fMRI study of bimanual coordination.

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Neuroscience

Background:

• The primary somato-motor cortex (SMC) and supplementary motor area (SMA) are crucial for motor control.
• Understanding the differential activation patterns within these areas during unimanual versus bimanual tasks is essential for mapping brain function.

Purpose of the Study:

• To investigate the hemodynamic responses in the SMC and SMA during unimanual and bimanual tapping tasks.
• To determine if asymmetries in activation exist between hemispheres during asymmetric bimanual tasks.
• To compare activation levels in SMC and SMA between unimanual and bimanual activities.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure hemodynamic responses.
• Eleven right-handed subjects performed unimanual and bimanual tapping tasks at varying rates.
• Activation levels in the contralateral SMC and SMA were analyzed.

Main Results:

• During bimanual tasks, the SMC contralateral to the faster hand showed greater activation.
• SMC activation was similar for unimanual and bimanual tasks at a given rate.
• SMA showed significantly greater activation during bimanual compared to unimanual tasks.
• An asymmetry was observed in SMA activation during asymmetric bimanual tasks, with the left SMA more active during right-fast/left-slow tapping.

Conclusions:

• Motor cortex activation during bimanual tasks is influenced by the rate of hand movement.
• The SMA plays a more significant role in bimanual coordination than previously thought.
• Hemispheric specialization in the SMA may occur during asymmetric bimanual tasks.