Patients in vegetative state show 'hidden awareness'

A new study has revealed that there is "hidden brain signatures" of consciousness in the patients in a vegetative state.

There has been a great deal of interest recently in how much patients in a vegetative state following severe brain injury are aware of their surroundings and although unable to move and respond, some of these patients are able to carry out tasks such as imagining playing a game of tennis.

Using a functional magnetic resonance imaging (fMRI) scanner, which measures brain activity, researchers have previously been able to record activity in the pre-motor cortex, the part of the brain which deals with movement, in apparently unconscious patients asked to imagine playing tennis.

The researchers showed that the rich and diversely connected networks that support awareness in the healthy brain are typically, but importantly, not always impaired in patients in a vegetative state and some vegetative patients had well-preserved brain networks that look similar to those of healthy adults, who had shown signs of hidden awareness by following commands such as imagining playing tennis.

Researcher Srivas Chennu said that understanding how consciousness arises from the interactions between networks of brain regions is an elusive but fascinating scientific question and their research could improve clinical assessment and help identify patients who might be covertly aware despite being uncommunicative.

The findings of the research are published in the journal PLOS Computational Biology.