ROLE OF THE HIPPOCAMPUS IN SEX-DIFFERENCES IN VERBAL MEMORY - MEMORY OUTCOME FOLLOWING LEFT ANTERIOR TEMPORAL LOBECTOMY

The authors examined the neural and cognitive bases for sex difference s in verbal memory in 57 patients who underwent left anterior temporal lobectomy (ATL) for the treatment of intractable seizures. On the Cal ifornia Verbal Learning Test (D. C. Delis, J. H. Kramer, E. Kaplan, & B. A. Ober, 1987), women recalled more words than men both before and after surgery, regardless of the extent of hippocampal damage. Extent of hippocampal sclerosis was related to memory loss in both men and wo men. Women's superiority in verbal memory appears to result in part fr om their use of an efficient encoding strategy. Women were more likely than men to use semantic clustering both before and after ATL, and se x differences in word recall were attenuated after scores were adjuste d for semantic clustering. There was no effect of ATL on semantic clus tering. Taken together, these results suggest that sex differences in verbal memory are not due to differences in the integrity of the left hippocampus.