Color signals in human motion-selective cortex

Brian A. Wandell, Allen B. Poirson, William T. Newsome, Heidi A. Baseler, Geoffrey M. Boynton, Alex Huk, Sunil Gandhi, Lindsay T. Sharpe

Research output: Contribution to journalArticlepeer-review


The neural basis for the effects of color and contrast on perceived speed was examined using functional magnetic resonance imaging (fMRI). Responses to S cone (blue-yellow) and L + M cone (luminance) patterns were measured in area V1 and in the motion area MT+. The MT+ responses were quantitatively similar to perceptual speed judgments of color patterns but not to color detection measures. We also measured cortical motion responses in individuals lacking L and M cone function (S cone monochromats). The S cone monochromats have clear motion-responsive regions in the conventional MT+ position, and their contrast-response functions there have twice the responsivity of S cone contrast-response functions in normal controls. But, their responsivity is far lower than the normals' responsivity to luminance contrast. Thus, the powerful magnocellular input to MT+ is either weak or silent during photopic vision in S cone monochromats.
Original languageEnglish
Pages (from-to)901-909
Number of pages9
Issue number4
Publication statusPublished - Dec 1999


  • Adaptation, Ocular
  • Adolescent
  • Adult
  • Color
  • Color Perception
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Motion Perception
  • Neuronal Plasticity
  • Photic Stimulation
  • Retinal Cone Photoreceptor Cells
  • Visual Cortex

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