June 20, 2011
Duncan Bannatyne: he is not rude but suffers from face blindness. Photograph: Stuart Clarke/Rex Features
Earlier this year, millionaire businessman Duncan Bannatyne told his 350,000 Twitter followers that he suffered from prosopagnosia, or "face blindness" – a condition that can leave sufferers struggling to identify their own close friends or family. Some were surprised: according to every business handbook for success, the Dragons' Den star would need to be a networking wizard to create the string of successful businesses that have seen him valued at £320m. But Bannatyne confirmed the diagnosis, and told his followers: "I would like prosopagnosia to become more known as it causes sufferers to be thought of as rude … Google prosopagnosia, you might suffer from it … or have a friend who does."
He is right: face blindness is more common than it sounds. According to Sarah Bate, a psychology lecturer at Bournemouth University who is devoting her career to investigating the condition, medical research over the last 10 years has thrown fresh light on prosopagnosia.
"One study has suggested that as many as 2.5% of the population might have developmental prosopagnosia," Bate explains. "Even if that's an overestimation, thousands of people in the UK must suffer."
Face blindness affects sufferers in different ways, ranging from those who struggle to put a name to an acquaintance to those who cannot recognise their own children coming out of school – or their own faces in photos. Prosopagnosians may also have difficulties with related problems, such as identifying other people's emotional expressions, or judging age or gender of faces.
Bate first heard about prosopagnosia in a lecture in the second year of her undergraduate degree. Finding it to be under-researched, she decided to examine it further for her PhD, and has continued doing so after completing it two years ago. Bate is particularly interested in whether face blindness is hereditary and physiological rather than psychological, as many had previously assumed. She explains that cases come in two categories: people with developmental prosopagnosia have usually failed to develop the processes for normal face recognition from birth, while others acquire problems later in life due to brain damage, for example after a stroke.
While some sufferers find prosopagnosia to lead to occasional embarrassment, for others it affects their social aptitude and employment options. "They might withdraw from social events, and work in jobs that avoid the need for face-to-face interaction with colleagues and clients," says Bate. "The condition can cause much anxiety and even depression. One young man told me about a time when he met a girl at a party and asked her out on a date. She agreed and then went on her way after giving him her number, but he then asked her out again later in the evening, thinking she was a completely different person." Perhaps unsurprisingly, Bate reports that the girl cancelled the date.
"Another of the individuals with face blindness I'm in contact with has suffered from the condition since childhood. His failure to recognise faces had been a long-standing joke in his family, and when he heard about my work he asked to be formally assessed. He turned out to be severely prosopagnosic, and found much relief in realising that it is a recognised condition and that many other people suffer from it."
Bate reports that some sufferers "cope remarkably well, and develop elaborate compensatory strategies that help them recognise people".
Teachers with face blindness, for example, often devise seating plans in the classroom. Others become very perceptive at recognising people from non-facial cues such as their gait, hairstyle or clothing – or even informing their colleagues, family and friends, and asking them to introduce themselves each time they meet.
"These strategies might work some or most of the time, but occasions do occur when a familiar person is met out of context and the strategy breaks down," Bate explains. "It's difficult to imagine how young children might cope with the disorder, particularly as most are required to wear school uniform and obey strict rules regarding their appearance at school."
Keen to find out more about the different sub-types of face blindness, the academic realised she needed to find a way to build a large pool of research participants, and took to the internet to launch prosopagnosiaresearch.org, a website designed to both inform the public and recruit candidates for research. The site hosts an online test where participants are shown 20 male bald faces and then repeatedly asked to identify them from a choice of three. Nearly 4,000 people worldwide have taken the test so far, with more than 300 registering to participate in research, and about 20 who live in southern England are travelling to Bournemouth to undergo the latest tests and analysis.
"When a new participant makes contact, I arrange a meeting at the university to carry out a screening session," Bate explains. She has used eye-tracking technology to assess how prosopagnosics take in faces visually, but so far that hasn't yielded conclusive results. "I've found a conflicting pattern of findings – while eye movements appeared normal in some cases, other individuals were ignoring the key inner features of the face – eyes, nose and mouth – which are critical for recognition," she says.
The academic is also working with genetics researchers to test families of prosopagnosics and examine any links. "Some individuals who have prosopagnosia suspect other members of their families suffer from the condition," she says. "We are attempting to test as many members of each family as possible – including those who believe they have normal face-processing abilities – to confirm that multiple members of the same family suffer from the disorder. The next step is to take samples of each person's DNA, by simply taking saliva swabs. But to collect meaningful data we need to identify more families of prosopagnosics who are willing to participate in this research."
Early findings suggest the condition "certainly does seem to run in some families. But some individuals suffer despite no apparent familial connection. It's important to understand the different causes and sub-types to develop appropriate treatment techniques, and then pick up prosopagnosia and its related deficits in children," she says.
"With prior knowledge about which children are at risk of developing the condition and the range of difficulties they might confront, we'd have a much better chance of successfully reducing these difficulties."