Your circadian body clock is influencing your behavior. Have you ever felt like you had peaks and valleys during the day. You’re right! A new study by researchers at the Swinburne’s Centre for Mental Health indicates that there is a connection between our brain’s reward system and our internal clock which primes 24-hr psychological and physiological functions. The reward center of the brain is located in the left putamen situated to the base of the forebrain. This center works differently across the day, with it’s peaks being in the morning and evening. In their study, researchers constructed a gambling task for 16 right-handed, healthy men at different times of the day. They were asked to predict the value of one card and for the best performance in three times, were given a financial bonus. During play, the participants’ brains were monitored using functional Magnetic Resonance Imaging. Compared to the start and end of the day, the measurements of activity in the left putamen were consistently lowest at 2 pm. The findings of this study are contrary to prior studies that indicate a reward center peak during the early afternoon. The reason for the disparity is that the brain is ‘expecting’ rewards at some times of day more than others, because it is adaptively primed by the body clock. The reward center of the brain may expect rewards during early afternoon and gets pleasantly surprised when they appear during the beginning or end of the day. More studies on this are sure to come!