DEVELOPMENTAL-CHANGES IN HEMISPHERIC-SPECIALIZATION FOR TACTILE SPATIAL ABILITY

64 1st-, 3rd, and 5th-grade children and adults (16 in each group) performed a tactile shape-discrimination task. On each of 40 trials, after exploring a randomly generated nonsense form using only finger motion, Ss judged a tactually presented comparison form as either the same as or different from the 1st stimulus. In Condition 1, a single stimulus form and the comparison form were successively presented to the same hand. In Condition 2, stimulus forms were simultaneously presented to both hands; however, a comparison form was presented to only one hand. Results indicate that the left hand (right hemisphere) was more accurate than the right hand (left hemisphere) for 5th-grade Ss and adults, but no significant differences between hands were found for 1st- and 3rd-grade Ss. Overall, Condition 2 was more difficult than Condition 1, but similar laterality effects were found in both groups. Sex differences were found only in the adult group in which males made somewhat fewer errors than females. These results suggest that the right hemisphere becomes progressively more specialized for tactile spatial ability with increasing age. (29 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.