The impact of the degree of action voluntariness on sense of agency in saccades.

Experiencing a sense of agency (SoA), the feeling of being in control over one's actions and their outcomes, typically requires intentional and voluntary actions. Prior research has compared the association of voluntary versus completely involuntary actions with the SoA. Here, we leveraged unique characteristics of oculomotor actions to partially manipulate the degree of action voluntariness. Participants performed either highly automatized prosaccades or highly controlled (voluntary) anti-saccades, triggering a gaze-contingent visual action effect. We assessed explicit SoA ratings and temporal action and effect binding as an implicit SoA measure. Anti-saccades were associated with stronger action binding compared to prosaccades, demonstrating a robust association between higher action voluntariness and a stronger implicit sense of action agency. We conclude that our manipulation of action voluntariness may have impacted the implicit phenomenological feeling of bodily agency, but it did not affect the SoA over effect outcomes or explicit agency perception.