Evil Eye asks the following question in the forums:
Is sleepwalking/talking/eating etc… related to Dreaming or completely a seperate event?
Here’s why I asked….
ORANGE COUNTY, Fla. (WOFL FOX 35, Orlando) — Justin Cox, whose sleepwalking as a defense against child molestation charges was found not guilty on all counts Thursday afternoon.
The jury took about three hours to return the verdict.
Cox had taken the stand in his own defense Wednesday and told the jury that he was sleepwalking when the incident occurred.
Sleepwalking is an interesting neurological phenomenon. In order to understand it you need a little background on sleep. Sleep is divided into two categories: REM and non-REM (NREM) – REM stands for “rapid eye movement” which is the hallmark feature of this stage of sleep. NREM sleep is divided into four stages, I-IV, which are characterized by progressively deeper sleep and defined by progressively slower rhythms on EEG.
Sleep has a typical “architecture” characterized by sleep cycles we go through throughout a night of sleeping. A normal sleep architecture includes cycles of progressing from stage I to stage IV NREM sleep followed by a period of REM sleep (which is when we dream), and then the cycle repeats itself. In the early part of sleep these cycles tend to be longer with long periods of stage III and IV NREM sleep (called deep sleep and also slow wave sleep because of the slow rhythms, <4 hz, on EEG) and short periods of REM dreaming sleep. As the night progresses we tend to have shorter overall cycles and longer REM periods. We do most of our dreaming in the hours prior to waking up, and we have most of our deep sleep in the first two sleep cycles.
Sleepwalking (also called somnambulism) is one of the parasomnias – disorders of the normal sleep architecture. They generally are cause by a problem with transitioning from one sleep stage to another, like getting stuck while shifting gears. In the different stages of sleep different brain nuclei in the pons (part of the primitive brain stem) that regulate sleep will be active or inactive. These various patterns of activity in the pons are what determine overall brain activity and sleep stage. Many parasomnias are caused by abnormalities in shifting from one pattern of neuronal activity to another. This may cause the fusion of features from different sleep-wake states.
Sleepwalking tends to occur early in sleep, in the first two sleep cycles and they almost always occur out of NREM sleep – so they do not occur while dreaming. In fact they tend to occur during deep or slow wave sleep. If one is awakened from deep sleep they will usually be in a confusional state for a time – up to 30 minutes. It is difficult for the brain to rouse itself from this deep sleep state (a phenomenon called sleep inertia). Sleepwalking typically includes this confusional state. It also includes partial or complete amnesia for the event – people usually do not remember the sleep walking event, unless they are awakened from it, rather than being put back to bed.
With this deep confusion state there are feature of dreaming, specifically hallucinations and imagined realities. However, during REM dreaming sleep a nucleus in the pons paralyzes our muscles from the neck down – so that we do not act out our dreams. This nucleus is not active during sleepwalking, so the sleepwalker is able to physically act out their confused imaginings.
Sleepwalking tends to occur in children, and most children outgrow it – it is therefore considered to be a symptom of an immature nervous system. But rarely sleepwalking can persist into adulthood.
The question at hand is whether or not people can commit purposeful and complex actions while sleepwalking. Mostly, sleepwalkers just roam about aimlessly, with their eyes open. They are able to see and interact with their environment but are confused and either do not respond at all to questioning or may give a nonsensical rambling response. They are glassy-eyed and to not attend directly to other individuals. Sleepwalkers can engage in simple automatic behavior, like getting dressed, but it is currently controversial whether or not they can perform more directed behavior, like assaulting someone.
For example, the SleepChannel has this to say:
Currently, there is nonspecific medical evidence that suggests that there may be psychiatric issues involved in sleepwalking and that the actions of sleepwalkers in certain cases may not be autonomous and need to be reevaluated.
For example, in Britain, a man actually killed someone while sleepwalking. The issue is whether or not to acquit the defendant on the basis of autonomic actions or to find him insane and, therefore, release him to treatment for mental illness. Subsequently, there is controversy surrounding an individual’s right to plead insanity in cases like this, which complicates our perspective of agency in sleepwalking behavior. Sleepwalking is not currently defined or treated as a mental illness.
Future research may involve the development of a medical-legal definition of sleepwalking. Of course, cases like this are rare, but the media coverage of it is greatly responsible for public recognition of sleepwalking.
I also found this (from the London Sleep Center):
Somnambulism or sleepwalking is a viable defence on the basis of automatism. The behaviours that occur during sleepwalking can be highly complex and include sexual behaviour of all types. Somnambulistic sexual behaviour (also called sexsomnia, sleep sex) is considered a variant of sleepwalking disorder as the overwhelming majority of people with Sexsomnia have a history of parasomnia and a family history of sleepwalking. Sexual behaviour during a sleep automatism can vary from explicit sexual vocalisations, to violent masturbation, to complex sexual acts including anal, oral and vaginal penetration. A recent case in England is reported where the defendant was acquitted on 3 charges of rape on the basis of automatism due to somnambulistic sexual behaviour.
To review – it seems to me that complex behavior during sleepwalking, like assault or rape, is rare but possible. However, this is based upon very few cases and remains somewhat controversial. An alternative interpretation is that such behavior is a mental illness masquerading as sleepwalking. Most discussions on the issue point to the need for further research.
With regard to this specific case, therefore, sleepwalking is a plausible defense – although the specific details would be important to forming an opinion. It seems that the prosecution’s alternative hypothesis is that Cox was simply drunk during the assault and is using sleepwalking as a convenient excuse. Since the sleepwalking defense has some plausibility and precedent, we will likely not get a definitive answer in this case.