Virtual reality is increasingly employed in behavioral research, providing immersive environments that combine high levels of experimental control with ecological validity. Within virtual reality, humans are represented by digital characters - or avatars - whose realism and behavioral fidelity are crucial for studying social cognition. This study introduces an accessible method for constructing avatars with facial animations of eye gaze and expression that can be used by behavioral scientists. In two pre-registered experiments, we validate the use of these avatars for psychological research. In Experiment 1, we demonstrate that observers orient attention in response to avatar eye gaze, replicating the classic gaze-cueing effect. In Experiment 2, we show that participants can recognize avatar facial expressions with accuracy and confusion patterns comparable to those reported for human faces. These findings establish our construction pipeline as a user-friendly approach for generating high-fidelity avatars, equipping researchers with tools to investigate social and cognitive processes in controlled yet ecologically valid virtual environments. We provide access to an extensive manual for constructing avatars, along with a video example demonstrating the procedure step-by-step. Using a relatively inexpensive hand-held scanner, this enables behavioral scientists to create avatars with accurate facial animation for experiments in virtual environments.

In virtual reality, observers readily calibrate to the bodies of digital human characters and consider changes to these in estimates of their action capabilities. This study investigates whether such calibration persists when somatosensory and visual information specifying the spatial location of limbs are incongruent. Across four experiments, virtual hand size and location was manipulated systematically while participants were placed in an immersive environment. Participants performed a calibration exercise to gain experience with the virtual hand before estimating their perceived grasping and reaching capabilities. In all experiments, observers consistently calibrated to the virtual hands and considered this in their perceived grasping and reaching estimates. This demonstrates that the properties of an artificial limb are integrated into observers' perception of their action capabilities, even when conditions for embodiment are not optimal.

Unfamiliar face identification is a challenging task, and is often considered to be perceptual in nature. This ignores the contribution of decision-making in face identification. Across three experiments we examined whether face-matching decisions would change depending on the framing of response options. In Experiment 1, participants completed an unfamiliar face matching task with the Same/Different, Same/Not-Same or Same/Proceed-to-Next-Trial response options. In Experiment 2, participants completed the task twice, once with the Same/Different response options and once with the Same/Different, Same/Not-Same or Same/Proceed-to-Next-Trial response options. In Experiment 3, participants completed the task when 50% or 80% of trials were matches, and used the Same/Different or Same/Proceed-to-Next-Trial response options. Whereas we found no evidence that face identification decisions were influenced by the framing of response options, we found evidence of a robust base rate effect. Together these findings suggest that decision making in unfamiliar face identification is a complex and selective process.

Technologies aiming to imitate human faces are becoming increasingly realistic. This study investigates a facial imitation technology that is becoming widespread - digital characters of people for presentation in virtual reality. Avatar faces were created from high-resolution 3D scans of real people. Across a series of four experiments, the photo-realism of these avatar faces was compared with passport-style face photographs of the same persons. In Experiments 1 and 2, these stimuli could be distinguished with high accuracy when a direct comparison of avatars and photographs was possible. In contrast, discrimination accuracy decreased when avatars and photographs were encountered in isolation, while awareness that avatar faces had been encountered was also low. Experiments 3 and 4 showed that avatars and face photographs generate similar trait inferences of attractiveness, dominance and trustworthiness. In cases where differences between avatars and photographs emerge, analysis of viewing patterns indicates that these originate from the eye region of these stimuli, which receive more fixations in avatars than face photographs. These findings demonstrate that the visual realism of avatars can closely resemble that of face photographs, particularly in contexts in which realism is not explicitly evaluated. Differences between avatars and photographs become more apparent when participants are cognizant and able to make direct comparisons.

The human face provides the primary visual means for identifying other people and important occupations depend on this task, such as passport control at borders and person identifications in police investigations. These tasks are performed by different types of professionals. There are facial reviewers, who receive limited training and perform a high volume of person identifications on a daily basis, whereas facial examiners receive extensive training and mentoring to perform a limited number of identifications following strict protocols. A third group of professionals also exists, reflecting so-called super-recognisers, who appear to have a naturally high aptitude for face perception. In this chapter, the identification accuracy of these three professions is reviewed at a group level, to demonstrate general performance, and at the level of the individual, to show the range of ability that exists between different personnel. The implications of these general and individual performance profiles are discussed.

Face matching is an important applied task that requires binary decisions to pairs of face images to determine whether these depict the same person (an identity match) or different people (a mismatch). While these choices are mutually exclusive, performance for match and mismatch trials appears to be dissociable, which poses a problem for theory development. The current study demonstrates that this dissociation arises from systematic response biases, which reflect individual differences in the placement of decision-making thresholds to distinguish matches from mismatches. When these biases are controlled or partialled out from classification accuracy, reliable associations between match and mismatch identifications are found. This is demonstrated over two experiments with a sample of over 500 participants, several face-matching tests, and a series of data simulations. These findings support a cognitive theory in which individual differences in the placement of decision-making thresholds provide the mechanism by which the identification of face matches and mismatches are linked.

Faces are highly informative social stimuli, yet before any information can be accessed, the face must first be detected in the visual field. A detection template that serves this purpose must be able to accommodate the wide variety of face images we encounter, but how this generality could be achieved remains unknown. In this study, we investigate whether statistical averages of previously encountered faces can form the basis of a general face detection template. We provide converging evidence from a range of methods-human similarity judgements and PCA-based image analysis of face averages (Experiment 1-3), human detection behaviour for faces embedded in complex scenes (Experiment 4 and 5), and simulations with a template-matching algorithm (Experiment 6 and 7)-to examine the formation, stability and robustness of statistical image averages as cognitive templates for human face detection. We integrate these findings with existing knowledge of face identification, ensemble coding, and the development of face perception.

For many decades, psychological science has been critically important for conducting experiments into eyewitness identification and memory. Over this time, two approaches to research have become dominant, comprising of highly controlled laboratory experiments to establish cause-and-effect with precision, and field studies that offer less control but greater complexity and ecological validity. In this chapter, we introduce virtual reality as a technology that can harness the advantages of both approaches, by providing interactive three-dimensional environments that also preserve experimental control and offer sophisticated measurement of human behavior. Based on its capacity to safely host a wide range of crime scenarios, virtual reality has the potential to transform the study of eyewitness identification and memory. We describe the state-of-the-art of current virtual reality technology for implementing such research. We then review relevant studies that have started to transition to this technology, focusing on research on forensic person identification, intergroup violence, crime scene visits and jury decision-making.

Theoretical understanding of first impressions from faces has been closely associated with the proposal that rapid approach-avoidance decisions are needed during social interactions. Nevertheless, experimental work has rarely examined first impressions of people who are actually moving-instead extrapolating from photographic images. In six experiments, we describe the relationship between social attributions (dominance and trustworthiness) and the motion and apparent intent of a perceived person. We first show strong correspondence between judgments of photos and avatars of the same people (Experiment 1). Avatars were rated as more dominant and trustworthy when walking toward the viewer than when stationary (Experiment 2). Furthermore, avatars approaching the viewer were rated as more dominant than those avoiding (walking past) the viewer, or remaining stationary (Experiment 3). Trustworthiness was increased by movement, but not affected by approaching/avoiding paths. Surprisingly, dominance ratings increased both when avatars were approaching and being approached (Experiments 4-6), independently of agency. However, diverging movement (moving backward) reduced dominance ratings-again independently of agency (Experiment 6). These results demonstrate the close link between dominance judgments and approach and show the updatable nature of first impressions-their formation depended on the immediate dynamic context in a more subtle manner than previously suggested.

Object and scene perception are intertwined. When objects are expected to appear within a particular scene, they are detected and categorised with greater speed and accuracy. This study examined whether such context effects also moderate the perception of social objects such as faces. Female and male faces were embedded in scenes with a stereotypical female or male context. Semantic congruency of these scene contexts influenced the categorisation of faces (Experiment 1). These effects were bi-directional, such that face sex also affected scene categorisation (Experiment 2), suggesting concurrent automatic processing of both levels. In contrast, the more elementary task of face detection was not affected by semantic scene congruency (Experiment 3), even when scenes were previewed prior to face presentation (Experiment 4). This pattern of results indicates that semantic scene context can affect categorisation of faces. However, the earlier perceptual stage of detection appears to be encapsulated from the cognitive processes that give rise to this contextual interference.

In visual environments, selective attention must be employed to focus on task-relevant stimuli. A key question here concerns the extent to which other stimuli within the visual field influence target processing. In this study, we ask whether face identity matching is subject to similar effects from irrelevant stimuli in the visual field, specifically task-irrelevant people. Although most previous studies rely on highly controlled face and body stimuli presented in isolation, here we use a more realistic environment. Participants take the role of passport officers and must match a person's face to their photo-ID, while other people appear in the background, waiting to be processed. Presenting an interactive virtual environment on screen (Experiments 1 and 2) or in immersive VR (Experiment 3), we generally found no evidence for distraction from background people on face-matching accuracy. However, when immersed in VR, an angry crowd in the background delayed matching speed while not affecting accuracy. We discuss the theoretical implications of these results and their potential importance in practical settings.

Many security settings rely on the identity matching of unfamiliar people, which has led this task to be studied extensively in Cognitive Psychology. In these experiments, observers typically decide whether pairs of faces depict one person (an identity match) or two different people (an identity mismatch). The visual similarity of the to-be-compared faces must play a primary role in how observers accurately resolve this task, but the nature of this similarity-accuracy relationship is unclear. The current study investigated the association between accuracy and facial similarity at the level of individual items (Experiments 1 and 2) and facial features (Experiments 3 and 4). All experiments demonstrate a strong link between similarity and matching accuracy, indicating that this forms the basis of identification decisions. At a feature level, however, similarity exhibited distinct relationships with match and mismatch accuracy. In matches, similarity information was generally shared across the features of a face pair under comparison, with greater similarity linked to higher accuracy. Conversely, features within mismatching face pairs exhibited greater variation in similarity information. This indicates that identity matches and mismatches are characterised by different similarity profiles, which present distinct challenges to the cognitive system. We propose that these identification decisions can be resolved through the accumulation of convergent featural information in matches and the evaluation of divergent featural information in mismatches.

Face detection has been studied by presenting faces in blank displays, object arrays, and real-world scenes. This study investigated whether these display contexts differ in what they can reveal about detection, by comparing frontal-view faces with those shown in profile (Experiment 1), rotated by 90 degrees (Experiment 2), or turned upside-down (Experiment 3). In blank displays, performance for all face conditions was equivalent, whereas upright frontal faces showed a consistent detection advantage in arrays and scenes. Experiment 4 examined which facial characteristics drive this detection advantage by rotating either the internal or external facial features by 90 degrees while the other features remained upright. Faces with rotated internal features were detected as efficiently as their intact frontal counterparts, whereas detection was impaired when external features were rotated. Finally, Experiment 5 applied Voronoi transformations to scenes to confirm that complexity of stimulus displays modulates the detection advantage for upright faces. These experiments demonstrate that context influences what can be learned about the face detection process. In complex visual arrays and natural scenes, detection proceeds more effectively when external facial features are preserved in an upright orientation. These findings are consistent with a cognitive detection template that focuses on general face-shape information.

Humans show improved recognition for faces from their own social group relative to faces from another social group. Yet before faces can be recognized, they must first be detected in the visual field. Here, we tested whether humans also show an ingroup bias at the earliest stage of face processing - the point at which the presence of a face is first detected. To this end, we measured viewers' ability to detect ingroup (Black and White) and outgroup faces (Asian, Black, and White) in everyday scenes. Ingroup faces were detected with greater speed and accuracy relative to outgroup faces (Experiment 1). Removing face hue impaired detection generally, but the ingroup detection advantage was undiminished (Experiment 2). This same pattern was replicated by a detection algorithm using face templates derived from human data (Experiment 3). These findings demonstrate that the established ingroup bias in face processing can extend to the early process of detection. This effect is 'colour blind', in the sense that group membership effects are independent of general effects of image hue. Moreover, it can be captured by tuning visual templates to reflect the statistics of observers' social experience. We conclude that group bias in face detection is both a visual and a social phenomenon.

Facial examiners make visual comparisons of face images to establish the identities of persons in police investigations. This study utilised eye-tracking and an individual differences approach to investigate whether these experts exhibit specialist viewing behaviours during identification, by comparing facial examiners with forensic fingerprint analysts and untrained novices across three tasks. These comprised of face matching under unlimited (Experiment 1) and time-restricted viewing (Experiment 2), and with a feature-comparison protocol derived from examiner casework procedures (Experiment 3). Facial examiners exhibited individual differences in facial comparison accuracy and did not consistently outperform fingerprint analysts and novices. Their behaviour was also marked by similarities to the comparison groups in terms of how faces were viewed, as evidenced from eye movements, and how faces were perceived, based on the made feature judgements and identification decisions. These findings further understanding of how facial comparisons are performed and clarify the nature of examiner expertise.

Investigations into human cognition typically control variables tightly in the laboratory or relinquish systematic control in field studies. Virtual Reality (VR) can provide an intermediate approach by facilitating research with complex but controlled environments. However, understanding of the correspondence between VR and laboratory paradigms is still limited. This study addresses this issue by comparing established laboratory tests of face identification with passport control at a VR airport. We show that test characteristics transcend comparison of the laboratory tests and VR and demonstrate consistent correlations between these tasks. However, person identification in VR was also marked by bias to accept mismatching identities. These findings support correspondence between laboratory tests of face perception and VR but also highlight the importance of understanding human behaviour under more complex conditions. This problem arises in many areas of psychology, and our study shows that VR offers a solution by providing complex but controlled environments. General Audience Summary Psychological experiments into human cognition either tend to study behaviour in the laboratory, where the conditions under which research is conducted are simplistic but tightly controlled or relinquish such control in field studies, where behaviour is examined in natural environments in which additional factors can be at play. Both approaches have some disadvantages that the development of Virtual Reality (VR) can bridge by facilitating behavioural research in environments that are both complex and controlled. However, how research in VR corresponds to traditional experimental approaches is still unknown. This study investigates this issue by comparing established laboratory tests of face identification with person identification at a VR airport, in which participants take on the role of passport control officers. We demonstrate that person identification in laboratory tests is linked to the same behaviour in VR. However, we also find that person identification in VR is marked by a tendency to incorrectly accept travellers who bear the identity documents of another person. These findings demonstrate the importance of understanding human behaviour under conditions that more closely mimic real life and show that VR can facilitate such research.

Studies of visual perspective-taking have shown that adults can rapidly and accurately compute their own and other peoples' viewpoints, but they experience difficulties when the two perspectives are inconsistent. We tested whether these egocentric (i.e., interference from one's own perspective) and altercentric biases (i.e., interference from another person's perspective) persist in ecologically valid complex environments. Participants (N = 150) completed a dot-probe visual perspective-taking task, in which they verified the number of discs in natural scenes containing real people, first only according to their own perspective and then judging both their own and another person's perspective. Results showed that the other person's perspective did not disrupt self perspective-taking judgements when the other perspective was not explicitly prompted. In contrast, egocentric and altercentric biases were found when participants were prompted to switch between self and other perspectives. These findings suggest that altercentric visual perspective-taking can be activated spontaneously in complex real-world contexts, but is subject to both top-down and bottom-up influences, including explicit prompts or salient visual stimuli.

Face detection is a prerequisite for further face processing, such as extracting identity or semantic information. Those later processes appear to be subject to strict capacity limits, but the location of the bottleneck is unclear. In particular, it is not known whether the bottleneck occurs before or after face detection. Here we present a novel test of capacity limits in face detection. Across four behavioural experiments, we assessed detection of multiple faces via observers' ability to differentiate between two types of display. Fixed displays comprised items of the same type (all faces or all non-faces). Mixed displays combined faces and non-faces. Critically, a 'fixed' response requires all items to be processed. We found that additional faces could be detected with no cost to efficiency, and that this capacity-free performance was contingent on visual context. The observed pattern was not specific to faces, but detection was more efficient for faces overall. Our findings suggest that strict capacity limits in face perception occur after the detection step.

When comparing images of faces in criminal investigations, forensic facial examiners report key features such as moles to be particularly diagnostic of identity. However, scientific evidence for the efficacy of moles in facial identification is still limited. The current study systematically examined the effect of moles on facial image comparison by manipulating the presence and location of these small features. We found that observers untrained in facial image comparison spontaneously use moles to support identification decisions (Experiment 1). These effects were amplified when observers were prompted to utilise moles for identification (Experiment 2) and were sensitive to subtle differences in spatial location (Experiment 3). Moreover, identification accuracy was higher when observers were instructed to use moles only and dissociated from facial identification (Experiment 4). These findings demonstrate that observers are sensitive to the presence and location of moles in facial image comparison and shows the power of these small visual features to influence identification decisions.