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Member-Initiated Symposia
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2012 Member-Initiated SymposiaPulvinar and Vision: New insights into
circuitry and function
Organizer: Vivien A. Casagrande, Department of Cell & Developmental Biology, Vanderbilt Medical School Time: Friday, May 11, 1:00 - 3:00 pm Room: Royal Ballroom 1-3 The most mysterious nucleus of the visual thalamus is the pulvinar. In most
mammals the pulvinar is the largest thalamic nucleus, and it has progressively
enlarged in primate evolution so that it dwarfs the remainder of the thalamus in
humans. Despite the large size of the pulvinar, relatively little is known
regarding its function, and consequently its potential influence on cortical
activity patterns is unappreciated. This symposium will outline new insights
regarding the role of the pulvinar nucleus in vision, and should provide the VSS
audience with a new appreciation of the interactions between the pulvinar
nucleus and cortex. What does fMRI tell us about brain
homologies?
Organizer: Reza Rajimehr, McGovern Institute for Brain
Research, Massachusetts Institute of Technology Time: Friday, May 11, 1:00 - 3:00 pm Room: Royal Ballroom 4-5 Over the past 20 years, the functional magnetic resonance imaging (fMRI) has
provided a great deal of knowledge about the functional organization of human
visual cortex. In recent years, the development of the fMRI technique in
non-human primates has enabled neuroscientists to directly compare visual
cortical areas across species. These comparative studies have shown striking
similarities ('homologies') between human and monkey visual cortex. Comparing
cortical structures in human versus monkey provides a framework for generalizing
results from invasive neurobiological studies in monkeys to humans. It also
provides important clues for understanding the evolution of cerebral cortex in
primates. Part-whole relationships in visual
cortex
Organizer: Johan Wagemans, Laboratory of Experimental
Psychology, University of Leuven Time: Friday, May 11, 1:00 - 3:00 pm Room: Royal Ballroom 6-8 In 1912 Wertheimer launched Gestalt psychology, arguing that the whole is
different from the sum of the parts. Wholes were considered primary in
perceptual experience, even determining what the parts are. How to reconcile
this position with what we now know about the visual brain, in terms of a
hierarchy of processing layers from low-level features to integrated object
representations at the higher level? What exactly are the relationships between
parts and wholes then? A century later, we will take stock and provide an answer
from a diversity of approaches, including single-cell recordings, human fMRI,
human psychophysics, and computational modeling. Distinguishing perceptual shifts from response
biases
Organizer: Joshua Solomon, City University London Time: Friday, May 11, 3:30 - 5:30 pm Room: Royal Ballroom 1-3 Our general topic will be the measurement of perceptual biases. These are
changes in appearance that cannot be attributed to changes in the visual
stimulus. One perceptual bias that has received a lot of attention lately is the
change in apparent contrast that observers report when they attend (or remove
attention from) a visual target. We will discuss how to distinguish reports of
truly perceptual changes from changes in response strategies. Human visual cortex: from receptive fields to
maps to clusters to perception
Organizer: Serge O. Dumoulin, Experimental Psychology,
Helmholtz Institute, Utrecht University, Utrecht, Netherlands Time: Friday, May 11, 3:30 - 5:30 pm Room: Royal Ballroom 4-5 This symposium will introduce current concepts of the visual cortex’
organization at different spatial scales and their relation to perception. At
the smallest scale, the receptive field is a property of individual neurons and
summarizes the visual field region where visual stimulation elicits a response.
These receptive fields are organized into visual field maps, which in turn are
organized in clusters that share a common fovea. We will relate these principles
to notions of population receptive fields (pRF), cortico-cortical pRFs,
extra-classical contextual effects, detailed foveal organization, visual
deprivation, prism-adaptation and plasticity. Neuromodulation of Visual Perception
Organizer: Jutta Billino, Justus-Liebig-University Giessen, and Ulrich Ettinger, Rheinische Friedrich-Wilhelms-Universität Bonn Time: Friday, May 11, 3:30 - 5:30 pm Room: Royal Ballroom 6-8 Although the neuronal bases of vision have been extensively explored over the
last decades we are just beginning to understand how visual perception is
modulated by neurochemical processes in our brain. Recent research provides
first insights into regulation of signal processing by different
neurotransmitters. This symposium is devoted to the questions (1) by which
mechanisms neurotransmitters influence perception and (2) how individual
differences in neurotransmitter activity could explain normal variation and
altered visual processing in mental disease and during ageing. Presentations
will provide an overview of state-of-the-art methods and findings concerning the
complexity of neuromodulation of visual perception.
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