This article is written like a personal reflection or essay rather than an encyclopedic description of the subject. Please help improve it by rewriting it in an encyclopedic style. (October 2009)

Benjamin Libet ( /ˈlɪbət/;^[1] April 12, 1916, Chicago, Illinois - July 23, 2007, Davis, California) was a pioneering scientist in the field of human consciousness. Libet was a researcher in the physiology department of the University of California, San Francisco. In 2003, he was the first recipient of the Virtual Nobel Prize in Psychology from the University of Klagenfurt, "for his pioneering achievements in the experimental investigation of consciousness, initiation of action, and free will".^[2]

In the 1970s, Libet was involved in research into neural activity and sensation thresholds. His initial investigations involved determining how much activation at specific sites in the brain was required to trigger artificial somatic sensations, relying on routine psychophysical procedures. This work soon crossed into an investigation into human consciousness; his most famous experiment was meant to demonstrate that the unconscious electrical processes in the brain called Bereitschaftspotential (or readiness potential) discovered by Lüder Deecke and Hans Helmut Kornhuber in 1964 precede conscious decisions to perform volitional, spontaneous acts, implying that unconscious neuronal processes precede and potentially cause volitional acts which are retrospectively felt to be consciously motivated by the subject. The experiment has caused controversy not only because it challenges the belief in free will, but because it relies on questionable methods and rather narrow assumptions regarding how free decisions occur. It has also inspired further study of the neuroscience of free will.

Volitional acts and readiness potential[link]

Equipment[link]

To gauge the relation between unconscious readiness potential and subjective feelings of volition and action, Libet required an objective method of marking the subject's conscious experience of the will to perform an action in time, and afterward comparing this information with data recording the brain's electrical activity during the same interval.^[3][4] For this, Libet required specialized pieces of equipment.

The first of these was the cathode ray oscilloscope, an instrument typically used to graph the amplitude and frequency of electrical signals. With a few adjustments, however, the oscilloscope could be made to act as a timer: instead of displaying a series of waves, the output was a single dot that could be made to travel in a circular motion, similar to the movements of a second hand around a clock face. This timer was set so that the time it took for the dot to travel between intervals marked on the oscilloscope was approximately forty-three milliseconds. As the angular velocity of the dot remained constant, any change in distance could easily be converted into the time it took to travel that distance.

To monitor brain activity during the same period, Libet used an electroencephalogram (EEG). The EEG uses small electrodes placed at various points on the scalp that measure neuronal activity in the cortex, the outermost portion of the brain, which is associated with higher cognition. The transmission of electrical signals across regions of the cortex causes differences in measured voltage across EEG electrodes. These differences in voltage reflect changes in neuronal activity in specific areas of the cortex.

To measure the actual time of the voluntary motor act, an electromyograph (EMG) recorded the muscle movement using electrodes on the skin over the activated muscle of the forearm. The EMG time was taken as the zero time relative to which all other times were calculated.

Methods[link]

Researchers carrying out Libet’s procedure would ask each participant to sit at a desk in front of the oscilloscope timer. They would affix the EEG electrodes to the participant’s scalp, and would then instruct the subject to carry out some small, simple motor activity, such as pressing a button, or flexing a finger or wrist, within a certain time frame. No limits were placed on the number of times the subject could perform the action within this period.

Libet's experiment:
0 repose
1 (-500 ms) EEG measures Readiness potential
2 (-200 ms) Person notes the position of the dot when decides
3 (  0 ms) Act

During the experiment, the subject would be asked to note the position of the dot on the oscilloscope timer when "he/she was first aware of the wish or urge to act" (control tests with Libet's equipment demonstrated a comfortable margin of error of only -50 milliseconds). Pressing the button also recorded the position of the dot on the oscillator, this time electronically. By comparing the marked time of the button's pushing and the subject's conscious decision to act, researchers were able to calculate the total time of the trial from the subject's initial volition through to the resultant action. On average, approximately two hundred milliseconds elapsed between the first appearance of conscious will to press the button and the act of pressing it.

Researchers also analyzed EEG recordings for each trial with respect to the timing of the action. It was noted that brain activity involved in the initiation of the action, primarily centered in the secondary motor cortex, occurred, on average, approximately five hundred milliseconds before the trial ended with the pushing of the button. That is to say, researchers recorded mounting brain activity related to the resultant action as many as three hundred milliseconds before subjects reported the first awareness of conscious will to act. In other words, apparently conscious decisions to act were preceded by an unconscious buildup of electrical charge within the brain - this buildup came to be called Bereitschaftspotential or readiness potential. As of 2008, the upcoming outcome of a decision could be found in study of the brain activity in the prefrontal and parietal cortex up to 7 seconds before the subject was aware of their decision.^[5]

Implications of Libet's experiments[link]

Libet's experiments suggest to some^[6] that unconscious processes in the brain are the true initiator of volitional acts, and free will therefore plays no part in their initiation. If unconscious brain processes have already taken steps to initiate an action before consciousness is aware of any desire to perform it, the causal role of consciousness in volition is all but eliminated, according to this interpretation. For instance, Susan Blackmore's interpretation is "that conscious experience takes some time to build up and is much too slow to be responsible for making things happen."^[7]

Libet finds that conscious volition is exercised in the form of 'the power of veto' (sometimes called "free won't"^[8][9]); the idea that conscious acquiescence is required to allow the unconscious buildup of the readiness potential to be actualized as a movement. While consciousness plays no part in the instigation of volitional acts, Libet suggested that it may still have a part to play in suppressing or withholding certain acts instigated by the unconscious. Libet noted that everyone has experienced the withholding from performing an unconscious urge. Since the subjective experience of the conscious will to act preceded the action by only 200 milliseconds, this leaves consciousness only 100-150 milliseconds to veto an action (this is because the final 50 milliseconds prior to an act are occupied by the activation of the spinal motor neurones by the primary motor cortex, and the margin of error indicated by tests utilizing the oscillator must also be considered).

Libet's experiments have received support from other research related to the Neuroscience of free will.

Reactions by dualist philosophers[link]

It has been suggested that consciousness is merely a side-effect of neuronal functions, an epiphenomenon of brain states. Libet's experiments are proffered in support of this theory; our reports of conscious instigation of our own acts are, in this view, a mistake of retrospection. However, some dualist philosophers have disputed this conclusion:

In short, the [neuronal] causes and correlates of conscious experience should not be confused with their ontology [...] the only evidence about what conscious experiences are like comes from first-person sources, which consistently suggest consciousness to be something other than or additional to neuronal activity.^[10]

A more general criticism from a dualist-interactionist perspective has been raised by Alexander Batthyany^[11] who points out that Libet asked his subjects to merely "let the urge [to move] appear on its own at any time without any pre-planning or concentration on when to act".^[12] According to Batthyany, neither reductionist nor non-reductionist agency theories claim that urges which appear on their own are suitable examples of (allegedly) consciously caused events because one cannot passively wait for an urge to occur while at the same time being the one who is consciously bringing it about. Libet's results thus cannot be interpreted to provide empirical evidence in favour of agency reductionism, since non-reductionist theories, even including dualist interactionism, would predict the very same experimental results.

Timing issues[link]

Daniel Dennett argues that no clear conclusion about volition can be derived from Libet's experiment because of ambiguities in the timings of the different events involved. Libet tells when the readiness potential occurs objectively, using electrodes, but relies on the subject reporting the position of the hand of a clock to determine when the conscious decision was made. As Dennett points out, this is only a report of where it seems to the subject that various things come together, not of the objective time at which they actually occur.

Suppose Libet knows that your readiness potential peaked at second 6,810 of the experimental trial, and the clock dot was straight down (which is what you reported you saw) at millisecond 7,005. How many milliseconds should he have to add to this number to get the time you were conscious of it? The light gets from your clock face to your eyeball almost instantaneously, but the path of the signals from retina through lateral geniculate nucleus to striate cortex takes 5 to 10 milliseconds — a paltry fraction of the 300 milliseconds offset, but how much longer does it take them to get to you. (Or are you located in the striate cortex?) The visual signals have to be processed before they arrive at wherever they need to arrive for you to make a conscious decision of simultaneity. Libet's method presupposes, in short, that we can locate the intersection of two trajectories: • the rising-to-consciousness of signals representing the decision to flick • the rising to consciousness of signals representing successive clock-face orientations so that these events occur side-by-side as it were in place where their simultaneity can be noted.

^[13][14]

Subjective backward referral or "antedating" of sensory experience[link]

It is worth noting that his early theory, resting on study of stimuli and sensation,^[15] was found bizarre by some commentators, including Patricia Churchland,^[16] due to the apparent idea of backward causation. Libet^[17] argued that data suggested that we retrospectively "antedate" the beginning of a sensation to the moment of the primary neuronal response. People interpreted Libet's work on stimulus and sensation in a number of different ways. John Eccles^[18] presented Libet's work as suggesting a backward step in time made by a non-physical mind. Edoardo Bisiach (1988)^[19] described Eccles as tendentious, but commented:

This is indeed the conclusion that the authors (Libet, et al.) themselves seem to be willing to force upon the reader. [...] They dispute an alternative explanation, suggested by Mackay in a discussion with Libet (1979, p. 219)^[15] to the effect that 'the subjective referral backwards in time may be due to an illusory judgment made by the subject when he reports the timings', and more significant, Libet, et al. (1979, p. 220)^[15] hint at 'serious though not insurmountable difficulties' for the identity theory (of mind and matter) caused by their data.

Libet later concluded^[20] that there appeared to be no neural mechanism that could be viewed as directly mediating or accounting for the subjective sensory referrals backward in time [emphasis Libet's]. Libet postulated that the primary evoked potential (EP) serves as a "time marker". The EP is a sharp positive potential appearing in the appropriate sensory region of the brain about 25 milliseconds after a skin stimulus. Libet's experiments demonstrated that there is an automatic subjective referral of the conscious experience backwards in time to this time marker.^[15] The skin sensation does not enter our conscious awareness until about 500 milliseconds after the skin stimulus, but we subjectively feel that the sensation occurred at the time of the stimulus.

For Libet, these subjective referrals would appear to be purely a mental function with no corresponding neural basis in the brain. Indeed this suggestion can be more broadly generalized:

The transformation from neuronal patterns to a subjective representation would appear to develop in a mental sphere that has emerged from that neuronal pattern. [...] My view of mental subjective function is that it is an emergent property of appropriate brain functions. The conscious mental cannot exist without the brain processes that give rise to it. However, having emerged from brain activities as a unique 'property' of that physical system, the mental can exhibit phenomena not evident in the neural brain that produced it.^[21]

Conscious Mental Field Theory[link]

In the later part of his career, Libet proposed a theory of the conscious mental field (CMF)^[22] to explain how the mental arises from the physical brain. The two main motivations prompting this proposal were: (1) the phenomenon of the unity of subjective conscious experience and (2) the phenomenon that conscious mental function appears to influence nerve cell activity.

Regarding the unity of conscious experience, it was increasingly evident to Libet that many functions of the cortex are localized, even to a microscopic level in a region of the brain, and yet the conscious experiences related to these areas are integrated and unified. We do not experience an infinite array of individual events but rather a unitary integrated consciousness, for example, with no gaps in spatial and colored images. For Libet, some unifying process or phenomenon likely mediates the transformation of localized, particularized neuronal representations into our unified conscious experience. This process seemed to be best accountable in a mental sphere that appears to emerge from the neural events, namely, the conscious mental field.

The CMF is the mediator between the physical activities of nerve cells and the emergence of subjective experience. Thus the CMF is the entity in which unified subjective experience is present and provides the causal ability to affect or alter some neuronal functions. Libet proposed the CMF as a "property" of an emergent phenomenon of the brain; it does not exist without the brain but emerges from the appropriate system of neural activity. This proposal is related to electromagnetic theories of consciousness.

To test the proposed causal ability of the CMF to affect or alter neuronal functions, Libet proposed an experimental design,^[23][24] which would surgically isolate a slab of cerebral cortex (in a patient for whom such a procedure was therapeutically required). If electrical stimulation of the isolated cortex can elicit an introspective report by the subject, the CMF must be able to activate appropriate cerebral areas in order to produce the verbal report. This result would demonstrate directly that a conscious mental field could affect neuronal functions in a way that would account for the activity of the conscious will.

Libet further elaborated on CMF:

The CMF is not a Cartesian dualistic phenomenon; it is not separable from the brain. Rather, it is proposed to be a localizable system property produced by appropriate neuronal activities, and it cannot exist without them. Again, it is not a ‘‘ghost’’ in the machine. But, as a system produced by billions of nerve cell actions, it can have properties not directly predictable from these neuronal activities. It is a non-physical phenomenon, like the subjective experience that it represents. The process by which the CMF arises from its contributing elements is not describable. It must simply be regarded as a new fundamental ‘‘given’’ phenomenon in nature, which is different from other fundamental ‘‘givens,’’ like gravity or electromagnetism.^[25]

Tributes[link]

Dr. Robert W. Doty, professor of Neurobiology and Anatomy at the University of Rochester:^[26]

Dr. Susan J. Blackmore, visiting lecturer at the University of the West of England, Bristol:^[27]

References[link]

Further reading[link]

• Benjamin Libet, Anthony Freeman, and J. K. B. Sutherland, Editors, The volitional brain: Towards a neuroscience of free will. Imprint Academic, 1999. ISBN 0-907845-50-9.
• Benjamin Libet, Mind time: The temporal factor in consciousness, Perspectives in Cognitive Neuroscience. Harvard University Press, 2004. ISBN 0-674-01320-4.
• Daniel C. Dennett, Freedom Evolves. Allen Lane, 2003. ISBN 0-14-028389-7.
• Michael Pauen (2004). Does Free Will Arise Freely?, Scientific American Mind, 14(1).
• In his Virtual Nobel acceptance speech, Libet summarized his life's research and highlighted his work on conscious volitional acts and the antedating of sensory awareness.

External links[link]

• Obituary from The Los Angeles Times, August 27, 2007.
• Obituary from The San Francisco Chronicle, August 18, 2007.
• Obituary from The Davis Enterprise, July 27, 2007.
• Virtual Nobel Prize in Psychology Including video of Libet's acceptance speech.
• Short account of Libet's experiments and theory

See also[link]

• Neuroscience of free will

Eric Richard Kandel
Kandel at Lange Nacht der Wissenschaften (Long Night of Science) in Austria in 2006
Born	(1929-11-07) November 7, 1929 (age 82) Vienna, Austria
Fields	Psychiatry and neuroscience
Institutions	Columbia University College of Physicians and Surgeons
Alma mater	New York University Medical School Harvard University
Known for	physiology of memory
Notable awards	Harvey Prize (1993) Wolf Prize in Medicine (1999) Nobel Prize in Physiology or Medicine 2000

Eric Richard Kandel (born November 7, 1929 in Vienna, Austria) is an American neuropsychiatrist who was a recipient of the 2000 Nobel Prize in Physiology or Medicine for his research on the physiological basis of memory storage in neurons. He shared the prize with Arvid Carlsson and Paul Greengard.

Kandel, who had studied psychoanalysis, wanted to understand how memory works. His mentor, Harry Grundfest, said, “If you want to understand the brain you’re going to have to take a reductionist approach, one cell at a time.” So he studied the neural system of a simple animal, Aplysia, a snail with very large nerve cells.^[1]

Kandel is a professor of biochemistry and biophysics at the Columbia University College of Physicians and Surgeons and a Senior Investigator in the Howard Hughes Medical Institute. He was also the founding director of the Center for Neurobiology and Behavior, which is now the Department of Neuroscience at Columbia. Kandel authored In Search of Memory: The Emergence of a New Science of Mind (WW Norton), which chronicles his life and research. The book was awarded the 2006 Los Angeles Times Book Award for Science and Technology.

Early years[link]

Kandel was born in 1929 in Vienna, Austria, in a middle-class Ashkenazi Jewish family. His mother, Charlotte Zimels, was born in 1897 in Kolomyya, Pokuttya (modern Ukraine), and came from a well-educated middle-class family. At that time Kolomyya was in Eastern Poland. His father was born in 1898 into a poor family in Olesko, Galicia (then part of Austria-Hungary). At the beginning of World War I his parents moved to Vienna where they met and married in 1923, shortly after Hermann Kandel, Eric's father, had established a toy store. They were a thoroughly assimilated and acculturated family, who had to leave Austria after the country had been annexed by Germany in March 1938. Aryanization (Arisierung) started; attacks on Jews escalated; Jewish property was confiscated. Eventually, when Eric was 9, he and his brother Ludwig, 14, boarded the "Gerolstein" at Antwerp in Belgium and joined their uncle in Brooklyn on May 11, 1939. Later his parents succeeded in moving to the US.

When Kandel won the Nobel Prize in 2000, it was claimed in Vienna that he was an "Austrian" Nobel, something he found "typically Viennese: very opportunistic, very disingenuous, somewhat hypocritical." He also said it was "...certainly not an Austrian Nobel, it was a Jewish-American Nobel." After that, he got a call from then Austrian president Thomas Klestil asking him, "How can we make things right?" Kandel said that first, Doktor-Karl-Lueger-Ring should be renamed; Karl Lueger was an anti-Semitic mayor of Vienna, cited by Hitler in Mein Kampf. Second, he wanted the Jewish intellectual community to be brought back to Vienna, with scholarships for Jewish students and researchers.^[2] He also proposed to have a symposium on the response of Austria to National Socialism.^[3] Kandel has since accepted an honorary citizenship of Vienna and participates in the academic and cultural life of his native city.^[4]

After arriving in the United States, and settling in Brooklyn, Kandel was tutored by his grandfather in Judaic studies, and was accepted at the Yeshiva of Flatbush, graduating in 1944. He attended Brooklyn's Erasmus Hall High School, a Public high school.^[5]

Kandel's initial intellectual interests lay in the area of history. (History and Literature was his undergraduate major at Harvard University.) He wrote an honors dissertation on "The Attitude Toward National Socialism of Three German Writers: Carl Zuckmayer, Hans Carossa, and Ernst Jünger." While at Harvard, a place dominated by the work of B. F. Skinner, Kandel became interested in learning and memory. It should be noted, however, that while Skinner championed a strict separation of psychology, as its own level of discourse, from biological considerations such as neurology, Kandel's work is essentially centered on an explication of the relationships between psychology and neurology.

The world of neuroscience was first opened up to Kandel through his interactions with a college girlfriend, Anna Kris, whose parents were Freudian psychoanalysts. Freud, a pioneer in revealing the importance of unconscious neural processes, was at the root of Kandel's interest in the biology of motivation and unconscious and conscious memory.

Medical school and early research[link]

In 1952 he started at the New York University Medical School. By graduation he was firmly interested in the biological basis of the mind. During this time he met his future wife, Denise Bystryn. Kandel was first exposed to research in Harry Grundfest's laboratory at Columbia University. Grundfest was known for using the oscilloscope to demonstrate that action potential conduction velocity depends on axon diameter. The researchers Kandel interacted with were contemplating the technically challenging idea of intracellular recordings of the electrical activity of the relatively small neurons of the vertebrate brain.

After starting his neurobiological work in the difficult thicket of the electrophysiology of the cerebral cortex, Kandel was impressed by the progress that had been made by Stephen Kuffler using a much more experimentally accessible system: neurons isolated from marine invertebrates. After becoming aware of Kuffler's work in 1955, Kandel graduated from medical school and learned from Stanley Crain how to make microelectrodes that could be used for intracellular recordings of relatively large crayfish giant axons.

Karl Lashley, a well-known American neuropsychologist, had tried but failed to identify an anatomical locus for memory storage in the cortex at the surface of the brain. When Kandel joined the Laboratory of Neurophysiology at the National Institutes of Health in 1957, William Beecher Scoville and Brenda Milner had recently described the patient HM, who had lost explicit memory storage following removal of the hippocampus. Kandel took on the task of performing electrophysiological recordings of hippocampal pyramidal neurons. Working with Alden Spencer, electrophysiological evidence was found for action potentials in the dendritic trees of hippocampal neurons. They also noticed the spontaneous pace-maker-like activity of these neurons and a robust recurrent inhibition in the hippocampus. With respect to memory, there was nothing in the general electrophysiological properties of hippocampal neurons that suggested why the hippocampus was special for explicit memory storage.

Kandel began to realize that memory storage must rely on modifications in the synaptic connections between neurons and that the complex connectivity of the hippocampus did not provide the best system for study of the detailed function of synapses. Kandel was aware that comparative studies of behavior, such as those by Konrad Lorenz, Niko Tinbergen, and Karl von Frisch had revealed conservation of simple forms of learning across all animals. Kandel felt it would be productive to select a simple animal model that would facilitate electrophysiological analysis of the synaptic changes involved in learning and memory storage. He believed that, ultimately, the results would be found to be applicable to humans. This decision was not without risks since many senior biologists and psychologists believed that nothing useful could be learned about human memory by studying invertebrate physiology.

In 1962, after completing his residency in psychiatry, Kandel went to Paris to learn about the marine mollusc Aplysia californica from Ladislav Tauc. Kandel had realized that simple forms of learning such as habituation, sensitization, classical conditioning, and operant conditioning could readily be studied with ganglia isolated from Aplysia. "While recording the behavior of a single cell in a ganglion, one nerve axon pathway to the ganglion could be stimulated weakly electrically as a conditioned [tactile] stimulus, while another pathway was stimulated as an unconditioned [pain] stimulus, following the exact protocol used for classical conditioning with natural stimuli in intact animals." Electrophysiological changes resulting from the combined stimuli could then be traced to specific synapses. In 1965 Kandel published his initial results, including a form of pre-synaptic potentiation that seemed to correspond to a simple form of learning.

Faculty member at New York University Medical School[link]

Kandel in 1978

Kandel took a position in the Departments of Physiology and Psychiatry at the New York University Medical School, eventually forming the Division of Neurobiology and Behavior. Working with Irving Kupferman and Harold Pinsker it was possible to develop protocols for demonstrating simple forms of learning by intact Aplysia. In particular, the now famous gill-withdrawal reflex, by which the tender Aplysia gill tissue is withdrawn from danger, was shown to be sensitive to both habituation and sensitization. By 1971 Tom Carew joined the research group and helped extend the work from studies restricted to short-term memory to additional experiments that included additional physiological processes required for long-term memory.

By 1981, laboratory members including Terry Walters, Tom Abrams, and Robert Hawkins had been able to extend the Aplysia system into the study of classical conditioning, a finding which helped close the apparent gap between the simple forms of learning often associated with invertebrates and more complex types of learning more often recognized in vertebrates. Along with the fundamental behavioral studies, other work in the lab traced the neuronal circuits of sensory neurons, interneurons, and motor neurons involved in the learned behaviors. This allowed analysis of the specific synaptic connections that are modified by learning in the intact animals. The results from Kandel's laboratory provided solid evidence for the mechanistic basis of learning as "a change in the functional effectiveness of previously existing excitatory connections."

Molecular changes during learning[link]

Starting in 1966 James Schwartz collaborated with Kandel on a biochemical analysis of changes in neurons associated with learning and memory storage. By this time it was known that long-term memory, unlike short-term memory, involved the synthesis of new proteins. By 1972 they had evidence that the second messenger molecule cyclic AMP (cAMP) was produced in Aplysia ganglia under conditions that cause short-term memory formation (sensitization). In 1974 the Kandel lab moved to Columbia University as founding director of the Center for Neurobiology and Behavior. It was soon found that the neurotransmitter serotonin acting to produce the second messenger cAMP is involved in the molecular basis of sensitization of the gill-withdrawal reflex. By 1980, collaboration with Paul Greengard resulted in demonstration that cAMP-dependent protein kinase (PKA) acted in this biochemical pathway in response to elevated levels of cAMP. Steven Siegelbaum identified a potassium channel that could be regulated by PKA, coupling serotonin's effects to altered synaptic electrophysiology.

In 1983 Kandel helped form the Howard Hughes Medical Research Institute at Columbia devoted to molecular neural science. The Kandel lab took on the task of identifying proteins that had to be synthesized in order to convert short-term memories into long-lasting memories. One of the nuclear targets for PKA is the transcriptional control protein CREB (cAMP response element binding protein). In collaboration with David Glanzman and Craig Bailey, CREB was identified as being a protein involved in long-term memory storage. One result of CREB activation is an increase in the number of synaptic connections. Thus, short-term memory had been linked to functional changes in existing synapses, while long-term memory was associated with a change in the number of synaptic connections.

Experimental support for Hebbian learning[link]

Some of the synaptic changes observed by Kandel's laboratory provide examples of Hebbian learning. One article describes the role of Hebbian learning in the Aplysia siphon-withdrawal reflex.^[6]

The Kandel lab has also performed important experiments using transgenic mice as a system for investigating the molecular basis of memory storage in the vertebrate hippocampus.^[7][8][9] Kandel's original idea that learning mechanisms would be conserved between all animals has been confirmed. Neurotransmitters, second messenger systems, protein kinases, ion channels, and transcription factors like CREB have been confirmed to function in both vertebrate and invertebrate learning and memory storage.^[10][11]

Continuing work at Columbia University[link]

Kandel actively contributes to science as a member of the Division of Neurobiology and Behavior at the Department of Psychiatry at Columbia University. In 2008, he and Daniela Pollak discovered that conditioning mice to associate a specific noise with protection from harm, a behavior called “learned safety,” produced a behavioral antidepressant effect comparable to medications. This finding, reported in Neuron, may inform further studies of the cellular interactions between antidepressants and behavioral treatments.

Kandel is also well known for the textbooks he has helped write such as Principles of Neural Science. First published in 1981 and entering its fifth edition, Principles of Neural Science is often used as a teaching and reference text in medical schools. Kandel has been a member of the National Academy of Sciences, USA, since 1974. His 2006 autobiographical book, "In Search of Memory: The Emergence of a New Science of Mind," is a popularized account of his life and career.

Kandel has been at Columbia University since 1974, and lives in New York City.

Awards[link]

• Albert Lasker Award for Basic Medical Research (1983)
• Gairdner Foundation International Award (1987)
• NAS Award for Scientific Reviewing of the National Academy of Sciences (1988)^[12]
• National Medal of Science (1988)
• Harvey Prize (1993)
• Wolf Prize in Medicine (1999)
• Nobel Prize in Physiology or Medicine (2000)
• Charles A Dana Award for Pioneering Achievement in Health (1997)
• Austrian Decoration for Science and Art (2005)
• Benjamin Franklin Medal for Distinguished Achievement in the Sciences of the American Philosophical Society (2006)^[13]
• Viktor Frankl Award of the City of Vienna (2008)

He is a member of the prize committee for neuroscience of Kavli Prize.

Filmography[link]

• Petra Seeger, In Search of Memory (2008)

See also[link]

• List of Jewish Nobel laureates

References[link]

• Tallis, Raymond. "From Neuroses To Neurons". http://online.wsj.com. http://online.wsj.com/article/SB10001424052702304023504577319903439493784.html. 

Further reading[link]

• Kandel, E. R. (2007), In Search of Memory: The Emergence of a New Science of Mind, New York: W. W. Norton & Company, ISBN 978-0-393-32937-7 .
• Kandel, Eric R.; Schwartz, James Harris; Jessell, Thomas M. (2000) [1981], Principles of Neural Science (Fourth ed.), New York: McGraw-Hill, ISBN 0-8385-7701-6 .
• Kandel, E. R. (2012), The Age of Insight: The Quest to Understand the Unconscious in Art, Mind, and Brain, from Vienna 1900 to the Present , New York: Random House, ISBN 978-1-4000-6871-5 

External links[link]

• Interview with Kandel June 2006 in German
• Eric Kandel’s Faculty Profile in the Department of Psychiatry at Columbia University
• Eric Kandel's Columbia University website
• Autobiography at the Nobel Prize website
• Science Friday: October 13, 2000 NPR interview
• Eric Kandel - A Nobel's Life
• Eric R. Kandel's United States Patents
• The Kavli Prize Prize Committee Member for neuroscience
• Explains a bit about the textbook Kandel wrote
• Eric Kandel on Charlie Rose

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (July 2011)

Slavoj Žižek

Slavoj Žižek at Warsaw, Poland, May 15, 2009.
Born	(1949-03-21) 21 March 1949 (age 63) Slovenia (then part of Yugoslavia)
Era	20th- / 21st-century philosophy
Region	Western philosophy
School	Hegelianism Psychoanalysis Marxism
Main interests	Ontology · Film theory Psychoanalysis Ideology · Theology Marxism
Influenced by G. W. F. Hegel · F. W. J. Schelling Jacques Lacan · Karl Marx Friedrich Engels · Theodor W. Adorno Sigmund Freud · Vladimir Lenin Ernesto Laclau Maximilien Robespierre Jean-Jacques Rousseau
Influenced Michael Hardt · Alenka Zupančič · Terry Eagleton

Slavoj Žižek (pronounced [ˈslavoj ˈʒiʒɛk]; born 21 March 1949) is a Slovenian philosopher and cultural critic^[1] working in the traditions of Hegelianism, Marxism and Lacanian psychoanalysis. He has made contributions to political theory, film theory and theoretical psychoanalysis.

Žižek is a senior researcher at the Institute of Sociology University of Ljubljana, Slovenia, and a professor at the European Graduate School.^[2] He has been a visiting professor at, among others, the University of Chicago, Columbia University, London Consortium, Princeton University, New York University, The New School, the University of Minnesota, the University of California, Irvine and the University of Michigan. He is currently the International Director of the Birkbeck Institute for the Humanities at Birkbeck, University of London and president of the Society for Theoretical Psychoanalysis, Ljubljana.^[3]

Žižek uses examples from popular culture to explain the theory of Jacques Lacan and uses Lacanian psychoanalysis, Hegelian philosophy and Marxist economic criticism to interpret and speak extensively on immediately current social phenomena, including the current ongoing global financial crisis. In a 2008 interview with Amy Goodman on the New York City radio show Democracy Now! he described himself as a "communist in a qualified sense" and in another appearance on the show in October 2009 he described himself as a "radical leftist".^[4][5]

It was not until the 1989 publication of his first book written in English, The Sublime Object of Ideology, that Žižek achieved international recognition as a social theorist. Since then, he has continued to develop his status as a confrontational intellectual.

He writes on many topics including subjectivity, ideology, capitalism, fundamentalism, racism, tolerance, multiculturalism, human rights, ecology, globalization, the Iraq War, revolution, utopianism, totalitarianism, postmodernism, pop culture, opera, cinema, political theology, and religion.

He has been called "the most dangerous political philosopher in the West".^[6]