Biology 202, Spring 2005
Second Web Papers
On Serendip

Eyewitnesses report that someone in the midst of a dissociative fugue appears to behave normally "apart from [an] inability to recall their past or personal information".(2) However, when a fuguer "comes to" he often behaves as though he has just been awoken from a deep sleep, that is, he appears dazed and disoriented. In addition, such an individual is unable to recall how she arrived at her destination, or why. "His brother found him in a nearby town helping a traveling umbrella salesman. Tapped on the shoulder, he acted as if he were awaking from a deep sleep, groggy and confused, astonished to find himself where he was, carting umbrellas."(3) This is very similar to the reports given by sleepwalkers and those who observe them in the act. An individual who is sleepwalking appears at first glance to be conscious, however when she awakens she has no recollection of her unconscious wanderings. Moreover, witnesses to both phenomenon report that fuguers and sleepwalkers both exhibit what is described as a "blank facial expression".(4) In other words, although both fuguers and sleepwalkers are able to perform a variety of complex functions, including mobility and verbal communication to some extent, it is still apparent that their "minds" are elsewhere during an episode. This is evident in their inability to recollect their actions upon "awakening". Therefore, from the perspective of an outside observer it would appear as though these two conditions, automatisme ambulatoire and somnambulism, look like the same thing. Is somnambulism a dissociative disorder? Are fuguers asleep? And if the answer to either of these questions is yes, then what is the difference between being awake and being asleep?

One method that scientists use to distinguish between the states of sleep and wakefulness is monitoring neurobiological status. That is, the patterns of brain functioning associated with being awake are different than the patterns associated with being asleep. For example, an electroencephalogram (EEG)-which monitors electrical activity in the brain-of an individual who is awake alternates between two patterns of activity. "One is low voltage (about 10-30 microvolts) fast (16-25 Hz or cps; cycles per second) activity, often called an "activation" or desynchronized pattern. The other is a sinusoidal 8-12 Hz pattern (most often 8 or 12 Hz in college students) of about 20-40 microvolts which is called "alpha" activity."(5) In contrast the patterns of brain activity in an individual who is asleep cycle between five different stages. The first four are the stages of NREM (non rapid eye movement) sleep and the last stage is REM (rapid eye movement) sleep. Although the first four stages are distinct, they are generally more similar and are characterized by a presence of slower, higher amplitude waves known as "delta" waves, which correlates to the increase in synchronicity of brain activity. REM sleep, however, exhibits a mix of frequencies (i.e. it is desynchronized) and appears similar to both the awakened state and Stage 1 of sleep.(6)

Sleepwalking is generally associated with the early stages of sleep and would therefore consist of high voltage low frequency brain activity patterns, similar to the "activated" state of wakefulness (10-30 microvolts, 16-25 Hz).(7) Not surprisingly, the brain activity of someone in the midst of a dissociative disorder like fugue is slightly slower than normal awake activity (approximately 8-13 Hz).(8) However, when we compare this to the brain activity of a sleepwalker, this is surprising. On the basis of brain activity alone it appears as though sleepwalking is a more "activated" state than fugue, which is a wakeful, albeit unaware, state. This seems to imply that despite the fact that fuguers are awake and are more functional than sleepwalkers (in that they are able to communicate clearly and to travel great distances), their conscious is actually less involved.

So what does this all mean? At most this has serious implications for the belief that sleep is distinct from wakefulness and that we are able to tell the difference. That is, fuguers, who are not asleep, are to the outside observer almost identical to sleepwalkers, and both conditions are rather difficult to distinguish from an awakened, fully conscious state. Moreover, the neurological activity of individuals who suffer from these two conditions would seem to produce a conclusion about the respective "awareness" of fuguers and sleepwalkers that is the opposite of the one we now hold. To conclude, however, that this means we cannot actually differentiate between wakefulness and sleep is perhaps a bit hasty. At the very least though, this poses an interesting challenge to our categorization of automatisme ambulatoire and somnambulism.

References

1), The National Society for Epilepsy. Dedicated to providing information and support for people with epilepsy.

2), Genesis Health System, a healthcare provider and information source for health related issues.

3) Hacking, Ian. Mad Travelers: Reflections on the Reality of Transient Mental Illnesses. University Press of Virginia. Charlottesville, VA. 1998 (p21)

4), Medicine Plus, a Service of the U.S. National Library of Medicine and the National Institutes of Health.

5), Basics of Sleep Behavior. A rich guide to information on a broad range of topics related to sleep.

6), Basics of Sleep Behavior. A rich guide to information on a broad range of topics related to sleep.

7), Basics of Sleep Behavior. A rich guide to information on a broad range of topics related to sleep.

8), EEG Research. A collection of research papers on the topics of EEG Biofeedback and Neurofeedback.


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