A grey area: how does image hue affect unfamiliar face matching?

i-Perception

The current study investigated whether small differences in the background colours between the lineup members would influence identification accuracy of own-race and other-race faces. Using the well-established 1-in-10 paradigm, half of the array faces had exactly the same backgrounds, and half were on backgrounds of slightly different hues of green. For target present arrays, participants were more accurate at identifying own-race faces when compared with the other-race faces when all backgrounds were the same. However, when backgrounds had slightly different hues, there was no difference in how accurate people were at identifying faces from both races. For target absent arrays, participants were more likely to incorrectly choose a face if the backgrounds were not all the same, regardless of the race of faces. Real-world implications from these findings are that using lineups where the backgrounds are slightly different hues may increase the likelihood of the false identification o...

2021

This study investigates whether variability in perceived trait judgements disrupts our ability to match unfamiliar faces. In this preregistered study, 174 participants completed a face matching task where they were asked to indicate whether two face images belonged to the same person or different people (17,748 total data points). Participants completed 51 match trials consisting of images of the same person that differed substantially on one trait (either trustworthiness, dominance, or attractiveness) with minimal differences in the alternate traits. Participants also completed 51 mismatch trials which contained two photos of similar-looking individuals. We hypothesised that participants would make more errors on match trials when images differed in terms of attractiveness ratings than those that differed on trustworthiness or dominance. Contrary to expectations, images that differed in terms of attractiveness were matched most accurately, and there was no relationship between the ...

Counter-terrorism and crime prevention often depend on our ability to match images of unfamiliar faces. For example, when issuing passports, staff must establish an applicant's identity by comparing the submitted photograph witht those in the database of current passports to ensure that multiple documents are not issued to the same person under different names. Previous research has shown that this is a difficult and error prone task. We suggest that this 'passport problem' may be due to an over-reliance on the appearance of external facial features that can be unreliable cues to identity. Compatible with this explanation, we demonstrate that in difficult trials involving a change of appearance or attempted fraud involving a similar looking foil, participants are better able to determine whether two images are of the same person when shown only the internal features of the faces rather than whole images. This discovery has significant practical implications and could form the basis of a procedure to improve the detection of identity fraud.

Behavior Research Methods, 2010

We describe a new test for unfamiliar face matching, the Glasgow Face Matching Test (GFMT). Viewers are shown pairs of faces, photographed in full-face view but with different cameras, and are asked to make same/ different judgments. The full version of the test comprises 168 face pairs, and we also describe a shortened version with 40 pairs. We provide normative data for these tests derived from large subject samples. We also describe associations between the GFMT and other tests of matching and memory. The new test correlates moderately with face memory but more strongly with object matching, a result that is consistent with previous research highlighting a link between object and face matching, specific to unfamiliar faces. The test is available free for scientific use.

Cognitive Research: Principles and Implications

This journal is dedicated to "use-inspired basic research" where a problem in the world shapes the hypotheses for study in the laboratory. This review considers the role of individual variation in face identification and the challenges and opportunities this presents in security and criminal investigations. We show how theoretical work conducted on individual variation in face identification has, in part, been stimulated by situations presented in the real world. In turn, we review the contribution of theoretical work on individual variation in face processing and how this may help shape the practical identification of faces in applied situations. We consider two cases in detail. The first case is that of security officers; gatekeepers who use facial ID to grant entry or deny access. One applied example, where much research has been conducted, is passport control officers who are asked to match a person in front of them to a photograph shown on their ID. What happens if they are poor at making such face matching decisions and can they be trained to improve their performance? Second, we outline the case of "superrecognisers", people who are excellent at face recognition. Here it is interesting to consider whether these individuals can be strategically allocated to security and criminal roles, to maximise the identification of suspects. We conclude that individual differences are one of the largest documented sources of error in face matching and face recognition but more work is needed to account for these differences within theoretical models of face processing.

Photo-ID is widely used in security settings, despite research showing that viewers find it very difficult to match unfamiliar faces. Here we test participants with specialist experience and training in the task: passport-issuing officers. First, we ask officers to compare photos to live ID-card bearers, and observe high error rates, including 14% false acceptance of 'fraudulent' photos. Second, we compare passport officers with a set of student participants, and find equally poor levels of accuracy in both groups. Finally, we observe that passport officers show no performance advantage over the general population on a standardised face-matching task. Across all tasks, we observe very large individual differences: while average performance of passport staff was poor, some officers performed very accurately -though this was not related to length of experience or training. We propose that improvements in security could be made by emphasising personnel selection.

Frontiers in human neuroscience, 2014

Faces provide information about multiple characteristics like personal identity and emotion. Classical models of face perception postulate separate sub-systems for identity and expression recognition but recent studies have documented emotional contextual influences on recognition of faces. The present study reports three experiments where participants were presented realistic face-body compounds in a 2 category (face and body) × 2 emotion (neutral and fearful) factorial design. The task always consisted of two-alternative forced choice facial identity matching. The results show that during simultaneous face identity matching, the task irrelevant bodily expressions influence processing of facial identity, under conditions of unlimited viewing (Experiment 1) as well as during brief (750 ms) presentation (Experiment 2). In addition, delayed (5000 ms) face identity matching of rapidly (150 ms) presented face-body compounds, was also influenced by the body expression (Experiment 3). The results indicate that face identity perception mechanisms interact with processing of bodily and facial expressions.

IEEE Transactions on Technology and Society, 2020

Face recognition technology has recently become controversial over concerns about possible bias due to accuracy varying based on race or skin tone. We explore three important aspects of face recognition technology related to this controversy. Using two different deep convolutional neural network face matchers, we show that for a fixed decision threshold, the African-American image cohort has a higher false match rate (FMR), and the Caucasian cohort has a higher false nonmatch rate. We present an analysis of the impostor distribution designed to test the premise that darker skin tone causes a higher FMR, and find no clear evidence to support this premise. Finally, we explore how using face recognition for one-to-many identification can have a very low false-negative identification rate and still present concerns related to the false-positive identification rate. Both the ArcFace and VGGFace2 matchers and the MORPH dataset used in our experiments are available to the research community so that others should be able to reproduce or reanalyze our results.

Applied Cognitive Psychology, 2013

Memory & Cognition, 2006

It is difficult to match two images of the same unfamiliar face, even under good conditions. Here, we show that there are large individual differences on unfamiliar face matching. Initially, we tried to predict these using tests of visual short-term memory, cognitive style, and perceptual speed. Moderate correlations were produced by various components of these tests. In three other experiments, we found very strong correlations between face matching and inverted face matching on the same test. Finally, we examined potential associations between familiar and unfamiliar face processing. Strong correlations were found between familiar and unfamiliar face processing, but only when the familiar faces were inverted. We conclude that unfamiliar faces are processed for identity in a qualitatively different way than are familiar faces.