Active and passive activation of left limbs: influence on visual and sensory neglect.

A case of severe left visual neglect who had previously shown reductions in visual neglect with left hand movements in left hemispace showed the same phenomenon when the experiment was repeated, but failed to show it when the left hand was moved passively. However, neglect did reduce when he moved his left leg. Sensory extinction was not affected by left hand movements. Finally, hand movements in left hemispace also reduced neglect for stimuli in far as well as in peripersonal space. These results confirm the close link between visual attention and motor function and provide further support for the idea that contralesional limb movements may reduce visual neglect, possibly by activating a poorly attended body schema which in turn activates corresponding areas of extrapersonal space in at least two spatial systems (reaching and far space, respectively).