Unilateral, 3D Arm Movement Kinematics Are Encoded in Ipsilateral Human Cortex

Area of Science:

• Neuroscience
• Motor Control
• Human Brain Activity

Background:

• Traditionally, motor control is attributed to the contralateral hemisphere.
• Neural activity in the ipsilateral hemisphere during limb movement is known but not fully understood.

Purpose of the Study:

• To investigate if 3D arm movement kinematics can be decoded from ipsilateral cortical signals.
• To compare the encoding of ipsilateral and contralateral limb movements within a single hemisphere.

Main Methods:

• Used electrocorticography (ECoG) in four epilepsy patients performing unilateral arm reaches.
• Decoded 3D arm movement kinematics (speed, velocity, position) from ipsilateral and contralateral cortical signals.

Main Results:

• Successfully decoded 3D arm movement kinematics from ipsilateral cortical signals above chance.
• Found similar spatial and spectral encoding for both ipsilateral and contralateral limb kinematics.
• Enabled cross-prediction of kinematics between the two arms.

Conclusions:

• The ipsilateral hemisphere significantly contributes to motor execution of unilateral limb movements.
• Complex human movements are represented bihemispherically, challenging traditional views.
• Findings have implications for neuroprosthetics and neurorehabilitation after brain injury.