Complementary localization and lateralization of orienting and motor attention

It is widely agreed that the right posterior parietal cortex has a preemine nt role in visuospatial and orienting attention. A number of lines of evide nce suggest that although orienting and the preparation of oculomotor respo nses are dissociable from each other, the two are intimately related. If th is is true, then it should be possible to identify other attentional mechan isms tied to other response modalities. We used repetitive transcranial mag netic stimulation (rTMS) to demonstrate the existence of a distinct anterio r parietal mechanism of motor attention. The critical area for motor attent ion is anterior to the one concerned with orienting, and it is lateralized to the left hemisphere in humans.