Covert visual spatial orienting and saccades: Overlapping neural systems

We used functional magnetic resonance imaging (fMRI) to investigate the fun ctional anatomical relationship between covert orienting of visual spatial attention and execution of saccadic eye movements. Brain areas engaged by s hifting spatial attention covertly and by moving the eyes repetitively towa rd visual targets were compared and contrasted directly within the same sub jects. The two tasks activated highly overlapping neural systems and showed that common parietal and frontal regions are more activated during the cov ert task than the overt oculomotor condition. The possible nature of the re lationship between these two operations is discussed. (C) 2000 Academic Pre ss.