New Yorker Silent Minds

New Yorker Silent Minds - Medical Dispatch: Silent Minds:...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
MEDICAL DISPATCH SILENT MINDS What scanning techniques are revealing about vegetative patients. T en years ago, Adrian Owen, a young British neuroscientist, was working at a brain-imaging center at Addenbrooke’s Hospital, at the University of Cambridge. He had recently returned from the Montreal Neurological Institute, where he used advanced scanning technology to map areas of the brain, including those involved in recognizing human faces, and he was eager to continue his research. The imaging center was next to the hospital’s neurological intensive-care unit, and Owen heard about a patient there named Kate Bainbridge, a twenty-six-year-old schoolteacher who had become comatose after a flulike illness, and was eventually diagnosed as being in what neurologists call a vegetative state. Owen decided to scan Bainbridge’s brain. “We were looking for interesting patients to study,” he told me. “She was the first vegetative patient I came across.” For four months, Bainbridge had not spoken or responded to her family or her doctors, although her eyes were often open and roving. (A person in a coma appears to be asleep and is unaware of even painful stimulation; a person in a vegetative state has periods of wakefulness but shows no awareness of her environment and does not make purposeful movements.) Owen placed Bainbridge in a PET scanner, a machine that records changes in metabolism and blood flow in the brain, and, on a screen in front of her, projected photographs of faces belonging to members of her family, as well as digitally distorted images, in which the faces were unrecognizable. Whenever pictures of Bainbridge’s family flashed on the screen, an area of her brain called the fusiform gyrus, which neuroscientists had identified as playing a central role in face recognition, lit up on the scan. “We were stunned,” Owen told me. “The fusiform-gyrus activation in her brain was not simply similar to normal; it was exactly the same as normal volunteers’.” Excited by this result, Owen resolved to try to conduct brain scans of other vegetative patients in the Cambridge area. Since 1997, he has studied several dozen people, though he decided to use speech sounds rather than photographs to stimulate their brains. (Owen was concerned that showing images of faces might not be a reliable way to test recognition, since the eyes of vegetative patients often wander. “We shifted to auditory responses because you can always put a pair of headphones on the person and know that you are transmitting sound,” he said.) Three years ago, he began using a functional MRI (fMRI) scanner, which is faster than a PET scanner, capturing changes in blood flow in the brain almost as they occur. The patients’ brains were scanned while they listened to a recording of simple sentences interspersed with meaningless “noise sounds.” The scans of some of the patients showed the same response to the sentences as scans of healthy volunteers, but Owen wasn’t sure that the patients had understood the words. “So we
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/15/2009 for the course BIO 208 taught by Professor Lorne-mendell,s during the Fall '08 term at SUNY Stony Brook.

Page1 / 6

New Yorker Silent Minds - Medical Dispatch: Silent Minds:...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online