Movement Planning Determines Sensory Suppression: An Event-related Potential Study

Area of Science:

• Neuroscience
• Cognitive Science
• Motor Control

Background:

• Sensory suppression is a phenomenon where self-generated sensory input elicits weaker neural responses than externally generated input.
• This is often explained by an internal forward model that uses motor commands to predict and suppress sensory consequences.
• It remains unclear if sensory suppression is driven by movement planning, execution, or both.

Purpose of the Study:

• To investigate the role of movement planning versus execution in sensory suppression.
• To determine if voluntary, semi-voluntary, or involuntary actions differentially affect sensory suppression.

Main Methods:

• Compared event-related potentials (ERPs) to self-generated tones (voluntary, semi-voluntary, involuntary button-presses) and externally generated tones.
• Used electrical nerve stimulation and manual force to induce different types of button-presses in two experiments.

Main Results:

• Voluntary button-presses produced significant sensory suppression, specifically reducing the N1 component of the ERP (N1-suppression).
• Semi-voluntary and involuntary button-presses did not result in significant N1-suppression.
• The degree of N1-suppression decreased linearly with decreasing voluntariness of the action.

Conclusions:

• Movement planning is a necessary condition for sensory suppression.
• The findings support the internal forward model as the most parsimonious explanation for sensory suppression.