Study links staying up late with big impact on emotions, performance

If you've been staying up later than usual to finish a work project or study for a big test, you may be harming your long-term performance and your mood, a new study warns. Researchers with the Norweigan University of Science and Technology found that it only takes a few days of staying up a couple of hours past bedtime to cause a noticeable impact on emotions and one's ability to concentrate.

Getting proper, restful sleep is vitally important for health and mental wellbeing, according to a large body of past studies. The exact impact of sleep deprivation varies based on things like duration, but can include impaired driving, high blood pressure, excessive appetite, obesity, increased cancer risk, and more. Despite these warnings, many people still fail to get adequate amounts of restful sleep.

The study found that participants who stayed up two hours late per night past their usual bedtime experienced a blunting of emotions, as well as decreases in performance linked to their ability to concentrate. These negative effects were observed after only three nights despite sleeping in their own beds and living their normal daily lives.

The participants were tasked with a simple computer-based test that required them to view random images and to press a button when an image included the letter "X" on it. NTNU Department of Psychology Associate Professor Ingvild Saksvik-Lehouillier detailed the results, saying:

We tested responsiveness and accuracy. The reaction time went down after the participants had been sleep deprived, but the error rate went up. It seems that we react more quickly to compensate for lower concentration. Then there'll be more mistakes. It may be smart to avoid activities that require a high level of accuracy the morning after sleeping less than usual.

As for emotions, the study didn't find that fewer hours spent asleep caused depression or a lowered mood, but rather that it essentially blunted positive emotions, making more neutral and decreasing the number experienced. This could pave the way for mental health issues over time; it's unclear how long it took the positive emotions to return to normal after regular sleep was resumed.