It is well established that sleep loss increases negative emotions, such as anxiety and sadness.
"Despite typical tendencies to get somewhat used to irritating conditions -- an uncomfortable shirt or a barking dog -- sleep-restricted individuals actually showed a trend toward increased anger and distress, essentially reversing their ability to adapt to frustrating conditions over time. No one has shown this before," Krizan professor of psychology at Iowa State said.
To measure anger, Krizan and Garrett Hisler, an ISU doctoral student in psychology, had participants come to the lab -- before and after the sleep manipulation - to rate different products while listening to brown noise or more aversive white noise (similar to a static signal).
Krizan says the purpose was to create uncomfortable conditions, which tend to provoke anger.
"In general, anger was substantially higher for those who were sleep restricted," Krizan said.