White Matter Integrity and Interhemispheric Function: Computerized Bimanual Coordination Task in Healthy Aging

The transfer of information throughout the brain, specifically from one hemisphere to the other, is dependent upon the integrity of white matter. The corpus callosum (CC) plays a crucial role for accurate and efficient interhemispheric transfer of information. Research findings suggest the CC diminishes in size with age and that tasks involving interhemispheric transfer become more difficult. As such, group differences were examined on a task of bimanual motor coordination between a group of young adults (n = 16, Mage = 28.13, age range = 23-39 years) and a group of healthy older adults (n = 12, Mage = 71.42, age range = 65-85 years). The computerized Bimanual Coordination Task (cBCT; Brown, 1991) was utilized, as this task is presumed to be a more accurate measure of bimanual coordination due to its sensitivity to fine motor movements. Generally, the older adult group performed slower and less accurately across all aspects of the task. Specifically, older adults exhibited increased difficulty compared to younger adults on accuracy of asymmetric hand responding when visual feedback was removed. These results indicate that older adults have declines in fine motor bimanual coordination potentially due to age-accompanying changes in the CC.