A GLIMMER of consciousness is all it takes to learn something new.
The discovery might mean that learning to make new associations could encourage people with consciousness disorders to recover. It also suggests that some patients diagnosed as being in a vegetative state (VS) are in fact minimally conscious (MCS).
Minimally conscious patients are more likely to recover than those in a VS and so receive different therapies. But telling them apart is tricky. Tristan Bekinschtein of the UK鈥檚 Medical Research Council鈥檚 Cognition and Brain Sciences Unit in Cambridge decided to investigate how both groups might respond to a Pavlovian conditioning test.
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His team taught 22 patients with consciousness disorders, including MCS and VS, to associate a beeping sound with air being puffed into the eye, which triggers a blink. The team found that most of the people diagnosed as being minimally conscious and some with a VS diagnosis blinked on hearing the beep. They were anticipating the air puff, even when it didn鈥檛 come, a sign that they had learned to make the association (Nature Neuroscience, ).
Next his team hopes to explore whether such learning might aid recovery. 鈥淚f you train networks in the brain, you can transform the network itself,鈥� he says.
Bekinschtein says this type of learning has to be consciously processed and concludes that those with a VS diagnosis who passed the test are in fact minimally conscious and had been misdiagnosed.