The results show that during nighttime dreaming, also known as REM sleep, the brain processes emotional experiences in a "safe" environment, or one in which stress chemicals are low. This processing may take the emotional edge off of difficult memories, the researchers said.
"We wake up the next day, and those experiences have been softened in their emotional strength," said study researcher Matthew Walker, an associate professor of psychology and neuroscience at the University of California, Berkeley."We feel better about them, we feel we can cope."