Space, although unitary when examined introspectively, is not represented in the brain as a single multipurpose map. On the contrary, in the brain there are numerous spatial maps (1–3). Of these, many are located in cortical areas that participate in the control of movement, such as eye movements, head movements, arm movements, and so on.

The map located in the ventral premotor cortex (area F4) is paradigmatic among the spatial maps related to skeletal movements. In this area, most neurons discharge in association with movements of the head or the arm (4). Furthermore, a large proportion of them are bimodal, responding both to visual three-dimensional stimuli and to tactile stimuli, mostly applied to the face or arm. A surprising property of F4 neurons is that their visual receptive fields (RFs) are circumscribed to the space around the tactile RFs, as if the cutaneous space extended into the visual space …