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Abstract:
Compared to correct rejections, event-related potentials
(ERPs) for correctly recognized old words are associated with two
positive-going ERP effects, over parietal regions and one over
frontal regions. ERP studies using words have shown that the
frontal effect is sensitive to the retrieval of contextual
information. We investigated the generalizability of this finding
to face recognition, using facial expression as contextual
information. Subjects studied unfamiliar faces with happy or
neutral expressions, and then performed a recognition test, which
included studied faces with the same expression as in the study
phase, studied faces with a different expression than in the study
phase, and new faces. In each test trial, subjects made a 3-choice
response between same expression, different expression, or new
face. ERPs associated with face recognition showed both the
parietal and the frontal effect, the frontal effect being sensitive
to the retrieval of contextual information. Faces that were
correctly assigned to the correct study context evoked larger
frontal positivities than those that were not. Results are
consistent with the view that the parietal effect is an index of
the successful retrieval of information about the prior occurrence
of a stimulus, while the frontal effect is an index of the
integration of this information with additional information about
the context in which the stimulus occurred, a process that is
dependent upon the prefrontal cortex.
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