Left hemisphere dominance for bilateral kinematic encoding in the human brain

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Neuroscience

Background:

• Neurophysiological studies indicate movement representations exist in both brain hemispheres.
• Clinical observations suggest potential hemispheric differences in bilateral movement representation.

Purpose of the Study:

• To investigate if the bilateral representation of movements differs between the left and right cerebral hemispheres.
• To explore the hemispheric asymmetry in neural encoding of arm movements.

Main Methods:

• Electrocorticography (ECoG) was used in human participants performing a reaching task.
• A cross-validated kinematic encoding model was applied to analyze neural data.
• Movements were executed with either the contralateral or ipsilateral arm.

Main Results:

• The left hemisphere exhibited stronger bilateral movement encoding compared to the right hemisphere.
• This effect was observed during movement preparation and intensified during execution.
• Enhanced across-arm generalization in the left hemisphere indicated similar neural representations for both arms.

Conclusions:

• The left hemisphere demonstrates a more extensive bilateral representation of arm movements.
• This hemispheric asymmetry contributes to the understanding of the left hemisphere's dominant role in praxis.
• Findings provide new insights into the neural basis of motor control and interhemispheric communication.