI.

Activity patterns

Both single neurons and groups of neurons can generate oscillatory activity spontaneously. In addition, they may show oscillatory responses to perceptual input or motor output. Some types of neurons will fire rhythmically in the absence of any synaptic input. Likewise, brain-wide activity reveals oscillatory activity while subjects do not engage in any activity, so-called resting-state activity. These ongoing rhythms can change in different ways in response to perceptual input or motor output. Oscillatory activity may respond by increases or decreases in frequency and amplitude or show a temporary interruption, which is referred to as phase resetting. In addition, external activity may not interact with ongoing activity at all, resulting in an additive response.

Ongoing activity

Spontaneous activity is brain activity in the absence of an explicit task, such as sensory input or motor output, and hence also referred to as resting-state activity. It is opposed to induced activity, i.e. brain activity that is induced by sensory stimuli or motor responses. The term ongoing brain activity is used in electroencephalography and magnetoencephalography for those signal components that are not associated with the processing of a stimulus or the occurrence of specific other events, such as moving a body part, i.e. events that do not form evoked potentials/evoked fields, or induced activity. Spontaneous activity is usually considered to be noise if one is interested in stimulus processing; however, spontaneous activity is considered to play a crucial role during brain development, such as in network formation and synaptogenesis. Spontaneous activity may be informative regarding the current mental state of the person (e.g. wakefulness, alertness) and is often used in sleep research. Certain types of oscillatory activity, such as alpha waves, are part of spontaneous activity. Statistical analysis of power fluctuations of alpha activity reveals a bimodal distribution, i.e. a high- and low-amplitude mode, and hence shows that resting-state activity does not just reflect a noise process. In case of fMRI, spontaneous fluctuations in the blood-oxygen-level dependent (BOLD) signal reveal correlation patterns that are linked to resting states networks, such as the default network. The temporal evolution of resting state networks is correlated with fluctuations of oscillatory EEG activity in different frequency bands.

Ongoing brain activity may also have an important role in perception, as it may interact with activity related to incoming stimuli. Indeed, EEG studies suggest that visual perception is dependent on both the phase and amplitude of cortical oscillations. For instance, the amplitude and phase of alpha activity at the moment of visual stimulation predicts whether a weak stimulus will be perceived by the subject.

Frequency response

In response to input, a neuron or neuronal ensemble may change the frequency at which it oscillates, thus changing the rate at which it spikes. Often, a neuron's firing rate depends on the summed activity it receives. Frequency changes are also commonly observed in central pattern generators and directly relate to the speed of motor activities, such as step frequency in walking. However, changes in relative oscillation frequency between different brain areas is not so common because the frequency of oscillatory activity is often related to the time delays between brain areas.

Amplitude response

Next to evoked activity, neural activity related to stimulus processing may result in induced activity. Induced activity refers to modulation in ongoing brain activity induced by processing of stimuli or movement preparation. Hence, they reflect an indirect response in contrast to evoked responses. A well-studied type of induced activity is amplitude change in oscillatory activity. For instance, gamma activity often increases during increased mental activity such as during object representation. Because induced responses may have different phases across measurements and therefore would cancel out during averaging, they can only be obtained using time-frequency analysis. Induced activity generally reflects the activity of numerous neurons: amplitude changes in oscillatory activity are thought to arise from the synchronization of neural activity, for instance by synchronization of spike timing or membrane potential fluctuations of individual neurons. Increases in oscillatory activity are therefore often referred to as event-related synchronization, while decreases are referred to as event-related desynchronization.

Phase resetting

Phase resetting occurs when input to a neuron or neuronal ensemble resets the phase of ongoing oscillations. It is very common in single neurons where spike timing is adjusted to neuronal input (a neuron may spike at a fixed delay in response to periodic input, which is referred to as phase locking) and may also occur in neuronal ensembles when the phases of their neurons are adjusted simultaneously. Phase resetting is fundamental for the synchronization of different neurons or different brain regions because the timing of spikes can become phase locked to the activity of other neurons.

Phase resetting also permits the study of evoked activity, a term used in electroencephalography and magnetoencephalography for responses in brain activity that are directly related to stimulus-related activity. Evoked potentials and event-related potentials are obtained from an electroencephalogram by stimulus-locked averaging, i.e. averaging different trials at fixed latencies around the presentation of a stimulus. As a consequence, those signal components that are the same in each single measurement are conserved and all others, i.e. ongoing or spontaneous activity, are averaged out. That is, event-related potentials only reflect oscillations in brain activity that are phase-locked to the stimulus or event. Evoked activity is often considered to be independent from ongoing brain activity, although this is an ongoing debate.

Asymmetric amplitude modulation

It has recently been proposed that even if phases are not aligned across trials, induced activity may still cause event-related potentials because ongoing brain oscillations may not be symmetric and thus amplitude modulations may result in a baseline shift that does not average out. This model implies that slow event-related responses, such as asymmetric alpha activity, could result from asymmetric brain oscillation amplitude modulations, such as an asymmetry of the intracellular currents that propagate forward and backward down the dendrites. Under this assumption, asymmetries in the dendritic current would cause asymmetries in oscillatory activity measured by EEG and MEG, since dendritic currents in pyramidal cells are generally thought to generate EEG and MEG signals that can be measured at the scalp.

Function

Neural synchronization can be modulated by task constraints, such as attention, and is thought to play a role in feature binding, neuronal communication, and motor coordination. Neuronal oscillations became a hot topic in neuroscience in the 1990s when the studies of the visual system of the brain by Gray, Singer and others appeared to support the neural binding hypothesis. According to this idea, synchronous oscillations in neuronal ensembles bind neurons representing different features of an object. For example, when a person looks at a tree, visual cortex neurons representing the tree trunk and those representing the branches of the same tree would oscillate in synchrony to form a single representation of the tree. This phenomenon is best seen in local field potentials which reflect the synchronous activity of local groups of neurons, but has also been shown in EEG and MEG recordings providing increasing evidence for a close relation between synchronous oscillatory activity and a variety of cognitive functions such as perceptual grouping and attentional top-down control.

Pacemaker

Cells in the sinoatrial node, located in the right atrium of the heart, spontaneously depolarize approximately 100 times per minute. Although all of the heart's cells have the ability to generate action potentials that trigger cardiac contraction, the sinoatrial node normally initiates it, simply because it generates impulses slightly faster than the other areas. Hence, these cells generate the normal sinus rhythm and are called pacemaker cells as they directly control the heart rate. In the absence of extrinsic neural and hormonal control, cells in the SA node will rhythmically discharge. The sinoatrial node is richly innervated by the autonomic nervous system, which up or down regulates the spontaneous firing frequency of the pacemaker cells.

Central pattern generator

Synchronized firing of neurons also forms the basis of periodic motor commands for rhythmic movements. These rhythmic outputs are produced by a group of interacting neurons that form a network, called a central pattern generator. Central pattern generators are neuronal circuits that—when activated—can produce rhythmic motor patterns in the absence of sensory or descending inputs that carry specific timing information. Examples are walking, breathing, and swimming, Most evidence for central pattern generators comes from lower animals, such as the lamprey, but there is also evidence for spinal central pattern generators in humans.

Information processing

Neuronal spiking is generally considered the basis for information transfer in the brain. For such a transfer, information needs to be coded in a spiking pattern. Different types of coding schemes have been proposed, such as rate coding and temporal coding. Neural oscillations could create periodic time windows in which input spikes have larger effect on neurons, thereby providing a mechanism for decoding temporal codes.

Perception

Synchronization of neuronal firing may serve as a means to group spatially segregated neurons that respond to the same stimulus in order to bind these responses for further joint processing, i.e. to exploit temporal synchrony to encode relations. Purely theoretical formulations of the binding-by-synchrony hypothesis were proposed first, but subsequently extensive experimental evidence has been reported supporting the potential role of synchrony as a relational code.

The functional role of synchronized oscillatory activity in the brain was mainly established in experiments performed on awake kittens with multiple electrodes implanted in the visual cortex. These experiments showed that groups of spatially segregated neurons engage in synchronous oscillatory activity when activated by visual stimuli. The frequency of these oscillations was in the range of 40 Hz and differed from the periodic activation induced by the grating, suggesting that the oscillations and their synchronization were due to internal neuronal interactions. Similar findings were shown in parallel by the group of Eckhorn, providing further evidence for the functional role of neural synchronization in feature binding. Since then, numerous studies have replicated these findings and extended them to different modalities such as EEG, providing extensive evidence of the functional role of gamma oscillations in visual perception.

Gilles Laurent and colleagues showed that oscillatory synchronization has an important functional role in odor perception. Perceiving different odors leads to different subsets of neurons firing on different sets of oscillatory cycles. These oscillations can be disrupted by GABA blocker picrotoxin, and the disruption of the oscillatory synchronization leads to impairment of behavioral discrimination of chemically similar odorants in bees and to more similar responses across odors in downstream β-lobe neurons. Recent follow-up of this work has shown that oscillations create periodic integration windows for Kenyon cells in the insect mushroom body, such that incoming spikes from the antennal lobe are more effective in activating Kenyon cells only at specific phases of the oscillatory cycle.

Neural oscillations are also thought be involved in the sense of time and in somatosensory perception. However, recent findings argue against a clock-like function of cortical gamma oscillations.

Motor coordination

Oscillations have been commonly reported in the motor system. Pfurtscheller and colleagues found a reduction in alpha (8–12 Hz) and beta (13–30 Hz) oscillations in EEG activity when subjects made a movement. Using intra-cortical recordings, similar changes in oscillatory activity were found in the motor cortex when the monkeys performed motor acts that required significant attention. In addition, oscillations at spinal level become synchronised to beta oscillations in the motor cortex during constant muscle activation, as determined by cortico-muscular coherence. Likewise, muscle activity of different muscles reveals inter-muscular coherence at multiple distinct frequencies reflecting the underlying neural circuitry involved in motor coordination.

Recently it was found that cortical oscillations propagate as travelling waves across the surface of the motor cortex along dominant spatial axes characteristic of the local circuitry of the motor cortex. It has been proposed that motor commands in the form of travelling waves can be spatially filtered by the descending fibres to selectively control muscle force. Simulations have shown that ongoing wave activity in cortex can elicit steady muscle force with physiological levels of EEG-EMG coherence.

Oscillatory rhythms at 10 Hz have been recorded in a brain area called the inferior olive, which is associated with the cerebellum. These oscillations are also observed in motor output of physiological tremor and when performing slow finger movements. These findings may indicate that the human brain controls continuous movements intermittently. In support, it was shown that these movement discontinuities are directly correlated to oscillatory activity in a cerebello-thalamo-cortical loop, which may represent a neural mechanism for the intermittent motor control.

Memory

Neural oscillations, in particular theta activity, are extensively linked to memory function. Theta rhythms are very strong in rodent hippocampi and entorhinal cortex during learning and memory retrieval, and they are believed to be vital to the induction of long-term potentiation, a potential cellular mechanism for learning and memory. Coupling between theta and gamma activity is thought to be vital for memory functions, including episodic memory. Tight coordination of single-neuron spikes with local theta oscillations is linked to successful memory formation in humans, as more stereotyped spiking predicts better memory.

Sleep and consciousness

Sleep is a naturally recurring state characterized by reduced or absent consciousness and proceeds in cycles of rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. Sleep stages are characterized by spectral content of EEG: for instance, stage N1 refers to the transition of the brain from alpha waves (common in the awake state) to theta waves, whereas stage N3 (deep or slow-wave sleep) is characterized by the presence of delta waves. The normal order of sleep stages is N1 → N2 → N3 → N2 → REM.

Development

Neural oscillations may play a role in neural development. For example, retinal waves are thought to have properties that define early connectivity of circuits and synapses between cells in the retina.

Pathology

Handwriting of a person affected by Parkinson's disease showing rhythmic tremor activity in the strokes
 
Generalized 3 Hz spike and wave discharges reflecting seizure activity

Specific types of neural oscillations may also appear in pathological situations, such as Parkinson's disease or epilepsy. These pathological oscillations often consist of an aberrant version of a normal oscillation. For example, one of the best known types is the spike and wave oscillation, which is typical of generalized or absence epileptic seizures, and which resembles normal sleep spindle oscillations.

Tremor

A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving to-and-fro movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal cords, trunk, and legs. Most tremors occur in the hands. In some people, tremor is a symptom of another neurological disorder. Many different forms of tremor have been identified, such as essential tremor or Parkinsonian tremor. It is argued that tremors are likely to be multifactorial in origin, with contributions from neural oscillations in the central nervous systems, but also from peripheral mechanisms such as reflex loop resonances.

Epilepsy

Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.

Thalamocortical dysrhythmia

In thalamocortical dysrhythmia (TCD), normal thalamocortical resonance is disrupted. The thalamic loss of input allows the frequency of the thalamo-cortical column to slow into the theta or delta band as identified by MEG and EEG by machine learning. TCD can be treated with neurosurgical methods like thalamotomy.

Applications

Clinical endpoints

Neural oscillations are sensitive to several drugs influencing brain activity; accordingly, biomarkers based on neural oscillations are emerging as secondary endpoints in clinical trials and in quantifying effects in pre-clinical studies. These biomarkers are often named "EEG biomarkers" or "Neurophysiological Biomarkers" and are quantified using quantitative electroencephalography (qEEG). EEG biomarkers can be extracted from the EEG using the open-source Neurophysiological Biomarker Toolbox.

Brain–computer interface

Neural oscillation has been applied as a control signal in various brain–computer interfaces (BCIs). For example, a non-invasive BCI can be created by placing electrodes on the scalp and then measuring the weak electric signals. Although individual neuron activities cannot be recorded through non-invasive BCI because the skull damps and blurs the electromagnetic signals, oscillatory activity can still be reliably detected. The BCI was introduced by Vidal in 1973 as challenge of using EEG signals to control objects outside human body.

After the BCI challenge, in 1988, alpha rhythm was used in a brain rhythm based BCI for control of a physical object, a robot. Alpha rhythm based BCI was the first BCI for control of a robot. In particular, some forms of BCI allow users to control a device by measuring the amplitude of oscillatory activity in specific frequency bands, including mu and beta rhythms.

Political psychology

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