Early Category-Specific Cortical Activation Revealed by Visual Stimulus Inversion
Meeren, Hanneke K. M.
Hämäläinen, Matti S.
MetadataShow full item record
CitationMeeren, Hanneke K. M., Nouchine Hadjikhani, Seppo P. Ahlfors, Matti S. Hämäläinen, and Beatrice de Gelder. 2008. Early category-specific cortical activation revealed by visual stimulus inversion. PLoS ONE 3(10): e3503.
AbstractVisual categorization may already start within the first 100-ms after stimulus onset, in contrast with the long-held view that during this early stage all complex stimuli are processed equally and that category-specific cortical activation occurs only at later stages. The neural basis of this proposed early stage of high-level analysis is however poorly understood. To address this question we used magnetoencephalography and anatomically-constrained distributed source modeling to monitor brain activity with millisecond-resolution while subjects performed an orientation task on the upright and upside-down presented images of three different stimulus categories: faces, houses and bodies. Significant inversion effects were found for all three stimulus categories between 70–100-ms after picture onset with a highly category-specific cortical distribution. Differential responses between upright and inverted faces were found in well-established face-selective areas of the inferior occipital cortex and right fusiform gyrus. In addition, early category-specific inversion effects were found well beyond visual areas. Our results provide the first direct evidence that category-specific processing in high-level category-sensitive cortical areas already takes place within the first 100-ms of visual processing, significantly earlier than previously thought, and suggests the existence of fast category-specific neocortical routes in the human brain.
Citable link to this pagehttp://nrs.harvard.edu/urn-3:HUL.InstRepos:10196736
- HMS Scholarly Articles