Q.What do psychologists mean when they describe mind and brain as 'interdependent but not identical'?

For a long period, 'mind' was treated almost as a taboo term within psychology, mainly because it resisted definition in concrete behavioural terms and could not be assigned a physical location the way the brain can. The term has since regained legitimacy, particularly through the work of neuroscientists such as Roger Sperry and physicists such as Roger Penrose, whose work has led some scientists to treat a genuinely unified theory of the mind as a real possibility.

A key question this raises is whether the mind is simply identical to the brain. Documented clinical cases suggest it is not, even though the mind plainly cannot exist without a functioning brain. Patients whose occipital lobes (the brain region responsible for vision) had been surgically removed have nonetheless been found to respond correctly to the location and shape of visual cues. An athlete who lost an arm in an accident continued to feel, and even reach out with, a 'phantom arm' that no longer physically existed. In a separate documented case, a man with a brain injury came to believe that his own parents had been replaced by impostor 'duplicates.' In each case, part of the brain was damaged or removed, yet aspects of the person's mind remained active, which is exactly why mind and brain are treated as interdependent but not identical.

Recent findings in affective neuroscience go a step further, showing a genuine working relationship between mind and behaviour rather than the two running along separate, parallel tracks. Positive visualisation and positive emotion have been shown to produce real, measurable bodily change -- patients with blocked arteries who repeatedly visualised blood flowing freely through the blockage showed a measurable reduction in blockage over time in Ornish's studies; mental imagery has similarly been used to treat phobias, and an entirely new field, psychoneuroimmunology, has emerged specifically to study how the mind helps strengthen the body's immune system.