There is a reason why we join our co-workers in a collective withdrawal of our noses from the grindstone around 2:00 in the afternoon. Have you noticed more yawning, office chatting, or disappearing for a cup of java around that time? And it’s not just the effect of a martini-or-two-lunch, or gorging on a buffet in a nearby restaurant. A new study says that we are hard-wired for a 2:00 p.m. brain pause.
In the recent Swinburne’s Centre for Mental Health study, sixteen healthy, right-handed men were given a gambling task at three different times of the day: 10 a.m., 2 p.m., and 7 p.m. Throughout this exercise, their brains were monitored by functional Magnetic Resonance Imaging.
The researchers found that the brain’s reward center activates differently across the day. The reward pathway is the central part of the brain which drives our feelings of motivation, reward, and behavior. Apparently, the activity in this part of the brain peaks in the morning and evening, but lags in the afternoon.
“We found that activation in the left putamen, the reward center located at the base of the forebrain, were consistently lowest at the 2 p.m. measurement compared to the start and end of the day,” says Ph.D. candidate Jamie Byrne who co-authored this study. “Our best bet is that the brain is ‘expecting’ rewards at some times of day more than others because it is adaptively primed by the body clock,” says Byrne.
The study doesn’t explain the reasons for this wiring of our grey matter, but the authors speculate that our brain’s peak alertness in the morning and evening is related to our primal experiences of high-risk times, survival-wise.
This is a fairly small-scope study and needs more follow-up research. But its findings do carry a greater importance than just giving us a good excuse to be lackadaisical in the afternoon, and some “scientific data” to throw at our bosses when confronted with our lack of stick-to-itiveness to our tasks around 2:00! The study disputes previous research showing brain’s reward activation peak in the early afternoon and validates the effect of the time of day factor in scanning brain activity. And that has ramifications for the treatment of brain-related issues such as bipolar disorders, depression, addictions and sleep problems.
So the Latin world has been right all along with their religious observance of the siesta! No point doing much when your brain is set to “not-motivated” mode!
