Action-effect prediction in volitional and stimulus-driven movement: An investigation of error monitoring

While volitional movement is thought to be initiated based on its anticipated capacity to achieve sensory goals, stimulus-driven movement may be produced with less regard for its specific effects. Differing use of action-effect predictions in each form of movement may influence processes to which they are commonly attributed, including sensory attenuation and error monitoring. In this study, we explored sensory attenuation by comparing the evoked response of externally-generated tones with those produced by participants (N = 61), both according to their own timing (i.e., volitionally) and in response to simple visual cues (i.e., stimulus-driven). The influence of stimulus predictability on N1 amplitudes was not found to differ between self- and externally-generated stimuli, or on the basis of volitional control. Reduced P2 amplitudes were observed in response to self-generated tones, which may suggest that these were subject to higher levels of attentional control, including processes involved in the termination of attention. To explore error monitoring, we compared the influence of stimulus predictability on N2b component amplitudes. A significant interaction was found to reflect error monitoring of sound produced by volitional action that was absent with respect to other stimuli. In light of recent evidence that attentional suppression may attenuate the primary cortical response of outcomes to stimulus-driven movement, we propose that this mechanism might also serve to diminish prediction error signals for such action. As such, these effects may represent important features of sensorimotor processing that assist in differentiating stimuli on the basis of self-generation and intentionality.