Abstract

At the behavioral level, humans are constantly engaged in performing motor acts, but the neural activity patterns that give rise to the initiation of such acts are poorly understood. Early studies by Deecke and Libet demonstrated robust changes in neural activity, which begin several hundreds of milliseconds prior to the overt performance of a voluntary motor act. Interestingly, these changes in neural activity start even before the subjective time point at which the subjects first feel the urge to move. Primate studies, neuroimaging studies in healthy human subjects, case reports of pathological conditions, and invasive electrophysiological data obtained from patients all support a model in which the intention to perform an action results from coordinated pre-conscious activity of neuron assemblies in parietal and frontal circuits. This chapter discusses neurophysiological studies examining the relationship between neural activity and the emergence of the subjective feeling of intention to act.