Agency in the sensorimotor system and its relation to explicit action awareness

Area of Science:

• Cognitive Neuroscience
• Motor Control
• Psychology

Background:

• Sense of agency is typically intuitive but can be illusory, challenging its grounding in the sensorimotor system.
• Shared neural representations for executed and observed actions complicate understanding agency perception.
• Previous research suggests agency is inferred rather than directly perceived.

Purpose of the Study:

• Investigate if the human motor system distinguishes between observed actions linked to agency and those not.
• Examine if observing actions impacts low-level sensorimotor agency measures and high-level explicit agency representations.
• Explore the relationship between sensorimotor processing and explicit judgments of agency.

Main Methods:

• Participants performed manual movements while observing actions.
• Temporal correspondence between executed and observed movements was manipulated.
• Motor-evoked potentials (MEPs) via single-pulse transcranial magnetic stimulation (TMS) measured sensorimotor agency.
• Participants provided explicit verbal judgments of agency.

Main Results:

• Corticospinal excitability, measured by MEPs, varied with the temporal congruence of executed and observed movements.
• Explicit agency judgments were predictable from corticospinal excitability.
• Low-level sensorimotor measures correlated with high-level explicit agency assessments.

Conclusions:

• The human motor system is sensitive to the agency associated with observed actions.
• Explicit judgments of agency may directly rely on sensorimotor system information.
• Findings support the grounding of agency perception within sensorimotor processing.