Prism adaptation produces neglect-like patterns of hand path curvature in healthy adults

Visuospatial neglect is a common consequence of brain injury in which patients fail to respond appropriately to stimuli or events occurring within their contralesional hemispace and may restrict eye and hand movements to objects or events occurring within ipsilesional space. Emerging evidence suggests, however, that neglect is a syndrome consisting of several components, including the impaired representation of corporeal and extrapersonal space. To better understand the neglect syndrome it is important to develop experimental models of each of these components. Here we develop an experimental model of the spatial impairment associated with visuospatial neglect based upon adaptation to laterally displacing optical prisms. We demonstrate that after a short period spent adapting to rightward displacing prisms, healthy subjects exhibit increases in hand-path curvature during reaches executed under visual guidance, but, not during reaches executed to proprioceptively-defined targets without vision.