Expected TMS excites the motor system less effectively than unexpected stimulation

The brain's response to sensory input is modulated by prediction. For example, sounds that are produced one's own actions, or those strongly predicted environmental cues, elicit an attenuated N1 component in the auditory evoked potential. It has been suggested this form of attenuation stimulation actions reason we unable tickle ourselves. Here examined whether neural direct brain prediction a similar manner. Transcranial magnetic (TMS) applied over primary motor cortex can be used gauge excitability system. Motor-evoked potentials (MEPs), elicited TMS and measured peripheral muscles, larger when being prepared smaller voluntarily suppressed. We tested amplitude MEPs was under circumstances where pulse reliably predicted, even though control relevant effector never required. Self-initiation reliable cuing both MEP amplitudes, compared generated programmatically unpredictable These results suggest predictive coding may governed domain-general mechanisms responsible for all forms learning. findings also have important methodological implications designing experiments predictability pulses.