We’ve all witnessed the classic toddler meltdown in the supermarket or at the mall. Experienced parents lock eyes and nod, murmuring, “Somebody needs a nap.” Yet that automatic recognition of the impact lack of sleep has on a small child is all too frequently lacking in adults who are experiencing the same kind of need. Not only do we as grownups have a peculiar tendency to take pride in the amount of sleep that we cheat ourselves of, but we also refuse to acknowledge the fact that it has an affect on the way that we perform, react or feel. But now a study conducted by researchers from Harvard Medical School and the University of California at Berkeley has made it extremely clear that sleep deprivation has a massive effect on the way that the brain reacts to stimuli, and it’s not a change for the better.
The research was published in the journal Current Biology, and though it makes a link directed at sleep problems and mental illness, much can be learned from its findings to relate to our every day lives. The group observed a cohort of volunteers who volunteered to be sleep deprived for a period of 35 hours and then submit to functional magnetic resonance imaging (fMRI) in order to see exactly how the lack of sleep affected their brains. The fMRI allowed the scientists to monitor the amount of blood flow to specific brain areas in order to measure brain activity. What they found was that upon displaying pictures of highly charged emotional subjects to the volunteers, those who were sleep deprived had a 60 percent stronger reaction in the amygdala than did those who had gotten normal sleep. Though the researchers had anticipated that there would be a distinction, they had not guessed it would be so extensive.
According to researcher Matthew Walker, “The size of the increase really surprised us. It is almost as though, without sleep, the brain reverts back to a more primitive pattern of activity, becoming unable to put emotional experiences into context and produce controlled, appropriate responses.” The study should be particularly notable to those of us who assume that being sleepy as no impact on the way that we interact with other people – there seems no doubt that being overly sensitive or reactive in our relationships when we’re not getting enough sleep is a result.
Though other scientists reviewing the data find it of questionable use in terms of its original goals, finding a link between mental illness and sleep deprivation, they do think it of interest in terms of people who are simply not aware of the impact that sleep deprivation has on their personalities. According to Professor Derk-Jan Dijk, a sleep researcher from the University of Surrey, “While there have been a lot of studies into the effects of sleep deprivation, this is the first to show what is happening in the brain in response to these emotional stimuli.”