Telling Whether a Brain is Alive or Not

What’s the Latest Development?

While a damaged patient’s brain may be able to understand all or part of his or her environment, the body may be unable to make observable responses. As a result, errors in diagnosing vegetative brain states are unfortunately common. But a new study out of Belgium, published this week in Science, may provide doctors with a new tool in determining the status of a patient with brain damage. The study found that patients with minimally conscious brains had a more robust response to a change in sound pitch—a burst of brain activity lasting about 170 milliseconds—than patients in vegetative states, whose responses lasted less than 100 milliseconds. 

What’s the Big Idea?

The thought of simultaneously being able to understand your environment yet unable to respond to it is terrifying, especially if a doctor is trying to determine that your brain is still functioning. The difficulty in diagnosing vegetative brain states results from the severe impairment caused by brain damage, but new studies are finding resiliency in the brain’s ability to communicate, at least among its constituent parts. Examining the connections between different brain parts in patients with brain damage may give scientists insight into how both healthy and debilitated brains process information.