August 2009
Volume 9, Issue 8
Free
Vision Sciences Society Annual Meeting Abstract  |   August 2009
Decoding and reconstructing color from responses in human visual cortex
Author Affiliations
  • Gijs Joost Brouwer
    New York University, Department of Psychology and Center for Neural Science
  • David Heeger
    New York University, Department of Psychology and Center for Neural Science
Journal of Vision August 2009, Vol.9, 365. doi:10.1167/9.8.365
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Gijs Joost Brouwer, David Heeger; Decoding and reconstructing color from responses in human visual cortex. Journal of Vision 2009;9(8):365. doi: 10.1167/9.8.365.

      Download citation file:


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

      ×
  • Supplements
Abstract

Introduction

How is color represented by the distributed spatial patterns of activity in visual cortex? We determined the accuracy with which stimulus color could be decoded and reconstructed from fMRI measurements of activity in visual cortex.

Methods

We used eight isoluminant colors, equally spaced in the CIE L*a*b color space, surrounding and equidistant from a central gray point. Each stimulus was a concentric grating modulating from central gray to one of the eight colors, presented in pseudo-randomized order (1.5 s duration, 3–6 s ISI). fMRI responses were analyzed with multivariate techniques: pattern classification and principal component analysis (PCA).

Results

Stimulus color was accurately decoded from spatially distributed patterns of responses within areas V1, V2, V3, V4 and VO, but not LO1, LO2, V3A/B or MT. In a complementary analysis, we used PCA to reconstruct a color space from activity in each visual area. PCA extracted the covariation between voxels' responses to the different colors. In V4, the first two principal components (the main source of variation) of the responses constituted a vector space that resembled perceptual color space, with similar colors evoking the most similar responses. By contrast, although decoding was more accurate in V1 than V4, the PCA of V1 activity did not reveal a similar progression. The mean responses, averaged across voxels in each visual area, were the same for all colors. Although voxels in each visual area exhibited different color preferences, no consistent spatial organization or topography was found.

Conclusion

Each stimulus color was associated with a unique spatially distributed pattern of activity within early visual areas. We assume that this reflects the color-selectivity of the neurons in those areas. If so, activity in V4 (but not V1) appears to depend primarily on the responses of color-selective neurons with color tuning that reflects perceptual color space.

Brouwer, G. J. Heeger, D. (2009). Decoding and reconstructing color from responses in human visual cortex [Abstract]. Journal of Vision, 9(8):365, 365a, http://journalofvision.org/9/8/365/, doi:10.1167/9.8.365. [CrossRef]
Footnotes
 Supported by: NIH R01-EY16752 (DJH) and NWO Rubicon Fellowship (GJB).
×
×

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.

×