A right hemisphere dominance for bimanual grasps

Area of Science:

• Neuroscience
• Motor Control
• Human Bimanual Coordination

Background:

• Stable grasping typically involves one cortical hemisphere.
• Bimanual grasping necessitates coordination between both cerebral hemispheres.
• Understanding hemispheric roles in bimanual actions is crucial.

Purpose of the Study:

• To investigate hemispheric coordination during bimanual grasping based on visual field.
• To determine if bimanual grasping utilizes both visual fields equally or shows lateralization.
• To elucidate the neural control mechanisms of bimanual grasping.

Main Methods:

• Participants fixated to the left or right of an object.
• Participants performed either a grasping or a pushing action.
• Measured maximum grip aperture (MGA), reaction time, and MGA onset time.

Main Results:

• Grasping objects in the right visual field resulted in larger, more variable MGA and slower reaction/MGA onset times compared to the left visual field.
• Pushing actions showed no significant visual field effects.
• These findings indicate a right-hemisphere dominance for grasp point computation in bimanual grasping.

Conclusions:

• Grasping with both hands, particularly the planning of grasp points, is predominantly processed by the right hemisphere.
• The visual field influences hemispheric control during bimanual grasping.
• This study offers novel insights into interhemispheric interactions during complex motor tasks.