Dreams and Sleep
not know much about why or how we dream, some have suggested that we typically spend more than two hours dreaming each night. Many people experience their most vivid dreams during REM sleep; less vivid dreams occur at other times of the night. Comparative research has shown that while most mammals and birds show signs of REM sleep, reptiles and other cold-blooded animals scientists still don't know—and probably never will—if animals dream during REM sleep, as humans do. "How can you prove that another person has dreams?" says Jerome Siegel, PhD, a professor of Psychiatry at the UCLA Center for Sleep Research. "You ask them."
For more information about dreams, including tips for remembering your dreams and suggestions on interpretation visit the Association for the Study of Dreams' Web site .