Steven Pinker

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Steven_Pinker 

 

Steven Pinker
Born	Steven Arthur Pinker September 18, 1954 Montreal, Quebec, Canada
Nationality	Canadian American
Notable work	The Language Instinct (1994) How the Mind Works (1997) The Blank Slate (2002) The Better Angels of Our Nature (2011) Enlightenment Now (2018)
Spouse(s)	Nancy Etcoff (m. 1980; div. 1992) Ilavenil Subbiah (m. 1995; div. 2006) Rebecca Goldstein (m. 2007)
Alma mater	Dawson College McGill University Harvard University
Awards	Troland Award (1993, National Academy of Sciences), Henry Dale Prize (2004, Royal Institution), Walter P. Kistler Book Award (2005), Humanist of the Year award (2006, issued by the AHA), George Miller Prize (2010, Cognitive Neuroscience Society), Richard Dawkins Award (2013)
Scientific career
Fields	Evolutionary psychology, experimental psychology, cognitive science, psycholinguistics, visual cognition
Institutions	Harvard University Massachusetts Institute of Technology New College of the Humanities
Thesis	The Representation of Three-dimensional Space in Mental Images (1979)
Doctoral advisor	Stephen Kosslyn
Influences	Noam Chomsky, Richard Dawkins, Sam Harris, Christopher Hitchens, Daniel Dennett,
Website	www.stevenpinker.com

Steven Arthur Pinker (born September 18, 1954) is a Canadian-American cognitive psychologist, linguist, and popular science author. He is Johnstone Family Professor in the Department of Psychology at Harvard University, and is known for his advocacy of evolutionary psychology and the computational theory of mind.

Pinker's academic specializations are visual cognition and psycholinguistics. His experimental subjects include mental imagery, shape recognition, visual attention, children's language development, regular and irregular phenomena in language, the neural bases of words and grammar, and the psychology of cooperation and communication, including euphemism, innuendo, emotional expression, and common knowledge. He has written two technical books that proposed a general theory of language acquisition and applied it to children's learning of verbs. In particular, his work with Alan Prince published in 1989 critiqued the connectionist model of how children acquire the past tense of English verbs, arguing instead that children use default rules such as adding "-ed" to make regular forms, sometimes in error, but are obliged to learn irregular forms one by one.

Pinker is also the author of eight books for general audiences. His earlier works argue that the human faculty for language is an instinct, an innate behavior shaped by natural selection and adapted to our communication needs. The Language Instinct (1994), How the Mind Works (1997), Words and Rules (2000), The Blank Slate (2002), and The Stuff of Thought (2007), describe aspects of [the field of] psycholinguistics and cognitive science, and include accounts of his own research. Pinker's The Sense of Style (2014), as a general style guide, is another language-oriented work. Informed by modern science and psychology, it offers advice on how to produce more comprehensible and unambiguous writing in nonfiction contexts and explains why so much of today's academic and popular writing is difficult for readers to understand.

Pinker's two other books for the public leave behind individual questions of language and learning in favor of broader societal themes. The Better Angels of Our Nature (2011) makes the case that violence in human societies has, in general, steadily declined with time, and identifies six major causes of this decline. Enlightenment Now (2018) continues the optimistic thesis of The Better Angels of Our Nature by using social science data from various sources to argue for a general improvement of the human condition over recent history.

Pinker has been named as one of the world's most influential intellectuals by various magazines. He has won awards from the American Psychological Association, the National Academy of Sciences, the Royal Institution, the Cognitive Neuroscience Society and the American Humanist Association. He delivered the Gifford Lectures at the University of Edinburgh in 2013. He has served on the editorial boards of a variety of journals, and on the advisory boards of several institutions. He has frequently participated in public debates on science and society.

Biography

Pinker was born in Montreal, Quebec, in 1954, to a middle-class Jewish family. His parents were Roslyn (Wiesenfeld) and Harry Pinker. His grandparents emigrated to Canada from Poland and Romania in 1926, and owned a small necktie factory in Montreal. His father, a lawyer, first worked as a manufacturer's representative, while his mother was first a home-maker then a guidance counselor and high-school vice-principal. He has two younger siblings. His brother Robert is a policy analyst for the Canadian government, while his sister, Susan Pinker, is a psychologist and writer who authored The Sexual Paradox and The Village Effect.

Pinker married Nancy Etcoff in 1980 and they divorced in 1992; he married Ilavenil Subbiah in 1995 and they too divorced. His third wife, whom he married in 2007, is the novelist and philosopher Rebecca Goldstein. He has two stepdaughters: the novelist Yael Goldstein Love and the poet Danielle Blau.

Pinker graduated from Dawson College in 1973. He received a Bachelor of Arts in psychology from McGill University in 1976, and earned his Doctorate of Philosophy in experimental psychology at Harvard University in 1979 under Stephen Kosslyn. He did research at the Massachusetts Institute of Technology for a year, after which he became an assistant professor at Harvard and then Stanford University.

From 1982 until 2003, Pinker taught at the Department of Brain and Cognitive Sciences at MIT, was the co-director of the Center for Cognitive science (1985–1994), and eventually became the director of the Center for Cognitive neuroscience (1994–1999), taking a one-year sabbatical at the University of California, Santa Barbara, in 1995–96. Since 2003, he has been serving as the Johnstone Family Professor of Psychology at Harvard and between 2008 and 2013 he also held the title of Harvard College Professor in recognition of his dedication to teaching. He currently gives lectures as a visiting professor at the New College of the Humanities, a private college in London.

About his Jewish background Pinker has said, "I was never religious in the theological sense ... I never outgrew my conversion to atheism at 13, but at various times was a serious cultural Jew." As a teenager, he says he considered himself an anarchist until he witnessed civil unrest following a police strike in 1969, when:

As a young teenager in proudly peaceable Canada during the romantic 1960s, I was a true believer in Bakunin's anarchism. I laughed off my parents' argument that if the government ever laid down its arms all hell would break loose. Our competing predictions were put to the test at 8:00 A.M. on October 17, 1969, when the Montreal police went on strike ... This decisive empirical test left my politics in tatters (and offered a foretaste of life as a scientist).

Pinker identifies himself as an equity feminist, which he defines as "a moral doctrine about equal treatment that makes no commitments regarding open empirical issues in psychology or biology". He reported the result of a test of his political orientation that characterized him as "neither leftist nor rightist, more libertarian than authoritarian." He describes himself as having "experienced a primitive tribal stirring" after his genes were shown to trace back to the Middle East, noting that he "found it just as thrilling to zoom outward in the diagrams of my genetic lineage and see my place in a family tree that embraces all of humanity".

Pinker also identifies himself as an atheist. In the 2007 interview with the Point of Inquiry podcast, Pinker states that he would "defend atheism as an empirically supported view." He sees theism and atheism as competing empirical hypotheses, and states that "we're learning more and more about what makes us tick, including our moral sense, without needing the assumption of a deity or a soul. It's naturally getting crowded out by the successive naturalistic explanations."

Throughout the criminal court trial of pedophile philanthropist Jeffrey Epstein, Pinker lent his name and expertise to Epstein's defense. Pinker notably prepared a linguistic argument that argued for Epstein's innocence and attempted to undermine the prosecution's case by casting doubt on the victim's credibility. Pinker also provided character reference for Epstein. In 2019, Epstein's case re-emerged in the public spotlight and Pinker retroactively repudiated his support for Epstein following Epstein's death.

Research and theory

Pinker discussing his book Enlightenment Now at CSICon.

Pinker's research on visual cognition, begun in collaboration with his thesis adviser, Stephen Kosslyn, showed that mental images represent scenes and objects as they appear from a specific vantage point (rather than capturing their intrinsic three-dimensional structure), and thus correspond to the neuroscientist David Marr's theory of a "two-and-a-half-dimensional sketch." He also showed that this level of representation is used in visual attention, and in object recognition (at least for asymmetrical shapes), contrary to Marr's theory that recognition uses viewpoint-independent representations.

In psycholinguistics, Pinker became known early in his career for promoting computational learning theory as a way to understand language acquisition in children. He wrote a tutorial review of the field followed by two books that advanced his own theory of language acquisition, and a series of experiments on how children acquire the passive, dative, and locative constructions. These books were Language Learnability and Language Development (1984), in Pinker's words "outlin[ing] a theory of how children acquire the words and grammatical structures of their mother tongue", and Learnability and Cognition: The Acquisition of Argument Structure (1989), in Pinker's words "focus[ing] on one aspect of this process, the ability to use different kinds of verbs in appropriate sentences, such as intransitive verbs, transitive verbs, and verbs taking different combinations of complements and indirect objects". He then focused on verbs of two kinds that illustrate what he considers to be the processes required for human language: retrieving whole words from memory, like the past form of the irregular verb "bring", namely "brought"; and using rules to combine (parts of) words, like the past form of the regular verb "walk", namely "walked".

In 1988 Pinker and Alan Prince published an influential critique of a connectionist model of the acquisition of the past tense (a textbook problem in language acquisition), followed by a series of studies of how people use and acquire the past tense. This included a monograph on children's regularization of irregular forms and his popular 1999 book, Words and Rules: The Ingredients of Language. Pinker argued that language depends on two things, the associative remembering of sounds and their meanings in words, and the use of rules to manipulate symbols for grammar. He presented evidence against connectionism, where a child would have to learn all forms of all words and would simply retrieve each needed form from memory, in favour of the older alternative theory, the use of words and rules combined by generative phonology. He showed that mistakes made by children indicate the use of default rules to add suffixes such as "-ed": for instance 'breaked' and 'comed' for 'broke' and 'came'. He argued that this shows that irregular verb-forms in English have to be learnt and retrieved from memory individually, and that the children making these errors were predicting the regular "-ed" ending in an open-ended way by applying a mental rule. This rule for combining verb stems and the usual suffix can be expressed as V_past → V_stem + d, where V is a verb and d is the regular ending. Pinker further argued that since the ten most frequently occurring English verbs (be, have, do, say, make ... ) are all irregular, while 98.2% of the thousand least common verbs are regular, there is a "massive correlation" of frequency and irregularity. He explains this by arguing that every irregular form, such as 'took', 'came' and 'got', has to be committed to memory by the children in each generation, or else lost, and that the common forms are the most easily memorized. Any irregular verb that falls in popularity past a certain point is lost, and all future generations will treat it as a regular verb instead.

In 1990, Pinker, with Paul Bloom, published the paper "Natural Language and Natural Selection", arguing that the human language faculty must have evolved through natural selection. The article provided arguments for a continuity based view of language evolution, contrary to then current discontinuity based theories that see language as suddenly appearing with the advent of Homo sapiens as a kind of evolutionary accident. This discontinuity based view was prominently argued by two of the main authorities, linguist Noam Chomsky and Stephen Jay Gould. The paper became widely cited and created renewed interest in the evolutionary prehistory of language, and has been credited with shifting the central question of the debate from "did language evolve?" to "how did language evolve". The article also presaged Pinker's argument in The Language Instinct.

Pinker's research includes delving into human nature and what science says about it. In his interview on the Point of Inquiry podcast in 2007, he provides the following examples of what he considers defensible conclusions of what science says human nature is:

• The sexes are not statistically identical; "their interests and talents form two overlapping distributions". Any policy that wants to provide equal outcomes for both men and women will have to discriminate against one or the other.
• "Individuals differ in personality and intelligence."
• "People favor themselves and their families over an abstraction called society."
• Humans are "systematically self deceived. Each one of us thinks of ourselves as more competent and benevolent than we are."
• "People crave status and power"

Pinker also speaks about evolutionary psychology in the podcast and believes that this area of science is going to pay off. He cites the fact that there are many areas of study, such as beauty, religion, play, and sexuality, that were not studied 15 years ago. It is thanks to evolutionary psychology that these areas are being studied.

Popularization of science

Pinker in 2011.

Human cognition and natural language

Pinker's 1994 The Language Instinct was the first of several books to combine cognitive science with behavioral genetics and evolutionary psychology. It introduces the science of language and popularizes Noam Chomsky's theory that language is an innate faculty of mind, with the controversial twist that the faculty for language evolved by natural selection as an adaptation for communication. Pinker criticizes several widely held ideas about language – that it needs to be taught, that people's grammar is poor and getting worse with new ways of speaking, the Sapir–Whorf hypothesis that language limits the kinds of thoughts a person can have, and that other great apes can learn languages. Pinker sees language as unique to humans, evolved to solve the specific problem of communication among social hunter-gatherers. He argues that it is as much an instinct as specialized adaptative behavior in other species, such as a spider's web-weaving or a beaver's dam-building. 

Pinker states in his introduction that his ideas are "deeply influenced" by Chomsky; he also lists scientists whom Chomsky influenced to "open up whole new areas of language study, from child development and speech perception to neurology and genetics" — Eric Lenneberg, George Miller, Roger Brown, Morris Halle and Alvin Liberman. Brown mentored Pinker through his thesis; Pinker stated that Brown's "funny and instructive" book Words and Things (1958) was one of the inspirations for The Language Instinct.

The reality of Pinker's proposed language instinct, and the related claim that grammar is innate and genetically based, has been contested by many linguists. One prominent opponent of Pinker's view is Geoffrey Sampson whose 1997 book, Educating Eve: The 'Language Instinct' Debate has been described as the "definitive response" to Pinker's book. Sampson argues that while it may seem attractive to argue the nature side of the 'nature versus nurture' debate, the nurture side may better support the creativity and nobility of the human mind. Sampson denies there is a language instinct, and argues that children can learn language because people can learn anything. Others have sought a middle ground between Pinker's nativism and Sampson's culturalism.

The assumptions underlying the nativist view have also been criticised in Jeffrey Elman's Rethinking Innateness: A Connectionist Perspective on Development, which defends the connectionist approach that Pinker attacked. In his 1996 book Impossible Minds, the machine intelligence researcher Igor Aleksander calls The Language Instinct excellent, and argues that Pinker presents a relatively soft claim for innatism, accompanied by a strong dislike of the 'Standard Social Sciences Model' or SSSM (Pinker's term), which supposes that development is purely dependent on culture. Further, Aleksander writes that while Pinker criticises some attempts to explain language processing with neural nets, Pinker later makes use of a neural net to create past tense verb forms correctly. Aleksander concludes that while he doesn't support the SSSM, "a cultural repository of language just seems the easy trick for an efficient evolutionary system armed with an iconic state machine to play."

Two other books, How the Mind Works (1997) and The Blank Slate (2002), broadly surveyed the mind and defended the idea of a complex human nature with many mental faculties that are adaptive (Pinker is an ally of Daniel Dennett and Richard Dawkins in many disputes surrounding adaptationism). Another major theme in Pinker's theories is that human cognition works, in part, by combinatorial symbol-manipulation, not just associations among sensory features, as in many connectionist models. On the debate around The Blank Slate, Pinker called Thomas Sowell's book A Conflict of Visions "wonderful", and explained that "The Tragic Vision" and the "Utopian Vision" are the views of human nature behind right- and left-wing ideologies.

In Words and Rules: the Ingredients of Language (1999), Pinker argues from his own research that regular and irregular phenomena are products of computation and memory lookup, respectively, and that language can be understood as an interaction between the two. "Words and Rules" is also the title of an essay by Pinker outlining many of the topics discussed in the book. Critiqueing the book from the perspective of generative linguistics Charles Yang, in the London Review of Books, writes that "this book never runs low on hubris or hyperbole". The book's topic, the English past tense, is in Yang's view unglamorous, and Pinker's attempts at compromise risk being in no man's land between rival theories. Giving the example of German, Yang argues that irregular nouns in that language at least all belong to classes, governed by rules, and that things get even worse in languages that attach prefixes and suffixes to make up long 'words': they can't be learnt individually, as there are untold numbers of combinations. "All Pinker (and the connectionists) are doing is turning over the rocks at the base of the intellectual landslide caused by the Chomskian revolution."

In The Stuff of Thought (2007), Pinker looks at a wide range of issues around the way words related to thoughts on the one hand, and to the world outside ourselves on the other. Given his evolutionary perspective, a central question is how an intelligent mind capable of abstract thought evolved: how a mind adapted to Stone Age life could work in the modern world. Many quirks of language are the result.

Pinker is critical of theories about the evolutionary origins of language that argue that linguistic cognition might have evolved from earlier musical cognition. He sees language as being tied primarily to the capacity for logical reasoning, and speculates that human proclivity for music may be a spandrel — a feature not adaptive in its own right, but that has persisted through other traits that are more broadly practical, and thus selected for. In How the Mind Works, Pinker reiterates Immanuel Kant's view that music is not in itself an important cognitive phenomenon, but that it happens to stimulate important auditory and spatio-motor cognitive functions. Pinker compares music to "auditory cheesecake", stating that "As far as biological cause and effect is concerned, music is useless". This argument has been rejected by Daniel Levitin and Joseph Carroll, experts in music cognition, who argue that music has had an important role in the evolution of human cognition. In his book This Is Your Brain On Music, Levitin argues that music could provide adaptive advantage through sexual selection, social bonding, and cognitive development; he questions the assumption that music is the antecedent to language, as opposed to its progenitor, noting that many species display music-like habits that could be seen as precursors to human music.

Pinker has also been critical of "whole language" reading instruction techniques, stating in How the Mind Works, "... the dominant technique, called 'whole language,' the insight that [spoken] language is a naturally developing human instinct has been garbled into the evolutionarily improbable claim that reading is a naturally developing human instinct." In the appendix to the 2007 reprinted edition of The Language Instinct, Pinker cited Why Our Children Can't Read by cognitive psychologist Diane McGuinness as his favorite book on the subject and noted:

One raging public debate involving language went unmentioned in The Language Instinct: the "reading wars," or dispute over whether children should be explicitly taught to read by decoding the sounds of words from their spelling (loosely known as "phonics") or whether they can develop it instinctively by being immersed in a text-rich environment (often called "whole language"). I tipped my hand in the paragraph in [the sixth chapter of the book] which said that language is an instinct but reading is not. Like most psycholinguists (but apparently unlike many school boards), I think it's essential for children to be taught to become aware of speech sounds and how they are coded in strings of letters.

The Better Angels of Our Nature

Violence in the middle ages: detail from "Mars" in Das Mittelalterliche Hausbuch, c. 1475 – 1480. The image is used by Pinker in The Better Angels of Our Nature, with the comment "as the Housebook illustrations suggest, [the knights] did not restrict their killing to other knights".

 

In The Better Angels of Our Nature, published in 2011, Pinker argues that violence, including tribal warfare, homicide, cruel punishments, child abuse, animal cruelty, domestic violence, lynching, pogroms, and international and civil wars, has decreased over multiple scales of time and magnitude. Pinker considers it unlikely that human nature has changed. In his view, it is more likely that human nature comprises inclinations toward violence and those that counteract them, the "better angels of our nature". He outlines six 'major historical declines of violence' that all have their own socio/cultural/economic causes:

1. "The Pacification Process" – The rise of organized systems of government has a correlative relationship with the decline in violent deaths. As states expand they prevent tribal feuding, reducing losses.
2. "The Civilizing Process" – Consolidation of centralized states and kingdoms throughout Europe results in the rise of criminal justice and commercial infrastructure, organizing previously chaotic systems that could lead to raiding and mass violence.
3. "The Humanitarian Revolution" – The 18th - 20th century abandonment of institutionalized violence by the state (breaking on the wheel, burning at the stake). Suggests this is likely due to the spike in literacy after the invention of the printing press thereby allowing the proletariat to question conventional wisdom.
4. "The Long Peace" – The powers of 20th Century believed that period of time to be the bloodiest in history. This led to a largely peaceful 65-year period post World War I and World War II. Developed countries have stopped warring (against each other and colonially), adopted democracy, and this has led a massive decline (on average) of deaths.
5. "The New Peace" – The decline in organized conflicts of all kinds since the end of the Cold War.
6. "The Rights Revolutions" – The reduction of systemic violence at smaller scales against vulnerable populations (racial minorities, women, children, homosexuals, animals).

The book was welcomed by many critics and reviewers, who found its arguments convincing and its synthesis of a large volume of historical evidence compelling. It also aroused criticism on a variety of grounds, such as whether deaths per capita was an appropriate metric, Pinker's atheism, lack of moral leadership, excessive focus on Europe (though the book covers other areas), the interpretation of historical data, questionable methodologies, and its image of indigenous people.

English writing style in the 21st century

In his seventh popular book, The Sense of Style: The Thinking Person's Guide to Writing in the 21st Century (2014), Pinker attempts to provide a writing style guide that is informed by modern science and psychology, offering advice on how to produce more comprehensible and unambiguous writing in nonfiction contexts and explaining why so much of today's academic and popular writing is difficult for readers to understand. 

In a November 2014 episode of the Point of Inquiry podcast, host Lindsay Beyerstein, asked Pinker how his style guide was different from the many guides that already exist. His answer,

The Thinking Person's Guide because I don't issue dictates from on high as most manuals do but explain why the various guidelines will improve writing, what they do for language, what they do for the reader's experience, in the hope that the users will apply the rules judiciously knowing what they are designed to accomplish, rather than robotically.

He also indicated that the 21st century was applicable because language and usage change over time and it has been a long time since William Strunk wrote Elements of Style.

Public debate

Pinker and Nils Brose speaking at a neuroscience conference.

Pinker is a frequent participant in public debates surrounding the contributions of science to contemporary society. Social commentators such as Ed West, author of The Diversity Illusion, consider Pinker important and daring in his willingness to confront taboos, as in The Blank Slate. This doctrine (the tabula rasa), writes West, remained accepted "as fact, rather than fantasy" a decade after the book's publication. West describes Pinker as "no polemicist, and he leaves readers to draw their own conclusions".

In January 2005, Pinker defended comments by then-President of Harvard University Lawrence Summers. Summers had commented that gender gaps in mathematics and science were due to "different availability of aptitude at the high end." In a debate between Pinker and Elizabeth Spelke on gender and science, Pinker argued in favor of gender essentialism and stereotype accuracy.

In 2009, in The New York Times, Pinker wrote a mixed review of Malcolm Gladwell's essays, criticizing his analytical methods. Gladwell replied, disputing Pinker's comments about the importance of IQ on teaching performance and by analogy, the effect, if any, of draft order on quarterback performance in the National Football League. Advanced NFL Stats addressed the issue statistically, siding with Pinker and showing that differences in methodology could explain the two men's differing opinions.

In 2009, David Shenk criticized Pinker for siding with the "nature" argument and for "never once acknowledg[ing] gene-environment interaction or epigenetics" in an article on nature versus nurture in The New York Times. Pinker responded to a question about epigenetics as a possibility for the decline in violence in a lecture for the BBC World Service. Pinker said it was unlikely since the decline in violence happened too rapidly to be explained by genetic changes. Helga Vierich and Cathryn Townsend wrote a critical review of Pinker's sweeping "Civilizational" explanations for patterns of human violence and warfare in response to a lecture he gave at Cambridge University in September 2015.

Steven Pinker is also noted for having identified the rename of Phillip Morris to Altria as an "egregious example" of phonesthesia, with the company attempting to "switch its image from bad people who sell addictive carcinogens to a place or state marked by altruism and other lofty values".

Pinker continued to court controversy through his 2018 book Enlightenment Now, in which he argued that enlightenment rationality should be defended against attacks from both the left and right. The Guardian criticized the book as a "triumphalist" work that has a "curious relationship to intellectual history" and overestimates the role of campus activists in mainstream discourse.

In a debate with Pinker, post-colonial theorist Homi Bhabha argued that, in Enlightenment Now, Pinker downplayed the immoral consequences of Enlightenment philosophy, such as inequality, slavery, imperialism, world wars, and genocide. Pinker responded that humanity, prior to the Enlightenment, had been characterized by poverty and disease.

Awards and distinctions

Pinker in Göttingen, 2010

Pinker was named one of Time's 100 most influential people in the world in 2004 and one of Prospect and Foreign Policy's 100 top public intellectuals in both years the poll was carried out, 2005 and 2008; in 2010 and 2011 he was named by Foreign Policy to its list of top global thinkers. In 2016, he was elected to the National Academy of Sciences.

His research in cognitive psychology has won the Early Career Award (1984) and Boyd McCandless Award (1986) from the American Psychological Association, the Troland Research Award (1993) from the National Academy of Sciences, the Henry Dale Prize (2004) from the Royal Institution of Great Britain, and the George Miller Prize (2010) from the Cognitive Neuroscience Society. He has also received honorary doctorates from the universities of Newcastle, Surrey, Tel Aviv, McGill, Simon Fraser University and the University of Tromsø. He was twice a finalist for the Pulitzer Prize, in 1998 and in 2003. On May 13, 2006, he received the American Humanist Association's Humanist of the Year award for his contributions to public understanding of human evolution.

Pinker has served on the editorial boards of journals such as Cognition, Daedalus, and PLOS One, and on the advisory boards of institutions for scientific research (e.g., the Allen Institute for Brain Science), free speech (e.g., the Foundation for Individual Rights in Education), the popularization of science (e.g., the World Science Festival and the Committee for Skeptical Inquiry), peace (e.g., the Peace Research Endowment), and secular humanism (e.g., the Freedom from Religion Foundation and the Secular Coalition for America).

Since 2008, he has chaired the Usage Panel of the American Heritage Dictionary, and wrote the essay on usage for the fifth edition of the Dictionary, which was published in 2011.

In February 2001, Pinker, "whose hair has long been the object of admiration, and envy, and intense study", was nominated by acclamation as the first member of the Luxuriant Flowing Hair Club for Scientists (LFHCfS) organized by the Annals of Improbable Research.

Wernicke–Korsakoff syndrome

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Wernicke%E2%80%93Korsakoff_syndrome 

 

Wernicke–Korsakoff syndrome
Other names	Korsakoff's psychosis, alcoholic encephalopathy
Thiamine
Specialty	Psychiatry, neurology

Wernicke–Korsakoff syndrome (WKS) is the combined presence of Wernicke encephalopathy (WE) and alcoholic Korsakoff syndrome. Due to the close relationship between these two disorders, people with either are usually diagnosed with WKS as a single syndrome. It mainly causes vision changes, ataxia and impaired memory.

The cause of the disorder is thiamine (vitamin B₁) deficiency. This can occur due to beriberi, Wernicke encephalopathy, and alcoholic Korsakoff syndrome. These disorders may manifest together or separately. WKS is usually secondary to alcohol abuse.

Wernicke encephalopathy and WKS are most commonly seen in people with an alcohol use disorder. Failure in diagnosis of WE and thus treatment of the disease leads to death in approximately 20% of cases, while 75% are left with permanent brain damage associated with WKS. Of those affected, 25% require long-term institutionalization in order to receive effective care.

Signs and symptoms

The syndrome is a combined manifestation of two namesake disorders, Wernicke encephalopathy and alcoholic Korsakoff syndrome. It involves an acute Wernicke-encephalopathy phase, followed by the development of a chronic alcoholic Korsakoff syndrome phase.

Wernicke encephalopathy

WE is characterized by the presence of a triad of symptoms:

1. Ocular disturbances (ophthalmoplegia)
2. Changes in mental state (confusion)
3. Unsteady stance and gait (ataxia)

This triad of symptoms results from a deficiency in vitamin B₁ which is an essential coenzyme. The aforementioned changes in mental state occur in approximately 82% of patients' symptoms of which range from confusion, apathy, inability to concentrate, and a decrease in awareness of the immediate situation they are in. If left untreated, WE can lead to coma or death. In about 29% of patients, ocular disturbances consist of nystagmus and paralysis of the lateral rectus muscles or other muscles in the eye. A smaller percentage of patients experience a decrease in reaction time of the pupils to light stimuli and swelling of the optic disc which may be accompanied by retinal hemorrhage. Finally, the symptoms involving stance and gait occur in about 23% of patients and result from dysfunction in the cerebellum and vestibular system. Other symptoms that have been present in cases of WE are stupor, low blood pressure (hypotension), elevated heart rate (tachycardia), as well as hypothermia, epileptic seizures and a progressive loss of hearing.

About 19% of patients have none of the symptoms in the classic triad at first diagnosis of WE; however, usually one or more of the symptoms develops later as the disease progresses.

Alcoholic Korsakoff syndrome

The DSM-V classifies Korsakoff syndrome under Substance/Medication-Induced Major or Mild Neurocognitive Disorders, specifically alcohol-induced amnestic confabulatory.^[6] The diagnostic criteria defined as necessary for diagnosis includes, prominent amnesia, forgetting quickly, and difficulty learning. Presence of thiamine deficient encephalopathy can occur in conjunction with these symptoms.

Despite the assertion that alcoholic Korsakoff syndrome must be caused by the use of alcohol, there have been several cases where it has developed from other instances of thiamine deficiency resulting from gross malnutrition due to conditions such as; stomach cancer, anorexia nervosa, and gastrectomy.

Cognitive effects

Several cases have been documented where Wernicke–Korsakoff syndrome has been seen on a large scale. In 1947, 52 cases of WKS were documented in a prisoner of war hospital in Singapore where the prisoners' diets included less than 1 mg of thiamine per day. Such cases provide an opportunity to gain an understanding of what effects this syndrome has on cognition. In this particular case, cognitive symptoms included insomnia, anxiety, difficulties in concentration, loss of memory for the immediate past, and gradual degeneration of mental state; consisting of confusion, confabulation, and hallucinations. In other cases of WKS, cognitive effects such as severely disrupted speech, giddiness, and heavy headedness have been documented. In addition to this, it has been noted that some patients displayed an inability to focus, and the inability of others to catch patients' attention.

In a study conducted in 2003 by Brand et al. on the cognitive effects of WKS, the researchers used a neuropsychological test battery which included tests of intelligence, speed of information processing, memory, executive function and cognitive estimation. They found that patients suffering from WKS showed impairments in all aspects of this test battery but most noticeably, on the cognitive estimation tasks. This task required subjects to estimate a physical quality such as size, weight, quantity or time (i.e. What is the average length of a shower?), of a particular item. Patients with WKS performed worse than normal control participants on all of the tasks in this category. The patients found estimations involving time to be the most difficult, whereas quantity was the easiest estimation to make. Additionally, the study included a category for classifying "bizarre" answers, which included any answer that was far outside of the normal range of expected responses. WKS patients did give answers that could fall into such a category and these included answers such as 15s or 1 hour for the estimated length of a shower, or 4 kg or 15 tonnes as the weight of a car.

Memory deficits

As mentioned previously, the amnesic symptoms of WKS include both retrograde and anterograde amnesia. The retrograde deficit has been demonstrated through an inability of WKS patients to recall or recognize information for recent public events. The anterograde memory loss is demonstrated through deficits in tasks that involve encoding and then recalling lists of words and faces, as well as semantic learning tasks. WKS patients have also demonstrated difficulties in perseveration as evidenced by a deficit in performance on the Wisconsin Card Sorting Test. The retrograde amnesia that accompanies WKS can extend as far back as twenty to thirty years, and there is generally a temporal gradient seen, where earlier memories are recalled better than more recent memories. It has been widely accepted that the critical structures that lead to the memory impairment in WKS are the mammillary bodies, and the thalamic regions. Despite the aforementioned memory deficits, non-declarative memory functions appear to be intact in WKS patients. This has been demonstrated through measures that assess perceptual priming.

Other studies have shown deficits in recognition memory and stimulus-reward associative functions in patients with WKS. The deficit in stimulus-reward functions was demonstrated by Oscar-Berman and Pulaski who presented patients with reinforcements for certain stimuli but not others, and then required the patients to distinguish the rewarded stimuli from the non-rewarded stimuli. WKS patients displayed significant deficits in this task. The researchers were also successful in displaying a deficit in recognition memory by having patients make a yes/no decision as to whether a stimulus was familiar (previously seen) or novel (not previously seen). The patients in this study also showed a significant deficit in their ability to perform this task.

Confabulation

People with WKS often show confabulation, spontaneous confabulation being seen more frequently than provoked confabulation. Spontaneous confabulations refer to incorrect memories that the patient holds to be true, and may act on, arising spontaneously without any provocation. Provoked confabulations can occur when a patient is cued to give a response, this may occur in test settings. The spontaneous confabulations viewed in WKS are thought to be produced by an impairment in source memory, where they are unable to remember the spatial and contextual information for an event, and thus may use irrelevant or old memory traces to fill in for the information that they cannot access. It has also been suggested that this behaviour may be due to executive dysfunction where they are unable to inhibit incorrect memories or because they are unable to shift their attention away from an incorrect response.

Causes

WKS is usually found in people who have used alcohol chronically. Wernicke–Korsakoff syndrome results from thiamine deficiency. It is generally agreed that Wernicke encephalopathy results from severe acute deficiency of thiamine (vitamin B₁), whilst Korsakoff's psychosis is a chronic neurologic sequela of Wernicke encephalopathy. The metabolically active form of thiamine is thiamine pyrophosphate, which plays a major role as a cofactor or coenzyme in glucose metabolism. The enzymes that are dependent on thiamine pyrophosphate are associated with the citric acid cycle (also known as the Krebs cycle), and catalyze the oxidation of pyruvate, α-ketoglutarate and branched chain amino acids. Thus, anything that encourages glucose metabolism will exacerbate an existing clinical or sub-clinical thiamine deficiency.

As stated above, Wernicke–Korsakoff syndrome in the United States is usually found in malnourished chronic alcoholics, though it is also found in patients who undergo prolonged intravenous (IV) therapy without vitamin B₁ supplementation, gastric stapling, intensive care unit (ICU) stays, hunger strikes, or people with eating disorders. In some regions, physicians have observed thiamine deficiency brought about by severe malnutrition, particularly in diets consisting mainly of polished rice, which is thiamine-deficient. The resulting nervous system ailment is called beriberi. In individuals with sub-clinical thiamine deficiency, a large dose of glucose (either as sweet food, etc. or glucose infusion) can precipitate the onset of overt encephalopathy.

Wernicke–Korsakoff syndrome in people with chronic alcohol use particularly is associated with atrophy/infarction of specific regions of the brain, especially the mammillary bodies. Other regions include the anterior region of the thalamus (accounting for amnesic symptoms), the medial dorsal thalamus, the basal forebrain, the median and dorsal raphe nuclei, and the cerebellum.

One as-yet-unreplicated study has associated susceptibility to this syndrome with a hereditary deficiency of transketolase, an enzyme that requires thiamine as a coenzyme.

Post-gastrectomy

The fact that gastrointestinal surgery can lead to the development of WKS was demonstrated in a study that was completed on three patients who recently undergone a gastrectomy. These patients had developed WKS but were not alcoholics and had never suffered from dietary deprivation. WKS developed between 2 and 20 years after the surgery. There were small dietary changes that contributed to the development of WKS but overall the lack of absorption of thiamine from the gastrointestinal tract was the cause. Therefore, it must be ensured that patients who have undergone gastrectomy have a proper education on dietary habits, and carefully monitor their thiamine intake. Additionally, an early diagnosis of WKS, should it develop, is very important.

Alcohol–thiamine interactions

Strong evidence suggests that ethanol interferes directly with thiamine uptake in the gastrointestinal tract. Ethanol also disrupts thiamine storage in the liver and the transformation of thiamine into its active form. The role of alcohol consumption in the development of WKS has been experimentally confirmed through studies in which rats were subjected to alcohol exposure and lower levels of thiamine through a low-thiamine diet. In particular, studies have demonstrated that clinical signs of the neurological problems that result from thiamine deficiency develop faster in rats that have received alcohol and were also deficient in thiamine than rats who did not receive alcohol. In another study, it was found that rats that were chronically fed alcohol had significantly lower liver thiamine stores than control rats. This provides an explanation for why alcoholics with liver cirrhosis have a higher incidence of both thiamine deficiency and WKS.

Pathophysiology

The vitamin thiamine also referred to as Vitamin B1, is required by three different enzymes to allow for conversion of ingested nutrients into energy.  Thiamine can not be produced in the body and must be obtained through diet and supplementation.  The duodenum is responsible for absorbing thiamine. The liver can store thiamine for 18 days. Prolonged and frequent consumption of alcohol causes a decreased ability to absorb thiamine in the duodenum. Thiamine deficiency is also related to malnutrition from poor diet, impaired use of thiamine by the cells and impaired storage in the liver. Without thiamine the Kreb's Cycle enzymes pyruvate dehydrogenase complex (PDH) and alpha-ketoglutarate dehydrogenase (alpha-KGDH) are impaired. The impaired functioning of the Kreb's Cycle results in inadequate production of adenosine triphosphate (ATP) or energy for the cells functioning.  Energy is required by the brain for proper functioning and use of its neurotransmitters. Injury to the brain occurs when neurons that require high amounts of energy from thiamine dependent enzymes are not supplied with enough energy and die. 

Brain atrophy associated with WKS occurs in the following regions of the brain: the mammillary bodies, the thalamus, the periaqueductal grey, the walls of the 3rd ventricle, the floor of the 4th ventricle, the cerebellum, and the frontal lobe. In addition to the damage seen in these areas there have been reports of damage to cortex, although it was noted that this may be due to the direct toxic effects of alcohol as opposed to thiamine deficiency that has been attributed as the underlying cause of Wernicke-Korsakoff Syndrome.

The amnesia that is associated with this syndrome is a result of the atrophy in the structures of the diencephalon (the thalamus, hypothalamus and mammillary bodies), and is similar to amnesia that is presented as a result of other cases of damage to the medial temporal lobe. It has been argued that the memory impairments can occur as a result of damage along any part of the mammillo-thalamic tract, which explains how WKS can develop in patients with damage exclusively to either the thalamus or the mammillary bodies.

Diagnosis

Diagnosis of Wernicke–Korsakoff syndrome is by clinical impression and can sometimes be confirmed by a formal neuropsychological assessment. Wernicke encephalopathy typically presents with ataxia and nystagmus, and Korsakoff's psychosis with anterograde and retrograde amnesia and confabulation upon relevant lines of questioning.

Frequently, secondary to thiamine deficiency and subsequent cytotoxic edema in Wernicke encephalopathy, patients will have marked degeneration of the mammillary bodies. Thiamine (vitamin B₁) is an essential coenzyme in carbohydrate metabolism and is also a regulator of osmotic gradient. Its deficiency may cause swelling of the intracellular space and local disruption of the blood-brain barrier. Brain tissue is very sensitive to changes in electrolytes and pressure and edema can be cytotoxic. In Wernicke this occurs specifically in the mammillary bodies, medial thalami, tectal plate, and periaqueductal areas. Sufferers may also exhibit a dislike for sunlight and so may wish to stay indoors with the lights off. The mechanism of this degeneration is unknown, but it supports the current neurological theory that the mammillary bodies play a role in various "memory circuits" within the brain. An example of a memory circuit is the Papez circuit.

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  Axial MRI FLAIR image showing hyperintense signal in the mesial dorsal thalami, a common finding in Wernicke encephalopathy. This patient was nearly in coma when IV thiamine was started, he responded moderately well but was left with some Korsakoff type deficits.
  
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  Axial MRI B=1000 DWI image showing hyperintense signal indicative of restricted diffusion in the mesial dorsal thalami.
  
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  Axial MRI FLAIR image showing hyperintense signal in the periaqueductal gray matter and tectum of the dorsal midbrain.
  

Prevention

As described, alcoholic Korsakoff syndrome usually follows or accompanies Wernicke encephalopathy. If treated quickly, it may be possible to prevent the development of AKS with thiamine treatments. This treatment is not guaranteed to be effective and the thiamine needs to be administered adequately in both dose and duration. A study on Wernicke–Korsakoff syndrome showed that with consistent thiamine treatment there were noticeable improvements in mental status after only 2–3 weeks of therapy. Thus, there is hope that with treatment Wernicke encephalopathy will not necessarily progress to WKS.

In order to reduce the risk of developing WKS it is important to limit the intake of alcohol in order to ensure that proper nutrition needs are met. A healthy diet is imperative for proper nutrition which, in combination with thiamine supplements, may reduce the chance of developing WKS. This prevention method may specifically help heavy drinkers who refuse to or are unable to quit.

A number of proposals have been put forth to fortify alcoholic beverages with thiamine to reduce the incidence of WKS among those heavily abusing alcohol. To date, no such proposals have been enacted.

Daily recommendations of thiamine requirements are 0.66 mg/2,000kcal daily or 1.2 mg for adult men and 1.1 mg for adult women per day.

Treatment

The onset of Wernicke encephalopathy is considered a medical emergency, and thus thiamine administration should be initiated immediately when the disease is suspected. Prompt administration of thiamine to patients with Wernicke encephalopathy can prevent the disorder from developing into Wernicke–Korsakoff syndrome, or reduce its severity. Treatment can also reduce the progression of the deficits caused by WKS, but will not completely reverse existing deficits. WKS will continue to be present, at least partially, in 80% of patients. Patients suffering from WE should be given a minimum dose of 500 mg of thiamine hydrochloride, delivered by infusion over a 30-minute period for two to three days. If no response is seen then treatment should be discontinued but for those patients that do respond, treatment should be continued with a 250 mg dose delivered intravenously or intramuscularly for three to five days unless the patient stops improving. Such prompt administration of thiamine may be a life-saving measure. Banana bags, a bag of intravenous fluids containing vitamins and minerals, is one means of treatment.

Epidemiology

WKS occurs more frequently in men than women and has the highest prevalence in the ages 55–65 approximately 71% are unmarried.

Internationally, the prevalence rates of WKS are relatively standard, being anywhere between zero and two percent. Despite this, specific sub-populations seem to have higher prevalence rates including people who are homeless, older individuals (especially those living alone or in isolation), and psychiatric inpatients. Additionally, studies show that prevalence is not connected to alcohol consumption per capita. For example, in France, a country that is well known for its consumption and production of wine, prevalence was only 0.4% in 1994, while Australia had a prevalence of 2.8%.

History

Wernicke encephalopathy

Carl Wernicke discovered Wernicke encephalopathy in 1881. His first diagnosis noted symptoms including paralyzed eye movements, ataxia, and mental confusion. Also noticed were hemorrhages in the gray matter around the third and fourth ventricles and the cerebral aqueduct. Brain atrophy was only found upon post-mortem autopsy. Wernicke believed these hemorrhages were due to inflammation and thus the disease was named polioencephalitis haemorrhagica superior. Later, it was found that Wernicke encephalopathy and alcoholic Korsakoff syndrome are products of the same cause.

Alcoholic Korsakoff syndrome

Sergei Korsakoff was a Russian physician after whom the disease "Korsakoff's syndrome" was named. In the late 1800s Korsakoff was studying long-term alcoholic patients and began to notice a decline in their memory function. At the 13th International Medical Congress in Moscow in 1897, Korsakoff presented a report called: "On a special form of mental illness combined with degenerative polyneuritis". After the presentation of this report the term "Korsakoff's syndrome" was coined.

Although WE and AKS were discovered separately, these two syndromes are usually referred to under one name, Wernicke–Korsakoff syndrome, due to the fact that they are part of the same cause and because the onset of AKS usually follows WE if left untreated.

Society and culture

The British neurologist Oliver Sacks describes case histories of some of his patients with the syndrome in the book The Man Who Mistook His Wife for a Hat (1985).

Effects of alcohol on memory

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Effects_of_alcohol_on_memory 

 

Ethanol is the type of alcohol found in alcoholic beverages. It is a volatile, flammable, colorless liquid that acts as a central nervous system depressant. Ethanol can impair different types of memory.

 

Ethanol

Alcoholic beverages

Mode of actions

Effects on the hippocampus

Alcohol acts as a general central nervous system depressant, but it also affects some specific areas of the brain to a greater extent than others. Memory impairment caused by alcohol has been linked to the disruption of hippocampal function — particularly affecting gamma-Aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA) neurotransmission which negatively impacts long-term potentiation (LTP). The molecular basis of LTP is associated with learning and memory. Particularly, damage to hippocampal CA1 cells adversely affects memory formation, and this disruption has been linked to dose-dependent levels of alcohol consumption. At higher doses, alcohol significantly inhibits neuronal activity in both the CA1 and CA3 pyramidal cell layers of the hippocampus. This impairs memory encoding, since the hippocampus plays an important role in the formations of new memories.

A Hippocampal Pyramidal Cell

Molecular effects on GABA and NMDA receptors

A GABA_A Receptor

Alcohol also acts as a positive allosteric modulator of GABA receptors, specifically type GABA_A. Upon activation, these GABA receptors conduct Cl-, resulting in neuronal hyperpolarization. This hyperpolarization decreases the chance of an action potential occurring and thus, it has an inhibitory effect on neurotransmission in the central nervous system. GABA_A receptor subtypes vary in their sensitivities to dosage of alcohol consumed. Furthermore, acute alcohol intake promotes GABAergic neurotransmission via the presynaptic release of GABA, the dephosphorylation of GABA_A receptors (increasing GABA sensitivity), and the elevation of endogenous GABAergic neuroactive steroids. Protein kinase C (PKC) has been implicated in differentially modulating the response of the GABA_A receptor to alcohol, with effects depending on the PKC isozyme. Alcohol effects have also implicated protein kinase A in affecting GABA_A receptor function, such as promoting sensitivity. Enhancement of GABAergic transmission due to alcohol consumption can also be brought about by neuroactive steroids, such as allopregnanolone, which act as GABA_A receptor agonists. Both chronic alcohol consumption and alcohol dependence are correlated with the altered expression, properties, and functions of the GABA_A receptor that may contribute to alcohol tolerance. There is still much yet to be discovered about alcohol's specific and varying effects on both the GABA_A receptor and its subtypes.

At higher doses, ethanol also affects NMDA receptors (NMDARs) by inhibiting the ion current induced by NMDA, a glutamate receptor agonist. This inhibition of synaptic excitation by alcohol has been shown to be dose-dependent (up to a certain point, after which it did not differ by much). Alcohol appears to produce this inhibition by using a site of the NMDAR that is accessible from the extracellular environment. Therefore, this inhibition of an ion current usually produced by NMDAR activation leads to decreased LTP in hippocampal areas. Alcohol negatively affects LTP to a greater degree in immature versus mature animals. In adolescents, alcohol decreases the expression of both the NMDAR NR2A subunit in the hippocampus and the NR1 subunit in the prefrontal cortex. Studies have also found that a decrease in phosphorylation of 2B subunit in the prefrontal cortex, the hippocampus, the nucleus accumbens, and the striatum. NMDARS may be affected by PKA regulation due to the actions of alcohol. Alcohol's effects on GABA_A neurotransmission may indirectly inhibit the activity of the NMDAR, and they may contribute to its blockade of LTP induction; however, alcohol's direct effects on NMDAR alone are sufficient for the inhibition of LTP. The varying dose-dependent response to alcohol relies on the combined interactions and responses of the GABA_A receptors, NMDARs, and metabotropic glutamate receptors subtype 5 (mGluR5). These changes prevent excitatory synaptic transmissions from occurring, affecting synaptic plasticity and, in turn, memory and learning. However, there is still much yet to be elucidated concerning specific molecular mechanisms of how alcohol affects memory formation.

Effects on other brain regions

Alcohol also impairs and alters the functioning in the cerebellum, which affects both motor function and coordination. It has a notable inhibitory effect on the neurons of the cerebral cortex, affecting and altering thought processes, decreasing inhibition, and increasing the pain threshold. It also decreases sexual performance by depressing nerve centers in the hypothalamus. Alcohol also has an effect on urine excretion via inhibition of anti-diuretic hormone (ADH) secretion of the pituitary gland. Lastly, it depresses breathing and heart rate by inhibiting neuronal functioning of the medulla.

Long-term memory

Long-term memory (LTM) has both a long duration and a large capacity. Memories that are stored in LTM can last from a few days to a lifetime. LTM consists of both explicit memory (requiring conscious awareness) and implicit memory (unconscious awareness). Information selected for LTM goes through three processes. First of all, in the encoding stage, information from the senses is incorporated into mental activity in the form of a memory. Secondly, storage involves taking this information and holding it indefinitely in memory. Lastly, retrieval is the ability to recall information from the long-term memory storage. Each of these processes can be affected by alcohol.

Animation: Hippocampus (red)

Explicit memory

Explicit memory requires conscious and intentional effort for recall. It includes both episodic memory (for specific events, such as a party) and semantic memory (for general information, such as one's name).

Alcohol impairs episodic encoding, specifically for cued recall, recognition of completed word fragments, and free recall. A blackout is an example of a difficulty in encoding episodic memories due to alcohol. Blackouts are caused by a rapid increase in blood alcohol concentration (BAC) which in turn distorts the neurons in the hippocampus. This distortion impairs a person's ability to form new episodic memories.

High doses of alcohol severely disrupt the storage process of semantic memories. Alcohol was found to impair the storage of novel stimuli but not that of previously learned information. Since alcohol affects the central nervous system, it hinders semantic storage functioning by restricting the consolidation of the information from encoding.

Retrieval of explicit memory is significantly impaired by alcohol. When compared to sober participants, intoxicated participants performed quite poorly on a recall task for everyday events (i.e., episodic memory). Intoxicated participants are also slower to respond in reaction time tasks. Alcohol also impairs retrieval in word recognition tasks. When both encoding and retrieval take place during intoxication, there are surprisingly more impairments for cued recall than for free recall. In terms of gender differences in retrieval processes, females tend to score lower than males on recall tasks when intoxicated.

Implicit memory

Implicit memory does not require conscious effort or intention for recall. It occurs when previous experience influences performance on a certain task. This is evident in priming experiments. Implicit memory includes procedural memory, which influences our everyday behaviours, such as riding a bike or tying shoes. People can perform these abilities without even thinking about them, which means procedural memory functions automatically. While retrieval of explicit memory is severely impaired by alcohol, retrieval of implicit memory is not. Intoxicated subjects score higher on recognition tasks (involving implicit memory) than they can on recall tasks (involving explicit memory).

Short-term memory

Short-term memory refers to the temporary storage of small amounts of information over short delays. Digit span refers to the proposed number of pieces of information (5-9) that can be held in short-term memory. This is also referred to as the magic number seven – plus or minus two. Any more pieces of information than this, and newer items replace previous items. Alcohol intoxication has been found to have dissociative effects on both short-term memory and cognitive functioning.

Anterior Cingulate Cortex (yellow)

 

Animation: Parietal Lobe (red)

Brain areas affected by alcohol

Alcohol affects the functioning of the brain. Neurochemical changes occurring in the anterior cingulate are correlated with altered short-term memory functions in the brains of young alcoholic men. fMRIs of alcohol-dependent women displayed significantly less blood oxygen in the frontal and parietal regions, especially in the right hemisphere. This is supported by findings of short-term memory impairment by lesions of both the parietal lobe and the prefrontal cortex. Associations between Third ventricle volume and cognitive performance on memory tests have been found in alcoholics. Specifically, increases in third ventricular volume correlate with a decline in memory performance.

Tasks and intoxication findings

Short-term memory is commonly tested with visual tasks. Short-term memory, especially for non-verbal and spatial material, are impaired by intoxication. Alcohol decreases iconic memory (a type of visual short-term memory). With BACs between 80–84 mg/dl, more intrusion errors occur in a delayed recall task compared to a control group. Intrusion errors, which represent reflective cognitive functioning, occur when irrelevant information is produced. Alcoholics have less control of inhibiting intrusions. Acute alcohol intoxication in social drinkers caused more intrusion errors in delayed recall tasks than in immediate free recall tasks. Acute alcohol intoxication increases the susceptibility to interference, which allows for more intrusion errors when there is a short delay. Free recall (given list of words then asked to recall list) is significantly lower and therefore impaired by alcohol intoxication. Encoding deficits were found in verbal free recall and recognition tasks under the influence of alcohol. A discrimination task found significant alcohol-related impairments both in depth perception and in visual short-term memory. State-dependent learning and relearning studies in male heavy drinkers demonstrate that the condition of intoxication while learning and sobriety when tested caused a performance deficit in free recall tasks. These findings are supportive of alcohol-induced storage deficits (not retrieval deficits). The effects of acute alcohol consumption on visual short-term memory, stereoscopic depth perception, and attention were all studied. A 33% alcohol condition showed significant impairments both in depth perception and in visual short-term memory (assessed by the vernier discrimination task).

Working Memory Model. Alcohol intoxication can disrupt rehearsal strategies which may involve the phonological loop and/or the visuospatial sketchpad.

Effects on working memory

Working memory allows one to keep things in mind while simultaneously performing complex tasks. It involves a system for both the temporary storage and the manipulation of information, subsequently forming a crucial link between perception and controlled action. Evidence suggests that working memory involves three components: the central executive which controls attention, the visuo-spatial sketchpad which holds and manipulates spatial information, and the phonological loop which performs a similar function for auditory and speech-based information.

In the short term

Alcohol consumption has substantial, measurable effects on working memory, although these effects vary greatly between individual responses. Not much is really known about the neural mechanisms that underlie these individual differences. It is also found that alcohol impairs working memory by affecting mnemonic strategies and executive processes rather than by shrinking the basic holding capacity of working memory. Isolated acute-moderate levels of alcohol intoxication do not physically alter the structures that are critical for working memory function, such as the frontal cortex, the parietal cortex, the anterior cingulate, and parts of the basal ganglia. One finding regarding the effects of alcohol on working memory points out that alcohol reduces working memory only in individuals with a high baseline working memory capacity, which suggests that alcohol might not uniformly affect working memory in many different individuals. Alcohol appears to impair the capacity of working memory to modulate response inhibition. Alcohol disinhibits behaviour, but it only does so in individuals with a low baseline working memory capacity. An interesting finding is that the incentive to perform well with working memory measurement tasks while under the influence of alcohol 'does, in fact, have some effect on working memory, as it boosts scores in the rate of mental scanning and reaction time to stimulus; however, it did not reduce the number of errors as opposed to subjects with no incentive to perform well. Even acute alcohol intoxication (a blood alcohol concentration of 0.08-0.09%) produces a substantial impairment of working memory processes that require mnemonic rehearsal strategies. It is less likely for alcohol to impair a working memory task that does not rely on memory rehearsal or associated mnemonic strategies. Because of this, working memory is very susceptible to falter when an individual participates in tasks involving retention concerning both auditory and visual sequences. An interesting example of this is the failure of guitarists or other musicians performing concerts to cue in on auditory patterns and make it known that their performance is hindered by intoxication, whereas professional basketball (a less sequence-heavy activity for working memory) standout Ron Artest recently admitted in an interview with Sporting News to drinking heavily during half-time early in his career and the fact that it had little — if not any recognizable — effect on his working memory. His former coach Fran Fraschilla has gone on record saying:

"It's a surprise because every day at practice, he came out in a mood to play. He came out in a basketball rage. He was fully committed; he wanted to let our upperclassmen know that he was the alpha male. It never came up that he had any sort of a problem with alcohol. This is the first I've heard of it."

In the long term

Alcohol has been shown to have just some long-term effects on working memory. Findings have shown that in order for working memory to be substantially affected, long-term heavy drinking must be sustained over a long period of time, as up to one drink per day does not impair any cognitive function and may actually decrease the risk of a cognitive decline. Furthermore, chronic alcoholism is associated with the impairment in both sustained attention and visual working memory. As a result, alcoholics have reduced ability, but not necessarily inability, to perform these executive tasks. This is assumed to be subserved by regions of the prefrontal cortex.

While it may not serve as a surprise that chronic alcoholism is linked to any decreased cognitive function such as working memory, one surprising finding is not only that even moderate levels of alcohol consumption during pregnancy were shown to have an adverse effect on the child's working memory when tested at 7.5 years of age, but also that working memory may be the most important aspect of attention that is adversely affected by prenatal alcohol exposure.

Prospective memory

Prospective memory involves remembering to carry out an intended action in the future without an explicit reminder. Alcohol has been found to impair this ability. Chronic heavy alcohol users report significantly more prospective forgetting compared to low-dose and alcohol-free controls. The Prospective Memory Questionnaire assesses short-term habitual prospective memory, long-term episodic prospective memory, and internally cued prospective memory. Chronic heavy alcohol users reported significantly greater deficits for all three aspects of prospective memory. Individuals that report heavy alcohol use report 24% more difficulties with prospective memory than those who report that they are light drinkers and 30% more difficulties than those who report that they never drink. The effects of alcohol on prospective memory can also be assessed in the laboratory by simulating prospective memory tasks that individuals face in everyday life. Individuals who are given 0.6 g/kg alcohol prior to performing prospective memory tasks do significantly poorer than a placebo group. Alcohol can damage the prefrontal and frontal areas of the brain, and this may be responsible for prospective memory impairments since prospective memory performance is highly correlated with frontal executive functions.

In popular culture

The memory inhibiting effects of alcohol are often a prominent topic in popular culture. It appears in movies, books, and television shows. Several movies show characters drinking alcohol to the point of memory loss and awakening the next morning with a host of problems due to actions they performed while intoxicated.

One example is The Hangover, where three groomsmen lose the groom during a bachelor party in Las Vegas, so they retrace their steps to find him. The characters still had functioning implicit/procedural memory, which allowed them to carry out the many acts they performed that night, but their episodic memory was impaired and thus they had no recollection of the events occurring. In addition to alcohol the characters were also under the influence of flunitrazepam.

Another movie is What Happens in Vegas. After an intoxicated night in "Sin City," two people wake-up to find they got married.

Songs such as Waking Up in Vegas by Katy Perry and Last Name by Carrie Underwood also depict characters waking up and not remembering the night before due to alcohol consumption. 

By some accounts, popular culture makes light of the memory problems that can result from alcohol consumption. 

The court case R. v. Daviault [1994] concerned the viability of a legal defense based on intoxication.

Law and Order: Special Victims Unit; in season 11 episode 4, Hammered, a recovering alcoholic was coerced to drink by a business partner and later wakes up to a dead woman in his bed.