Dr. Dan Pollen
Professor of Neurology,
Department of Neurology,
University of Massachusetts Medical Center
will speak on
Does conscious visual perception emerge globally within
transcortical multi-level recursive neural networks or do such
networks endow selective cortical areas with properties that locally
engender particular conscious experiences?
Abstract:
By the end of the twentieth century, a considerable body of evidence
suggested that conscious sensory experience requires activation of at
least some minimal recursive neural network (Grossberg, 1995; Pollen,
1999). However, the fundamental question as to whether any conscious
visual experience is instantiated locally within a given cortical area
within that recursive network or is an emergent property of neuronal
activity across the entire loop remains unresolved. We now inquire as
to whether such recursive processing is essential only for loops between
extrastriate cortical areas explicitly representing experiences such as
color or motion back to V1 or whether it is processing between the areas
computing such explicit representations and still higher levels that is
exclusively or additionally essential for visual experience (Pollen,
2003). If recursive processing is not essential for the emergence
of conscious visual experience, then it should also be possible to
determine whether it is only the intracortical sensory processing within
areas computing explicit sensory representations that is required for
perceptual experience or whether it is the subsequent processing of the
output of such areas within more anterior cortical regions that engenders
perception. The present analysis suggests that the questions posed here
may ultimately become experimentally resolvable using techniques that
combine electrical activation of afferent pathways with selective blocks
of various recurrent pathways together with reversible inactivation of
early cortical areas. Whatever the outcome, the results will likely
open new approaches to identify the neural correlates of conscious
visual perception.
The lecture will take place in
Room 203, 44 Cummington St.
on Thursday, September 18, 2003
at 12:30 pm
Hosted by the
Brain and Vision Research Laboratory