Mental rotation abilities in language-disordered children

This study investigated the possibility that language-disordered children suffer a pervasive representational deficit. A mental rotation task was used to measure proficiency in visual imagery, one of the major nonlinguistic symbolic modes. Normal and language-disordered first and third graders (matched for sex and cognitive level) were asked to decide whether two geometric arrays were similarly ordered. Arrays were presented parallel or with the right hand array rotated about its center either 45 degrees, 90 degrees, or 135 degrees in the picture plane. A significant (p less than .001) linear relationship between degree of rotation and reaction time indicated that children in all groups were using imagistic processes. Language-disordered children did not differ from normal children in accuracy of judgment or require more training trials, but they did respond more slowly (p less than .02). These findings suggest an impairment of visual imagery and hence representational deficits which extend beyond language. Current evidence does not, however, indicate whether difficulties with nonverbal and verbal symbolic modes stem from a single source.