This paper reflects the research and thoughts of a student at the time the paper was written for a course at Bryn Mawr College. Like other materials on Serendip, it is not intended to be "authoritative" but rather to help others further develop their own explorations. Web links were active as of the time the paper was posted but are not updated. Contribute Thoughts | Search Serendip for Other Papers | Serendip Home Page |
Dreams
While we sleep, our bodies rest from the events of the day and recharge
in order to face the next round of challenges it will face during its waking
life. During sleep, our brains produce a
fractured, often nonsensical amalgamation of random events and people, otherwise
known as dreams. These dreams often
provoke powerful reactions of fear or pleasure, as, for all their
improbability, they follow reality in such a way as to trick the dreamer into
reacting to this fantasy world as if it actually existed. However, although dreaming undeniably is a
large and memorable part of one's nightly sleep cycle, scientists have yet to
define for certain the biological function of dreams. Some believe dreams are a remnant of our
Neanderthal past, when our ancestors used dreams as a sort of training ground
for developing appropriate reactions in the life or death struggles they faced
every day. Others thinks
dreams simply stem from random impulses which produce images from one's daily
life with no particular significance. Others believe that dreams serve to "clean
out" the emotional stress accumulated during the day. Whatever the hypothesis, it is difficult to
prove for certain the purpose of dreams.
Researchers have identified four
distinct stages to the sleep cycle (1). Of these, the phase known as Rapid Eye
Movement (REM) is most closely associated with dreaming. The REM phase, characterized by rapid heart
rate, distinct brain waves, and an increased amount of electrical activity in
the brain, produces the most vivid and memorable dreams (2). Initially, scientists believed that dreams
only occurred during REM sleep. While
studies have identified dreams during other phases of the sleep cycle, the most
powerful dreams are still associated with REM sleep(1). Previously,
scientists and psychologists believed that dreams were simply a byproduct of
the functions of REM sleep, but the discovery of the possibility of dreams occurring
during non-REM stages of the sleep cycle undermines the validity of this
theory. This has led many in the
scientific community to develop new and often farfetched theories of the
biological function of dreams.
The formal study of dreams first
began with psychoanalysts like Sigmund Freud, whose dream theory of 1900 served
as an influential and widely accepted conception of why humans dream. Freud believed that dreams reflected the
baser impulses of the human subconscious, impulses which could not be acted
upon in society. His observations were
based on subjects whose disturbing dreams haunted them even while they were awake (2). However, while dreams certainly can reflect
the subject undertaking actions which they would never have the opportunity to
do in real life, Freud's theory seems to imply that
only the seriously troubled dream.
Research has shown that all humans dream, whether or not they remember
their dreams the next day.
In the 1960s and 70s, researchers at
the Harvard Laboratory of Neurophysiology focused on observing the biological
causes of REM sleep in order to better understand why humans dream. They discovered that REM sleep is induced by
the release of the brain chemical acetylcholine. The release of this chemical stimulates nerve
impulses which recreate random bits of one's internal information in a sequence
which may not conform to logic. J. Allan
Hobson and Robert McCarley, the primary researchers
at the Harvard laboratory, named this new theory the activation-synthesis
hypothesis. From this hypothesis, Hobson
developed an idea of dreaming not as an arena in which to explore hidden urges,
but as an opportunity for mental "housekeeping". He also believed that dreams could serve to
solidify emotional ties to memories (2).
Since scientists like Hobson
established a biological basis for why humans dream, other researchers have
developed their own theories regarding the purpose of dreams, while undermining
others' hypotheses. Hobson's concept of
dreams as an opportunity for mental reorganization has been criticized as
research has shown that very little of the day's events recurs in that night's dreams
(4).
Rather, dreams tend to deal with larger issues of conflict and emotions,
which has led others to develop a concept of dreams as stimulated by a threat simulation mechanism, a
remnant of the days when humans faced life or death struggles on a daily
basis. This theory also takes into
consideration the recurring dreams of war veterans and trauma victims, as in
these cases the brain attempts to present the dreamer with the former conflict
again and again in order to prepare them to deal more effectively with such a
catastrophe in case they are ever in such a position again (3). Many agree with this theory in part, as they
recognize the problem solving aspect of dreams, but may not believe in the
existence of a threat simulation mechanism (5). Still others believe dreams have no
biological function at all, only a cultural significance assigned by human
attempts to make sense of dreams (4).
Humans may never discover the actual
biological function of dreams. While many
theories of dreams as an opportunity to reorganize one's thoughts and to solve problems
sound feasible, it is difficult to prove anything conclusively, due to the relative
youth of neurobiology and the shadowy nature of dreams themselves. As our general understanding of the brain
develops, scientists may be better able to understand why we dream.
Works Cited
3. "The Biological
Function of Dreaming"
