On May 23, 1987 Kenneth Parks drove to his in-laws' house in the middle of the night and brutally murdered his wife’s mother and attempted to kill her father. Prior to that there were no signs of violence, no horrible childhood, no shocking past trauma from a war experience. There was nothing particularly stressful at work. He had some financial issues, a gambling addiction and marital problems, but up until that evening by all accounts he’d been a mild mannered guy with a cordial relationship with his in-laws.
Remarkably that night he confessed to the crime and during a subsequent trial was acquitted by a jury of his peers of the murder and attempted murder. A case of injustice, you might ask? No, according to the court documents, it was a case of homicidal somnambulism, sometimes known as lethal sleepwalking.
Sleepwalking is a strange occurrence, part of a larger category of phenomenon known as parasomnias according to David Eagleman in Incognito: The Secret Life of the Brain. “While the brain normally emerges from slow-wave sleep into lighter stages, and finally to wakefulness, Kenneth’s electroencephalogram (EEG) showed a problem in which his brain tried to emerge straight from a deep sleep stage directly into wakefulness - and it attempted this hazardous transition two to twenty times per night. In a normal sleeping brain, such a transition is not attempted even once in a night. Because there was no way for Kenneth to fake his EEG results, he was exonerated of the crimes.”
Normally during sleep your muscles move into a mild form of paralysis, which keeps you from walking. But during parasomnias your brain moves into a kind of limbo, between a waking state and a sleeping state. And in this limbo actions are not voluntary. So who is actually directing the show? It’s hard to say.
What is known is that the prefrontal cortex, the part of the brain that serves the role of advisor, is not engaged in its normal advisory role. And with the prefrontal taking a nap, all hell can break lose, as we see with the Parks case. Inhibitions fall to the wayside, and odd, sometimes dark behavior takes over. (An overindulgence of alcohol can produce similar inhibition reductions in some people.)
There are certain individuals who when forced to sleep in unfamiliar surroundings display the brain’s ability to be partially awake and partially asleep at the same time, literally sleeping with one eye open. Some scientists believe this was a common trait demonstrated by our ancient ancestors for safety reasons, and the genetic remnants of this behavior continue to linger in a few people today. It’s hard to say how many people have this ability but it is known that when sleeping in a strange place most peoples’ brains don’t go into a fully relaxed modality until they have slept in that same place for roughly five nights in a row and there is some sense that they are safe.
For those who travel regularly this is an unwelcome piece of news but perfectly explained by how worn-weary they feel at the end of a travel week.
As Kenneth Parks proves, sleepwalking can be a dangerous business. Some suffering from this disorder sleep in specially designed sleeping bags that keep their hands restrained so they don’t go off on a ‘walkabout’ at night.
So, next time you climb into bed, ponder the plight of people like poor Kenneth Parks - even during sleep they cannot rest.