Journal of the International Neuropsychological Society



Components of verbal learning and hippocampal damage assessed by T2 relaxometry


AMANDA G.  WOOD a1a3, MICHAEL M.  SALING a1a3c1, MARIE F.  O'SHEA a1a3, SAMUEL F.  BERKOVIC a2a4 and GRAEME D.  JACKSON a2a4
a1 Department of Psychology, University of Melbourne
a2 Department of Medicine, University of Melbourne
a3 Department of Neuropsychology, Austin and Repatriation Medical Centre, Victoria, Australia
a4 Department of Neurology, Austin and Repatriation Medical Centre, Victoria, Australia

Abstract

We studied a group of 31 temporal lobe epilepsy patients (25 left, 6 right) with unilateral hippocampal sclerosis evident on magnetic resonance imaging. Single slice T2 relaxation times were acquired for the left and right hippocampi. Principal components analysis of preoperative memory data resulted in two factors that reflect a distinction between arbitrary and semantic forms of verbal recall. The former component correlated with left hippocampal T2 relaxation time, while the latter component did not. This study suggests that variation in left hippocampal integrity is more related to the acquisition of arbitrary associates than semantically structured material, and reinforces the possibility that the left temporal lobe is functionally heterogeneous with respect to memory. (JINS, 2000, 6, 529–538.)

(Received July 6 1998)
(Revised July 12 1999)
(Accepted July 12 1999)


Key Words: Memory; Verbal learning; Epilepsy; Temporal lobe; Imaging; Magnetic resonance.

Correspondence:
c1 Reprint requests to: Michael M. Saling, Department of Psychology, University of Melbourne, Parkville, 3010, VIC, Australia. E-mail: m.saling@psych.unimelb.edu.au