Neurophysiologic evidence for increased retrieval suppression among negative ruminators.

Introduction: Events (e.g., seeing a familiar face) may initiate retrieval of associated information (e.g., person's name), but not all cue-initiated memory retrieval is welcome (e.g., trauma). Retrieval suppression refers to the ability to halt unwanted retrieval, and any erosion of memory associations in response to repeatedly excluding a memory from consciousness. The current study sought to examine event-related potential (ERP, averaged scalp electrical recordings) correlates of inhibitory cognitive control of memory retrieval and any linkage of such control to ruminative memory styles.

Methods: Participants (N = 23) first learned face-picture pairings. ERPs were then recorded as they viewed face cues while either bringing the associated picture to mind (think trial), or not allowing the associated picture to come to mind (no-think trial).

Results: Emotional valence of learned pictures (negative versus neutral) modulated a posterior (P1, 100-150 ms) ERP associated with attention to the face cue. Memory strategy (think versus no-think) modulated a frontal (P3, 350-450 ms) associated with alerting of the need to control retrieval. Both valence and strategy worked in combination to modulate a late posterior (LC, 450-550 ms) ERP associated with successful memory retrieval. Brooding, a negative form of rumination, was found to be positively correlated with the LC ERP.

Conclusion: The results suggest early separation of emotional and strategic control of retrieval, but later combined control over access to working memory. Moreover, the positive correlation of brooding and the LC suggest that individuals who are high in application of perseverative strategies to memory retrieval will show greater modulation of the retrieval-related LC ERP.