Scientifically speaking, dreams (study of oneirology) are successions of images, ideas, emotions, and sensations that occur involuntarily in the mind during certain stages of sleep. Scientists believe that, in addition to humans, birds and other mammals also dream. Continue reading for more.
Dreams can last for a few seconds, or as long as twenty minutes. People are more likely to remember the dream if they are awakened during the REM phase. The average person has three to five dreams per night, but some may have up to seven dreams in one night. The dreams tend to last longer as the night progresses. During a full eight-hour night sleep, two hours of it is spent dreaming.