Prism Adaptation Therapy (PAT) is an intervention method for treatment of attentional disorders, such as neglect ^{e.g. 1,2}. The method involves repeated pointing at specified targets with or without prism glasses using a specifically designed wooden box. The aim of this study was to ascertain whether the PAT method can be executed with similar effect using a computer with a touch screen.

 

62 healthy subjects were subjected to two experimental conditions: 1) pointing out at targets using the original box, 2) pointing out at targets on a computer attached touch screen. In both conditions, the subjects performed a pre-test consisting of 30 targets without feedback, then an exposure-test of 90 targets with prism glasses and feedback, and finally a post-test of 60 targets, with no glasses and no feedback. Two experiments were carried out, 1) the feedback was provided by showing a cross on the touch screen (indirect feedback), 2) the feedback was provided by seeing one's own pointing finger, with no graphical feedback on the computer screen (direct feedback).

 

The results show that it is possible to obtain similar aftereffects from PAT by using a computer method but only when providing a direct feedback (physical finger) on pointing precision. Attempts to provide feedback indirectly via icons on the computer screen fail to create the aftereffects observed in the original PAT. The findings have direct implications for future implementations of computer-based methods in treatment of visuospatial disorders.  

 

1. Rossetti et al. Nature 1998, 395: 166-169

2. Frassinetti et al. Brain 2002, 125: 608-623