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Abstract:
Abstract: Expertise with organic-like novel objects
(Greebles) can recruit the fusiform "face area" in ventral temporal
cortex, as well as a more lateral and posterior face-selective area
in the occipital lobe. We considered whether these areas can be
recruited with expertise for other homogeneous categories. We
tested 8 bird experts and 11 car experts with extensive experience
recognizing bird species or car models. Brain activity was measured
with functional magnetic resonance imaging while subjects attended
either to the location or the identity of faces, familiar objects,
cars and birds. Face-selective areas were defined in a passive
viewing paradigm with faces and common objects. Homogeneous
categories activated the fusiform "face area" more than familiar
objects, bilaterally. In addition, the right fusiform and occipital
"face areas" showed significant expertise effects. Even the very
few (mean of 3) most face-selective voxels in the fusiform were
modulated by expertise. Finally, the results of an independent
behavioral test of expertise predicted the amount of relative
activation in the right "face area" for birds vs. cars, but only
while subjects attended to the location of the objects. The results
confirm a role for categorization level bilaterally in the "face
area" while expertise seems to contribute mainly to specialization
in the right hemisphere. Subordinate-level expertise with any
category may be mediated by a common neural substrate in
extrastriate cortex.
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