The identification of letters and their left-right mirror-images : development of hemispheric asymmetry

• Main Author: Bryson, Susan E.
• Format: Others
• Language: en
• Published: McGill University 1981
• Subjects: Left and right (Psychology); Cerebral dominance.; Cerebral hemispheres.; Memory in children.; English language > Alphabet.
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68602

Three reaction time experiments were conducted to determine when and how memory for the normal left-right orientation of letters is mediated by the developing brain. In each experiment, participants identified forward and backward letters presented unilaterally to each visual field and thus to each hemisphere (VF-H). === The main findings were as follows: (1) For the five-year-olds, no VF-H differences were found in the speed of identifying either forward or backward letters or in the difference in speed between forward and backward letters. (2) The seven-year-olds identified forward letters faster than backward letters in the right visual field-left hemisphere (RVF-LH) with the contralateral, right hand, and the boys, unlike the girls, also showed this difference in the left visual field-right hemisphere (LVF-RH) independent of the responding hand. (3) Performance of the nine-year-olds was similar to that of the seven-year-olds. (4) Adults identified forward letters faster than backward letters in the RVF-LH with each hand, whereas in the LVF-RH this difference was found for the ipsilateral, right but not for the contralateral, left hand. === Support was provided for the Corballis-Beale (1976) hypothesis, and discussion centered on the implications of the results for the development of cerebral lateralization of memory for the normal left-right orientation of letters in normal and reading disabled children.