Imagine not being able to recognise your own child at nursery or even pick out your own face from a line-up of photos. This is just how severe face blindness or prosopagnosia can be. BU psychologist Dr Sarah Bate (pictured) says: “In extreme cases, people might withdraw socially – become depressed, leave their job, or just suffer endless embarrassment.”
Until the last decade or so, face blindness was virtually unknown, but now thousands of people, including children as young as four, have contacted BU; one of the largest research centres worldwide to investigate face blindness. Dr Bate estimates one in 50 suffers from prosopagnosia to some degree – some struggle to put a name to a face whereas others can’t recognise people they have known their whole lives.
Whether this condition is caused by nature or nurture is under debate and BU is working closely with Dartmouth College in the United States to investigate and develop training programmes to improve face recognition.
“We are seeing two types of developmental prosopagnosia (face blindness from birth),” says Dr Bate. “Those who have what we believe to be a genetic form and those who simply fail to develop the ability to recognise faces. Why is this? That is where the work needs to be done.”
Very rarely, individuals may develop prosopagnosia later in life, after a stroke or head injury. People with autism may also be unable to recognise faces. BU’s research may also provide new information about how readily the brain can adapt and change. “If the brain is very plastic, we would assume it could rewire itself and people will show great improvement in response to training. But if neural pathways are fixed, we will try and find out when it becomes reluctant to change.”
Some 10,000 people have taken BU’s online diagnostic test and 50 prosopagnosics have come in person for laboratory analysis. Researchers use a range of equipment to examine the condition: eye-tracking investigates how sufferers scan faces and researchers assess unconscious face recognition by measuring the skin conductance response.
Once diagnosed, prosopagnosics will undertake BU’s online training programme, involving an hour of visual training every day for 20 days. Participants are repeatedly shown images and learn to see differences between similar features. “We hope this will improve their ability to make fine-grained discrimination between faces, resulting in an improvement in everyday face recognition,” says Dr Bate.
“Face blindness may be influenced by factors such as not having glasses at a critical time when young or perhaps being deprived of enough social interaction as a baby,” she says. Early intervention could improve the condition.
In another significant study, researchers at BU are investigating whether the hormone oxytocin – commonly associated with creating bonds between mother and newborn – will improve face recognition in the longer term. Clinical trials at BU have already shownit brings about short-term improvement, and Dr Bate wants to see if it will work in conjunction with the training programme.
“Prosopagnosia can make life really difficult – we hope to make this training freely available to anyone who needs it,” she concludes.