Motor-based prediction during preparation of hand movement modulates auditory processing in two distinct directions

Area of Science:

• Neuroscience
• Auditory Perception
• Motor Control

Background:

• Differentiating self-generated from external stimuli is vital for survival.
• Action-outcome contingency and predictive coding are key mechanisms for distinguishing stimulus origins.
• Motor preparation can modulate sensory processing, but its dependence on action-outcome contingency and timing is not fully understood.

Purpose of the Study:

• To investigate how motor preparation affects auditory processing under different action-outcome contingency conditions.
• To explore whether these modulations occur during distinct stages of action (intention, preparation, execution).

Main Methods:

• Three electroencephalography (EEG) experiments using a delayed keypress paradigm.
• Participants prepared to press a key to trigger a sound with varying degrees of action-outcome predictability.
• Analysis focused on event-related potentials (ERPs), specifically N1 and P2 components.

Main Results:

• Motor preparation consistently enhanced early auditory evoked potentials (N1 component, ~100ms).
• Later auditory evoked potentials (P2 component, ~200ms) showed suppression only when participants had extensive, reliable keypress-sound mapping experience (pianists with familiar sounds).
• N1 enhancement was observed even with unfamiliar key-sound pairings, but P2 suppression was absent.

Conclusions:

• Preparatory motor predictions can influence auditory processing in a multi-stage manner.
• The precision or reliability of action-outcome associations is critical for later stages of sensory attenuation (P2 suppression).
• These findings support a two-stage gain-to-attenuation hypothesis for predictive sensory processing.