Benucci A, Frazor R A, Carandini M, 2007, "Dynamics of population activity in cat primary visual cortex" Perception 36 ECVP Abstract Supplement
Dynamics of population activity in cat primary visual cortex
A Benucci, R A Frazor, M Carandini
An oriented stimulus causes activity in a population of neurons in primary visual cortex (V1). A sudden shift in orientation changes this population activity. Understanding the dynamics of this change can shed light on the underlying computations. We measured population activity with voltage-sensitive dye imaging in area V1 of anesthetized, paralyzed cats (Grinvald and Hildesheim, 2004 Nature Reviews Neuroscience 5 874 - 885). Stimuli were sequences of flashed gratings of random orientation (Ringach et al, 1997 Nature 387 281 - 284). Population activity could be explained (correlation r=0.997±0.002) by a simple linear model, ie by convolving the stimulus with an elemental response, the average response to a single orientation. The linear model, however, underestimated (by tens of milliseconds) the duration of the response when a stimulus was followed by a blank screen. We conclude that the dynamics of population responses to changes in orientation reflect a simple linear computation. However, the brief maintenance of cortical activity can only be explained by a nonlinear mechanism. This maintenance may underlie perceptual phenomena of visual persistence.
[Supported by the National Eye Institute and by the McKnight Endowment Fund for Neuroscience.]
These web-based abstracts are provided for ease of seaching and access, but certain aspects (such as as mathematics) may not appear in their optimum form. For the final published version of this abstract, please see
ECVP 2007 Abstract Supplement (complete) size: 2091 Kb