Catherine J. Mondloch

Configural face processing develops more slowly than featural face processing.

Expertise in face processing takes many years to develop. To determine the contribution of different face-processing skills to this slow development, we altered a single face so as to create sets of faces designed to measure featural, configural, and contour processing. Within each set, faces differed only in the shape of the eyes and mouth (featural set), only in the spacing of the eyes and mouth (spacing set), or only in the shape of the external contour (contour set). We presented adults, and children aged 6, 8, and 10 years, with pairs of upright and inverted faces and instructed them to indicate whether the two faces were the same or different. Adults showed a larger inversion effect for the spacing set than for the featural and external contour sets, confirming that the spacing set taps configural processing. On the spacing set, all groups of children made more errors than adults. In contrast, on the external contour and featural sets, children at all ages were almost as accurate as adults, with no significant difference beginning at age 6 on the external contour set and beginning at age 10 on the featural set. Overall, the results indicate that adult expertise in configural processing is especially slow to develop.

Impairment in Holistic Face Processing Following Early Visual Deprivation

Unlike most objects, faces are processed holistically: They are processed as a whole rather than as a collection of independent features. We examined the role of early visual experience in the development of this type of processing of faces by using the composite-face task, a measure of holistic processing, to test patients deprived of visual experience during infancy. Visually normal control subjects showed the expected composite-face effect: They had difficulty perceiving that the top halves of two faces were the same when the top halves were aligned with different bottom halves. Performance improved when holistic processing was disrupted by misaligning the top and bottom halves. Deprived patients, in contrast, showed no evidence of holistic processing, and in fact performed significantly better than control subjects when top and bottom halves were aligned. These findings suggest that early visual experience is necessary to set up or maintain the neural substrate that leads to holistic processing of faces.

Developmental Changes in Face Processing Skills.

Expertise in processing differences among faces in the spacing among facial features (second-order relations) is slower to develop than expertise in processing the shape of individual features or the shape of the external contour. To determine the impact of the slow development of sensitivity to second-order relations on various face-processing skills, we developed five computerized tasks that require matching faces on the basis of identity (with changed facial expression or head orientation), facial expression, gaze direction, and sound being spoken. In Experiment 1, we evaluated the influence of second-order relations on performance on each task by presenting them to adults (N=48) who viewed the faces either upright or inverted. Previous studies have shown that inversion has a larger effect on tasks that require processing the spacing among features than it does on tasks that can be solved by processing the shape of individual features. Adults showed an inversion effect for only one task: matching facial identity when there was a change in head orientation. In Experiment 2, we administered the same tasks to children aged 6, 8, and 10 years (N=72). Compared to adults, 6-year-olds made more errors on every task and 8-year-olds made more errors on three of the five tasks: matching direction of gaze and the two facial identity tasks. Ten-year-olds made more errors than adults on only one task: matching facial identity when there was a change in head orientation (e.g., from frontal to tilted up). Together, the results indicate that the slow development of sensitivity to second-order relations causes children to be especially poor at recognizing the identity of a face when it is seen in a new orientation.

What Aspects of Face Processing Are Impaired in Developmental Prosopagnosia

Developmental prosopagnosia (DP) is a severe impairment in identifying faces that is present from early in life and that occurs despite no apparent brain damage and intact visual and intellectual function. Here, we investigated what aspects of face processing are impaired/spared in developmental prosopagnosia by examining a relatively large group of individuals with DP (n = 8) using an extensive battery of well-established tasks. The tasks included measures of sensitivity to global motion and to global form, detection that a stimulus is a face, determination of its sex, holistic face processing, processing of face identity based on features, contour, and the spacing of features, and judgments of attractiveness. The DP cases showed normal sensitivity to global motion and global form and performed normally on our tests of face detection and holistic processing. On the other tasks, many DP cases were impaired but there was no systematic pattern. At least half showed deficits in processing of facial identity based on either the outer contour or spacing of the internal features, and/or on judgments of attractiveness. Three of the eight were impaired in processing facial identify based on the shape of internal features. The results show that DP is a heterogeneous condition and that impairment in recognizing faces cannot be predicted by poor performance on any one measure of face processing.

Do small white balls squeak? Pitch-object correspondences in young children

Adults with auditory-visual synesthesia agree that higher pitched sounds induce smaller, brighter visual percepts. We have hypothesized that these correspondences are remnants of cross-modal neural connections that are present at birth and that influence the development of perception and language even in adults and children without synesthesia. In this study, we explored these correspondences in preschoolers (30-36 months; n=12 per experiment). The children were asked to indicate which of two bouncing balls was making a centrally located sound. The balls varied in size and/or surface darkness; the sound varied in pitch. The children reliably matched the higher pitched sound to a smaller and lighter (white) ball (Experiment 1), to a lighter (white) ball (Experiment 2), and in one of two groups, to a smaller ball (Experiment 3). Children’s matching of pitch and size cannot be attributed to intensity matching or to learning. These data support the hypothesis that some cross-modal correspondences may be remnants of the neural mechanisms underlying neonatal perception.

The effect of early visual deprivation on the development of face processing

We evaluated the importance of early visual input for the later development of expertise in face processing by studying 17 patients, aged 10 to 38 years, treated for bilateral congenital cataracts that deprived them of patterned visual input for the first 7 weeks or more after birth. We administered five computerized tasks that required matching faces on the basis of identity (with changed facial expression or head orientation), facial expression, gaze direction and lip reading. Compared to an age-matched control group, patients’ recognition of facial identity was impaired significantly when there was a change in head orientation (e.g. from frontal to tilted up), and tended to be impaired when there was a change in facial expression (e.g. from happy to surprised). Patients performed normally when matching facial expression and direction of gaze (e.g. looking left or right), and in reading lips (e.g. pronouncing ‘u’ or ‘a’). The results indicate that visual input during early infancy is necessary for the normal development of some aspects of face processing, and are consistent with theories postulating the importance of early visual experience (de Schonen & Mathivet, 1989; Johnson & Morton, 1991) and separate neural mediation of different components of face processing (Bruce & Young, 1986).

The composite face effect in six-year-old children: Evidence of adult-like holistic face processing

Holistic processing (i.e., gluing facial features together into a gestalt) is a hallmark of adults’ expert face recognition. Children make more errors than adults on a variety of face processing tasks even during adolescence. To determine whether this slow development can be attributed to immature holistic processing of unfamiliar faces, we tested 6-year-old children (n=24) with a classic measure of adults’ holistic processing, the composite face effect: They made same/different judgements about the top halves of face pairs when each top half was combined with a different bottom half, with which it was aligned (so that holistic processing creates the impression of a different face) or misaligned (a manipulation that disrupts holistic processing). Six-year-olds showed an adult-like composite face effect: Like adults, they made 26% more errors on aligned trials than on misaligned trials. These results suggest that the improvements after age 6 in the recognition of the facial identity are not caused by the onset or increasing strength of holistic face processing.

Processes underlying the cross-race effect: An investigation of holistic, featural, and relational processing of own-race versus other-race faces

Adults are often better at recognising own-race than other-race faces. Unlike previous studies that reported an own-race advantage after administering a single test of either holistic processing or of featural and relational processing, we used a cross-over design and multiple tasks to assess differential processing of faces from a familiar race versus a less familiar race. Caucasian and Chinese adults performed four tasks, each with Caucasian and Chinese faces. Two tasks measured holistic processing: the composite face task and the part/whole task. Both tasks indicated holistic processing of own-race and other-race faces that did not differ in degree. Two tasks measured featural and relational processing: the Jane/Ling task, in which same/different judgments were made about face pairs that differed in features of their spacing, and the scrambled/blurred task, in which test faces were scrambled (isolates memory for components) or blurred (isolates memory for relations). Both tasks provided evidence of an own-race advantage in both featural and relational processing. We conclude that even when adults process other-race faces holistically, other manifestations of an own-race advantage remain.

Developmental Changes in the Processing of Hierarchical Shapes Continue into Adolescence.

The present study was designed to trace the normal development of local and global processing of hierarchical visual forms. We presented pairs of hierarchical shapes to children and adults and asked them to indicate whether the two shapes were the same or different at either the global or the local level. In Experiments 1 (6-year-olds, 10-year-olds, adults) and 2 (10-year-olds, 14-year-olds, adults), we presented stimuli centrally. All age groups responded faster on global trials than local trials (global precedence effect), but the bias was stronger in children and diminished to the adult level between 10 and 14 years of age. In Experiment 3 (10-year-olds, 14-year-olds, adults), we presented stimuli in the left or right visual field so that they were transmitted first to the contralateral hemisphere. All age groups responded faster on local trials when stimuli were presented in the right visual field (left hemisphere); reaction times on global trials were independent of visual field. The results of Experiment 3 suggest that by 10 years of age the hemispheres have adult-like specialization for the processing of hierarchical shapes, at least when attention is directed to the global versus local level. Nevertheless, their greater bias in Experiments 1 and 2 suggests that 10-year-olds are less able than adults to modulate attention to the output from local versus global channels-perhaps because they are less able to ignore distractors and perhaps because the cerebral hemispheres are less able to engage in parallel processing.

Contact and other-race effects in configural and component processing of faces

Other-race faces are generally recognized more poorly than own-race faces. There has been a long-standing interest in the extent to which differences in contact contribute to this other-race effect (ORE). Here, we examined the effect of contact on two distinct aspects of face memory, memory for configuration and for components, both of which are better for own-race than other-race faces. Configural and component memory were measured using recognition memory tests with intact study faces and blurred (isolates memory for configuration) and scrambled (isolates memory for components) test faces, respectively. Our participants were a large group of ethnically Chinese individuals who had resided in Australia for varying lengths of time, from a few weeks to 26 years. We found that time in a Western country significantly (negatively) predicted the size of the ORE for configural, but not component, memory. There was also a trend for earlier age of arrival to predict smaller OREs in configural, but not component, memory. These results suggest that memory for configural information in other-race faces improves with experience with such faces. However, as found for recognition memory generally, the contact effects were small, indicating that other factors must play a substantial role in cross-race differences in face memory.