Brain activation during episodic memory retrieval: Sex differences

Behavioral studies have shown a tendency for women to outperform men on epi sodic memory tasks. Here, data from a series of positron emission tomograph y (PET) studies were analyzed to examine sex differences in brain activity associated with episodic memory retrieval (yes/no recognition). A total of 17 women and 17 men were included in the analyses. The strongest effect of the design was a retrieval-related increase in activity, involving right pr efrontal and anterior cingulate regions, that was common to women and men. In addition, a significant task-by-sex interaction effect was observed whic h involved a distributed set of brain regions, including several frontal ar eas. These results suggest that while the neural correlate of episodic memo ry retrieval is largely the same for men and women, some differences do exi st. Possible explanations for the observed differences are discussed, and i t is concluded that biological and experiential factors jointly contribute to sex differences in brain activity. (C) 2000 Elsevier Science B.V. All ri ghts reserved.