Researchers develop test to diagnose 'face blindness'
4 Nov 2015
Researchers have created a short questionnaire for people who suspect they have prosopagnosia, a condition that causes an inability to recognise faces. The researchers hope the questionnaire will help improve diagnosis of the condition.
There are currently no tests that can conclusively diagnose prosopagnosia – more commonly known as ’face blindness’ – which is estimated to affect up to 2 per cent of people in the UK. Many people with face blindness cope by using alternative ways to recognise individuals, such as the way they walk, hairstyle or voice. It can often lead to people avoiding social situations and feeling embarrassed about actual or imagined offence to others.
The new 20 item questionnaire asks respondents to indicate the extent to which they agree or disagree with certain phrases about their facial recognition experiences. Some of the questions include:
- I have always had a bad memory for faces
- I often mistake people I have met before for strangers
- I sometimes find movies hard to follow because of difficulties recognising characters
- At family gatherings, I sometimes confuse individual family members.
Each question is scored out of five giving a total score of up to 100. This final score could be used to help determine the severity of face-blindness.
To verify the questionnaire’s effectiveness it was tested in several validation studies. These showed its ability to detect face blindness and – by comparing questionnaire scores with computerised face recognition tasks – confirmed that people had the necessary insight into their face blindness for a self-reporting test to be effective.
Punit Shah, lead researcher based at the MRC Social, Genetic and Developmental Psychiatry Centre at King’s College London, said: “In its most extreme form people with face blindness cannot even recognise their family or friends. This can have a disabling impact on their life, including on their career prospects. And whilst it was once thought to be rare, it is increasingly being seen as a more common condition that is often overlooked. To address this, we need a simple and accurate way to identify people with the condition, so they can receive any support they may need.
“Combining our test – termed the ‘20-item Prosopagnosia Index’ – with others will help improve diagnosis of face blindness, helping to remove much of the uncertainty around many existing tests.”
The research on the new questionnaire is published in a paper published today (Wednesday) in Royal Society Open Science.
An earlier study of the test was published in June: Shah, P., Gaule, A., Sowden, S., Bird, G., & Cook, R. (2015). "The 20-item prosopagnosia index (PI20): a self-report instrument for identifying developmental prosopagnosia". Royal Society Open Science.