Developmental aspects of parietal hemispheric asymmetry during mental rotation.

Response times, accuracy and event-related potentials were measured in 24 children (mean age 7.6 years), 24 juveniles (11.4 years) and 24 adults (23.8 years) during a mental rotation task with letters. Response time and error rates increased with angular displacements for all age groups. Increasing accuracy with increasing age suggested that this task was more difficult for younger participants. An event-related potential amplitude modulation at parietal electrodes as a function of letter orientation was present for all age groups. The effect was lateralized to the left for children only, but was bilateral for adults, a finding in line with the idea of an analytic to holistic processing shift in cognitive development and a left-hemisphere involvement in analytic, piecemeal mental rotation.