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Abstract:
Neuropsychology and neuroimaging have revealed evidence of
cortical modules dedicated to processing high-level visual
categories such as faces and places. Do all visual categories have
their own dedicated, localizable neural modules, or is cortical
specialization reserved for categories that are evolutionarily
and/or experientially privileged? Specializations for faces and
places do not answer this question as the ability to recognize
instances of these categories has been important in both individual
and species experience. In an fMRI experiment we presented eight
subjects with pictures from eight categories falling into four
classes: a) categories with likely evolutionarily significance that
are still relevant in modern life (faces, places, and food); b)
categories with possible evolutionary significance but of little
importance in the lives of our undergraduate subjects (animals and
flowers); c) objects that have only appeared recently in
evolutionary terms, but are ubiquitous in daily life (chairs and
cars); d) items that are not generally significant in daily life,
and have no evolutionary significance (microbes). Previous work on
the face and place areas was replicated. Additionally, a lateral
occipitotemporal region responded more strongly to pictures of food
than to the other seven categories in 8/9 subjects. There was
little evidence to suggest unique neural responses to objects from
the other five categories tested. These results suggest that
neurally localized stimulus selective visual modules may be
restricted to evolutionarily and experientially critical
categories.
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