Dreams

Type of psychology: Cognition; consciousness
Fields of study: Classic analytic themes and issues; cognitive processes;
sleep; thought
Dreams are the series of images, thoughts, and feelings that occur in the mind of the
sleeping person. Dreams are usually confused with waking reality while they are occurring.
Distinctive neurological phenomena are associated with the production of
dreams, and diverse psychological experiences are conveyed in dreaming.

Key concepts
• D-sleep
• latent content
• manifest content
• NREM sleep
• REM sleep
• S-sleep
• sleep mentation
Humans spend roughly one-third of their lives sleeping, and laboratory research
indicates that at least a third of the sleep period is filled with dreaming.
Thus, if a person lives seventy-five years, he or she will spend more than
eight of those years dreaming. People throughout the millennia have pondered
the meaning of those years of dreaming, and their answers have
ranged from useless fictions to psychological insights.

Some of the earliest known writings were about dreams. The Epic of
Gilgamesh, written around 3500 b.c.e., contains the first recorded dream
interpretation. An Egyptian document dating to the Twelfth Dynasty (1991-
1786 b.c.e.) called the Chester Beatty Papyrus (after its discoverer) presented
a system for interpreting dreams. The biblical book of Genesis, attributed
to Moses, who is claimed to have lived between 1446 and 1406 b.c.e.,
records a dream of Abimelech (a contemporary of Abraham and Sarah)
from a period that appears to antedate the Twelfth Dynasty. Other classics of
antiquity, such as the Iliad and Odyssey of Homer (c. 725 b.c.e.), the Republic
of Plato (427-347 b.c.e.), and On the Senses and Their Objects, written by Aristotle
(384-322 b.c.e.), grappled with discerning the meaning of dreams.
Artemidorus Daldianus (c. second century c.e.) provided a comprehensive
summary of ancient thinking on dreams in his famous book, Oneirocritica
(the interpretation of dreams).

To understand dreaming, it must be distinguished from related phenomena.
If the person is fully awake and perceives episodes departing from natural
reality, the person is said to have experienced a vision. Experiencing an
unintended perceptual distortion is more properly called a hallucination. A
daydream is a purposeful distortion of reality. In the twilight realm of
dreamlike imagery occurring just before falling asleep or just before becoming fully awake, hypnagogic or hypnopompic reverie, respectively, are said
to occur. Dreams occur only in the third state of consciousness�"being fully
asleep. Another distinction is needed to differentiate between the two types
of psychological phenomena that occur when a person is in this third realm
of consciousness. Dreams have the attributes of imagery, temporality (time
sequence), confusion with reality, and plot (an episode played out). Those
subjective experiences that occur during sleep and are lacking in these attributes
can be labeled as sleep mentation.