Rom Houben of Brussels was trapped in his paralysed body for 23 years before doctors discovered he was not a "vegetable," and he is now able to communicate with the outside world with one finger and a touchscreen. His story is a harbinger of a world in which thousands of locked-in people will be able to find expression for their inner lives, thoughts, emotions and choices, thanks in part to groundbreaking work by a Canadian researcher, Tom Chau.

Hell is surely being sealed inside a mentally aware mind without anyone else knowing. Some, like Mr. Houben, have become disabled in car crashes. Others, like Jean-Dominique Bauby, the late author of The Diving Bell and the Butterfly, suffered strokes. Still others, perhaps, suffer from severe forms of cerebral palsy. As the 46-year-old Mr. Houben is now able to express so eloquently, "I screamed, but there was nothing to hear."

Until now, many of those trapped like Mr. Houben were seen as virtually without any recognizable humanity. Scientific advances are beginning to change that. In one study that included Mr. Houben, of 44 patients deemed by doctors to be in a vegetative state, 18 were discovered to be in a higher level of awareness.

The finger-on-a-touchscreen technology that allows Mr. Houben to communicate is not nearly as futuristic as that being developed by Dr. Chau, of Toronto's Bloorview Kids Rehab. Dr. Chau calls his approach "body talk:" changes in facial temperature, or in hydration of the sweat glands, may reveal what is going on in a person's thoughts. If the person can be trained to trigger, say, his sweat glands to communicate a thought or preference, he might one day turn on his room lights or use a computer with equipment developed by Dr. Chau.

How many are locked-in and wish to scream out their humanity, as Mr. Houben did? Perhaps as many as 400,000 in Canada, the United States and Britain alone. The work of Dr. Chau and other scientists may be leading towards a very large prison break.