Two hands, one brain: cognitive neuroscience of bimanual skill.

Bimanual coordination, a prototype of a complex motor skill, has recently become the subject of intensive investigation. Whereas past research focused mainly on the identification of the elementary coordination constraints that limit performance, the focus is now shifting towards overcoming these coordination constraints by means of task symbolization or perceptual transformation rules that promote the integration of the task components into a meaningful "gestalt". The study of these cognitive penetrations into action will narrow the brain-mind gap and will facilitate the development of a cognitive neuroscience perspective on bimanual movement control.