Workshop 6: Information Processing in the Visual System (April 23-27, 2007)
The traditional feedforward model of the visual system invokes a
sequence of processing stages, beginning with the relay of retinal
input to neurons in the primary visual cortex (V1), via the lateral
geniculate nucleus (LGN), and subsequent higher-order processing
through a hierarchy of cortical areas. According to this model,
neurons at each successive stage process inputs from increasingly
larger regions of space, and code for increasingly more complex
aspects of visual stimuli. The selectivity of a neuron to a given
stimulus parameter (e.g., orientation, color, depth) is assumed
to result from the ordered convergence of afferents from the lower
stages.
In this workshop, three different aspects of visual information
processing will be considered.
- Thalamus: There is growing evidence that thalamocortical and
corticothalamic interactions play an important role in controlling
the flow of visual information, both at the initial entry stage
where it can be modulated by attentional states, and at higher-order
stages involving sensory and motor processing.
- Early visual processing: There is considerable physiological
and psychophysical evidence that long-distance integration of
visual signals can occur at very early stages of processing including
V1. In particular, the response of a V1 cell to stimulation of
its classical receptive field (RF) can be selectively modulated
by contextual stimuli lying far outside its RF.
- Top-down processing: An important source of top-down influences
on bottom-up sensory processing arises from selective attention,
in which the saliency of an object can be altered in light of
behavioral relevance.
Schedule |
Monday, April 23
The Role of the Thalamus and Thalamocortical Relationships in Visual Processing |
| 9:00-9:15am |
Welcome and introduction from Avner Friedman, Paul Bressloff, and Alessandra Angelucci |
| 9:15-10:00am |
Murray Sherman: The Role of Thalamus: Relay Functions and More |
| 10:00-10:30am |
Coffee break |
| 10:30-11:15am |
Martin Usrey: Feedforward and feedback contributions to visual processing in the lateral geniculate nucleus |
| 11:15-11:45am |
Coffee break |
| 11:45-12:30pm |
Gregory Smith: Feedback inhibition and throughput properties of network models of retinogeniculate transmission |
| 12:30-2:00pm |
Lunch break |
| 2:00-2:45pm |
Vivien Casagrande |
| 2:45-3:15pm |
Coffee break |
| 3:15-4:00pm |
David Fitzpatrick: Learning to see: The experience-dependent emergence of direction selectivity in visual cortex |
| 4:00-4:30pm |
Coffee break |
| 4:30-7:00pm |
Reception in MW 724 |
Tuesday, April 24
Early Visual Processing |
| 9:00-9:45am |
Robert Shapley: Visual feature selectivities and spatial interactions in V1 cortex |
| 9:45-10:00am |
Coffee break |
| 10:00-10:45am |
Ralph Freeman: Dynamic spatial processing originates in early visual pathways |
| 10:45-11:00am |
Coffee break |
| 11:00-11:45am |
Steven Zucker |
| 11:45-1:30pm |
Lunch break |
| 1:30-2:15pm |
Amiram Grinvald and David B. Omer: The dynamics of evoked and ongoing activity in the behaving monkey |
| 2:15-2:30pm |
Coffee break |
| 2:30-3:15pm |
Mriganka Sur: Plasticity and Dynamics of V1 Networks |
| 3:15-3:30pm |
Coffee break |
| 3:30-4:30pm |
Panel discussion: Lead by Ray Guillery and Jennifer Lund |
Wednesday, April 25
Early Visual Processing |
| 9:00-10:00am |
David Ferster and Kenneth Miller: Contrast-invariant orientation tuning, surround suppression, and
inhibition-stabilized networks |
| 10:00-10:15am |
Coffee break |
| 10:15-11:00am |
To be determined |
| 11:00-11:15am |
Coffee break |
| 11:15-12:00pm |
Charles Gray: Neuronal Processing of Natural Scenes in Visual Cortex |
| 12:00-1:30pm |
Lunch break |
| 1:30-2:15pm |
Thomas Albright |
| 2:15-2:30pm |
Coffee break |
| 2:30-3:15pm |
Ning Qian: Physiologically Based Models for Conventional and da Vinci Stereopsis |
| 3:15-3:30pm |
Coffee break |
Thursday, April 26
Higher Visual Processing, Feedback and Top-down Processing |
| 9:00-9:45am |
Risto Miikkulainen: The computational role of lateral and feedback connections in the
primary visual cortex |
| 9:45-10:00am |
Coffee break |
| 10:00-11:00am |
Rudiger von der Heydt: Neurophysiological Experiments on Figure-Ground Organization and Selective Visual Attention; and
Zhaoping Li: Surface border ownership in V2 by Intra-cortical mechanisms --- a model |
| 11:00-11:15am |
Coffee break |
| 11:15-12:00pm |
Andreas Burkhalter: Inhibitory control of excitation in feedforward and feedback circuits between lower and higher areas of mouse visual cortex |
| 12:00-1:30pm |
Lunch break |
| 1:30-2:30pm |
Alessandra Angelucci and Paul Bressloff: The contribution of top-own feedback to the far surround of V1 neurons |
| 2:30-2:45pm |
Coffee break |
| 2:45-3:30pm |
Tai Sing Lee: Natural scene statistics and visual inference |
| 3:30-3:45pm |
Coffee break |
| 3:45-4:30pm |
Panel discussion: Lead by Jonathan Levitt and Jack Gallant |
| 6:00-8:00pm |
Dinner at the Holiday Inn on the Lane |
Friday, April 27
Top-Down Processing |
| 9:00-9:45am |
Dana Ballard: Discrete predictive feedback can account for
biphasic responses of LGN cells |
| 9:45-10:00am |
Coffee break |
| 10:00-10:45am |
Jack Gallant: Feature-based attention dynamically changes shape representation in area V4 |
