When I was younger, I could bounce back more easily from sleep deprivation; as I get older, it’s becoming harder to deal with a short night or worse yet, a series of short nights. My mind becomes muddy and my body feels sluggish. Studies have investigated the physical and cognitive effects of sleep deprivation, but not as much has been done to examine the emotional effects of sleep loss.
A recent study looked at 26 healthy volunteers, some of whom kept a normal sleep/wake schedule and some of whom had to stay awake for 35 hours. Then, while their brains were scanned with fMRI, both groups were exposed to images that started out bland and became increasingly emotionally disturbing. The sleep-deprived group showed much more activity in areas of the brain involved in processing emotions (the press release doesn’t say specifically which areas) compared to the group who slept normally. The press release also doesn’t say if the people were monitored in any other way for the strength of the emotion they were feeling (self-reporting, respiration or heart rate, etc.). (I’d be particularly interested in correlations with what people reported they were feeling.) At this point there’s no telling why this should be the case or how sleep might buffer the effects of emotional stimuli, but this is an interesting start. This press release from EurekAlert has more information.