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Abstract:
Abstract: Electrophysiological, neuropsychological and
functional imaging research has provided evidence for a monitoring
role of the prefrontal cortex in learning, memory, and emotion
regulation. Cognitive studies have shown that negative emotional
valence enhances not only veridical but also false recognition,
i.e. it increases the tendency to respond "old" irrespective of
old/new discrimination accuracy. The present study investigated the
nature and origin of emotion-induced response bias effects using
ERPs. There was a significantly greater positivity (250-650 ms) to
old items when they were accurately discriminated from new ones.
However, when the ERPs to these correctly classified old items are
compared to those for new items that are incorrectly classified as
"old", there were significant effects of valence posteriorly, and
valence x old/new interaction effects at prefrontal/frontal sites
from 300-500 ms. This is consistent with the view that participants
tended to mistakenly attribute the salience of negative valence to
familiarity (oldness) during the old/new discrimination, leading
them to respond "old" more often to negative than to neutral items.
Additional analyses revealed that ERPs at (pre)frontal sites are
very sensitive to variations of the response bias in general,
irrespective of valence-induced effects. Participants with a lax
response bias as compared to those with a strict response bias show
a marked sustained prefrontal positivity starting around 300 ms and
lasting for 1200 ms.
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