Prism Adaptation Therapy (PAT) is an intervention method in the treatment of the attention disorder neglect (Frassinetti, Angeli, Meneghello, Avanzi, & Ladavas, 2002; Rossetti, et al., 1998). The aim of this study was to investigate whether one session of PAT using a computer-attached touchscreen would produce similar aftereffects as the conventional physical box normally used in PAT.

In four experiments, 81 healthy subjects and 7 brain-injured patients diagnosed with neglect were subjected to a single session of PAT under two conditions: 1) using the original physical box, 2) using a computer-based implementation with an attached touchscreen. The session of PAT included a pre-exposure step pointing at 30 targets without feedback; an exposure step pointing at 90 targets with prism goggles and feedback; and a post-exposure step pointing at 60 targets, with no goggles and no feedback.

The results indicate that the expected similarity in the aftereffect produced by the two conditions seems to occur only if subjects get feedback on pointing precision by seeing their fingertip during the exposure step. Attempts to provide feedback indirectly via icons on the computer screen failed to produce the expected size in the aftereffect. The findings have direct implications for future implementations of computer-based methods of treatment of visuospatial disorders and computer-assisted rehabilitation in general.