Student Information

Currently, we are investigating four-year-old children's ability to recognize facial expressions and whether that ability is influenced by body posture. Adults and 8-year-old children perform very well when asked to categorize sad and fearful facial expressions--unless the face is shown on an incongruent body! When, for example, a sad face is shown on a body posing fear, both 8-year-olds and adults are quite likely to say that the face looks afraid. This is true even when we ask them to ignore the body. This congruency effect is absent when we show adults happy and sad expressions, perhaps because these two expressions are opposites. Happy is a positive emotion and indicates high levels of arousal, whereas sad is a negative emotion and indicates a low level of arousal. We are currently investigating whether four-year-olds' perception of happy versus sad expressions is influenced by body posture. This work has important implications for social interactions; recognizing and responding appropriately to others' feelings helps us to successfully navigate our social world.

Studies involving older children

We are investigating the development of face prototypes. Adults walk around the world with an average face in their mind (i.e., with a face prototype). They rate faces like the prototype as most attractive and they rate faces farther away from that prototype as most distinctive. They also find it easier to recognize the identity of faces that are farther from the prototype. This prototype is updated continuously: if adults are adapted to distorted faces (such as the way faces appear in a convex or concave mirror) they report that slightly distorted faces are more attractive than unaltered faces, presumably because their prototype has shifted towards the distorted faces. This effect is temporary. Recent studies have shown that adults have multiple face prototypes that code for different face categories (e.g., mal/female; young/old; Caucasian/Asian). We are investigating the development of these category-specific prototypes. This research will provide insights about the development of face recognition and the development of social categories during childhood.

We are also investigating the development of sensitivity to emotional facial expressions. We recently showed (see studies involving preschool children) that 8-year-old children's perception of facial expressions is influenced by body posture. In fact, this influence is much stronger in 8-year-olds than adults. To investigate why this happens, we are testing children with our new eye trackers. This will allow us to study where children look when they see emotional faces presented in a context (e.g., background scenes, body postures, gestures) that is either congruent (e.g., a sad face shown next to a broken toy) or incongruent (e.g., a sad face is shown at a birthday party with the facial expression.

In a related set of studies we are investigating whether children encode facial identity independently of facial expressi9on. We know that adults are easily able to recognize a particular facial identity even when the emotional expression changes (i.e., even when they encounter someone who looks happy and later see that same person displying fear); this task is harder for children. One explanation for this is that children encode identity and emotional expressions in an integrated format (e.g., 'happy Sue') rather than as two separate pieces of information (e.g., 'that's Sue'; 'she is happy'). We have designed computer games to investigate when children's representation of facial identity becomes independent of emotional expression.

We are in the midst of conducting several studies involving adults:

• Are adults more sensitive to emotional expressions in own-age and own-race faces than in other-age and other-race faces?
• Does experience influence our ability to recognize other-age faces?
• How accurate are adults and children when guessing how old someone is?

We are conducting several projects in collaboration with other research groups. For example in collaboration with Professors Sid Segalowitz and Jane Dywan at Brock and Professor Maurer at McMaster we are measuring the neural correlates of face perception using ERP technology. In collaboration with Cheryl Grady at the Rotman Research Institute in Toronto we are measuring the neural correlates of face perception using fMRI. Both of these projects involve comparing visually normal adults with patients who were deprived of early visual experience by congenital (present at birth) cataracts. These projects allow us to assess the role of early visual experience in setting up or maintaining the neural architecture that underlies expert face processing.

We recently completed a large project with researchers in Australia, China, and Canada in which we investigated the other-race effect (i.e., the difficulty that adults around the world have when asked to recognize the identity of faces that belong to a race with which they have minimal experience.) That work will soon be published in the journal Perception. We continue to collaborate with Professor Kang Lee (University of Toronto), Cheryl McCormick (Brock) and researchers in China to investigate both the development of sensitivity to structural cues that signal propensity for aggression.

How can you become involved?