To dream or not to dream; Do people have a choice without the right equipment?

Dreaming is considered an activity that takes place when one enters the REM cycle during sleep. (1) Often times, most people do not remember their dreams, but it seems that as long as one sleeps long enough to enter the REM cycle, everyone dreams. Dreams are thought to be based on one's recent past experiences or declarative memories. What happens when one does not remember one's past experiences? Do they dream?

Those who suffer from amnesia have damaged their hippocampus. The damage can result from head trauma, Alzheimer's, anoxia (oxygen deprivation), or encephalitis (acute inflammation of the brain). (2) The hippocampus is in the temporal lobe of the brain and is part of the limbic system, which includes parts of the cerebral cortex that are responsible for manifesting emotions. (3) The general thought of the role of the hippocampus in memory is the hippocampus is responsible for creating new memories of experienced events. Some also believe the hippocampus plays a role in declarative memory, a component of memory for facts. (4) When there is damage to the hippocampus, it becomes very difficult to form new memories and to access memories prior to the damage; therefore amnesiacs do not have information in their brain about their recent past experiences to dream about.

Although patients with amnesia can remember new information temporarily it is generally forgotten after a few minutes. Dreaming seems impossible for amnesiacs based on previous research and data; however those with amnesia do dream. According to new research directed by Robert Stickgold of Harvard Medical School, although amnesiacs do not remember their recent past experiences, they do dream about them. . (4) The research concluded that dreams do not come from declarative but implicit memories. Implicit memory is when previous experiences aid in the performance of a task without conscious awareness or memory of these previous experiences. (6) Types of implicit memory are procedural memory and semantic memory. Procedural memories provide the information one uses without understanding how one knows what one is doing, such as typing without looking at the keyboard. Semantic knowledge provides general abstract ideas. Based on the conclusions made by Stickgold, it makes sense that dreams are based on implicit memories because dreams usually seem illogical, random, and they do not seem to have a set time or place. If dreams came from declarative memories, one would think dreams would be more organized in the sense that since one's episodic memory, a subset of declarative memory, is the memory of events and their time and place, dreams would include information such as time and place.

Dreams seem to play a necessary but unknown function in the way the brain processes information. "Dreams let you consolidate and integrate your experiences, without conflict with other input from real life," Stickgold said. "Dreaming is like saying, ‘I'm going home, disconnecting the phone, nobody talk to me. I have to do work.'" (5) Based on Stickgold's statement, one can conclude dreaming is needed for the brain to make emotional connections to new pieces of information.

According to Dr. Mark Solms, from St Bartholomew's Hospital in London, he has found those that have damage to the parietal lobes and to the ventromesial quadrant of the frontal lobes do not dream. (7) The parietal lobes have two functional regions; one deals with sensation and perception and the other with integrating sensory input, mostly with the visual system. (8) The first function combines sensory information to form a single perception. The second function creates a spatial coordinate system to represent the world around us. Damage to the parietal lobes seems to affect the second function in the ability to dream. Without the ability to create spatial imagery, the brain is unable to create pictures in the mind therefore how can one dream. The ventromesial quadrant of the frontal lobes has fibers that transmit dopamine. This dopamine system has been implicated in schizophrenia. As a result of damage to this part of the brain, the patients lost dreaming; and became very apathetic, inert, lost all their spontaneity, similar to being depressed. This is a surprising result since the ventromesial quadrant of the frontal lobes and dopamine are associated with urges for something/addictions only. There is further evidence to support the correlation between dopamine and dreaming. Dr. Solms mentions a pharmacological study done by Ernest Hartman. Hartman showed that levadopa, a drug that creates dopamine transmission in the brain is given to patients while they are asleep, it causes them to have vivid, frequent and long dreams. However it does not have any effect on their REM sleep. One of the well known symptoms of cocaine intoxication or amphetamine psychosis is vivid, repeated, strange hallucinatory dreams which patients have immense difficulty distinguishing from reality. Haloperidol is a drug used to treat cocaine intoxication and amphetamine psychosis. Haloperidol works to block dopamine activity, which would stop the hallucinatory dreams. A conclusion that could be drawn from this data is dreams must be involved driving urges for something. It seems that Freud was correct when he stated dreams represent the unconscious desires of the dreamer.

Dreams themselves are complex and dreaming seems to be even more complicated. It would be interesting to see if there are differences in brain function of those who dream and those who do not. If Freud's theories about dreams are indeed correct, is there a way to obtain and analyze these unconscious desires while one is in a conscious state of mind? Of course, one can argue that the brain is just making emotional connections to new pieces of information. The controversial arguments about dreams and their meaning will continue and although the function of dreams is debatable one can still conclude dreams do indeed have a function.

1)Wikipedia: Dream

2)Wikipedia: Amnesia

3) Campbell, Neil A. and Reece, Jane B. Biology. California: Pearson Education, Inc, 7th Edition: Hippocampus, p. 1034.

4)Wikipedia: Hippocampus

5)MSNBC: Wren, Kathleen. How the brain turns reality into dreams

6)Wikipedia: Implicit Memory

7)Radio National: Health Report

8)Parietal Lobes

9)Sigmund Freud- Life and Work