Osaka,M. Yaoi,K., Minamoto,T.,& Osaka,N.
When do negative and positive emotions modulate working memory performance?
The present study investigated when emotion modulates working memory
from the perspective of neural activation. Using fMRI, we measured brain
activity during the encoding and retrieval phases of a reading span test
(RST) that used emotional contexts. The emotional RST required
participants to read sentences that elicited negative, neural or
positive emotional states while they were memorizing target words from
the sentences. Compared with the neutral RST, the negative RST activated
the right amygdala during the reading phase. Significant activation was
also found in the parahippocampal gyrus, albeit only after activation of
the amygdala became comparable to that in the neutral RST. In contrast,
the positive RST activated the substantia nigra during the reading phase
relative to the neutral RST. These findings suggest that negative and
positive emotions modulate working memory through distinctive neural
circuits. We also discuss possible relationships between emotional
modulation and working memory capacity.