MOTOR PREPARATION PREDICTS AUDITORY SELF-GENERATION EFFECTS AND REACTION TIME DYNAMICS IN A CUED PARADIGM

Actions modulate auditory cortical responses, yet the contribution of motor preparation to these self-generation effects remains unclear. Prior work suggests that information about expected action consequences is embedded in the premovement buildup of activity prior to action, or readiness potential (RP). It remains unknown how these preparatory dynamics unfold in cued actions, how they relate to reaction time variability, or how they shape auditory stimulus processing. Participants underwent EEG while performing a two-cue task: a warning cue (Motor-only, Motor-Auditory, or Auditory-only) preceded an imperative instruction to press or listen, which was followed by either a button press without auditory outcome, a button press producing a tone (self‑generated), or an externally generated tone without movement. Sounds were presented at near- and suprathreshold intensities. We examined pre-movement ERPs at Cz, and auditory N1 at FCz. Cluster-based permutation analyses identified two windows differentiating motor preparation for actions with and without expected auditory consequences. Within these windows, RP slope and area under the curve were extracted. Self-generation effects on sensory processing were computed as the N1 amplitude difference between motor-corrected self-generated and externally generated tones. Results showed that late‑window area‑under‑the‑curve values predicted participants’ action speed, and that RP slope differences between Motor-only and Motor-Auditory conditions correlated with the magnitude of the self-generation effects for near- and suprathreshold tones. These findings indicate that motor preparation plays a graded role in shaping how self‑generated stimuli are processed, demonstrating that these effects emerge from preparatory dynamics rather than movement execution alone.