Sensory Experience and Motor Signals Shape Auditory Processing in an Independent Manner

Voluntary actions are usually accompanied by sensory consequences that evoke neural responses in relevant sensory regions. These responses are different when compared to those evoked by otherwise identical physical stimulation not associated with preceding actions (sensory attenuation). A common model suggests that sensory attenuation is caused by efference signals associated with the binding of actions with sensory outcomes. Nevertheless, the information encoded in such signals is debated, with some theories suggesting they convey predictive information while others suggest they convey global motor information regardless of outcome expectations. To address this debate, we recorded EEG data, while participants (n = 30) learned to associate motor or visual cues with corresponding tones. Following eight cue-outcome presentations, participants successfully learned the association (> 84% correct). At the neural level, the amplitude of auditory-evoked responses (N100) decreased during learning, as experience with cues and tones was gained. In addition, N100 amplitude was attenuated when preceded by motor vs. visual cues (sensory attenuation). Most importantly, we did not find an interaction effect between learning phase and cue type, suggesting a similar magnitude of sensory attenuation throughout learning. Moreover, we find significant sensory attenuation even before tone-specific expectations were formed. Thus, our results suggest that the magnitude of sensory attenuation is invariant to short-term experience with specific action-outcome contingency. Exploratory time-frequency analysis suggests experience affects EEG signals prior to tone onset and earlier than motor signals. Together, our results are consistent with models suggesting a distinct influence of action on sensory processing that is independent of experience.