Action-effect proximity, order, and predictability differentially modulate electrophysiological responses and explicit judgements of agency.

Attenuation of neural responses to self- versus externally generated stimuli is widely considered an implicit marker of the Sense of Agency and often interpreted within predictive processing and comparator frameworks. Agency is thought to arise from the integration of multiple cues, including action-effect timing and outcome predictability. How these factors jointly shape electrophysiological correlates of agency remains unclear. In this study, we manipulated the temporal relationship and pitch congruency of sounds generated by button presses to examine their effects on explicit agency judgments and event-related potentials. Sounds were presented up to 120 ms before/after actions, allowing investigation of action-effect proximity irrespective of temporal order and electrophysiological correlates of illusory agency perception. Temporal proximity and outcome congruency strongly influenced agency judgments. While the typical order of action preceding effect was critical, participants reported illusory agency when congruent sounds preceded actions by up to 60 ms, consistent with predictive accounts. Neurally, sounds preceding actions elicited an N200 mismatch response, congruent outcomes evoked a late positive orienting response, and P2 attenuation occurred for temporally proximal events regardless of order. These findings support cue integration accounts by showing that temporal structure and predictability jointly shape agency judgments and their electrophysiological signatures.