Movement-related potentials associated with self-paced, cued and imagined arm movements

Area of Science:

• Neuroscience
• Motor Control
• Electrophysiology

Background:

• Movement-related potentials (MRPs) are EEG signals preceding voluntary movements.
• The supplementary motor area (SMA) is implicated in motor preparation.
• Different movement types (self-paced, cued, imagined) may elicit distinct preparatory brain activity.

Purpose of the Study:

• To compare the premovement components of MRPs for self-paced, cued, and imagined movements.
• To investigate the role of the SMA in different movement types.
• To analyze movement-related potentials during proximal arm movements.

Main Methods:

• Electroencephalography (EEG) recordings were used to measure brain activity.
• Subjects performed self-paced, cued (regular and random), and imagined movements of the right arm.
• Analysis focused on the Bereitschaftspotential (BP) and negative slope (NS') components of MRPs.

Main Results:

• Self-paced movements showed a two-phase MRP (early BP, later NS').
• Proximal movements exhibited larger peak amplitudes, primarily due to a more pronounced NS' phase.
• Cued movements had an earlier, less distinct NS' phase, while imagined movements showed only slow negativity without a clear NS' phase.

Conclusions:

• MRPs preceding self-paced, cued, and imagined movements possess distinct electrophysiological characteristics, particularly the NS' phase.
• The MRP associated with regular cued movements may resemble the S2-related negativity of contingent negative variation (CNV).
• Findings align with functional imaging data on cortical activation patterns during similar movements.