Directional anisotropies reveal a functional segregation of visual motion processing for perception and action.

Journal Article (Journal Article)

Human exhibits an anisotropy in direction perception: discrimination is superior when motion is around horizontal or vertical rather than diagonal axes. In contrast to the consistent directional anisotropy in perception, we found only small idiosyncratic anisotropies in smooth pursuit eye movements, a motor action requiring accurate discrimination of visual motion direction. Both pursuit and perceptual direction discrimination rely on signals from the middle temporal visual area (MT), yet analysis of multiple measures of MT neuronal responses in the macaque failed to provide evidence of a directional anisotropy. We conclude that MT represents different motion directions uniformly, and subsequent processing creates a directional anisotropy in pathways unique to perception. Our data support the hypothesis that, at least for visual motion, perception and action are guided by inputs from separate sensory streams. The directional anisotropy of perception appears to originate after the two streams have segregated and downstream from area MT.

Full Text

Duke Authors

Cited Authors

  • Churchland, AK; Gardner, JL; Chou, IH; Priebe, NJ; Lisberger, SG

Published Date

  • March 27, 2003

Published In

Volume / Issue

  • 37 / 6

Start / End Page

  • 1001 - 1011

PubMed ID

  • 12670428

International Standard Serial Number (ISSN)

  • 0896-6273

Digital Object Identifier (DOI)

  • 10.1016/s0896-6273(03)00145-4


  • eng

Conference Location

  • United States