By Brian Alexander
For as long as she could remember a 60-year-old British woman, known only as KH, has been unable to recognize voices, not even the voice of her own daughter. Unless she sees the face of the person speaking, she often has no idea who is talking to her. If her daughter calls on the phone, or an unseen colleague from work says something to her, it's as if she's hearing the voice for the first time.
Except when Sean Connery speaks.
KH didn't know what caused her problem until a few years ago when she read a magazine article about a neurological defect which makes it extremely difficult for people to recognize faces — a condition called prosopagnosia, or face blindness. She wondered if there could be some connection to her experiences. Hoping the doctors might solve her own mystery, she contacted prosopagnosia researcher Dr. Brad Duchaine at University College London.
"She thought she had a vocal [version of] prosopagnosia," Duchaine said in an interview. "But we had never done anything involving voices. So we ran her through some face tests, some voice tests, and we could see she was on the level."
An MRI showed no obvious structural defects or injuries. So Duchaine and colleague Lucia Garrido of UCL's Institute of Cognitive Neuroscience created a series of more complex tasks to more thoroughly test KH's ability to recognize faces, voices, emotions, music and overall perception of speech.
Duchaine and Garrido exposed KH to the voices of famous people with distinctive voices. Actress Joanna Lumley (known best in the U.S. for her role in the British comedy series "Absolutely Fabulous"), former British prime minister Margaret Thatcher, and David Beckham were easily tagged by a group of people participating in the research, although none of them rang a bell for KH.
Only one of the voices perked up her ears with recognition: the unmistakable Scottish burr of actor Sean Connery, the original James Bond.
"His accent is distinctive," Duchaine explained. "And she is a British woman in her sixties…let's say it's probable he got her attention."
Eventually Duchaine and his colleagues realized KH was the first documented case of someone born without the ability to detect familiar voices. Doctors do sometimes see this condition called phonagnosia typically in the aftermath of a stroke when brain damage affects auditory perception. Developmental phonagnosia, however, is an inborn defect whose cause is still unknown.
To learn more about the condition, Duchaine is conducting further research with KH. The scientists will use specialized scans to compare her brain while listening to voices with those of normal subjects to see which areas of brain are stimulated -- or not, in her case. But based on his work with prosopagnosia, in which few, if any, differences can be seen, he doubts his team will find much.
As for KH, her neurological defect has not prevented her from leading a highly successful professional life, although she has had to adopt several coping mechanisms.
For example, she must make rigid appointments to receive telephone calls so that if the phone rings at, say, 7 p.m., she knows who will be on the other end. And there have been embarrassing social encounters, like the time a former boss spoke to her while standing behind a couch where KH was sitting. Because she didn't turn to acknowledge him, he thought he was being snubbed.
Duchaine has issued a call for any others who think they might be phonagnosic and invites them to contact him through a Web site, www.faceblind.org. So far, he says, five or six people have called. He expects to finds that developmental phonagnosia may not be all that uncommon. In comparison, developmental face blindness appeared to be very rare ten years ago, but it's now known that many people cope with it.
"We hope that studies with KH's condition will help us better understand a range of issues related to voice recognition," says Duchaine. "Developmental prosopagnosia has helped us understand the cognitive, neural, and genetic basis of face recognition, and voice agnosia could do the same for voice recognition."
The research could help not only people like KH, but others who have problems understanding voices due to other kinds of developmental issues or brain damage.