Left hand is a term that has been used throughout history to describe the predominantly automatic, unconscious and holistic nature of the right hemisphere of the brain. Here, the right hemisphere has been seen as the 'emotive', 'intuitive' and 'spontaneous' side of the brain, operating in a holistic, global and creative manner, as opposed to the predominantly analytic, conscious and logical processing of the left side. The two sides of the brain were thus seen as opposite sides of the same coin, with the left representing methodical and structured cognitive processing, and the right representing a more holistic and expressive approach. The result of this hemispheric balance is what many refer to as 'the integrative power of the human brain'.

See also: left hemisphere, right hemisphere, corpus callosum, split brain, brain damage