Did you ever have one of those days at work when you thought everyone was out to get you? It may have had nothing to do with the weak coffee from the break room or your delusional mind. Your brain just probably needed a nap.
A new study out of the University of California at Berkeley suggests that sleep deprivation can make it harder for people to recognize facial cues that indicate another person's emotions and reactions, researchers said in a statement this week.
A paper about their study was published Wednesday in the Journal of Neuroscience.
In the experiment, two groups of "healthy young adults" were asked to examine photos of faces. One group got a full night's sleep before the photo examination and the other had to stay up for 24 hours. Presuming that all of the participants were already in college, something tells me that staying up all night wasn't that big of a stretch.
The participants who went without a good night's sleep interpreted more of the faces in the photographs as threatening, even those considered to be friendly or neutral faces, according to the statement.
The participants also underwent fMRI (functional magnetic resonance imaging) and heart scans during the photo examinations. The fMRI scans showed that a lack of sleep makes it hard for the brain to "distinguish between threatening and friendly faces, specifically in the emotion-sensing regions of the brain," according to the statement.
The heart scans also showed a weakened neural connection between the heart and the brain in people from the sleep deprived group. This disconnect made it harder for them to identify distress signals in social situations. In other words, your brain can't listen to your heart when it's tired.
Matthew Walker, a professor of psychology and neurobiology at UC Berkeley, said that the brain's threat level is raised when people don't get enough sleep, which may explain why sleep deprivation can lead to feeling lonely and being less social.
A lack of sleep could also cause the person who's been up all night to have trouble with their own facial expressions. A study published in 2013 in the journal Sleep found that a lack of sleep made it harder for people to control the expressiveness of their eyes and mouth and gave off more cues that they've been tossing and turning all night such as redder eyes, paler skin and even the appearance of more wrinkles and fine lines.
Sleep deprivation actually causes a whole host of problems besides just being unable to tell if you're about to get hugged or cursed. According to the American Academy of Sleep Medicine, sleep deprivation can increase a person's risk of suffering from symptoms of depression, high blood pressure, heart attacks and diabetes.
So what can you do about it? Get some sleep! Let your TiVo record that episode of "Halt and Catch Fire" and wait until the next day to watch it. Take some melatonin and avoid caffeine and sugar before you hit the sack. Or try watching this TED talk called "How to Tie Your Shoes" and you'll be unconscious in no time.
(Via Medical XPress)