A recent study shows that lack of sleep may cause you to have higher than normal anxiety levels. This research comes from the University of California, where researchers used brain scanning on 18 adults. The subjects were tested after a normal nights sleep and also after being sleep deprived. In both situations the participants were exposed to an emotional task which required them to have a period of anticipation. In the end the brain scans showed that sleep deprivation amplified feelings of anxiety and build-up to the emotional event. In addition, the researchers found that the sleep deprivation effect was even more amplified if the person was already a naturally anxious person. The main part of the brain that is effected by this correlation of emotion and sleep patterns is the amygdala.