Rumination occurs when an individual becomes mentally stuck and cannot redirect attention away from an unwanted thought demonstrating cognitive inflexibility. Cognitive flexibility is important for various cognitive functions, including episodic memory. Trait rumination is a partial mediator in the relationship between depression and overgeneral episodic memory, suggesting that rumination may negatively influence memory for contextual details. Oscillations in the alpha (8-12 Hz) and beta (13-30 Hz) frequency bands are crucial for various cognitive functions (e.g., attention control and episodic memory) and may help to explain the relationship between trait rumination and memory for contextual details. Our study uses EEG recorded during a source memory task to assess how alpha and beta oscillations during memory for contextual details may change as a function of trait rumination, anxiety, and depression level (n = 43). The source memory task instructs participants to remember objects and their associated contextual details. Memory for contextual details is lessened for participants higher in trait rumination paired with higher trait anxiety. Oscillations were analyzed in posterior parietal/occipital regions. During encoding, an interaction of nonclinical depression level and rumination predicts higher alpha power for items that were later not successfully remembered. During test, depression and rumination interact and predict higher alpha power for both successful and unsuccessful memory. These results suggest that trait anxiety, depression, and rumination impact accuracy and alpha oscillatory dynamics during contextual memory via changes in attention control.
Keywords: Anxiety; Brain oscillations; Cognitive flexibility; Episodic memory; Rumination.