The effects of biofeedback training on self regulation of pupillary diameter
Until recently psychologists taught that it was impossible to condition the autonomic nervous system and the smooth muscles and glands it controls by any other means than by Pavlovian techniques. In 1960, Kimmel and Hill demonstrated the possibility of instrumental conditioning of the galvanic skin response. Since then, there have been reports of learned control of a wide range of autonomic responses. In the present study, it was hypothesized that pupillary size with it's bi-directional autonomic innervation would be an excellent candidate for illustration of the same rules of conditioning by biofeedback training as has been demonstrated by other autonomic nervous system functions. A total of 10 subjects were split into 2 groups and randomly assigned to either a dilation training group or a constriction group. As hypothesized self-control of pupil diameter via the use of external feedback was demonstrated.