I became aware just now that there are muscles in my artist's hand (right) which have not developed in my left hand. Actual muscle mass which exists in the palm of one hand while being completely undetectable in the palm of the other. Then it occurs to me that in order for muscle mass to develop, there must be a corresponding development in a specific area of motor regions of the brain. It stands to reason that if a muscle can develop, the brain must have mapped it. As far as i know, nothing can move unless the brain says it moved or tells it to. So this could serve as one example of how creative process modifies the brain through repeated practice, which in turn might modify muscle mass. It is actually a prefect example of bio-feedback. Art therapy activates biofeedback mechanisms and it is for this reason that i believe it is currently on a level to compete with cognitive behavioural interventions in terms of efficacy of treatment. Art therapy may actually be the treatment of choice when biofeedback in highly indicated. Think about it for a second: you have an artist with a brush in hand. The artist feeds pigment to the brush by sopping it up on the palette. Then the artist moves an arm towards a canvas and applies pressure through the brush onto the surface. The specific tension of the canvas mirrors or replies with afferent vibrations which are reintegrated through the central nervous system in the sensory cortex. If biofeedback is useful in psychotherapy then i can think of no greater illustration of it's usefulness.