OCULOMOTOR SEQUENCE LEARNING - A POSITRON-EMISSION-TOMOGRAPHY STUDY

The purpose of this study was to identify the brain regions activated in relation to oculomotor sequence learning. Nine healthy subjects par ticipated in the study, which consisted of three positron emission tom ography scans. In the initial learning task, subjects were instructed to track a sequence of seven successive positions of visual targets an d to memorize the order of the targets as well as their spatial locati ons. In the saccade task, subjects were instructed to track visual tar gets presented at random locations. In the control task, subjects were instructed to gaze at a fixation point. Fields showing significant re gional cerebral blood flow change were determined from task-minus-cont rol subtraction images. We determined that fields in the pre-supplemen tary motor area (pre-SMA), the intraparietal cortex, and the prefronta l cortex were activated not only in the learning-minus-control images but also in the learning-minus-saccade images. Although pre frontal an d parietal activations were bilateral, pre-SMA activation was confined to the left hemisphere. The results indicate that these fields functi on as a part of the neural network involved in the learning of sequent ial saccadic eye movements.