L.C. Osborne, S.G. Lisberger, and W. Bialek

Time course of information about motion direction in visual area MT in primates

University of California, San Francisco

Sensory signals in visual cortical area MT guide the direction and speed of smooth pursuit eye movements on a 100ms timescale. To ask how target direction could be decoded on this time scale, we have calculated the time course of Shannon information about motion direction in individual MT neurons. We recorded from single units in area MT of anesthetized macaques. Stimuli were random dot patterns, stepped from stationary to the preferred speed of the cell for 256ms, in a direction randomly chosen with 15 degree increments. All methods of analysis indicated that the majority of information about motion direction was encoded during an early transient of firing at the onset of the response. If the calculation was based on cumulative spike count, then information rose rapidly in the first 50ms and then saturated (or even peaked) so that continued counting of spikes contributed little additional information. If the calculation was based on spike count in a sliding 50ms window, then information often showed an early peak and was much lower during the response to sustained motion. The early peak could not be attributed to differences in directional tuning bandwidth as a function of time during the response. The enhanced spike rate at motion onset contributes to the effect, but the information carried by each spike is also higher in the initial transient response, because of the temporal structure of correlations in the response variability. Thus almost all of the available directional information could be extracted from the first few spikes of the neuron's response, on a time scale comparable to the initiation of smooth pursuit eye movements.
Monday, June 5, 2023
About the Swartz Foundation...
The Swartz Foundation was established by Jerry Swartz (bio) in 1994 . . .
Follow us...
The Swartz Foundation is on Twitter: SwartzCompNeuro
2013 Stony Brook Mind/Brain Lecture - Michael Wigler, PhD
2012 Stony Brook Mind/Brain Lecture - John Donoghue
Sloan-Swartz Centers Annual Meeting 2011
2011 Stony Brook Mind/Brain Lecture - Allison J. Doupe
2011 Banbury Workshop
Sloan-Swartz Centers Annual Meeting 2010
2010 Stony Brook Mind/Brain Lecture
Sloan-Swartz Centers Annual Meeting 2009
Conference on Neural Dynamics
2009 Stony Brook Mind/Brain Lecture
Canonical Neural Computation, April 2009
2009 Banbury Workshop
Sloan-Swartz Centers Annual Meeting 2008
Theoretical and Experimental Approaches to Auditory and Visual Attention - Banbury 2008
Stony Brook Mind/Brain 2008: Patricia Smith Churchland, B. Phil. D
Sloan-Swartz Centers Annual Meeting 2007
New Frontiers In Studies Of Nonconscious Processing - Banbury 2007
Stony Brook Mind/Brain 2007: Professor Michael Shadlen, MD, PhD
Multi-level Brain Modeling Workshop 2006
Sloan Swartz Centers Annual Meeting 2006
Banbury 2006: Computational Approaches to Cortical Functions
Stony Brook Mind/Brain 2006: Helen Fisher -- Lecture Videos
Sloan-Swartz Centers for Theoretical Neurobiology
Swartz Center for Computational Neuroscience
Banbury Center Workshop Series
Other Events
www.theswartzfoundation.org                           Copyright © The Swartz Foundation 2023