One-third of our lives consist of sleeping. Sometimes we pull all-nighters; unfortunately this makes some brain areas really groggy. A study conducted by Jan Dijk of the University of Belgium showed that brain activities are diminished in regions such as the thalamus, (which is in sync with our circadian rhythm), when you experience little or no sleep. Sleep deprivation can affect the performance of even simple tasks. The results of this study also showed more of an understanding of the rhythmic nature of symptoms in certain psychiatric or neurodegenerative disorders. For example, people who suffer from dementia experience what is called “sundowning” or worsening symptoms more towards the end of the day. However, according to Charles Czeisler, a sleep expert at Harvard Medical School, it still isn’t quite clear where the drive to sleep is derived from. The need for sleep may grow as toxic metabolites build up after a day of constant brain activity or when certain areas run out of fuel. So, if you are a student (or anyone who wants to function more optimally), balance your study time wisely and try not to pull any all-nighters. If you want to keep a healthy weight, try to go to sleep before midnight and get at least 7-8 hours of sleep a night. Sweet Dreams!