Abstract
Motor imagery (MI) involves the internal simulation of a movement and its sensory outcomes. Although definitions of MI exclude overt execution of the imagined movement, this exclusion does not mean that motor system is inactive during MI. In fact, most accounts of MI are based on the premise that the neural codes activated during overt movement execution are also active during MI, though at a sub-threshold level. Evidence for the sub-threshold activation of motor codes during MI has been drawn from studies using behavioural and neurophysiological methods. Behaviourally, small muscle contractions and micromovements that resemble the imagined movements can be observed during MI; a phenomenon termed motor overflow. Neurophysiologically, changes in the magnitudes of involuntary muscle contractions that have been evoked via transcranial magnetic stimulation can be detected during or after MI. The present talk will consist of a review of these methods and of the new understandings of MI that have been generated using these methods including: how task experience shapes MI and how individual differences in MI ability are related to adaptation following MI.
