4. The Three Brain Explanation

In a series of studies Paul MacLean, chief brain researcher at the National Institute for Mental Health (US), has produced convincing evidence that the human brain has three separate physiological layers, each corresponding to an evolutionary stage. In this "Triune Brain Theory," the oldest layer is called the reptile brain, and it controls basic self–preservative, reproductive and life sustaining functions. Sitting atop the reptile brain is the limbic system, dubbed the visceral brain, because it generates all our emotions. The most recent part of the brain to develop is the neocortex, seat of our abstract, cognitive functions; memory, intellect, language, and consciousness. Unfortunately, there is insufficient communication and coordination between the neocortex and the two older levels. This results in a chronic dissociation between the higher and lower brains which we experience in the form of conflicting drives - unconscious and conscious, savage and civilised, lusty and loving, ritualistic and symbolicThere are times when the levels do act in harmony, as in peak experiences when body and mind unite in exhilarating moments of vitality, when our actions come effortlessly, spontaneously. Now there is evidence that suggests that, due to heightened internal awareness and decreased physical arousal, floating increases the vertical organisation of the brain, enhancing communication and harmony between the separate levels. Floating, it has been hypothesised, can provide us with peak experiences almost at will.