SYMPOSIA...
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| Expertise effects in face processing |
| William Hayward
- The University of Hong Kong, China
Co-authors: Mintao Zhao, Gillian Rhodes
Configural and component processing of own-race and other-race faces
A common experience for travelers landing in a new country is that faces of people from different races seem more difficult to individuate than faces of one's own race. This own-race advantage has been verified experimentally in many studies, and across a variety of races. However, the cause of the own-race advantage remains elusive. In an ongoing research project, we have been investigating the extent to which the own-race advantage is caused by better processing of both configural and component processing for own-race faces. On one study, we adopted a sequential-matching task, and showed that observers had better processing of both second-order configurations and component information for own-race than other-race faces. A subsequent study showed better processing of both blurred faces (which isolate configural information) and scrambled faces (component information) in a recognition memory paradigm. More recently, we have been investigating the nature of memory for face components in own-race and other-race faces. Taken together, these studies show that the own-race advantage is not restricted to a single type of facial information, but seems to occur due to better processing of all types of facial information. |
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Gillian Rhodes - The University of Western Australia, Australia
Co-authors: Emma Jaquet, William Hayward
Norm-based coding of faces: One norm or many?
Aftereffects have been called the psychologist’s microelectrode because of their power to reveal underlying perceptual mechanisms. Traditionally used to study simple sensory coding, aftereffects are now widely used to study higher-level perceptual mechanisms. We argue that face identity aftereffects provide compelling evidence for norm-based coding of faces and use figural face aftereffects to explore the nature of these norms. We ask whether there is a single generic face norm or multiple category-specific norms. Figural face aftereffects occur when adaptation to consistently distorted faces biases the norm (towards the adapting distortion), making previously normal faces look distorted in the opposite direction. We show that opposite figural aftereffects can be induced at the same time for male and female faces and for Chinese and Caucasian faces, suggesting that there are multiple category-specific norms. However, there was also some transfer of aftereffects across sex and race categories, consistent with a generic face norm. These results suggest that the visual system represents both generic and category-specific information about faces, analogous to the representation of basic-level and subordinate-level representations in the conceptual system. |
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Linda Jeffery - The University of Western Australia, Australia
Co-authors: Elinor Mckone, Rebecca Haynes, Eloise Firth, Gillian Rhodes
Face aftereffects during development: Pre-school children show adaptive norm-based coding of faces
Children’s face recognition ability does not reach adult levels until adolescence, yet it is not clear whether this developmental change is qualitative, with children using different coding mechanisms, or quantitative, involving refinement of the mechanisms used by adults. Accumulating evidence suggests that even young children use many qualitatively similar mechanisms to adults. However, little is known about the development of adaptive norm-based coding mechanisms which are central to adult face coding. Figural aftereffects, in which participants adapt to consistently distorted faces, suggest that adult face norms are updated by the diet of faces experienced. Further, the more extreme the adaptor, the larger the aftereffect, supporting a norm-based, rather than exemplar based, model of face coding. We sought evidence for adaptive norm-based coding in pre-school children (4-6 years), the youngest age groups in which adult-like paradigms can be used. We adapted children and adults to distorted faces (spherised) and found significant face aftereffects for both groups. In a second experiment we adapted children to faces with eyes raised, or lowered, and found significant aftereffects. Crucially, the size of this aftereffect was reduced when a less extreme adaptor was used. These data suggest that young children use adaptive norm-based coding to code faces.
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Romina Palermo - Macquarie University, Australia
Co-authors: Carmen Atkinson, Megan Willis, Peter de Lissa, Christopher Sewell, Genevieve McArthur
The development of facial expression perception
The brain regions involved in emotion processing develop dramatically between childhood and adulthood, especially during adolescence. These changes are reflected behaviourally, with the ability to label or match facial expressions improving over time. Facial expressions can be subject to explicit evaluation, but they can also be processed implicitly. Implicit and explicit facial expression processing may be differentially affected by development. The aim of this study was to examine implicit and explicit processing of facial expressions in children (6-7 years), adolescents (11-15 years) and adults (20-44 years). In addition to behavioural data, event-related potentials were collected to index emotional processing. Differences in expression processing were evident at the face-sensitive N170 component measured over occipito-temporal regions. For adults, the N170 response was enhanced for negative compared to positive expressions, for both implicit and explicit tasks. The N170 amplitude for adolescents was reduced compared to that observed for the adults and implicit and explicit facial expression processing differentially affected the N170 component. Although, N170 amplitudes for the children were large, they did not differentiate between the expressions. The results suggest that there is a critical transition period between childhood and adolescence, which affects both implicit and explicit facial expression coding. |
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Alan Chun Nang Wong - The Chinese University of Hong Kong, China
Co-authors: Thomas Palmeri, Isabel Gauthier
Configural processing of non-face objects as a result of individuation training but not categorization training
Previous training studies show that several hours of individuation experience with novel objects result in behavioral and neural phenomena similar to those found for face perception. However, it is unknown whether such training effects are specifically caused by experience individuating objects or whether other kinds of experience might be equally potent in causing these changes. We compared two types of training to probe the effects of different kinds of object recognition experience. Two groups of participants went through training procedures that either emphasized individuation or categorization of a set of novel objects ('Ziggerins'). Individuation training involved learning to uniquely identify each Ziggerin. Categorization training involved learning to rapidly categorize classes of Ziggerins. Like the earlier training studies, individuation training resulted in more improvement in recognition at the individual level than at the category level, and an increase in holistic and configural processing. In contrast, categorization training resulted in a larger improvement in recognition at the class than individual level, and led to little or no evidence for holistic or configural processing. Our finding suggests that the type of experience is an important factor for understanding specialization in the object recognition system. |
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