Theta oscillations predict the detrimental effects of memory retrieval

Abstract

Retrieving a target item from episodic memory typically enhances later memory for the retrieved item but causes forgetting of competing irrelevant memories. This finding is termed retrieval-induced forgetting, and is assumed to be the consequence of an inhibitory mechanism resolving retrieval competition. The present study examines brain oscillatory processes related to retrieval-induced forgetting, as induced by competitive memory retrieval. Contrasting a competitive with a non-competitive retrieval condition, we found a stronger increase in early evoked theta (4-7 Hz) activity, which specifically predicted retrieval-induced forgetting, but not retrieval-induced enhancement. Within the cognitive framework of retrieval-induced forgetting, these findings suggest that theta oscillations reflect arising interference and its resolution during competitive retrieval in episodic memory.