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
Language
- eng
Conference Location
- United States