Patient in a 'Vegetative State' Paid Attention and Listened to Words

A patient in a seemingly vegetative state may actually be able to pay attention. Scientists found that a patient without the ability to move or speak showed signs of attentive awareness that had not been detected before. In fact, this patient was able to focus on words signaled by the experimenters as auditory targets as successfully as healthy individuals. The findings could pave the way for future studies that may allow those in vegetative states to interact with the outside world.

In order to learn a bit more about how vegetative patients might sense the outside world, the researchers used electroencephalography (EEG), which non-invasively measures the electrical activity over the scalp. In all, the scientists tested 21 patients diagnosed as vegetative or minimally conscious, and eight healthy volunteers. Participants heard a series of different words while asked to alternatingly attend to either the word "yes" or the word "no." This was repeated over a period of 30 minutes to detect whether patients could attend to the correct target word.

So what did the researchers find? It turned out that one of the vegetative patients was able to filter out unimportant information and home in on relevant words they were being asked to pay attention to. The researchers then used brain imaging (fMRI) and discovered that this same patient could follow simple commands to imagine playing tennis. They also found that three other minimally conscious patients reacted to novel but irrelevant words.

"Not only did we find the patient had the ability to pay attention, we also found independent evidence of their ability to follow commands--information which could enable the development of future technology to help patients in a vegetative state communicate with the outside world," said Srivas Chennu, one of the researchers, in a news release. "In order to try and assess the true level of brain function and awareness that survives in the vegetative and minimally conscious states, we are progressively building up a fuller picture of the sensory, perceptual and cognitive abilities in patients."

The findings could be huge for understanding how to communicate with patients in a vegetative state. More specifically, scientists could learn to develop new tools so that those patients can interact with the outside world.

The findings are published in the journal NeuroImage: Clinical.