June 2007
Volume 7, Issue 9
Free
Vision Sciences Society Annual Meeting Abstract  |   June 2007
Dynamic modulation of direction selectivity by task demands in prefrontal cortex
Author Affiliations
  • Cory Hussar
    Dept. of Neurobiology & Anatomy and Center for Visual Science
  • Tatiana Pasternak
    Dept. of Neurobiology & Anatomy and Center for Visual Science
Journal of Vision June 2007, Vol.7, 345. doi:10.1167/7.9.345
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Cory Hussar, Tatiana Pasternak; Dynamic modulation of direction selectivity by task demands in prefrontal cortex. Journal of Vision 2007;7(9):345. doi: 10.1167/7.9.345.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Responses of neurons in the prefrontal cortex (PFC) have been shown to represent behaviorally relevant sensory information. Recent work revealed that PFC neurons exhibit direction selective (DS) responses to visual motion used in a delayed match-to-sample (DMTS) task in which the monkeys compared two directions of motion separated by a brief delay (Zaksas & Pasternak, J. Neurosci, 2006). We asked whether this directionality is preserved when the monkeys were asked to ignore stimulus direction. We compared responses of PFC neurons to identical visual motion stimuli presented during three different tasks. In separate blocks of trials the animals discriminated the direction or the speed of motion, or were rewarded for passively maintaining fixation. We found that DS responses were drastically attenuated under both conditions in which stimulus direction was irrelevant and that the nature of this attenuation was task dependent. When the monkey discriminated stimulus speed and ignored its direction, DS activity was strongly attenuated early in the response and emerged about 100ms later than during the direction discrimination task. This early reduction of DS activity resulted not from a decrease in the response to the preferred direction, but from an increase in the response to the anti-preferred direction, suggesting an active release from inhibition characteristic of direction selectivity in visual cortical neurons. In contrast, during the passive fixation task, reduction in DS activity resulted largely from the decrease in the response to the preferred direction, which unlike the more transient loss in DS during the speed task, persisted throughout the response. Our results demonstrate the existence of a dynamic gating mechanism by which PFC neurons can modulate direction selectivity characteristic of visual cortical neurons.

Hussar, C. Pasternak, T. (2007). Dynamic modulation of direction selectivity by task demands in prefrontal cortex [Abstract]. Journal of Vision, 7(9):345, 345a, http://journalofvision.org/7/9/345/, doi:10.1167/7.9.345. [CrossRef]
Footnotes
 Supported by EY11749, T32 EY07125, P30 EY01319
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×