PAVLOVIAN CONDITIONING MAY PARTLY EXPLAIN THE EFFECTS OF LIGHT THERAPY

Explicit pairings of a non-photic stimulus and exposure to light are c apable of inducing behavioural responses that are characteristic of th e resetting of the circadian system by light as well as cellular effec ts in the neural regions that are normally activated only by light. Th e setting of tight therapy as used for treatment of winter seasonal af fective disorder resembles that of Pavlovian conditioning. The conditi oning may provide a rationale for the sustained therapeutic response t o light treatment observed to last for the rest of the season in some of the patients treated with light.