William & Mary

Does your left hand know what your right hand is doing?

Dr. Robert KohlThis rhetorical question is often posed to indicate poor communication within a organization, but Dr. Robert Kohl has been exploring the physiological realities of this question.

Recently, Dr. Kohl has been conducting research to explore the neural interactions influencing coordination between hands and he presented a collaborative research project stemming from the Honors research conducted by Crystal Rader ('07) and biomechanics professor, Dr. Ray McCoy this past week (Nov. 15-18, 2007). Their study titled "Interhand Coordination Across Age" was part of the 48th Annual Meeting of the Psychonomic Society.

Understanding how the two hemispheres of the brain interact to create coordinated movements has been a long-term interest of Dr. Kohl's. In the study being presented at the Psychonomic Society meeting these scientists demonstrate that reaction times were significantly slower in older adults compared to younger adults but the degree of coordination remained consistent across age groups. As part of this study subjects were asked to move their hands as fast as possible over different sized barriers, as shown in this video clip. The subject is asked to move both hands an equal distance toward the center, however, one hand has to move over a barrier. Despite the fact that the other hand does not have to negotiate the same barrier the movement of that hand mimics the height of movement of the hand going over the barrier. These results showing striking patterns in hand movements indicate that the movement of one hand really does influence movement of the other hand. So, try as we might the left hand always has some idea what the right hand is doing.