Massed versus distributed exposure and imaging of faces: Changing the test view

This research examined the effects of massed versus distributed exposure and imaging of faces, and the effects of changing the study-to-test view on subsequent recognition performance. The massed procedure consisted of individual faces exposed once for 6 s, followed by a 30 s off period. The distributed procedure consisted of faces exposed three times for 2 s, followed by a 10 s off period after each exposure. During the off periods, groups of participants either imaged the previous face, imaged another face, or performed an irrelevant letter-search task. Results showed that distributed exposure and post-exposure imaging of target faces facilitated recognition, but these effects primarily occurred when the same facial view was given at both study and test. Recognition diminished when the target was presented in a different view at test, but when combined with distributed presentation and target imaging, performance was enhanced. Implications for suspect identification and recognition of other kinds of complex visual stimuli are discussed.     

Anxiety and terrorism: Automatic stereotypes affect visual attention and recognition memory for White and Middle Eastern faces

Automatic stereotypes and emotional state can affect cognitive processes such as attention, perception, and memory. Two experiments were carried out to investigate whether anxiety and stereotypes of Middle Easterners influence attention and recognition memory in White participants. A dot‐probe procedure was used, with White and Middle Eastern faces as stimuli. The results showed that anxious participants who were exposed to terrorism‐related words showed a visual bias toward Middle Eastern faces, and were more accurate at recognizing both White and Middle Eastern faces. Non‐anxious participants, after exposure to the same primes, showed an attentional bias toward the White faces. Overall, participants were more accurate at recognizing the White faces than the Middle Eastern faces. Copyright © 2008 John Wiley & Sons, Ltd.     

Subliminal exposure to faces and racial attitudes: Exposure to Whites makes Whites like Blacks less

Despite recent social and political advances, most interracial contact is still superficial in nature, and White individuals interact mainly with other Whites. Based on recent mere exposure research, we propose that repeated exposure to Whites may actually increase prejudice. In a series of experiments, White participants were subliminally exposed to White faces or nothing (control) and then completed various explicit and implicit measures of racial attitudes. Exposure to White faces consistently led to more prejudice by making attitudes toward Blacks more negative, rather than by making attitudes toward Whites more positive. A final experiment demonstrated that the pattern of increased prejudice following exposure to Whites was moderated by the strength of participants’ attitudes toward Whites. Only when White attitudes were strong did Black attitudes became more negative after exposure to White faces.     

Dissociating averageness and attractiveness: attractive faces are not always average

Although the averageness hypothesis of facial attractiveness proposes that the attractiveness of faces is mostly a consequence of their averageness, 1 study has shown that caricaturing highly attractive faces makes them mathematically less average but more attractive. Here the authors systematically test the averageness hypothesis in 5 experiments using both rating and visual adaptation paradigms. Visual adaptation has previously been shown to increase both preferences for previously viewed face types (i.e., attractiveness) and their perceived normality (i.e., averageness). The authors used a visual adaptation procedure to test whether facial attractiveness is dependent upon faces' proximity to average (averageness hypothesis) or their location relative to average along an attractiveness dimension in face space (contrast hypothesis). While the typical pattern of change due to visual adaptation was found for judgments of normality, judgments of attractiveness resulted in a very different pattern. The results of these 5 experiments conclusively support the proposal that there are specific nonaverage characteristics that are particularly attractive. The authors discuss important implications for the interpretation of studies using a visual adaptation paradigm to investigate attractiveness.     

Lecturers' faces fatigue their students: Face identity aftereffects for dynamic and static faces

Face adaptation has been used as a tool to probe our representations for facial identity. It has also been claimed to play a functional role in face processing, perhaps calibrating the visual system towards encountered faces. However, for this to be so, face aftereffects must be observable following adaptation to ecologically valid moving stimuli, not just after prolonged viewing of static images. We adapted our participants to videos, static image sequences or single images of the faces of lecturers who were personally familiar to them. All three stimulus types produced significant, and equivalent, face identity aftereffects, demonstrating that aftereffects are not confined to static images but can occur after exposure to more naturalistic stimuli. It is also further evidence against explanations of face adaptation effects solely in terms of low-level visual processing.     

Effects of exposure to alcohol‐related cues on racial discrimination

Prior research has shown that exposure to alcohol‐related images exacerbates expression of implicit racial biases, and that brief exposure to alcohol‐related words increases aggressive responses. However, the potential for alcohol cue exposure to elicit differential aggression against a Black (outgroup) relative to a White (ingroup) target—that is, racial discrimination—has never been investigated. Here, we found that White participants (N = 92) exposed to alcohol‐related words made harsher judgments of a Black experimenter who had frustrated them than participants who were exposed to nonalcohol words. These findings suggest that exposure to alcohol cues increases discriminatory behaviors toward Blacks.     

Peak shift but not range effects in recognition of faces

University students were trained to discriminate between two gray-scale images of faces that varied along a continuum from a unique face to an average face created by morphing. Following training, participants were tested without feedback for their ability to recognize the positive face (S+) within a range of faces along the continuum. In Experiments 1 and 4, the range of stimuli presented during testing was manipulated. In Experiment 2, participants viewed different ranges of faces during an adaptation period that followed training and preceded testing. In all experiments, generalization functions revealed peak shifts or area shifts (fewer “yes” responses to novel faces on the negative side of the S+), but no systematic effects of the test or adaptation range. Peak shift was found both for upright and inverted faces and occurred even if the orientation of the face was reversed between training and test. Using similar methods, either an area shift or range effect (but not both together) was demonstrated for line tilt stimuli (Experiment 3), and the appearance of these effects depended on instructions. It appears that peak shift and area shift are robust across many different kinds of stimuli, but range effects may not readily occur with complex multidimensional stimuli.     

Category contingent aftereffects for faces of different races, ages and species

Exposure to faces biases perceptions of subsequently viewed faces such that normality judgments of similar faces are increased. Simultaneously inducing such an aftereffect in opposite directions for two groups of faces might indicate discrete responding of the neural populations coding for those groups. Here we show such "category contingent" aftereffects following exposure to faces differing in eye-spacing (wide versus narrow) for European versus African faces, adult versus infant faces, and human versus monkey faces. As aftereffects reflect changes in responses of neural populations that code faces, our results may then suggest that functionally distinct neural populations code faces of different ages, races and species and that the human brain potentially contains discrete representations of these categories.     

Priming race in biracial observers affects visual search for Black and White faces

We examined whether or not priming racial identity would influence Black-White biracial individuals' ability to visually search for White and Black faces. Black, White, and biracial participants performed a visual search task in which the targets were Black or White faces. Before the task, the biracial participants were primed with either their Black or their White racial identity. All participant groups detected Black faces faster than White faces. Critically, the results also showed a racial-prime effect in biracial individuals: The magnitude of the search asymmetry was significantly different for those primed with their White identity and those primed with their Black identity. These findings suggest that top-down factors such as one's racial identity can influence mechanisms underlying the visual search for faces of different races.     

Recognition memory for distractor faces depends on attentional load at exposure

Incidental recognition memory for faces previously exposed as task-irrelevant distractors was assessed as a function of the attentional load of an unrelated task performed on superimposed letter strings at exposure. In Experiment 1, subjects were told to ignore the faces and either to judge the color of the letters (low load) or to search for an angular target letter among other angular letters (high load). A surprise recognition memory test revealed that despite the irrelevance of all faces at exposure, those exposed under low-load conditions were later recognized, but those exposed under high-load conditions were not. Experiment 2 found a similar pattern when both the high- and low-load tasks required shape judgments for the letters but made differing attentional demands. Finally, Experiment 3 showed that high load in a nonface task can significantly reduce even immediate recognition of a fixated face from the preceding trial. These results demonstrate that load in a nonface domain (e.g., letter shape) can reduce face recognition, in accord with Lavie’s load theory. In addition to their theoretical impact, these results may have practical implications for eyewitness testimony.     

Attentional inhibition has social-emotional consequences for unfamiliar faces

Visual attention studies often rely on response time measures to show the impact of attentional facilitation and inhibition. Here we extend the investigation of the effects of attention on behavior and show that prior attentional states associated with unfamiliar faces can influence subsequent social-emotional judgments about those faces. Participants were shown pairs of face images and were asked to withhold a response if a transparent stop-signal cue appeared over one of the faces. This served to associate the cued face with an inhibitory state. Later, when asked to make social-emotional choices about these face pairs, participants chose uncued faces more often than cued faces as "more trustworthy" and chose cued faces more often than uncued faces as "less trustworthy." For perceptual choices, there was no effect of how the question was framed (which face is "on a lighter background" vs. "on a darker background"). These results suggest that attentional inhibition can be associated with socially relevant stimuli, such as faces, and can have specific, deleterious effects on social-emotional judgments.     

Second-order isomorphism of internal representations of familiar faces

Following a suggestion by Shepard and Chipman (1970), photographs and names of 15 well-known faces were used as stimuli in judgments of similarity. Ss ranked all pairs of stimuli in terms of facial similarity either from memory when presented with pairs of names, or from photographs. There was a highly significant positive correlation between these two types of judgment. A simple classificatory analysis of the 15 faces in terms of the physical features provided evidence that judgments based on the internal representation of the faces utilized pictorial information. These results extend the generality of Shepard and Chipman’s findings and confirm the usefulness of an approach to the problem of mental images based on the concept of second-order isomorphism.     

Getting to know you: From view-dependent to view-invariant repetition priming for unfamiliar faces

Recent research suggests that repetition priming (RP) for unfamiliar faces is highly view dependent and is eliminated when the viewpoint of target faces changes between study and test. The current research examined whether increased familiarity with novel faces from a single viewpoint at study would support RP from an alternative viewpoint at test. Participants passively viewed novel face images from a single viewpoint at study (i.e., either front or three-quarters), with half of the images seen once and half seen on five occasions. During a sex classification task at test, participants were faster to respond to face images seen from the same view as that at study than they were to previously unseen distractor faces for both single exposure faces and faces seen on five occasions (i.e., standard RP). When, however, face images at test were shown from a different viewpoint from that at study, RP only occurred for faces viewed on five occasions.     

Getting to know you: from view-dependent to view-invariant repetition priming for unfamiliar faces

Recent research suggests that repetition priming (RP) for unfamiliar faces is highly view dependent and is eliminated when the viewpoint of target faces changes between study and test. The current research examined whether increased familiarity with novel faces from a single viewpoint at study would support RP from an alternative viewpoint at test. Participants passively viewed novel face images from a single viewpoint at study (i.e., either front or three-quarters), with half of the images seen once and half seen on five occasions. During a sex classification task at test, participants were faster to respond to face images seen from the same view as that at study than they were to previously unseen distractor faces for both single exposure faces and faces seen on five occasions (i.e., standard RP). When, however, face images at test were shown from a different viewpoint from that at study, RP only occurred for faces viewed on five occasions.     

Judging trustworthiness from faces: Emotion cues modulate trustworthiness judgments in young children

By adulthood, people judge trustworthiness from appearances rapidly and reliably. However, we know little about these judgments in children. This novel study investigates the developmental trajectory of explicit trust judgments from faces, and the contribution made by emotion cues across age groups. Five‐, 7‐, 10‐year‐olds, and adults rated the trustworthiness of trustworthy and untrustworthy faces with neutral expressions. The same participants also rated faces displaying overt happy and angry expressions, allowing us to investigate whether emotion cues modulate trustworthiness judgments similarly in children and adults. Results revealed that the ability to evaluate the trustworthiness of faces emerges in childhood, but may not be adult like until 10 years of age. Moreover, we show that emotion cues modulate trust judgments in young children, as well as adults. Anger cues diminished the appearance of trustworthiness for participants from 5 years of age and happy cues increased it, although this effect did not consistently emerge until later in childhood, that is, 10 years of age. These associations also extended to more subtle emotion cues present in neutral faces. Our results indicate that young children are sensitive to facial trustworthiness, and suggest that similar expression cues modulate these judgments in children and adults.     

Opposite effects of visual versus imagined presentation of faces on subsequent sex perception

Viewing faces of one sex changes the perception of subsequently seen ambiguous faces. Here we investigate if the mechanisms responsible for this sex aftereffect are also activated during mental imagery of faces. Participants categorized the sex of ambiguous faces after either viewing images of male or female actors' faces or imagining these same faces. As in previous studies, the ambiguous images were categorized as female more often after viewing male faces than after viewing female faces. The opposite effect was found for imagined faces, however; the ambiguous images were categorized as female more often after imagining female faces than after imagining male faces. Although our results are inconsistent with findings that imagined faces cause either no aftereffects or similar aftereffects to visually presented faces, our results are consistent with recent evidence that visual and imagined presentation of faces cause opposite adaptation effects on an early electrophysiological response associated with face processing.     

Figural aftereffects in the perception of faces

We examined figural aftereffects in images of human faces, for which changes in configuration are highly discriminable. Observers either matched or rated faces before or after viewing distorted images of faces. Prior adaptation strongly biases face perception by causing the original face to appear distorted in a direction opposite to the adapting distortion. Aftereffects transferred across different faces and were similar for upright or inverted faces, but were weaker when the adapting and test faces had different orientations (e.g., adapt inverted and test upright). Thus the aftereffects depend on which images are distorted, and not simply on the type of distortion introduced. We further show that the aftereffects are asymmetric, for adapting to the original face has little effect on the perception of a distorted face. This asymmetry suggests that adaptation may play an important normalizing role in face perception. Our results suggest that in normal viewing, figural aftereffects may strongly influence form perception and could provide a novel method for probing properties of human face perception.     

Holistic processing underlies gender judgments of faces

In three experiments, we investigated whether holistic processing underlies gender judgments about faces. Chinese participants were asked to make gender judgments for inverted, scrambled, or composite faces. Results showed that judgments were dramatically impaired by these manipulations (as compared with performance for normal upright faces), demonstrating three hallmark effects of holistic face processing that have been observed in perception of face identity. Whether the test faces were Chinese or Caucasian showed no effect on holistic processing of gender perception, in contrast to studies of identity analysis. These results suggest that holistic processing is a general mechanism for different aspects of face perception and are consistent with the idea that physiognomic properties that determine the gender of a face are universal, rather than race specific.     

Race-specific perceptual discrimination improvement following short individuation training with faces

This study explores the effect of individuation training on the acquisition of race-specific expertise. First, we investigated whether practice individuating other-race faces yields improvement in perceptual discrimination for novel faces of that race. Second, we asked whether there was similar improvement for novel faces of a different race for which participants received equal practice, but in an orthogonal task that did not require individuation. Caucasian participants were trained to individuate faces of one race (African American or Hispanic) and to make difficult eye-luminance judgments on faces of the other race. By equating these tasks we are able to rule out raw experience, visual attention, or performance/success-induced positivity as the critical factors that produce race-specific improvements. These results indicate that individuation practice is one mechanism through which cognitive, perceptual, and/or social processes promote growth of the own-race face recognition advantage.