Distinct neural modes carry information about grasp force and phase in the sensorimotor cortex

Area of Science:

• Neuroscience
• Motor Control
• Rehabilitation Engineering

Background:

• Restoring dexterous hand function after spinal cord injury is challenging due to limited understanding of neural control.
• Sensorimotor cortex dynamics are critical for precise force modulation during grasping.

Purpose of the Study:

• To investigate neural activity patterns in motor and somatosensory cortices during attempted isometric grasps in individuals with tetraplegia.
• To identify neural modes informative of force timing and magnitude during static and dynamic grasping tasks.

Main Methods:

• Recorded neural activity from motor and somatosensory cortices using intracortical microelectrode arrays.
• Analyzed population-level neural activity to identify distinct neural modes.
• Correlated neural modes with task phases (onset, offset, holding, force ramping).

Main Results:

• Neural activity in motor and somatosensory cortex was modulated during attempted grasps, despite paralysis.
• Identified independent neural modes encoding force timing and magnitude.
• Observed distinct neural modes for static (holding) versus dynamic (changing) force conditions.

Conclusions:

• Distinct neural modes exist for maintaining and changing grasp forces.
• These native neural modes can inform the design of intracortical brain-computer interfaces (iBCIs).
• Leveraging these modes may help restore dexterous hand function after neurological injury.