Changes in the Bereitschaftspotential due to subsequent voluntary autotriggered stimulus

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Motor Control

Background:

• The Bereitschaftspotential (BP) is a key indicator of voluntary movement preparation.
• Previous studies have explored BP under various conditions, but the impact of predictable negative outcomes requires further investigation.

Purpose of the Study:

• To investigate how the expectation of an electrical shock influences the Bereitschaftspotential (BP) during voluntary thumb movements.
• To differentiate the effects of subjective expectation versus physical action on motor-related brain potentials.

Main Methods:

• Participants performed simple voluntary thumb flexion/opposition in two conditions: separate series with predictable outcomes (simple movement vs. movement followed by shock) and a single series with intermixed trials.
• Electroencephalography (EEG) was used to record the Bereitschaftspotential (BP).

Main Results:

• When expecting an electrical shock in separate series, BP onset was delayed, amplitude decreased, and N2 was smaller compared to simple voluntary contractions.
• These changes were more pronounced over postcentral cortical areas.
• In a single series with intermixed trials, no significant differences in BP measures were observed between conditions.

Conclusions:

• The subject's attitude and preparedness significantly modulate brain potentials related to voluntary movement.
• Predictable negative outcomes (electrical shock) can induce stress and selective cortical suppression, altering motor preparation.
• The context and predictability of outcomes are crucial factors influencing the Bereitschaftspotential (BP).