Sensory attenuation in the absence of movement: Differentiating motor action from sense of agency.

Sensory attenuation is the phenomenon that stimuli generated by willed motor actions elicit a smaller neurophysiological response than those generated by external sources. It has mostly been investigated in the auditory domain, by comparing ERPs evoked by self-initiated (active condition) and externally-generated (passive condition) sounds. The mechanistic basis of sensory attenuation has been argued to involve a duplicate of the motor command being used to predict sensory consequences of self-generated movements.

Attenuation of visual evoked responses to hand and saccade-initiated flashes.

Sensory attenuation refers to reduced brain responses to self-initiated sensations relative to those produced by the external world. It is a low-level process that may be linked to higher-level cognitive tasks such as reality monitoring. The phenomenon is often explained by prediction error mechanisms of universal applicability to sensory modality; however, it is most widely reported for auditory stimuli resulting from self-initiated hand movements.

Act Now, Play Later: Temporal Expectations Regarding the Onset of Self-initiated Sensations Can Be Modified with Behavioral Training.

Mechanisms of motor-sensory prediction are dependent on expectations regarding when self-generated feedback will occur. Existing behavioral and electrophysiological research suggests that we have a default expectation for immediate sensory feedback after executing an action. However, studies investigating the adaptability of this temporal expectation have been limited in their ability to differentiate modified expectations per se from effects of stimulus repetition.

Modifying temporal expectations: Changing cortical responsivity to delayed self-initiated sensations with training.

The perceptual system makes a specific prediction regarding the timing of impending, self-initiated sensations to facilitate the attenuation of these sensations. The current study used electroencephalography to investigate whether temporal expectations can be modified with training. Participants underwent a button-press-for-tone task and evoked responses to the tones were measured.