. The integration of sensory information from different parts of the visual field is a vital process underlying visual pattern recognition. The neuronal mechanisms mediating these integrative processes, however, are poorly understood. Evidence from theoretical, psychophysical and physiological studies suggest that specific, temporally coordinated interactions between spatially separate neuronal populations, within and between different areas of the visual cortex, mediate the integrative processes underlying visual perception. Extensive preliminary evidence, obtained from electrophysiological experiments in the cat, suggests that the stimulus-specific synchronization of oscillary neuronal responses within and between the cortical areas may provide a plausible mechanism for visual feature integration. The long-term objective of the proposed research is to perform a rigorous test of this hypothesis. Specifically, four sets of neurophysiological experiments are proposed to achieve this goal: 1) Record from pairs of closely spaced neurons within a cortical column in area 17 in the cat to determine the mechanisms underlying the generation and coordination of oscillatory neuronal responses. 2) Record oscillatory responses from spatially separate groups of neurons within area 17 of the cat, using multi-electrode techniques, to determine the conditions of visual stimulation which enable their temporal synchronization. 3) Record oscillatory responses from spatially separate groups of neurons in area 17 and a second area, 18 or PMLS, in the cat, to determine the conditions of visual stimulation which enable their temporal synchronization. 4) Record neuronal responses from areas V1 and V2 of the Macaque monkey, using single-unit as well as multi-electrode recording techniques, to determine if neurons within these areas exhibit stimulus-specific oscillatory responses, and if so, to determine what the cell type are, what their laminar positions within the cortex are, and the stimulus conditions under which they become synchronized. The results of these studies will enable future experiments to determine whether the interactions between oscillatory responses are utilized by a behaving animal to make perceptual discriminations.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29EY008686-06
Application #
2162421
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1993-07-01
Project End
1996-04-30
Budget Start
1995-05-01
Budget End
1996-04-30
Support Year
6
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of California Davis
Department
Neurosurgery
Type
Schools of Medicine
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618
Jagadeesh, B; Gray, C M; Ferster, D (1992) Visually evoked oscillations of membrane potential in cells of cat visual cortex. Science 257:552-4