Dreams have fascinated humans from the earliest of times. Yet modern research is still struggling to understand the nature and functions of dreaming. It has been observed that sleep mentation tends to be in continuity with waking mentation but that the memory sources of dreams are significantly transformed into new expressions of past experience and current concerns. Some dreams are creative and useful. Dreams can also be used to increase self-knowledge or as complement in psychotherapy. Negative emotions prevail in dreams and can culminate in nightmares. Fortunately, dreams can be controlled...

Dreams have fascinated humans from the earliest of times. Yet modern research is still struggling to understand the nature and functions of dreaming. It has been observed that sleep mentation tends to be in continuity with waking mentation but that the memory sources of dreams are significantly transformed into new expressions of past experience and current concerns. Some dreams are creative and useful. Dreams can also be used to increase self-knowledge or as complement in psychotherapy. Negative emotions prevail in dreams and can culminate in nightmares. Fortunately, dreams can be controlled by suggestion, imagery rehearsal, and lucid dreaming. Electrophysiological and neuroimaging studies suggest that the unique features of dreaming are due to the fact that key brain structures are activated and interact differently in REM sleep than in waking. While many dream function theories have been proposed, more rigorous scientific research is needed to determine whether dreaming by itself serves an adaptive function.