Dreams can be fascinating, scary, mesmerizing, or just plain random. “During a typical lifespan, a human spends a total of about six years dreaming”. Have you ever wondered why we dream? Here’s a brief introduction to all the current major dream theories.
Freudian Dream Theory
Sigmund Freud’s theory of dreams was first codified in his work The Interpretation of Dreams. He argues dreams are attempts by our unconscious to express our hidden desires, fears, and feelings. Furthermore, Freud believed dreams contain an encoded language. This language is highly subjective to the individual person because it is based on sensory symbolisms that are derived from personal experience. These symbolisms may be sights, sounds, tastes, smell, or touch.
Moreover, Freud argues that the explicit, “manifest”, content of dreams (what actually happens) is not as important as the implicit, “latent”, meaning. The latent meaning is what repressed desires our unconscious is trying to communicate.
Freud’s theory of dreams was the dominate theory until the discovery of REM sleep in 1953. 
Jungian Dream Theory
Carl Jung’s theory of dreams differed from Freud’s because he saw dreams not as symptoms of repressed desires but as our brains method of forming connections and relationships between our waking experiences. Jung also believed the manifest content of dreams are more important than the latent.
Jung argues that dreams often touch upon universal archetypes. That is, our personal dream images relay to us parts of the universal, collective human unconsciousness. Jung’s archetypes include the Shadow, the Persona, the Animus/Anima, the Trickster, the Divine Child, the Wise Old Man/Woman, and the Great Mother.
Activation synthesis theory argues dreams are the result of randomly firing neurons during REM sleep. During REM sleep, the motor sensory neurons of the body are paralyzed in a phenomenon known as sleep atonia. The random messages sent to the motor sensory neurons during REM sleep creates a paradox for the brain because the motor sensory neurons will not respond. The brain therefore constructs imaginative narratives using cached sensory memories from you daily life to make sense of the neuronal messages. These narratives are dreams.
The basic assumption of the activation-synthesis theory is that the same mechanisms that control REM sleep also controls dream production. The theory future argues that because some dreams are recurring, the process cannot be completely random.
Continual-activation theory challenges activation-synthesis theory by arguing the brain actually uses different mechanisms for REM sleep than for dreams. The theory was published by Jie Zhang in 2004. It relies on the model of memory known as consolidation theory.
Consolidation theory argues our brains are do not save all of our working memories to long term memory during our waking hours. Instead, part of the function of sleep is to allow for the “consolidation” of our waking experiences into long term memory. Basically, imagine that your brain is your computer. Your computer has a hard drive memory and a RAM, these are analogous to your long term memory and your working memory respectively. When you are using your computer’s applications, you are mainly using its RAM (random access memory). When you are idle, it gives your computer a chance to store information onto its hard drive memory.
Our working memories are further divided into declarative memory, which is conscious, and procedural memory, which is unconscious.
Continual-activation theory argues that there are two types of dreams, type I and type II. Type I dreams are individual “thoughts” and occur during NREM sleep when declarative memory is transferred to long term memory. Type II dreams are what we traditionally refer to as dreams, a continual narrative. Type II dreams occur during REM sleep when procedural memory is transferred to long term memory. Note that continual-activation theory stresses that the occurrence of type II dreams during REM sleep is only a correlation not a causation.
Dreams are still largely not understood despite the amount of research conducted. Perhaps that’s precisely what adds to their mystique. Regardless of why we dream, we will eternally be fascinated by them. Sweet dreams!
 “Dream.” Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 Jul. 2004. Web. 28 Jun. 2010.
 “Sigmund Freud’s Theories of Dreams.” Here Be Dreams. Web. 28 Jun. 2010.
 Zhang, Jie. “Continual-Activation Theory of Dreaming.” DynaPsych. 28 Jun. 2010.
 “Carl Jung’s Archetypes.” Dream Moods. Web. 28 Jun. 2010.
 “Activation-synthesis hypothesis.” Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 Jul. 2004. Web. 28 Jun. 2010.