The selectivity of responses to red-green colour and achromatic contrast in the human visual cortex: an fMRI adaptation study.

ABSTRACT: There is controversy as to how responses to colour in the human brain are organized within the visual pathways. A key issue is whether there are modular pathways that respond selectively to colour or whether there are common neural substrates for both colour and achromatic (Ach) contrast. We used functional magnetic resonance imaging (fMRI) adaptation to investigate the responses of early and extrastriate visual areas to colour and Ach contrast. High-contrast red-green (RG) and Ach sinewave rings (0.5 cycles/degree, 2 Hz) were used as both adapting stimuli and test stimuli in a block design. We found robust adaptation to RG or Ach contrast in all visual areas. Cross-adaptation between RG and Ach contrast occurred in all areas indicating the presence of integrated, colour and Ach responses.

SUBMITTER: Mullen KT 

PROVIDER: S-EPMC4738417 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature