| |
Abstract:
Abstract: Compared to new words, event-related potentials
(ERPs) of correctly recognized old words typically show a
positivity over left parietal regions. Although the
left-lateralization of this effect has been attributed to the use
of verbal materials, a recent study found it also for pictures of
objects (Schloerscheidt et al., 1997). One possibility is that the
parietal effect is left-lateralized for verbalizable materials,
such as words and nameable objects, but not for nonverbalizable
materials. To investigate this possibility, we recorded ERPs during
the recognition of unfamiliar faces. Additionally, we investigated
whether the ERPs of face recognition would be modulated by face
expression. There is fMRI evidence that positive emotions are
processed in the left hemisphere (Canli et al., 1998). In the
experiment, subjects rated the expression of happy and neutral
unfamiliar faces, and ERPs were recorded while they recognized
studied faces mixed with new faces. Preliminary analyses yielded
two results. First, the parietal old/new ERP effect was bilateral.
This result suggests that the left-lateralization of this effect in
previous studies reflects the verbal nature of words and nameable
objects. Second, correctly recognized old faces were associated
with a positivity over frontal regions, which was larger on the
left hemisphere for happy faces and on the right hemisphere for
neutral faces. In sum, the results suggest that the parietal effect
for nonverbalizable materials is bilateral and that the ERPs of
face recognition can be modulated by face expression.
|
