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Deficits in the initiation and utilization of strategies contribute importantly to memory impairments in depression. Other research on depression has documented memory biases toward negative and away from positive material. This study investigated brain mechanisms accompanying the initiative deficit and negative bias processes affecting memory in depressed individuals. Electroencephalography was recorded prior to and during emotional narratives and correlated with subsequent memory recognition of narrative material. Hypothesized to reflect strategy initiation, bilateral activity of the prefrontal cortex (PFC) preceding a sad narrative was associated with memory performance for that narrative in nondepressed controls only. Negative memory bias in depressed participants was inferred from their association between right prefrontal activity during the sad narrative and memory performance, consistent with research implicating that region in withdrawal-related unpleasant emotions. These results highlight the importance of distinguishing processes that influence memory performance when investigating the neural mechanisms of cognitive deficit and bias in depression.

The present study examined EEG gamma (35-70 Hz) spectral power distributions during worry inductions in participants suffering from generalized anxiety disorder (GAD) and in control participants without a history of psychiatric illness. As hypothesized, the EEG gamma band was useful for differentiating worry from baseline and relaxation. During worry induction, GAD patients showed higher levels of gamma activity than control participants in posterior electrode sites that have been previously associated with negative emotion. Gamma fluctuations in these electrode sites were correlated with subjective emotional experience ratings lending additional support to interpretations of negative affect. Following 14 weeks of psychotherapy, the GAD group reported less negative affect with worry inductions and the corresponding gamma sites that previously differentiated the clinical from control groups changed for the GAD patients in the direction of control participants. These findings suggest converging evidence that patients suffering from GAD experience more negative emotion during worry and that the EEG gamma band is useful for monitoring fluctuations in pathological worry expected to follow successful treatment.