Attending to identity cues reduces the own-age but not the own-race recognition advantage

Ensemble coding of facial identity is robust, but may not contribute to face learning

Ensemble coding - the rapid extraction of a perceptual average - has been proposed as a potential mechanism underlying face learning. We tested this proposal across five pre-registered experiments in which four ambient images of an identity were presented in the study phase. In Experiments 1 and 2a-c, participants were asked whether a test image was in the study array; these experiments examined the robustness of ensemble coding. Experiment 1 replicated ensemble coding in an online sample; participants recognize images from the study array and the average of those images. Experiments 2a-c provide evidence that ensemble coding meets several criteria of a possible learning mechanism: It is robust to changes in head orientation (± 60o), survives a short (30s) delay, and persists when images of two identities are interleaved during the study phase. Experiment 3 examined whether ensemble coding is sufficient for face learning (i.e., facilitates recognition of novel images of a target identity). Each study array comprised four ambient images (variability + average), a single image, or an average of four images (average only). Participants were asked whether a novel test image showed the identity from a study array. Performance was best in the four-image condition, with no difference between the single-image and average-only conditions. We conclude that ensemble coding of facial identity is robust but that the perceptual average per se is not sufficient for face learning.

Stable individual differences in unfamiliar face identification: Evidence from simultaneous and sequential matching tasks

Matching identity in images of unfamiliar faces is difficult: Images of the same person can look different and images of different people can look similar. Recent studies have capitalized on individual differences in the ability to distinguish match (same ID) vs. mismatch (different IDs) face pairs to inform models of face recognition. We addressed two significant gaps in the literature by examining the stability of individual differences in both sensitivity to identity and response bias. In Study 1, 210 participants completed a battery of four tasks in each of two sessions separated by one week. Tasks varied in protocol (same/different, lineup, sorting) and stimulus characteristics (low vs. high within-person variability in appearance). In Study 2, 148 participants completed a battery of three tasks in a single session. Stimuli were presented simultaneously on some trials and sequentially on others, introducing short-term memory demands. Principal components analysis revealed two components that were stable across time and tasks: sensitivity to identity and bias. Analyses of response times suggest that individual differences in bias reflect decision-making processes. We discuss the implications of our findings in applied settings and for models of face recognition.

Understanding the mechanisms underlying the other-'race' effect: An attempt at integrating different perspectives

Although different human races do not exist from the perspective of biology and genetics, ascribed 'race' influences psychological processing, such as memory and perception of faces. Research from this Special Issue, as well as a wealth of previous research, shows that other-'race' faces are more difficult to recognize compared to own-'race' faces, a phenomenon known as the other-'race' effect. Theories of expertise attribute the cause of the other-'race' effect to less efficient visual representations of other-'race' faces, which results from reduced visual expertise with other-'race' faces compared to own-'race' faces due to limited contact with individuals from other 'racial' groups. By contrast, social-cognitive accounts attribute the cause of the other-'race' effect to reduced motivation to individuate other-'race' faces compared to own-'race' faces. Evidence for both types of theories is still mixed, but progress in understanding the phenomenon has also been hampered by the fact that there has been little crosstalk between these accounts, which tend to be rooted in separate domains of experimental perception science and social psychology, respectively. To promote an integrative perspective on current knowledge on own- versus other-'race' face processing, the present Special Issue bridges different psychological subdisciplines, showcasing research using a large variety of methodological approaches and measures. In this guest editorial, we briefly highlight individual contributions to this Special Issue and offer what we see as important avenues for future research on the other-'race' effect.

Stable middle-aged face recognition: No moderation of the own-age bias across contexts

The own-age bias (OAB) has been proposed to be caused by perceptual expertise and/or social-cognitive mechanisms. Investigations into the role of social cognition have, however, yielded mixed results. One reason for this might be the tendency for research to focus on the OAB in young adults, between young and older adult faces where other-age individuation experience is low. To explore whether social-cognitive manipulations may be successful when observers have sufficient other-age individuation experience, we examined biases involving middle-aged other-age faces and the influence of a context manipulation. Across four experiments, young adult participants were presented with middle-aged faces alongside young or older adult faces to remember. We predicted that in contexts where middle-aged faces were positioned as other-age faces (alongside young adult faces), recognition performance would be worse than when they were positioned as relative own-age faces (alongside older adult faces). However, the context manipulations did not moderate middle age face recognition. This suggests that past findings that context does not change other-age face recognition holds for other-age faces for which observers have higher individuation experience. These findings are consistent with a perceptual expertise account of the OAB but more investigation of the generality of these results is required.

Enhanced Matching of Children's Faces in "Super-Recognisers" But Not High-Contact Controls

Face matching is notoriously error-prone, and some work suggests additional difficulty when matching the faces of children. It is possible that individuals with natural proficiencies in adult face matching ("super-recognisers" [SRs]) will also excel at the matching of children's faces, although other work implicates facilitations in typical perceivers who have high levels of contact with young children (e.g., nursery teachers). This study compared the performance of both of these groups on adult and child face matching to a group of low-contact controls. High- and low-contact control groups performed at a remarkably similar level in both tasks, whereas facilitations for adult and child face matching were observed in some (but not all) SRs. As a group, the SRs performed better in the adult compared with the child task, demonstrating an extended own-age bias compared with controls. These findings suggest that additional exposure to children's faces does not assist the performance in a face matching task, and the mechanisms underpinning superior recognition of adult faces can also facilitate the child face recognition. Real-world security organisations should therefore seek individuals with general facilitations in face matching for both adult and child face matching tasks.

Voice gender categorization in the connected and disconnected hemispheres

The role of the left and right hemispheres in processing the gender of voices is controversial, some evidence suggesting a bilateral involvement, some others suggesting a right-hemispheric superiority. We investigated this issue in a gender categorization task involving healthy participants and a male split-brain patient: female or male natural voices were presented in one ear during the simultaneous presentation of white noise in the other ear (dichotic listening paradigm). Results revealed faster responses by the healthy participants for stimuli presented in the left than in the right ear, although no asymmetries emerged between the two ears in the accuracy of both the patient and the control group. Healthy participants were also more accurate at categorizing female than male voices, and an opposite-gender bias emerged - at least in females - showing faster responses in categorizing voices of the opposite gender. The results support a bilateral hemispheric involvement in voice gender categorization, without asymmetries in the patient, but with a faster categorization when voices are directly presented to the right hemisphere in the healthy sample. Moreover, when the two hemispheres directly interact with one another, a faster categorization of voices of the opposite gender emerges, and it can be an evolutionary grounded bias.

An own-age bias in mixed- and pure-list presentations: No evidence for the social-cognitive account

The own-age bias (OAB) is suggested to be caused by perceptual-expertise and/or social-cognitive mechanisms. Bryce and Dodson (2013, Psychology and Aging, 28, 87, Exp 2) provided support for the social-cognitive account, demonstrating an OAB for participants who encountered a mixed-list of own- and other-age faces, but not for participants who encountered a pure-list of only own- or other-age faces. They proposed that own-age/other-age categorization, and the resulting OAB, only emerge when age is made salient in the mixed-list condition. Our study aimed to replicate this finding using methods typically used to investigate the OAB to examine their robustness and contribution to our understanding of how the OAB forms. Across three experiments that removed theoretically unimportant components of the original paradigm, varied face sex, and included background scenes, the OAB emerged under both mixed-list and pure-list conditions. These results are more consistent with a perceptual-expertise than social-cognitive account of the OAB, but may suggest that manipulating age salience using mixed-list and pure-list presentations is not sufficient to alter categorization processes.

Two Sides of Face Learning: Improving Between-Identity Discrimination While Tolerating More Within-Person Variability in Appearance

Two photos of an unfamiliar face are often perceived as belonging to different people—an error that disappears when a face is familiar. Face learning has been characterized as increased tolerance of within-person variability in appearance and is facilitated by exposure to such variability (e.g., differences in expression, lighting, and aesthetics). We hypothesized that increased tolerance of variability in appearance might lead to reduced discrimination and that misidentifications would be reduced if a face was learned in the context of a similar-looking identity. After validating our stimuli (Experiments 1a and 1b), we conducted three experiments investigating face learning. In two of these, participants learned three faces (Experiment 2: 15 images/identity and Experiment 3: 5 images/identity), two of which were similar. In a recognition task, misidentifications did not change as a function of similarity, although participants recognized more images of the target in Experiment 2 (i.e., after learning 15 images). In Experiment 4, participants learned one identity and the number of images studied varied across groups. Recognition of new images increased with the number of images studied, with no changes in false alarms; sensitivity (A′) marginally increased. The results suggest that recognition and discrimination reflect separable processes with minimal influence of between-person similarity on discrimination.