Enhancing Visuomotor Adaptation by Reducing Error Signals: Single-step (Aware) versus Multiple-step (Unaware) Exposure to Wedge Prisms

Abstract Neglect patients exhibit both a lack of awareness for the spatial distortions imposed during visuomanual prism adaptation procedures, and exaggerated postadaptation negative after-effects. To better understand this unexpected adaptive capacity in brain-lesioned patients, we investigated the contribution of awareness for the optical shift to the development of prism adaptation. The lack of awareness found in neglect was simulated in a multiple-step group where healthy subjects remained unaware of the optical deviation because of its progressive stepwise increase from 2° to 10°. We contrasted this method with the classical single-step group in which subjects were aware of the visual …