Researchers at The University of Western Australia’s School of Psychology and the ARC Centre of Excellence in Cognition and its Disorders have been looking at how we use adaptive norm-based coding using experience to determine how faces differ to an average or norm and discovered that four-year-olds already have this expertise.
The findings, published in the journal Cognition, have implications for identifying when crucial developments form in children and potentially contribute to a better understanding of face perception difficulties in autism.
Sixteen four-year-olds from a Perth pre-school were recruited for the study. They participated in a game called Robbers involving the face of a burglar, the person who caught them and an average or ‘test’ face. The children were then exposed to faces with varying degrees of similarity and asked to identify the catcher’s team.
“The norm is like a statistical average of all the faces we’ve seen, representing the average length and width of noses, for example. When we see a new face we just code how it differs from this norm, rather than coding the exact length and width of its nose,” explained lead author Assistant Professor Linda Jeffery.
“The norms we establish over time could be why people struggle to recognise individuals when they go to a different culture, with different ‘statistically average’ facial features.”
The results showed for the first time that experience before the age of four is enough to develop a norm-based ‘face-space’.
“Many researchers think that recognising a face requires expertise and that’s why adults are so good at recognising really quite subtle differences where kids are not as good,” Assistant Professor Jeffery said. “There is an argument that you need 10 years’ experience before you develop the perceptual mechanisms used to identify faces. But we’ve found that younger kids do have this mechanism and this shows you don’t need 10 years’ experience to develop it.”
“It is interesting from the general idea of how experience interacts with early or innate abilities. When we’re born we are already interested in faces and look at them more than other things. But we also know that experience with faces is crucial for developing normal face recognition skills. We just don’t know how much experience we need. Our results show that at least four years of experience is enough to develop norm-based coding. But we may need much less than that. To find that out we need to test even younger children and infants.”