Developmental changes in face processing: results from multidimensional scaling

Multidimensional scaling procedures were used to investigate developmental changes in the ability to process previously unfamiliar faces. Eighty male subjects, aged 7, 9, 12, or adult, rated the similarity of pairs of faces. The faces were presented to subjects in either the upright or the inverted orientation. Multidimensional scaling analyses suggest that subjects of all ages use similar information in judging the similarity of faces. However, for upright faces, individual subjects under age 10 seem to use fewer features at a time. The results argue against a qualitative shift in face processing at age 10, and suggest that the improvement in face recognition ability noted at this age is due at least in part to an increased ability to consider more features simultaneously.     

Reducing the own-race bias in face recognition by shifting attention

The own-race bias (ORB) in face recognition can be interpreted as a failure to generalize expert perceptual encoding developed for own-race faces to other-race faces. Further, black participants appear to use different features to describe faces from those used by white participants (Shepherd & Deregowski, 1981). An experiment is reported where the size of the ORB was assessed using a standard face recognition procedure. Four groups were tested at two time intervals. One group received a training regime involving learning to distinguish faces that varied only on their chin, cheeks, nose, and mouth. Three control groups did not receive this training. The ORB, present prior to training, was reduced after the critical perceptual training. It is concluded that the ORB is a consequence of a failure of attention being directed to those features of other race faces that are useful for identification.     

Reducing the own-race bias in face recognition by shifting attention

The own-race bias (ORB) in face recognition can be interpreted as a failure to generalize expert perceptual encoding developed for own-race faces to other-race faces. Further, black participants appear to use different features to describe faces from those used by white participants (Shepherd & Deregowski, 1981). An experiment is reported where the size of the ORB was assessed using a standard face recognition procedure. Four groups were tested at two time intervals. One group received a training regime involving learning to distinguish faces that varied only on their chin, cheeks, nose, and mouth. Three control groups did not receive this training. The ORB, present prior to training, was reduced after the critical perceptual training. It is concluded that the ORB is a consequence of a failure of attention being directed to those features of other race faces that are useful for identification.     

Children's face recognition in different contexts: the role of encoding strategies

In this study, the relationship between face recognition and different facial encoding strategies was investigated. Children (6-8 years, N= 134) participated in both a face recognition task and an encoding task. During the recognition task, they saw 7 target faces in an eyewitness context (video) or in a neutral context (static black and white slides) which they later had to recognize from a set of 21 faces. On the encoding task, the same children had to categorize new faces (schematic and photorealistic) into two categories. The construction of the categories allowed participants to encode the faces either analytically (by focusing on a single attribute) or holistically (in terms of overall similarity). The results showed that face recognition was better in the social than in the neutral context. In the neutral context, only holistic encoding was connected to better face recognition. In the social context, children seemed to use not only information about the faces but also information about the persons.     

Recognizing faces across continents: The effect of within-race variations on the own-race bias in face recognition

People are better at recognizing faces of their own race than faces of other racial groups. This own-race bias (ORB) in face recognition manifests in some studies as a full crossover interaction between race of observer and race of face, but in others the interaction is accompanied by main effects or other complexities. We hypothesized that this may be due in part to unacknowledged within-race variation and the implicit assumption that the terms white and black describe perceptually homogeneous race categories. We therefore tested white and black South Africans on their recognition of black and white American faces and black and white South African faces. Our results showed the expected interaction, but only for South African faces. This finding supports explanations of the ORB that are premised on intergroup contact and perceptual experience and highlights the danger of assuming homogeneity of appearance within groups. Author Note     

Predicting face similarity judgements with a computational model of face space

Current models of face representation involve the notion of a high-dimensional face space. Computational models of face space based on principal components analysis (PCA) have been successfully used to predict human judgements of face sex or race. In this work the capability of PCA-based face spaces to predict human judgements of face similarity is examined. Three different paradigms were used. In Experiment 1 subjects learned face-name associations for 18 faces and identified these faces on tachistoscopic presentation. The number of confusions was used as a measure of face similarity. In Experiment 2 the same subjects subjectively rated the similarity of all 153 possible face pairs. In Experiment 3 reaction time to identify a face in an odd-man-out task was measured as an index of face similarity. These empirical measures were correlated with distance of the faces in PCA-based spaces of different dimensionalities. For Experiments 1 and 2 these correlations were highest for one-or two-dimensional face spaces (r=−0.27 vs. −0.28). For Experiment 3 the correlation was highest for a space consisting of 13 dimensions (r=−0.51). Thus PCA-based spaces seem capable to predict human similarity judgements to some extent. Possible reasons for the differences in predictability between paradigms are discussed.     

About face: left-hemisphere involvement in processing physiognomies

Three experiments were concluded to investigate the involvement of the two cerebral hemispheres in processing faces. Perceptual discrimination of pairs of faces was equally speedy overall when the stimuli were presented in the right visual field (RVF) or left visual field (LVF). For faces differing in one or two features, however, a qualitatively different pattern of results was obtained for the two visual fields, and an RVF advantage emerged when the difference lay in the upper part of the faces (Experiment 1). An examination of the discriminability of the facial features from which the faces were constructed (Experiment 2) showed that the processes involved in RVF comparisons of faces were not dependent on the saliency of the features but, rather, followed a top-to-bottom serial analysis of the stimuli; the speed of the processing involved in LVF presentations was a function of the degree of similarity of the different comparison faces. Evidence for a serial type of comparison faces were used (Experiment 3). It was concluded that even though comparisons were equally speedy overall in LVF and RVF presentations, qualitatively different processes take place in the two hemispheres, which prove competent at processing faces, each in its own way. Some methodological problems inherent in tachistoscopic studies are discussed, and it is proposed that the quality of the stimulus representation achieved or required for cognitive processing may be determinant in the emergence of functional hemispheric asymmetries.     

Evidence for kinship information contained in the rhesus macaque (Macaca mulatta) face

The ability to recognize kin is an important social skill for primates. Humans are adept at using facial similarity to recognize likely kin, and there is evidence that nonhuman primates are also able to use facial similarity to make judgments about kinship. However, if and how nonhuman primate faces actually contain kinship information remains unclear. To test whether there is objectively measurable facial similarity in related nonhuman primates, we compared facial measurements from related (paternal half-sisters) and unrelated adult female rhesus macaques (Macaca mulatta). Facial measurements were first summarized into 5 factors using a principal component analysis. Differences in these factors between the faces of related macaques were compared with differences between the faces of random unrelated macaques and of age-matched unrelated macaques. The difference in facial measurements between related macaques was significantly smaller than the difference in facial measurements of either group of unrelated macaques, constituting an objective measure of facial similarity in macaque kin. These results indicate that kinship information is contained in the rhesus macaque face and suggest that nonhuman primates may rely in part on facial similarity to distinguish kin.     

Black male client, white female counsellor: Making positive use of transference phenomena

The content and process of transference issues over a 9-month period of counselling contact between a white, female counsellor and a black, male client are examined. An attempt is made to show the positive effects that may come about through a non-ethnic- and non-gender-matched counsellor-client dyad, and to explore the benefits to the client of counsellor similarity and difference.     

Other race recognition: a comparison of black American and African subjects

The ability of black American and black African men to recognize previously seen white male faces was assessed. Relationships between recognition, performance scores and quality of interracial experience were also examined. Black American participants (n = 10) performed significantly better and made fewer false responses than the Nigerian participants (n = 10). Significant positive relationships were found between performance scores and interracial experience. Differential use of cues for discriminating white male faces by both groups was also found.     

A dissociation between similarity effects in episodic face recognition

University of Newcastle, Callaghan, New South Wales, Australia Memory similarity, the similarity between a test lure and memory traces, reduces confidence and accuracy in all forms of recognition memory. In contrast, Tulving (1981) showed that, in recognition memory for scenic pictures, choice similarity, the similarity between forced choice test alternatives, increased accuracy but decreased confidence. In the present study, we replicated both memory and choice similarity effects and the dissociation between accuracy and confidence with pictures of faces. State-trace analysis confirmed the dissociation and identified two dimensions underlying these effects, one associated with choice similarity and another associated with memory similarity. Further analysis showed that the effect of study—test lag was associated with the memory-similarity dimension.     

Repetition priming of face recognition

Three experiments investigating the priming of the recognition of familiar faces are reported. In Experiment 1, recognizing the face of a celebrity in an “Is this face familiar?” task was primed by exposure several minutes earlier to a different photograph of the same person, but not by exposure to the person's written name (a partial replication of Bruce and Valentine, 1985). In Experiment 2, recognizing the face of a personal acquaintance was again primed by recognizing a different photograph of their face, but not by recognizing the acquaintance from that person's body shape, clothes etc. Experiment 3 showed that maximum repetition priming is obtained from prior exposure to an identical photograph of a famous face, less from a similar photograph, and least (but still significant) from a dissimilar photograph.

We argue that repetition priming is a function of the degree of physical similarity between two stimuli and that lack of priming between different stimulus types (e.g., written names and faces, or bodies and faces) may be attributable to lack of physical similarity between prime and test stimuli. Repetition priming effects may be best explained by some form of “instance-based” model such as that proposed by McClelland and Rumelhart (1985).     

A multidimensional scaling analysis of own- and cross-race face spaces

We examined predictions derived from Valentine’s (1991) Multidimensional Space (MDS) framework for own- and other-race face processing. A set of 20 computerized faces was generated from a single prototype. Each face was saved as Black and White, changing only skin tone, such that structurally identical faces were represented in both race categories. Participants made speeded “same-different” judgments to all possible combinations of faces, from which we generated psychological spaces, with “different” RTs as the measure of similarity. Consistent with the MDS framework, all faces were pseudo-normally distributed around the (unseen) prototype. The distribution of faces was consistent with Valentine’s (1991) predictions: despite their physical identity to the White faces, Black faces had lower mean inter-object distances in psychological space. Other-race faces are more densely clustered in psychological space, which could underlie well-known recognition deficits.     

An Investigation of the Contact Hypothesis of the Own-race Bias in Face Recognition

Although previous studies have demonstrated that faces of one's own race are recognized more accurately than are faces of other races, the theoretical basis of this effect is not clearly understood at present. The experiment reported in this paper tested the contact hypothesis of the own-race bias in face recognition using a cross-cultural design. Four groups of subjects were tested for their recognition of distinctive and typical own-race and other-race faces: (1) black Africans who had a high degree of contact with white faces, (2) black Africans who had little or no contact with white faces, (3) white Africans who had a high degree of contact with black faces, and (4) white Britons who had little contact with black faces. The results showed that although on the whole subjects recognized own-race faces more accurately and more confidently than they recognized other-race faces, the own-race bias in face recognition was significantly smaller among the high-contact subjects than it was among the low-contact subjects. Also, although high-contact black and white subjects showed significant main effects of distinctiveness in their recognition of faces of both races, low-contact black and white subjects showed significant main effects of distinctiveness only in their recognition of own-race faces. It is argued that these results support the contact hypothesis of the own-race bias in face recognition and Valentine's multidimensional space (MDS) framework of face encoding.     

Sex-contingent face aftereffects depend on perceptual category rather than structural encoding

Many studies have used visual adaptation to investigate how recent experience with faces influences perception. While faces similar to those seen during adaptation phases are typically perceived as more 'normal' after adaptation, it is possible to induce aftereffects in one direction for one category (e.g. female) and simultaneously induce aftereffects in the opposite direction for another category (e.g. male). Such aftereffects could reflect 'category-contingent' adaptation of neurons selective for perceptual category (e.g. male or female) or 'structure-contingent' adaptation of lower-level neurons coding the physical characteristics of different face patterns. We compared these explanations by testing for simultaneous opposite after effects following adaptation to (a) two groups of faces from distinct sex categories (male and female) or (b) two groups of faces from the same sex category (female and hyper-female) where the structural differences between the female and hyper-female groups were mathematically identical to those between male and female groups. We were able to induce opposite aftereffects following adaptation between sex categories but not after adaptation within a sex category. These findings indicate the involvement of neurons coding perceptual category in sex-contingent face aftereffects and cannot be explained by neurons coding only the physical aspects of face patterns.     

Normal face-based judgements of social characteristics despite severely impaired holistic face processing

Initial evidence indicates that face-based judgements of socially relevant characteristics such as people's trustworthiness or attractiveness are linked to the configural/holistic processing of facial cues. What remains a matter of debate, however, is whether such processing is actually necessary for normal social judgements to occur and whether it resembles the type of integrative processing as required for facial identification. To address these issues, we asked a well-characterized case of acquired prosopagnosia (PS) with a marked deficit in holistic processing for face identity to rate a series of faces on several dimensions of social relevance. PS provided ratings within the normal range for most of the social characteristics probed (i.e., aggression, attractiveness, confidence, intelligence, sociability, trustworthiness). Her evaluations deviated from those of healthy controls only when facial dominance was concerned. Taken together, these data demonstrate that the inability to integrate facial information during face individuation does not necessarily translate into a generalized deficit to evaluate faces on social dimensions.     

Physical and perceptual accuracy of upright and inverted face drawings

This study considers the conception that drawing or copying a face that is vertically inverted will improve the accuracy of the drawing by preventing holistic interference. We used a novel parameterized face space both for generating face stimuli and for measuring the physical accuracy of drawings. One group of participants (the artists) were asked to draw 16 parameterized faces (eight upright and eight inverted). We computed two physical measures of accuracy by comparing the face-space representation of each drawing to the original face. A second and third group of participants (the raters) compared the similarity between each original face and each pair of drawings of that face (one upright and one inverted per artist). For the second group, all faces were presented upright; for the third group, all faces were presented inverted. Our results showed that upright drawings were more accurate than inverted drawings, both in terms of the physical face-space measure and in terms of the perceptual judgments for both orientations. Our data suggest that holistic processing may aid rather than hinder face drawing accuracy.     

Female face preference in 4-month-olds: The importance of hairline

At 3–4 months of age, infants respond to gender information in human faces. Specifically, young infants display a visual preference toward female over male faces. In three experiments, using a visual preference task, we investigated the role of hairline information in this bias. In Experiment 1, we presented male and female composite faces with similar hairstyles to 4-month-olds and observed a preference for female faces. In Experiment 2, the faces were presented, but in this instance, without hairline cues, and the preference was eliminated. In Experiment 3, using the same cropping to eliminate hairline cues, but with feminized female faces and masculinized male faces, infants’ preference toward female faces was still not in evidence. The findings show that hairline information is important in young infants’ preferential orientation toward female faces.