The effect of face orientation on holistic processing

Holistic processing, a hallmark of face processing, can be measured by the composite face effect: adults have difficulty recognising the top half of a face when it is aligned with a new bottom half, unless holistic processing is disrupted by misaligning the two halves. Like the recognition of facial identity, holistic processing is impaired when faces are inverted. To obtain a more refined measure of the influence of orientation on holistic face processing, we administered the composite face task to adults at each of seven orientations. In both experiment 1 (in which orientations were randomly intermixed) and experiment 2 (in which orientations were blocked), the composite face effect decreased linearly with rotation. We conclude that holistic processing is tuned to upright faces, diminishes as faces deviate from upright, and becomes insignificant once faces reach a sideways orientation. We propose a hierarchical model of face perception in which linear decreases in holistic processing underlie qualitative shifts in other aspects of face perception.     

I know your face but not where I saw you: Context memory is impaired for other-race faces

People are more likely to falsely identify a face of another race than a face of their own race. When witnesses make identifications, they often need to remember where they have previously encountered a face. Failure to remember the context of an encounter can result in unconscious transference and lead to misidentifications. Forty-five White participants were shown White and Black faces, each presented on one of five backgrounds. The participants had to identify these faces in an old/new recognition test. If participants stated that they had seen a face, they had to identify the context in which the face had originally appeared. Participants made more context errors with Black faces than with White faces. This shows that the own-race bias extends to context memory.     

The role of holistic face processing in acquired prosopagnosia: evidence from the composite face effect

Faces are processed more holistically than other objects, and it has been suggested that the loss of holistic face processing causes acquired prosopagnosia. Support for this hypothesis comes from several cases who failed to show holistic face effects as well as the absence of reports of prosopagnosics with unequivocally normal holistic face perception. The current study examines the relationship between holistic face processing and prosopagnosia by testing seven acquired prosopagnosics with the face composite task, a classic measure of holistic face processing. To enhance the robustness of the findings, each prosopagnosic was tested with two versions of the composite task showing upright faces. We also tested an inverted condition to exclude the possibility that more general factors account for composite effects for upright faces. Four of the seven acquired prosopagnosic participants showed consistent upright face composite effects with minimal inverted face composite effects. We conclude that severe face processing deficits can co-occur with intact holistic face processing and that factors other than a loss of holistic processing contribute to the perceptual and recognition deficits in acquired prosopagnosia.     

The contribution of shape and surface information in the other-race face effect

Faces from another race are generally more difficult to recognize than faces from one's own race. However, faces provide multiple cues for recognition and it remains unknown what are the relative contribution of these cues to this “other-race effect”. In the current study, we used three-dimensional laser-scanned head models which allowed us to independently manipulate two prominent cues for face recognition: the facial shape morphology and the facial surface properties (texture and colour). In Experiment 1, Asian and Caucasian participants implicitly learned a set of Asian and Caucasian faces that had both shape and surface cues to facial identity. Their recognition of these encoded faces was then tested in an old/new recognition task. For these face stimuli, we found a robust other-race effect: Both groups were more accurate at recognizing own-race than other-race faces. Having established the other-race effect, in Experiment 2 we provided only shape cues for recognition and in Experiment 3 we provided only surface cues for recognition. Caucasian participants continued to show the other-race effect when only shape information was available, whereas Asian participants showed no effect. When only surface information was available, there was a weak pattern for the other-race effect in Asians. Performance was poor in this latter experiment, so this pattern needs to be interpreted with caution. Overall, these findings suggest that Asian and Caucasian participants rely differently on shape and surface cues to recognize own-race faces, and that they continue to use the same cues for other-race faces, which may be suboptimal for these faces.     

Neural perspectives on the other-race effect

Psychological studies have long shown that human memory is superior for faces of our own-race than for faces of other-races. In this paper, we review neural studies of own- versus other-race face processing. These studies divide naturally into those focused on socioaffective aspects of the other-race effect and those directed at high-level visual processing differences. The socioaffective studies consider how subconscious bias and emotional responses affect brain areas such as the amygdala, anterior cingulate cortex, and parahippocampal gyrus. The visual studies focus on face-selective areas in the ventral stream, such as the fusiform face area (FFA). In both cases, factors such as experience, familiarity, social/emotional responses, cultural learning, and bias modulate the patterns of neural activity elicited in response to own- and other-race faces.     

Paying attention to attention: evidence for an attentional contribution to the size congruity effect

Understanding the mechanisms supporting our comprehension of magnitude information represents a key goal in cognitive psychology. A major phenomenon employed in the pursuit of this goal has been the physical size congruity effect—namely, the observation that comparing the relative numerical sizes of two numbers is influenced by their relative physical sizes. The standard account of the physical size congruity effect attributes it to the automatic influence of the comparison of irrelevant physical magnitudes on numerical judgments. Here we develop an alternative account of this effect on the basis of the operation of attention in the typical size congruity display and the temporal dynamics of number comparison. We also provide a test of a number of predictions derived from this alternative account by combining a physical size congruity manipulation with a manipulation designed to alter the operation of attention within the typical size congruity display (i.e., a manipulation of the relative onsets of the digits). This test provides evidence consistent with an attentional contribution to the size congruity effect. Implications for our understanding of magnitude and the interactions between attention and magnitude are discussed.     

Inferring social attributes from different face regions: evidence for holistic processing

Two experiments investigated the role that different face regions play in a variety of social judgements that are commonly made from facial appearance (sex, age, distinctiveness, attractiveness, approachability, trustworthiness, and intelligence). These judgements lie along a continuum from those with a clear physical basis and high consequent accuracy (sex, age) to judgements that can achieve a degree of consensus between observers despite having little known validity (intelligence, trustworthiness). Results from Experiment 1 indicated that the face's internal features (eyes, nose, and mouth) provide information that is more useful for social inferences than the external features (hair, face shape, ears, and chin), especially when judging traits such as approachability and trustworthiness. Experiment 2 investigated how judgement agreement was affected when the upper head, eye, nose, or mouth regions were presented in isolation or when these regions were obscured. A different pattern of results emerged for different characteristics, indicating that different types of facial information are used in the various judgements. Moreover, the informativeness of a particular region/feature depends on whether it is presented alone or in the context of the whole face. These findings provide evidence for the importance of holistic processing in making social attributions from facial appearance.     

The influence of attention on holistic face encoding

We examined the influence of attention on the formation of holistic face representations using the composite effect (Perception 16 (1987) 747). In Experiment 1, stimuli composed of a face superimposed on a house were shown during encoding. Subjects delineated either the face or the house, thus manipulating attention away or toward the face. In Experiment 2, an intact face image was presented with letters scrolling from top to bottom. Subjects were asked to either ignore the letters or read them and decipher the words that they formed. Aligned and misaligned composites were shown at testing. Recognition performance was consistently better for misaligned than aligned stimuli, regardless of the allocation of attention during encoding. In Experiment 3, we show that the composite effect can be eliminated by a disruption in holistic processing at the time of encoding. We conclude that holistic encoding is one aspect of face analysis that occurs equally well with or without attention.     

Structural aspects of face recognition and the other-race effect

The other-race effect was examined in a series of experiments and simulations that looked at the relationships among observer ratings of typicality, familiarity, attractiveness, memorability, and the performance variables ofd’ and criterion. Experiment 1 replicated the other-race effect with our Caucasian and Japanese stimuli for both Caucasian and Asian observers. In Experiment 2, we collected ratings from Caucasian observers on the faces used in the recognition task. A Varimax-rotated principal components analysis on the rating and performance data for the Caucasian faces replicated Vokey and Read’s (1992) finding that typicality is composed of two orthogonal components, dissociable via their independent relationships to: (1) attractiveness and familiarity ratings and (2) memorahility ratings. For Japanese faces, however, we fond that typicality was related only to memorahility. Where performance measures were concerned, two additional principal components dominated by criterion and byd’ emerged for Caucasian faces. For the Japanese faces, however, the performance measures ofd’ and criterion merged into a single component that represented a second component of typicality, one orthogonal to thememorability-dominated component. A measure offace representation quality extracted from an autoassociative neural network trained with a majority of Caucasian faces and a minority of Japanese faces was incorporated into the principal components analysis. For both Caucasian and Japanese faces, the neural network measure related both to memorability ratings and to human accuracy measures. Combined, the human data and simulation results indicate that the memorahility component of typicality may be related to small, local, distinctive features, whereas the attractiveness/familiarity component may be more related to the global, shape-based properties of the face.     

The interplay of spatial attention and memory: evidence for memory-driven spatial compatibility effects, but not for a facilitating role of attention in memory retrieval

The visual indexing theory proposed by Zenon Pylyshyn (Cognition, 32, 65-97, 1989) predicts that visual attention mechanisms are employed when mental images are projected onto a visual scene. Recent eye-tracking studies have supported this hypothesis by showing that people tend to look at empty places where requested information has been previously presented. However, it has remained unclear to what extent this behavior is related to memory performance. The aim of the present study was to explore whether the manipulation of spatial attention can facilitate memory retrieval. In two experiments, participants were asked first to memorize a set of four objects and then to determine whether a probe word referred to any of the objects. The results of both experiments indicate that memory accuracy is not affected by the current focus of attention and that all the effects of directing attention to specific locations on response times can be explained in terms of stimulus-stimulus and stimulus-response spatial compatibility.     

Attention to faces modulates early face processing during low but not high face discriminability

In the present study, we investigated whether attention to faces results in sensory gain modulation. Participants were cued to attend either to faces or to scenes in superimposed face—scene images for which face discriminability was manipulated parametrically. The face-sensitive N170 event-related potential component was used as a measure of early face processing. Attention to faces modulated N170 amplitude, but only when faces were not highly discriminable. Additionally, directing attention to faces modulated later processing (~230—300 msec) for all discriminability levels. These results demonstrate that attention to faces can modulate perceptual processing of faces at multiple stages of processing, including early sensory levels. Critically, the early attentional benefit is present only when the “face signal” (i.e., the perceptual quality of the face) in the environment is suboptimal.     

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.     

Domain‐specific development of face memory but not face perception

How does the remarkable human ability for face recognition arise over development? Competing theories have proposed either late maturity (beyond 10 years) or early maturity (before 5 years), but have not distinguished between perceptual and memory aspects of face recognition. Here, we demonstrate a perception–memory dissociation. We compare rate of development for (adult, human) faces versus other social stimuli (bodies), other discrete objects (cars), and other categories processed in discrete brain regions (scenes, bodies), from 5 years to adulthood. For perceptual discrimination, performance improved with age at the same rate for faces and all other categories, indicating no domain‐specific development. In contrast, face memory increased more strongly than non‐face memory, indicating domain‐specific development. The results imply that each theory is partly true: the late maturity theory holds for face memory, and the early maturity theory for face perception.     

The other-race effect does not rely on memory: Evidence from a matching task

Viewers are typically better at remembering faces from their own race than from other races; however, it is not yet established whether this effect is due to memorial or perceptual processes. In this study, UK and Egyptian viewers were given a simultaneous face-matching task, in which the target faces were presented upright or upside down. As with previous research using face memory tasks, participants were worse at matching other-race faces than own-race faces and showed a stronger face inversion effect for own-race faces. However, subjects' performance on own and other-race faces was highly correlated. These data provide strong evidence that difficulty in perceptual encoding of unfamiliar faces contributes substantially to the other-race effect and that accounts based entirely on memory cannot capture the full data. Implications for forensic settings are also discussed.     

The other-race effect does not rely on memory: Evidence from a matching task

Viewers are typically better at remembering faces from their own race than from other races; however, it is not yet established whether this effect is due to memorial or perceptual processes. In this study, UK and Egyptian viewers were given a simultaneous face-matching task, in which the target faces were presented upright or upside down. As with previous research using face memory tasks, participants were worse at matching other-race faces than own-race faces and showed a stronger face inversion effect for own-race faces. However, subjects' performance on own and other-race faces was highly correlated. These data provide strong evidence that difficulty in perceptual encoding of unfamiliar faces contributes substantially to the other-race effect and that accounts based entirely on memory cannot capture the full data. Implications for forensic settings are also discussed.     

Children's face recognition memory: more evidence for the cross-race effect

It is well established that own-race faces are recognized more accurately than cross-race faces. However, there are mixed results regarding the developmental consistency of the cross-race effect White and Black kindergarten children, 3rd graders, and young adults viewed a Black and a White target individual. One day later, recognition memory for each target was tested with a 6-person lineup. The interaction of race of participant by race of target face on Ag scores was significant, demonstrating an overall cross-race effect. The 2nd-order interaction with age did not approach significance; for each age group, own-race identification was more accurate than cross-race identification. The age consistency of the cross-race effect in light of the significant main effect of age suggests quantitative but not qualitative differences in face memory processing at various ages. For children, as well as adults, own-race faces are recognized more accurately than cross-race faces.     

Stroop dilution but not word-processing dilution: evidence for attention capture

Stroop dilution refers to the observation that the impact of a color word on the naming of a color bar is reduced if another word-like object is displayed simultaneously. Recently, Brown, Roos-Gilbert, and Carr (1995) concluded that Stroop dilution is due to early-visual interference. This conclusion was evaluated in three experiments. Experiment 1 showed that, contrary to the predictions of an early-visual interference account, (a) diluters that are similar in terms of visual complexity induced different amounts of dilution and (b) the size of the dilution effect is proportional to the size of the Stroop interference effect when the diluters are used as single distractors. Experiments 2 and 3 revealed that when the position of the color bar is pre-cued, Stroop dilution disappears. We argue that these findings support Van der Heijden's (1992) attention-capture account of Stroop dilution.     

The influence of divided attention on holistic face perception.

There is evidence that upright, but not inverted, faces are encoded holistically. The holistic coding of faces was examined in four experiments by manipulating the attention allocated to target faces. In Experiment 1, participants in a divided attention condition were asked to match two upright flanker faces while encoding a centrally presented upright target face. Although holistic coding was evident in the full attention conditions, dividing attention disrupted holistic coding of target faces. In Experiment 2, we found that while matching upright flanker faces disrupted holistic coding, matching inverted flanker faces did not. Experiment 3 demonstrated that the differential effects of flanker orientation were not due to participants taking longer to match upright, than inverted, flanker faces. In Experiment 4, we found that matching fractured faces had an intermediate effect to that of matching upright and inverted flankers, on the holistic coding of the target faces. The findings emphasize the differences in processing of upright, fractured and inverted faces and suggest that there are limitations in the number of faces that can be holistically coded in a brief time.     

Reversibility of the other-race effect in face recognition during childhood

Early experience with faces of a given racial type facilitates visual recognition for this type of face relative to others. To assess whether this so-called other-race effect can be reversed by subsequent experience with new types of faces, we tested adults of Korean origin who were adopted by European Caucasian families when they were between the ages of 3 to 9. The adoptees performed a face recognition task with photographs of Caucasian and Asian faces. They performed exactly like a control group of French participants, identifying the Caucasian faces better than the Asiatic ones. In contrast, a control group of Koreans showed the reverse pattern. This result indicates that the face recognition system remains plastic enough during childhood to reverse the other-race effect.