According to research pioneered by Paul MacLean, M.D., the human brain has three formations, each with a different shape, size, chemistry, structure, and pattern of function that reflect our development during distinct eras. In essence, the human brain consists of three separate sub-brains. MacLean’s research suggests that the three brains amount to three interconnected biological computers. Each possesses its own intelligence, its own individual subjectivity, its own sense of time and space, and its own memory, as well as other functions.2
