Emotion enhances remembrance of neutral events past

Abstract

Emotional events are bestowed with special prominence in memory. This may reflect greater attention oriented to these events during encoding, and/or enhancement of memory consolidation after emotional events have passed. Here we show invoked emotional arousal results in a retrograde enhancement of long-term memory, determining what will later be remembered or forgotten. Subjects saw pictures of neutral faces and houses followed by emotionally arousing scenes at varying intervals. Self-reported emotional arousal responses predicted a retrograde enhancement of memory for preceding neutral events in a 1-week delayed recognition memory test. At longer picture-scene intervals, no enhancement was found, implicating a critical window in which emotional arousal must occur for retrograde memory enhancement. Postencoding manipulation of emotional arousal specifically enhanced conscious recollection rather than familiarity-based discrimination. An additional study revealed no retrograde enhancement for pictures preceding highly memorable, but nonarousing, distinctive scenes. These findings indicate an important role for emotional arousal in the postencoding enhancement of episodic memory consolidation.

Fig. 1.

Relation between modulator arousal and recognition memory for modulator and test events. (a and b) Overall recognition memory for modulator events (a) and preceding test events (b) sorted by trial specific arousal ratings (Q1 = low arousal quartile, Q4 = high arousal quartile). Test events are separated by test-modulator interstimulus interval (short = 4 s; long = 9 s). (c) Effect of modulator arousal on quality of test memory (remember vs. familiar responses proportional to overall recognition) at short test-modulator intervals. Dotted lines represent linear best fit.

Fig. 2.

Relation between modulator distinctiveness and recognition memory for modulator and test events. Overall recognition memory for modulator events (a) and preceding test events (b) sorted by trial specific distinctiveness ratings (Q1 = low distinctive quartile, Q4 = high distinctive quartile) (short = 4 s; long = 9 s, interstimulus interval). Dotted lines represent linear best fit.