Cerebral potentials during skilled slow positioning movements

Area of Science:

• Neuroscience
• Motor Control
• Electrophysiology

Background:

• Understanding the neural mechanisms underlying voluntary movement is crucial.
• Movement-related potentials (MRPs) provide insights into cortical activity preceding and during motor tasks.

Purpose of the Study:

• To investigate the characteristics of scalp-recorded movement-related potentials during self-paced, skilled upper extremity positioning tasks.
• To differentiate between the Bereitschaftspotential and subsequent potentials during goal-directed movements.

Main Methods:

• Electroencephalography (EEG) was used to record scalp potentials in human subjects.
• Subjects performed two skilled positioning tasks involving upper extremity flexions without external cues.
• Delayed visual feedback was provided after each trial.

Main Results:

• A negative potential shift, the Bereitschaftspotential, preceded electromyographic (EMG) onset.
• A persisting negativity, the goal-directed movement potential, was observed during movement execution until the target position was reached.
• This potential comprised a central negativity and a contralateral sensorimotor negativity.
• Anticipation of visual feedback elicited a different potential topography, predominantly over the right hemisphere.

Conclusions:

• The study identified distinct phases of cortical activity during voluntary movement, characterized by the Bereitschaftspotential and the goal-directed movement potential.
• The findings suggest specific neural processes associated with movement initiation, execution, and response to feedback.