Neural long-term effects of emotion regulation on episodic memory processes.

Emotions can enhance memory which is on the one hand advantageous, but on the other hand may be detrimental in the long term, for example in the case of traumatic events. Although cognitive emotion regulation may reduce emotion experience and corresponding neural activation, at present little is known about its influence on long-term memory. We investigated memory for emotional pictures in healthy female subjects 1 year after voluntary emotion regulation using fMRI. Whereas memory performance was not affected by regulation, our data revealed a dissociation of brain regions involved in memory encoding and recognition depending on whether emotional engagement during encoding had been downregulated. Emotional engagement during encoding resulted in a long-term subsequent memory effect in mesolimbic brain regions and hippocampus, and in recognition-related activation in the amygdala. In contrast, when negative emotions had been downregulated during encoding memory performance was predicted by prefrontal activation. Our data suggest that memory for emotionally encoded stimuli is supported by emotional re-activation, whereas memory for successfully encoded items during emotion regulation is rather supported by recognition of features and cognitive contents. These results contribute to research on long-term effects of emotion regulation in everyday life and open new avenues to understand and possibly influence traumatic memory traces. Copyright (c) 2009 Elsevier Ltd. All rights reserved.