Brain control of movement execution onset using local field potentials in posterior parietal cortex

Area of Science:

• Neuroscience
• Biomedical Engineering
• Brain-Computer Interfaces

Background:

• Precise control of movement execution onset is crucial for developing autonomous cortical motor prosthetics.
• Local field potentials (LFPs) in the parietal reach region (PRR) show distinct spectral changes between planning and execution states.
• Previous studies suggested these spectral changes could indicate movement timing, but a preceding visual stimulus raised questions about causality.

Purpose of the Study:

• To determine if LFP spectral changes in the PRR are time-locked to movement onset, independent of visual stimuli.
• To investigate the potential of using LFP spectral changes as a control signal for brain-computer interfaces.

Main Methods:

• Recorded LFPs from the PRR in macaque monkeys during self-paced reaches.
• Analyzed LFP spectral power in the 0-10 Hz and 20-40 Hz bands.
• Trained macaques to use LFP spectral changes as a 'go' signal in a closed-loop brain-control task, dissociating LFP modulation from physical movement.

Main Results:

• LFP spectral changes were time-locked to movement onset even in the absence of visual events.
• Macaques successfully learned to use LFP spectral shifts as a 'go' signal to control a brain-computer interface.
• The LFP spectrum change served as a reliable indicator of movement initiation.

Conclusions:

• LFP spectral dynamics in the PRR are a robust neural correlate of movement execution onset.
• These findings support the use of LFP spectral changes for precise control of execution timing in cortical prosthetics.