The Dream Difference.

The article reports a study which indicates that a person is more likely to dream about fighting with his spouse, or other aggressive interactions, during rapid eye movement (REM) sleep than non-REM sleep. While we dream, the brain cycles through REM and non-REM sleep stages at 90-minute intervals. Dreams during both stages tend to mull over social interactions, leading some sleep researchers to speculate that dreams may help people better deal with these encounters. Researchers have also known that REM and non-REM sleep activate different areas of the brain.