Intentional action has proved difficult to study experimentally. An intentional action feels quite different from a physically identical involuntary movement, yet few studies have described this phenomenal difference in detail. The most developed approach has investigated the perceived time of intentions and of actions, without addressing their phenomenal content directly. This approach was pioneered by Benjamin Libet, but has been substantially extended in recent years. Thechronometric approach has allowed scientists to link the time of awareness of intentions and actions to the time of the underlying neural processes that prepare, specify and execute movements. As a result, the neural correlates of temporal awareness of intention have been
identified in a circuit comprising frontal and parietal lobes. Other studies have focussed on the perceived time of actual movement. These studies show that judgements about a movement are profoundly influenced by the neural preparation that precedes it, and also by its predicted sensory consequences of action. Physical movement is necessary for normal action, but comprises only a part of its phenomenal content. In general, our conscious experience of intentional action seems much more integrated and coherent than the underlying neural and physical events involved.