Seminars

GRASP Special Seminar - Avi Ziskind, Columbia University, "Neurons In Cat V1 Cluster By Degree Of Tuning But Not By Absolute Spatial Phase Or Temporal Response Phase"

Presenter: Avi Ziskind

Event Dates:
  Friday December 14, 2012 from 11:00am to 12:00pm

* Alternate Location: Levine 512 (3330 Walnut Street)*

Nearby neurons in cat primary visual cortex (V1) have similar preferred orientation, direction, and spatial frequency. How diverse is their degree of tuning for these properties? Are they also clustered in their tuning for the spatial phase of a flashed grating or the temporal phase of a drifting grating? To address these questions, we used tetrode recordings to simultaneously isolate multiple cells at single recording sites and record their responses to gratings of multiple orientations, spatial frequencies, and spatial/temporal phases. We found that orientation tuning width, spatial frequency tuning width and direction selectivity index all showed significant clustering. Tuning for the spatial phase of a flashed grating stimulus (“absolute spatial phase”) and temporal phase of a drifting grating stimulus (“temporal phase”) however, showed no clustering.


Presenter's Biography:

Avi Ziskind graduated from Princeton in 2007 with a major in Physics and minors in Computer Science and Biophysics. For his senior thesis he studied information coding in retinal ganglion cells. He is now completing his PhD at the Center for Theoretical Neuroscience at Columbia University, where he has been studying the network dynamics of randomly-connected neurons and the tuning properties of neurons in primary visual cortex. His research interests include studying and modeling networks of neurons, with a view to applying insights from neuroscience to develop bio-inspired algorithms for computer vision, language processing and artificial intelligence.