People with an intriguing talent are proving themselves useful as a crime-fighting force. Could anyone learn their superpowers?
AT NEARLY 2 metres tall, Idris Bada is a big man with a big reputation. His colleagues in the Metropolitan Police Service call him Idris the Jailer, thanks to his remarkable track record in catching criminals.
On arriving for our meeting at a London police station, I am unnerved by an angry youth at the entrance, who I suspect has more contact with the police force than I usually do. Matters aren't helped when I call my contact to let them know I'm here. "I'll send Idris to get you," says the voice on the other end of the line. "Don't be scared..."
Bada certainly towers over me but he turns out to be a friendly giant with a deep, infectious laugh. He is one of the Met's "super-recognisers", officers who have been singled out for their astonishing ability to put names to faces. Their talents went unnoticed until 2010, when Detective Chief Inspector Mick Neville started keeping track of the number of people that officers had identified from CCTV images.
There are 35,000 officers in the Met, all with access to the images, but Neville found that the same few officers were topping the league time and again. Their identification rates were so impressive that Neville started to wonder if his top cops had special powers of recognition. So he called in a forensic psychologist to investigate.
What Neville didn't know is that face recognition is a hot topic in neuroscience. For one thing, it appears to be a deep-seated skill. Babies who are just a few days old appear more interested in pictures of faces than any other images, and brain scans show that the neural networks we use to process faces are separate from those we use for recognising other complex objects, such as animals or cars. Because we know roughly which areas of the brain are involved, facial recognition is seen as an ideal model for understanding visual processing more generally.
And on a practical level, working out what is different about the way that people like Bada recognise faces could allow us to harness their powers more effectively, and perhaps even help train the rest of us to improve our skills. "Whatever it is that they're doing, can we polish it?" asks Neville.
The first clues to the special way that we recognise faces came from people whose ability in this area is impaired. Brain damage caused by a stroke or head injury occasionally leaves people unable to recognise close family and friends, sometimes even their own face in the mirror. Yet they have no problem identifying other kinds of objects.
These people tend to have damage to the fusiform gyrus or the occipital face area, both regions at the back of the brain. Studying uninjured people in brain scanners showed these two regions respond more strongly to pictures of faces than anything else.
It emerged that this condition, known as face blindness, or prosopagnosia, can also be present from birth in people with no sign of brain damage. As many as 1 in 40 people may be naturally face-blind, although some may be unaware of it because they have developed strategies for recognising people by their hair, clothing or gait.
Neuroscientists were starting to get to grips with what goes wrong in face blindness when along came people at the other end of the ability scale, claiming to be able to recognise individuals they had met years ago and then only fleetingly.
Secret powers
Four such people contacted Richard Russell, then at Harvard University, and Brad Duchaine, then at University College London, in the mid-2000s after reading press reports of their research into face blindness (New Scientist, 25 November 2006, p 34). All said they sometimes hid their exceptional ability for fear of making people uncomfortable. "I do have to pretend that I don't remember [people]," said one, "when I recall that we saw each other once on campus four years ago."
Such anecdotes are hard to verify, but when Duchaine and Russell made the four perform standard face memory tests, they got perfect or near-perfect scores. A more difficult test had to be devised, on which the four duly scored far higher than a control group; in fact, the super-recognisers turned out to be about as good at recognising people as those with face blindness are bad - in the top 2 per cent of the ability range, compared with the bottom 2 per cent for prosopagnosics (Psychonomic Bulletin & Review, vol 16, p 252).
That suggests there is a broad spectrum of face-recognition abilities within the population, say the researchers. Since then, Duchaine and Russell have amassed more than 50 similarly talented individuals, who they are still studying.
Super-recognisers do not seem to be especially rare people. An interactive exhibit at London's Science Museum that tested face-recognition abilities classified about 1 in 50 of people who tried it as super-recognisers.
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