Researchers, at The University of California Berkeley and Harvard Medical School, have used brain imaging machines to study people?s brains after they had either a full night sleep or an 'all-nighter'. Both groups showed the same baseline response when asked to view innocuous images. However, those who had spent 35 hours awake showed a heightened emotional response when exposed to increasingly distressing images, eg a tarantula on a person?s arm, when compared to those who had slept all night. The sleep deprived participants displayed 60% more activity in the amygdala compared to the normal populations? response.
Matthew Walker, the lead researcher, said that they had never seen a magnitude of increase between two groups that big in any of their studies before. They also found that between the two groups the amygdala was communicating to different regions of the brain. The amygdala of the sleep deprived patients seemed to rewire to the area of the brain which produces the fight or flight hormone, where as the rested individuals' amygdala was wired to more rational areas of the brain. The research team suggests that this evidence may help researchers to think about a new potential function for sleep, which is that it might serve to prepare our emotional brains for the next days social and emotional interactions. To purchase this article click here and to read the Scientific American article click here