Facial Wipes don't Wash: Facial Image Comparison by Video Superimposition Reduces the Accuracy of Face Matching Decisions

In cases of disputed CCTV identification, expert testimony based on the results of analysis by facial image comparison may be presented to the Jury. However, many of the techniques lack empirical data to support their use. Using a within‐participants design, we compared the accuracy of face‐matching decisions when images were presented using a ‘facial wipe’ technique (where one image is superimposed on another and the display gradually ‘wipes’ between the two) with decisions based on static images. Experiment 1 used high‐quality image pairs; Experiment 2 used disguised target images; and Experiment 3 used degraded target images. Across all three experiments, rather than optimising performance, facial wipes reduced accuracy relative to static presentations. Further, there is evidence that video wipes increase false positives and therefore may increase the likelihood that images of two different people will be incorrectly judged to show the same individual.Copyright © 2016 John Wiley & Sons, Ltd.     

Performance of typical and superior face recognizers on a novel interactive face matching procedure

Unfamiliar simultaneous face matching is error prone. Reducing incorrect identification decisions will positively benefit forensic and security contexts. The absence of view-independent information in static images likely contributes to the difficulty of unfamiliar face matching. We tested whether a novel interactive viewing procedure that provides the user with 3D structural information as they rotate a facial image to different orientations would improve face matching accuracy. We tested the performance of ‘typical’ (Experiment 1) and ‘superior’ (Experiment 2) face recognizers, comparing their performance using high-quality (Experiment 3) and pixelated (Experiment 4) Facebook profile images. In each trial, participants responded whether two images featured the same person with one of these images being either a static face, a video providing orientation information, or an interactive image. Taken together, the results show that fluid orientation information and interactivity prompt shifts in criterion and support matching performance. Because typical and superior face recognizers both benefited from the structural information provided by the novel viewing procedures, our results point to qualitatively similar reliance on pictorial encoding in these groups. This also suggests that interactive viewing tools can be valuable in assisting face matching in high-performing practitioner groups.     

Image-size disparity reduces difference detection in face matching

Face matching is the act of deciding whether two facial images depict the same person or different people. The real-world face-matching task of checking photo IDs typically occurs under conditions of image-size disparity: A small picture is compared with a life-size face. We examined the effect of image-size disparity on face-matching accuracy. In three experiments, subjects were presented with pairs of equivalently or disparately sized images that depicted the same person or different people. Subjects made same/different judgments and, in two experiments, also reported confidence. Difference detection was significantly poorer given disparate (versus equivalent) image size. Confidence was significantly higher when responses were correct versus incorrect. These findings held whether viewing and decision time was unlimited or limited. Our results raise the practical concern that image-size disparity may undermine difference detection in ID checking, while also indicating that people have some insight into the accuracy of their face-matching judgments.     

Perceptual asymmetries are preserved in memory for highly familiar faces of self and friend

We investigated the effect of familiarity on people's perception of facial likeness by asking participants to choose which of two mirror-symmetric chimeric images (made from the left or right half of a photograph of a face) looked more like an original image. In separate trials the participants made this judgment for their own face and for the face of a close friend; half of them matched to a true image of the original and half matched to a mirror image of the original. In the case of matching to a friend's face presented in the familiar orientation, over 80% of participants chose the left-left composite to be a better likeness to the original, whereas only 62% showed the same left-side bias when matching to a mirror image. The difference is significant, and the result contrasts markedly with a second experiment where participants who were unfamiliar with the faces showed comparable left-side biases when matching to true or mirror reversed images. The result suggests that perceptual asymmetries are retained in our long-term memory for highly familiar faces. While matching to images of self also showed an effect of familiarity, the data in this condition show less evidence of perceptual asymmetry and are discussed in relation to recent research on the representation of one's own face.     

A bottleneck in face identification: repetition priming from flanker images

There is evidence that face processing is capacity-limited in distractor interference tasks and in tasks requiring overt recognition memory. We examined whether capacity limits for faces can be observed with a more sensitive measure of visual processing, by measuring repetition priming of flanker faces that were presented alongside a face or a nonface target. In Experiment 1, we found identity priming for face flankers, by measuring repetition priming across a change in image, during task-relevant nonface processing, but not during the processing of a concurrently-presented face target. Experiment 2 showed perceptual priming of the flanker faces, across identical images at prime and test, when they were presented alongside a face target. In a third Experiment, all of these effects were replicated by measuring identity priming and perceptual priming within the same task. Overall, these results imply that face processing is capacity limited, such that only a single face can be identified at one time. Merely attending to a target face appears sufficient to trigger these capacity limits, thereby extinguishing identification of a second face in the display, although our results demonstrate that the additional face remains at least subject to superficial image processing.     

The facilitating effect of verbalization on the recognition memory of incidentally learned faces

The purpose of this study was to test the hypothesis that requiring people to verbally describe a target face from memory facilitates their subsequent recognition when their memory for the target is poor and interferes with recognition when such memory is strong. In Experiment 1, a target face was presented to participants for 30 s or 100 s under a nominal task instruction, and they incidentally familiarized themselves with it. Verbalization increased the rate of correct recognition only when the target was presented for 30 s and the performance of control participants was poor. In Experiment 2, participants observed a target without instruction for intentional learning or other nominal instruction, in a more ecologically valid context. Recognition performance was poor for control participants and verbalization increased the rate of correct recognition. These results appear to support the hypothesis. The implications for the identification of persons by eyewitnesses are discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

Disguising Superman: How Glasses Affect Unfamiliar Face Matching

Could a simple pair of glasses really fool us into thinking Superman and Clark Kent are two different people? Here, we investigated the perception of identity from face images with a task that relies on visual comparison rather than memory. Participants were presented with two images simultaneously and were asked whether the images depicted the same person or two different people. The image pairs showed neither image with glasses, both images with glasses, and ‘mixed’ pairs of one image with and one without glasses. Participants' accuracies, measured by both percentage correct and d′ sensitivity, were significantly lower for ‘mixed’ trials. Analysis of response bias showed that when only one face wore glasses, people tended to respond ‘different’. We demonstrate that glasses affect face matching ability using unconstrained images, and this has implications for both disguise research and authenticating identity in the real world. Copyright © 2016 John Wiley & Sons, Ltd.     

Repetition priming from moving faces

Recent experiments have suggested that seeing a familiar face move provides additional dynamic information to the viewer, useful in the recognition of identity. In four experiments, repetition priming was used to investigate whether dynamic information is intrinsic to the underlying face representations. The results suggest that a moving image primes more effectively than a static image, even when the same static image is shown in the prime and the test phases (Experiment 1). Furthermore, when moving images are presented in the test phase (Experiment 2), there is an advantage for moving prime images. The most priming advantage is found with naturally moving faces, rather than with those shown in slow motion (Experiment 3). Finally, showing the same moving sequence at prime and test produced more priming than that found when different moving sequences were shown (Experiment 4). The results suggest that dynamic information is intrinsic to the face representations and that there is an advantage to viewing the same moving sequence at prime and test.     

Not looking yourself: The cost of self‐selecting photographs for identity verification

Photo‐identification is based on the premise that photographs are representative of facial appearance. However, previous studies show that ratings of likeness vary across different photographs of the same face, suggesting that some images capture identity better than others. Two experiments were designed to examine the relationship between likeness judgments and face matching accuracy. In Experiment 1, we compared unfamiliar face matching accuracy for self‐selected and other‐selected high‐likeness images. Surprisingly, images selected by previously unfamiliar viewers – after very limited exposure to a target face – were more accurately matched than self‐selected images chosen by the target identity themselves. Results also revealed extremely low inter‐rater agreement in ratings of likeness across participants, suggesting that perceptions of image resemblance are inherently unstable. In Experiment 2, we test whether the cost of self‐selection can be explained by this general disagreement in likeness judgments between individual raters. We find that averaging across rankings by multiple raters produces image selections that provide superior identification accuracy. However, benefit of other‐selection persisted for single raters, suggesting that inaccurate representations of self interfere with our ability to judge which images faithfully represent our current appearance.     

The State of Ecological Psychology

We report on two experiments that investigated the role of facial motion in the recognition of degraded famous face images. The results of these experiments suggest that seeing a face move is advantageous for the correct recognition of identity. This effect is not solely due to the extra static-based information contained in a moving sequence but is also due to additional dynamic information available from a moving face. Furthermore, famous faces were recognized more accurately when the original dynamic characteristics of the motion were maintained (Experiment 1), compared to when either the tempo or the direction of motion were altered (Experiment 2). It is suggested that there may be general benefit for viewing naturally moving faces, not specific benefit to any particular face identity. Alternatively, individual faces may have associated characteristic motion signatures.     

A matching advantage for dynamic human faces

In a series of three experiments, we used a sequential matching task to explore the impact of non-rigid facial motion on the perception of human faces. Dynamic prime images, in the form of short video sequences, facilitated matching responses relative to a single static prime image. This advantage was observed whenever the prime and target showed the same face but an identity match was required across expression (experiment 1) or view (experiment 2). No facilitation was observed for identical dynamic prime sequences when the matching dimension was shifted from identity to expression (experiment 3). We suggest that the observed dynamic advantage, the first reported for non-degraded facial images, arises because the matching task places more emphasis on visual working memory than typical face recognition tasks. More specifically, we believe that representational mechanisms optimised for the processing of motion and/or change-over-time are established and maintained in working memory and that such 'dynamic representations' (Freyd, 1987 Psychological Review 94 427-438) capitalise on the increased information content of the dynamic primes to enhance performance.     

Appearance-based inferences bias source memory

Previous research varying the trustworthiness of appearance has demonstrated that facial characteristics contribute to source memory. Two studies extended this work by investigating the contribution to source memory of babyfaceness, a facial quality known to elicit strong spontaneous trait inferences. Young adult participants viewed younger and older babyfaced and mature-faced individuals paired with sentences that were either congruent or incongruent with the target??s facial characteristics. Identifying a source as dominant or submissive was least accurate when participants chose between a target whose behavior was incongruent with facial characteristics and a lure whose face mismatched the target in appearance but matched the source memory question. In Experiment 1, this effect held true when older sources were identified, but not own-age, younger sources. When task difficulty was increased in Experiment 2, the relationship between face?Cbehavior congruence and lure facial characteristics persisted, but it was not moderated by target age even though participants continued to correctly identify fewer older than younger sources. Taken together, these results indicate that trait expectations associated with variations in facial maturity can bias source memory for both own- and other-age faces, although own-age faces are less vulnerable to this bias, as is shown in the moderation by task difficulty.     

Judging approachability on the face of it: the influence of face and body expressions on the perception of approachability

The aim of the current study was to examine how emotional expressions displayed by the face and body influence the decision to approach or avoid another individual. In Experiment 1, we examined approachability judgments provided to faces and bodies presented in isolation that were displaying angry, happy, and neutral expressions. Results revealed that angry expressions were associated with the most negative approachability ratings, for both faces and bodies. The effect of happy expressions was shown to differ for faces and bodies, with happy faces judged more approachable than neutral faces, whereas neutral bodies were considered more approachable than happy bodies. In Experiment 2, we sought to examine how we integrate emotional expressions depicted in the face and body when judging the approachability of face-body composite images. Our results revealed that approachability judgments given to face-body composites were driven largely by the facial expression. In Experiment 3, we then aimed to determine how the categorization of body expression is affected by facial expressions. This experiment revealed that body expressions were less accurately recognized when the accompanying facial expression was incongruent than when neutral. These findings suggest that the meaning extracted from a body expression is critically dependent on the valence of the associated facial expression.     

Why 8-year-olds cannot tell the difference between Steve Martin and Paul Newman: factors contributing to the slow development of sensitivity to the spacing of facial features

Children are nearly as sensitive as adults to some cues to facial identity (e.g., differences in the shape of internal features and the external contour), but children are much less sensitive to small differences in the spacing of facial features. To identify factors that contribute to this pattern, we compared 8-year-olds' sensitivity to spacing cues with that of adults under a variety of conditions. In the first two experiments, participants made same/different judgments about faces differing only in the spacing of facial features, with the variations being kept within natural limits. To measure the effect of attention, we reduced the salience of featural information by blurring faces and occluding features (Experiment 1). To measure the role of encoding speed and memory limitations, we presented pairs of faces simultaneously and for an unlimited time (Experiment 2). To determine whether participants' sensitivity would increase when spacing distortions were so extreme as to make the faces grotesque, we manipulated the spacing of features beyond normal limits and asked participants to rate each face on a "bizarreness" scale (Experiment 3). The results from the three experiments indicate that low salience, poor encoding efficiency, and limited memory can partially account for 8-year-olds' poor performance on face processing tasks that require sensitivity to the spacing of features, a kind of configural processing that underlies adults' expertise. However, even when the task is modified to compensate for these problems, children remain less sensitive than adults to the spacing of features.