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After a wonderfully relaxing and much-needed vacation break, I've been trying to figure out which topic to tackle next in the blog. I have a couple of installments left on the writing of research grants and plenty of science news articles that caught my eye... many weeks ago. Thus I am afraid I am not quite current and up to date.
Then New Scientist came to the rescue.
New Scientist is a science news magazine based in the UK, and they have a great daily news feed with many interesting articles. They are a high-quality magazine (and I'm not saying that just because they've interviewed me) because they have scientists with real communications skills writing about science.
Just a few minutes ago I received the following on my RSS news feed: "Mindscapes: First interview with a dead man" (http://www.newscientist.com/article/dn23583-mindscapes-first-interview-with-a-dead-man.html). To say that I was merely curious would be to deny the excitement and trepidation I felt - was this about near-death experience? pharmacological states of "zombie-like" mindlessness? Some other metaphysical mumbo-jumbo?
Of course not. This is New Scientist. Instead, I found a fascinating article about "Cotard's Syndrome" an extremely rare psychological disorder in which patients are convinced (despite evidence to the contrary) that portions of their body are dead or missing.
I have mentioned in prior posts on amnesia and brain damage that there are syndromes of "Neglect" in which damage to sensory areas of brain lead a patient to "neglect" or ignore a body part and act as if it is not there. Visual neglect causes a patient to ignore part of their visual field - to the point of not consciously being aware of objects in that portion of their field of view, even though they can still have emotional or reflex reactions to those objects. Somatic neglect (i.e. applied to the body) can cause a person to "forget" that they have arms, legs, fingers, toes - until they become rather surprised to actually see them, or touch them with the limbs from the opposite side of the body.
"Neglect" typically results from stroke or head injury, and results from real damage to the portions of the brain that receive sensory feedback from the neglected body part. Not so Cotard's syndrome, which is not associated with obvious injury.
The most profound and puzzling example of Cotard's Syndrome is detailed in the New Scientist article - "Graham" is a man who was convinced that his brain was dead, and he was merely an empty shell that was walking around. Neurologists and psychologists believed that Cotard's was simply a manifestation of depression, and there may be some common origins. However, Graham not only told told doctors that his brain had died after a failed suicide attempt, his body eventually started to show signs of decay: He lost sense of taste and smell, his hair fell out, his gums blackened, and felt like he was simply going through empty motions.
Brain scans provided the first clue to what was really going on. Positron emission tomography (PET) scans of the metabolic activity of the brain showed that the activity in the Frontal and Parietal Lobes were suppressed well below normal activity. Within the brain, particularly the deep areas of the Frontal Lobe is what is termed by neurologists the "Default Mode Network" which is always active when an individual is conscious. The network is central to memory of self, personal history and awareness of surroundings. Yet in Graham, those brain areas were more typical of a person in a coma or vegetative state - so yes, as far as activity was concerned, his brain was "dead."
Eight years of psychotherapy and medication have returned Graham to the land of the living - and his brain scans show a return to more normal patterns - but this case, and others with Cotard's syndrome point out a fascinating linkage between the brain, the mind and the body. Without a certain minimal activity of the Default Mode Network, Graham had no sense of self - exaggerated to a sense that that self was in fact dead. With no psychological investment in life, his body started to show signs of death as well, manifesting the lack of involvement in the physical world.
We often joke about "Zombies" as brainless individuals (as opposed to mystical walking dead) but could a complete suppression of Frontal Lobe function really produce the Walking Dead of story and myth? I'll be exploring these themes this summer in an article I am writing for Baen Books, and I'll link it here when published.
Until then - enjoy your weekend and don't let your brain wander needlessly!