Wednesday, July 02, 2008

Towards the Neuronal Basis of Consciousness

Christof Koch gives an interesting talk (OK, so I only read it, couldn't watch) as part of the 2004 Brain and Mind symposium at Columbia 250. Found this through Channel N.
Historically, neural scientists have taken one of two somewhat parallel approaches to the complex problem of understanding the biological mechanisms that account for mental activity. The first, or molecular model, analyzes the nervous system in terms of its elementary components, by examining one molecule, cell, or circuit at a time. The second, or cognitive model, focuses on mental functions in human beings and animals in an attempt to relate behavior to higher-order features of large systems of neurons.

The symposium "Brain and Mind," at Miller Theatre May 13 and 14, helped outline the accomplishments and limitations of these two approaches in attempts to delineate the problems that still confront neural science. Organized by Tom Jessell, professor of biochemistry and molecular biophysics, and Joanna Rubinstein, senior associate dean for institutional and global initiatives at Columbia University Medical Center, the symposium featured a number of distinguished faculty members, including Eric Kandel, Columbia's Nobel Prize–winning neurophysiologist, as well as visiting scholars from the National Institutes of Health, Rockefeller University, King's College London, Caltech, MIT, and elsewhere.

The course of the program, according to Rubinstein, was to "turn from reductionist to holistic approaches," looking first at what is known about cells and neural networks before addressing research into perceptions and behaviors. Participating scholars discussed current understandings and answers to key questions: How do the actions of individual neurons shape the function of neural populations? What is the underlying logic of signaling in complex neural circuits? How do dynamic mechanisms modify the processing of this information? And ultimately, how does the activity of neural ensembles generate cognitive and emotional behavior?

They also confronted some of the enduring mysteries regarding the biology of mental functioning: How does signaling activity in different regions of the visual system permit us to perceive discrete objects in the visual world? How do we recognize a face? How do we become aware of that perception? How do we reconstruct that face at will, in our imagination, at a later time and in the absence of ongoing visual input? What are the biological underpinnings of our acts of will?
Here's a bit about Christof Koch, PhD.
View Abstract


Born in 1956 in the American Midwest, Christoff Koch grew up in Holland, Germany, Canada, and Morocco, where he graduated from the Lycè Descartes in 1974. He studied physics and philosophy at the University of Tübingen in Germany and was awarded his PhD in biophysics in 1982.

After four years at the Massachusetts Institute of Technology, Dr. Koch joined the faculty at the California Institute of Technology in 1986, where he is now the Lois and Victor Troendle Professor of Cognitive and Behavioral Biology. He lives with his family in Pasadena, and loves to run and to climb.

The author of close to three hundred scientific papers and journal articles, and several books, Dr. Koch studies the biophysics of computation, and the neuronal basis of visual perception, attention, and consciousness. Together with his long-time collaborator, Francis Crick, he has pioneered the scientific study of consciousness. His latest book is The Quest for Consciousness: A Neurobiological Approach. For more information, see


"Towards the Neuronal Basis of Consciousness"

Much excitement has been generated in the scientific community by electrophysiological techniques of recording from individual nerve cells in behaving monkeys and other animals that, combined with functional brain imaging in humans, enables us to study the neuronal basis of subjective, conscious experience. Researchers are interested in discovering the neuronal correlates of consciousness (NCC). This would be an enormous step in understanding the age-old mind-body problem: How can a physical system have subjective feelings?

I will outline the two-pronged research program we are following by studying visual consciousness in humans using psychophysics, functional brain imaging and electrophysiological investigations at the single neuron level and contingency awareness in rodents in certain forms of aversive Pavlovian conditioning using behavioral techniques in combination with pharmacological and genetic interventions. For more information, see

The lecture is indexed into 11 brief "chapters" (navigating is not great). incuding "recording single neurons in conscious humans," chapters on zombies, motion-induced blindness, flash suppression, and more. Accompanied by slides, a transcript pdf, and a link to a NYT profile of Koch and Crick.

[I couldn't get the video to work this morning, but that just may be my computer acting weird. The transcript is very cool, though, in a geeky kind of way.]

View Slides
Play Video
Read Transcript (PDF)

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