Anatomy of verbal memory: a functional MRI study

Abstract.

The recent advent of new functional neuroimaging techniques such as functional magnetic resonance imaging (fMRI) makes it possible to examine cerebral activations in healthy individuals. In the present study, we attempted to examine the anatomical distribution of neocortical and mediotemporal activations in control subjects during episodic memory tasks over 24 h. BOLD (blood oxygenation-level-dependent) fMRI data were collected from 10 control subjects. Twenty-two contiguous images covering the whole brain were acquired using an EPI echoplanar sequence. Subjects were instructed to learn a list of 17 words, and to recall it immediately and after a 24-h interval. Individual and group analyses were performed using SPM96. The results demonstrated that a similar left occipito-temporo-frontal network was activated during both immediate and 24-h-delayed retrieval conditions. In addition, the 24-h-delayed retrieval also activated a larger parietal region and the right hippocampus. These findings suggest that fMRI is a reliable method with which to perform anatomical studies.