quarta-feira, 25 de fevereiro de 2009

BRAIN AND MIND

Lectures Video Archive

Leading neuroscientists gathered at this C250 symposium to discuss the accomplishments and limitations of reductionist and holistic approaches to examining the nervous system and mental functions.

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?