EFFECT OF MORNING BRIGHT LIGHT ON BODY-TEMPERATURE, PLASMA-CORTISOL AND WRIST MOTILITY MEASURED DURING 24-HOUR OF CONSTANT CONDITIONS

Using 24 h constant conditions, time course of body temperature, plasm a cortisol and wrist motility was measured in response to a 3 day morn ing 2 h bright light pulse. This protocol demonstrated that a 2000 lux illumination was sufficient to elicit a shift of about 2 h of tempera ture minimum and cortisol peak. In reference session, actimetric recor dings showed a circadian time course, closely in relation with core te mperature. Bright light pulse resulted in a decrease of amplitude and a disappearance of circadian pattern of actimetry.