Orientation Decoding Depends on Maps, Not Columns
- 1Center for Neural Science and
- 2Department of Psychology, New York University, New York, New York 10003
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Author contributions: J.F., G.J.B., D.J.H., and E.P.M. designed research; J.F., G.J.B., and E.P.M. performed research; J.F., G.J.B., and E.P.M. analyzed data; J.F., D.J.H., and E.P.M. wrote the paper.
Abstract
The representation of orientation in primary visual cortex (V1) has been examined at a fine spatial scale corresponding to the columnar architecture. We present functional magnetic resonance imaging (fMRI) measurements providing evidence for a topographic map of orientation preference in human V1 at a much coarser scale, in register with the angular-position component of the retinotopic map of V1. This coarse-scale orientation map provides a parsimonious explanation for why multivariate pattern analysis methods succeed in decoding stimulus orientation from fMRI measurements, challenging the widely held assumption that decoding results reflect sampling of spatial irregularities in the fine-scale columnar architecture. Decoding stimulus attributes and cognitive states from fMRI measurements has proven useful for a number of applications, but our results demonstrate that the interpretation cannot assume decoding reflects or exploits columnar organization.
- Received September 30, 2010.
- Revision received February 10, 2011.
- Accepted February 11, 2011.
- Copyright © 2011 the authors 0270-6474/11/314792-13$15.00/0
