Slashdot Mirror
"Vegetative State" Patients Can Communicate
Kittenman writes "The BBC is carrying a story about researchers in the UK and Belgium who can detect the thinking processes within a patient previously thought to be in a vegetative state. The researchers ask the patient verbally to think in certain ways to indicate a 'yes', in other ways to indicate a 'no' — and have successfully communicated with 4 out of 23 patients previously thought to be in a coma."
From TFA:
"Patients in a vegetative state are awake, not in a coma, but have no awareness because of severe brain damage. "
It's official. Most of you are morons.
This is not really surprising if you are aware what a real coma is. There is a lot of states between fully consciousness and complete unconsciousness. In movies, and in soaps you switch between those states in a surprise wake-up. In reality this is much more complex.
Anyway, better diagnosis is needed to prevent accidents like Brain scan finds man was not in a coma--23 years later and other possible improvements in brain damage treatment.
The problem of improper controls and false positives is really serious with these fMRI studies. It can be summed up in three words, really: Thinking dead salmon.
I don't think they addressed the "no answer" vs. "B", however, they did assess the patients' ability to answer a series of factual questions about the patient's life prior to whatever put them where they were - I think that pretty much shows that there is something non-spurious being measured here and it's not just the dead salmon fMRI effect as another reply suggested - the probability of random readings matching up with the correct answers to a series of such questions seems very minute.
And 4 out of 23 is not a success rate - it's a misdiagnosis rate! Nobody in their right mind is claiming that *all* patients in persistent vegetative states have meaningful cognition occurring (except the EXTREMELY inaccurate and misleading Slashdot article title). Rather, some patients who failed the standard tests to assess consciousness levels are perhaps more conscious than was previously detectable.
Of the 54 patients examined in the study most had suffered either from traumatic brain injury or anoxic brain injury. Anoxic brain injury for the most part means your heart had stopped for a prolonged period of time (although other things such as severe prolonged hypoglycemia or carbon monoxide can do the same thing). Anoxic brain injury is a diffuse process and its course is highly predictable. Depending on the severity of the initial event with anoxia patients will either improve after a relatively short period of time or they never will. Of all of the 'miracle' re-awaking cases that have occurred (extremely rare cases of people waking up to a severely disabled state) none of them have been by someone who has suffered anoxia.
Traumatic brain injury has a less predictable course as some of the parts of the brain are destroyed while other parts can be relatively undamaged. Of the five patients in the study who were found with some brain activity all of them were traumatic brain injury cases.
Schiavo suffered anoxic brain injury due to cardiac arrest. These patients never need fancy brains scan as their external findings accurately reflect what has happened to their entire brain. The current New England Journal of Medicine article actually serves to support that anoxia patients have no cognition.