Spatial attention affects sensorimotor reorganisation in human motor cortex.

It is well known that the somatotopic representation of sensory and motor cortices reorganises in response to sustained changes in sensory input. It is also clear that the extent of the effect depends on whether or not subjects pay attention during the procedure. Here we show that the pattern of reorganisation produced by sustained sensory input depends not only on the subjects' attention but also on the spatial focus of their attention on the body surface. Maximal effects are observed only when subjects pay attention to the site of the input; if they attend to an adjacent body part then the effects are reduced. These results may be relevant to rehabilitation procedures commonly used in patients after stroke.