Remembering the Details: Effects of Emotion

Abstract

Though emotion conveys memory benefits, it does not enhance memory equally for all aspects of an experience nor for all types of emotional events. In this review, I outline the behavioral evidence for arousal's focal enhancements of memory and describe the neural processes that may support those focal enhancements. I also present behavioral evidence to suggest that these focal enhancements occur more often for negative experiences than for positive ones. This effect of valence appears to arise because of valence-dependent effects on the neural processes recruited during episodic encoding and retrieval, with negative affect associated with increased engagement of sensory processes and positive affect leading to enhanced recruitment of conceptual processes.

Figure 1. Anatomy of an emotional memory

The memory boost for emotional information seems to occur because affective processing regions (e.g., the amygdala and the orbitofrontal cortex) modulate the processing of regions that facilitate encoding of sensory detail (fusiform gyrus) and memory consolidation (hippocampal formation).

Figure 2. The subsequent-memory paradigm

The neural activity during encoding is sorted based upon whether the items are later recognized (correctly called “old”) or later forgotten (incorrectly called “new”). Regions whose activity is enhanced during the encoding of items later recognized (solid lines) compared to later forgotten (dotted lines) are those regions implicated in the successful encoding of information.

Figure 3. Sensory-mnemonic correlations

During the encoding of negative items that would later be remembered with specific visual detail, participants showed a robust correlation between the amount of activity in the right amygdala (x-axis) and the amount of activity in the right fusiform gyrus (y-axis). Each diamond represents one participant. Data from those published in Kensinger, Garoff-Eaton, & Schacter, 2007.

Figure 4. Event Valence Affects Memory Consistency

Yankees fans, displeased with the outcome of the game, remembered event details more consistently than Red Sox fans. Consistency refers to the overlap in detail provided at two different points in time: within one week of the game and 23-27 weeks later. Data from Kensinger & Schacter (2006).

Figure 5. Valence affects the neural encoding processes that correspond with later “remembering” (upper panel) versus later “knowing” (bottom panel)

Red regions are those that show the correspondence for negative items but not positive ones, green regions are those that show the correspondence for positive items but not negative ones, and blue regions are those that show the correspondence for both negative and positive items. Data from Mickley & Kensinger (2008).

Figure 6. Amygdala activity corresponds with successful encoding for positive and negative items, but not for neutral items

For positive and negative items, amygdala activity is higher during the encoding of items later recognized (recog) than during the encoding of items later forgotten (forgot). Data from Kensinger & Schacter (2008).

Figure 7. Valence influences the neural processes that are related to subsequent memory

The fusiform gyrus was disproportionately associated with the encoding of negative information (upper panel), while activity in fronto-temporal regions was associated with the encoding of positive information (lower panel). Data are from the young adults reported in Kensinger & Schacter, 2008.