In the study, Dr Duchaine and Lucia Garrido of the UCL Institute of Cognitive Neuroscience presented KH with a series of tasks involving the recognition of faces, voices, vocal emotions, speech perception and music. KH struggled to recognise the voices of famous actors and politicians, and also had difficulty learning and recognising new voices. Compared to a control group of volunteers, nearly all of whom identified the voices of Margaret Thatcher, David Beckham, Dawn French, Chris Tarrant, Joanna Lumley, Sean Connery and Ann Widdecombe, KH was only able to identify the voice of Sean Connery.
However, KH performed well on nearly all other tasks. For example, in a test involving emotional sounds - achievement/triumph, amusement, anger, disgust, fear, pleasure, relief, sadness and surprise - KH could identify the emotional state of the person speaking roughly 80 per cent of the time, similar to the control group. KH also did well on all music tasks, identifying famous tunes and discriminating between instruments. KH says that she is able to enjoy and appreciate music, though she usually doesn't recognize singers.
Phonagnosia has only been documented so far in people with brain lesions in the right hemisphere following a stroke or brain damage, and the mechanisms behind it are not well understood. In KH's case, a MRI brain scan showed no evidence of brain damage in regions associated with voice or auditory perception, and her hearing abilities were found to be normal.
|Contact: Jenny Gimpel|
University College London