Using positron emission tomography (PET), the brain regions recruited for the tapping movement by different fingers and different tapping modes were investigated in 10 healthy adult males (20-30yrs). The experimental tasks consisted of auditory-paced (2 Hz) tapping movements by one of the fingers (single-finger tapping) and two of the fingers used alternately (double-finger tapping). Data were obtained from the index and ring fingers for the single-finger tapping conditions, the index-middle finger and ring-little finger pairs for the double-finger tapping conditions, and a resting condition as a control. Each subject also provided a subjective ranking of task difficulty among the tapping tasks. Brain areas activated with the ring finger or ring-little finger-combination were greater and more distributed than the index finger or index-middle finger-combination. Activation in most of these areas was closely related to perceived task difficulty. These findings thus suggested that the movement of different fingers was supported by a set of different central neural network. A comparison of the two tapping modes revealed that in addition to the brain areas activated during single-finger tapping, the bilateral dorsal premotor and left primary motor/sensory areas, and the right anterior cerebellum were also activated during double-finger tapping, confirming the difference in their neural network. The additionally activated areas can be related to motor sequence operation of the two fingers. The results overall suggest that active use of the ring and little fingers is important for the maintenance of higher cognitive function.

DESCENTE SPORTS SCIENCE Vol.26/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE