It reads like something from a sci-fi novel – a small population with extraordinary powers of identification, able to recall almost every face they have ever seen: the Super Recognisers.
They do exist, however; their incredible ability to remember faces often called upon by, for example, the Metropolitan Police to identify perpetrators of crimes from photographs or CCTV footage.
At the other end of the spectrum is a population that can’t identify their friends, their partner, their children.
Just how some people never forget a face while others struggle to distinguish between their loved ones is something that has intrigued and been the focus of research by Gunter Loffler, Professor of Visual Neuroscience and expert on face perception, for more than 15 years.
Gunter completed his undergraduate studies in optometry in Germany – a natural choice, following in the footsteps of his father and grandfather, both optometrists. He was, however, fascinated not just by the eye but by the role of the brain in helping make sense of the world. It was this fascination that led to Gunter’s first encounter with GCU, in 1999, when he completed a PhD on motion perception, looking beyond the eyes to the role of the brain in understanding movement.
“When someone walks towards you, that person’s projection hits the back of your eye, and the closer they get, the bigger that projected image will be,” explains Gunter. “If your visual brain wasn’t processing the incoming information from the eyes in a rather sophisticated way, you would see someone growing in size as they move towards you. The brain somehow uses prior knowledge about the world and the fact that people don’t grow that rapidly, so you perceive – correctly – a person walking towards you without changing in size.”
It was as a postdoctoral student at the University of Chicago (“spending hours and hours in a basement lab with no windows, co-habited in the moist mid-American summers by centipedes and other interesting species”) that Gunter and his supervisor developed their first test of face perception. This initial work was carried out on a ‘typical’ population – people who have no known problems with their eyes or the brain – to try to understand how brains process face information.
“It’s been a puzzling thing for people for centuries,” says Gunter, who returned to GCU to take up a lectureship in 2001. “Why is it that we are extremely good at discriminating between faces and in reading facial expressions when faces are, essentially, all the same – two eyes, a nose and a mouth?”
The test found measurable variation among typical people; some were more sensitive; others less so. This only shows average human ability, however; the whole spectrum extends from the best of the typical people to those who can’t tell faces apart at all.
Recent research at GCU by PhD student Andrew Logan (now a lecturer in optometry at the University of Bradford), and supervised by Gunter and Dr Gael Gordon, focused on the development of a quick, simple test to check the entire range of face ability. The test has proven to be superior to other tests available in quantifying face blindness, or prosopagnosia. Gunter is now keen to use the same test to identify the super recognisers.
“There are two obvious outcomes,” explains Gunter. “These guys are actually no better than the norm and are simply using other pieces of information such as clothing or posture. Or it could be that they are just that much better than typical people and, if so, there is the potential for further tests to find out why. In the first instance, we would like to see if they perform in our test at a level that would classify them as exceptional.”
Of course, people’s ability to see any object, including faces, is affected by their eyesight, and a proper set of spectacles could be the difference between recognising someone or not. However, as Gunter points out, for students of vision sciences, it is important to understand that there is more to seeing than a pair of eyes or glasses.
“You can’t assume that just because the eye is functional, vision is fine,” says Gunter. “There are people with perfectly sharp acuity who can’t distinguish between faces and there are people who can do faces and can read small text but can’t perceive motion. The concept that there are compartments in the brain that deal with different aspects of seeing beyond the basic input unit – the eye – is an important aspect for students to appreciate.”