Developing mental rotation skill among visually impaired students

Mental rotation tasks have been used to probe the mental imagery of both sighted and visually impaired people. People who have been blind since birth display a response pattern which is qualitatively similar to that of sighted people but tend to respond more slowly or with a higher error rate. It has been suggested that visually impaired people code the stimulus and its (or their own) motion in a different way from sighted people-in particular, congenitally blind people may ignore the external reference framework provided by the stimulus and surrounding objects, and instead use body-centred or movement-based coding systems. Congenitally blind and partially sighted children were tested for their ability to learn and recall a layout of tactile symbols. Children explored layouts of one, three or five shapes which they then attempted to reproduce. In an aligned condition children reproduced the array from the same position at which they had explored it; in a rotated condition children were asked to move 90° round the table between exploring and reproducing the layout. Thus, representation of self-relevant past or future events may underlie successful rotation. This may explain why it is not related to mental scanning, which relies on developments in visual working memory and distance coding ability.