Neuroscience
It’s difficult to imagine anything worse than lying paralysed, being fully aware and yet unable to signal to your loved ones sitting around you that – yes, you can hear them, you are there. If only the doctors could scan your brain and see that you were listening and thinking. Remarkably, that’s what British researchers Adrian Owen and colleagues at the MRC Cognition and Brain Sciences Unit claim to have done.
Owen’s team scanned the brain of a 23-year-old woman left in a coma by a car accident. She had emerged from coma into what’s known as a persistent vegetative state, characterised by periods of sleep and wakefulness but showing no outward signs of being consciously aware.
First they found the language parts of her brain responded to spoken sentences, and that ambiguous sounding words like creak/creek triggered activity in an area known to be involved in selecting between alternative meanings. More amazing, however, was what happened when they asked her to imagine either playing tennis or walking around her home. The tennis instruction prompted activity in the motor control parts of her brain, whereas the home instruction triggered memory-related activity associated with navigation – both in a way indistinguishable from the activity observed when healthy participants followed the same instructions.
“Her decision to cooperate by imagining particular tasks when asked to do so represents a clear act of intention, which confirmed beyond any doubt that she was consciously aware of herself and her surroundings”, the researchers concluded.
However, commentators have advised caution in interpreting the results. “We should not generalise from this single patient, who suffered relatively few cerebral lesions, to most other vegetative state patients, who typically have massive structural brain lesions” said Lionel Naccache at the Cognitive Neuroimaging Unit, INSERM, writing in the same journal issue. “If this patient is actually conscious, why wouldn’t she be able to engage in intentional overt motor acts, given that she had not suffered functional or structural lesion of the motor pathways”, he asked.
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Owen, A.M., Coleman, M.R., Boly, M., Davis, M.H., Laureys, S., & Pickard, J.D. (2006). Detecting awareness in the vegetative state. Science, 313, 1402.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Neuroscience
Finding consciousness within
It’s difficult to imagine anything worse than lying paralysed, being fully aware and yet unable to signal to your loved ones sitting around you that – yes, you can hear them, you are there. If only the doctors could scan your brain and see that you were listening and thinking. Remarkably, that’s what British researchers Adrian Owen and colleagues at the MRC Cognition and Brain Sciences Unit claim to have done.Owen’s team scanned the brain of a 23-year-old woman left in a coma by a car accident. She had emerged from coma into what’s known as a persistent vegetative state, characterised by periods of sleep and wakefulness but showing no outward signs of being consciously aware.
First they found the language parts of her brain responded to spoken sentences, and that ambiguous sounding words like creak/creek triggered activity in an area known to be involved in selecting between alternative meanings. More amazing, however, was what happened when they asked her to imagine either playing tennis or walking around her home. The tennis instruction prompted activity in the motor control parts of her brain, whereas the home instruction triggered memory-related activity associated with navigation – both in a way indistinguishable from the activity observed when healthy participants followed the same instructions.
“Her decision to cooperate by imagining particular tasks when asked to do so represents a clear act of intention, which confirmed beyond any doubt that she was consciously aware of herself and her surroundings”, the researchers concluded.
However, commentators have advised caution in interpreting the results. “We should not generalise from this single patient, who suffered relatively few cerebral lesions, to most other vegetative state patients, who typically have massive structural brain lesions” said Lionel Naccache at the Cognitive Neuroimaging Unit, INSERM, writing in the same journal issue. “If this patient is actually conscious, why wouldn’t she be able to engage in intentional overt motor acts, given that she had not suffered functional or structural lesion of the motor pathways”, he asked.
__________________________________
Owen, A.M., Coleman, M.R., Boly, M., Davis, M.H., Laureys, S., & Pickard, J.D. (2006). Detecting awareness in the vegetative state. Science, 313, 1402.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
- Inside The Brain Of A Woman With Conversion Paralysis
A new brain imaging study shows the difference, in terms of brain activity, between a person feigning having a paralysed arm and a patient with conversion paralysis - that is, paralysis with no clinically identifiable neurological cause. Conversion paralysis...
- Detecting Consciousness In A Totally Locked-in Patient
Alert to your surroundings but helpless to respond. It's difficult to imagine a worse situation, but this is the terrifying reality for a minority of brain damaged patients with total locked-in syndrome. Fortunately, researchers are developing ways...
- The Precuneus And Recovery From A Minimally Conscious State
You've probably heard about the case of Terry Wallis, a 42 year old man in Arkansas who spent 19 years in a "minimally conscious state" following severe traumatic brain injury. Then one day he saw his mother walk into the room and (after not speaking...
- Hypnosis And Consciousness
Next in a continuing series on hypnosis: Functional neuroanatomy of the hypnotic state In Press, Corrected Proof, Journal of Physiology (Paris). Marie-Elisabeth Faymonville, Mélanie Boly and Steven Laureys What is hypnosis and how to induce it There...
- News In Science - Woman In Coma Plays Tennis - 08/09/2006
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