2020-02-19T18:08:56+08:002018-09-06|News and events, Seminars and Workshops, Uncategorized|
Talk title Circuit transformation of neural information in primary visual cortex
Speaker Professor Cheng-Hang LIU
Research Scientist
University of Florida
Date & Time 05 September 2018 (Wednesday) 11:00 – 12:00
Venue Room G004, E12 Building (University of Macau)
Abstract In the primary visual cortex (V1), retinal input representing the external environment we encounter is actively transformed in the six-layered cortical circuit in an experience- and context-dependent manner. As a critical step toward our perceptual reasoning of the visual surroundings, I study how intra- and sub-cortical pathways engage in the re-calibration of V1 output as a function of input variability. I will irst discuss how experimentally elicited disparity in binocular input leads to a rapid and concurrent changes in electrophysiological properties of V1 neurons in two different cortical layers. The recruitment of distinct synaptic mechanisms in achieving ocular dominance shifts in these layers depicts potential extra-dimensionality in the decoding scheme of V1 mediated by parallel input. I will then focus on recent progress in understanding neural incorporation of contextually salient temporal information in V1. We found that behavioral pairing between visual cues and delayed reward provided at ix intervals entrains V1 activity predicative of the outcome causally instructed by the visual cue. Furthermore, this form of temporal difference (Td) learning can be recapitulated by optogenetic conditioning of local V1 circuit with “virtual” reward experience. V1 is therefore a sufficient substrate for reinforcement learning that
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