Developmental improvement and age-related decline in unfamiliar face matching

Age-related changes have been documented widely in studies of face recognition and eyewitness identification. However, it is not clear whether these changes arise from general developmental differences in memory or occur specifically during the perceptual processing of faces. We report two experiments to track such perceptual changes using a 1-in-10 (Experiment 1) and 1-in-1 (Experiment 2) matching task for unfamiliar faces. Both experiments showed improvements in face matching during childhood and adult-like accuracy levels by adolescence. In addition, face-matching performance declined in adults of the age of 65. These findings indicate that developmental improvements and aging-related differences in face processing arise from changes in the perceptual encoding of faces. A clear face inversion effect was also present in all age groups. This indicates that those age-related changes in face matching reflect a quantitative effect, whereby typical face processes are engaged but do not operate at the best-possible level. These data suggest that part of the problem of eyewitness identification in children and elderly persons might reflect impairments in the perceptual processing of unfamiliar faces

Perceived ability and actual recognition accuracy for unfamiliar and famous faces

In forensic person recognition tasks, mistakes in the identification of unfamiliar faces occur frequently. This study explored whether these errors might arise because observers are poor at judging their ability to recognize unfamiliar faces, and also whether they might conflate the recognition of familiar and unfamiliar faces. Across two experiments, we found that observers could predict their ability to recognize famous but not unfamiliar faces. Moreover, observers seemed to partially conflate these abilities by adjusting ability judgements for famous faces after a test of unfamiliar face recognition (Experiment 1) and vice versa (Experiment 2). These findings suggest that observers have limited insight into their ability to identify unfamiliar faces. These experiments also show that judgements of recognition abilities are malleable and can generalize across different face categories

Pupillary Response as an Age-specific Measure of Sexual Interest

In the visual processing of sexual content, pupil dilation is an indicator of arousal that has been linked to observers’ sexual orientation. This study investigated whether this measure can be extended to determine age-specific sexual interest. In two experiments, the pupillary responses of heterosexual adults to images of males and females of different ages were related to self-reported sexual interest, sexual appeal to the stimuli, and a child molestation proclivity scale. In both experiments, the pupils of male observers dilated to photographs of women but not men, children or neutral stimuli. These pupillary responses corresponded with observer’s self-reported sexual interests and their sexual appeal ratings of the stimuli. Female observers showed pupil dilation to photographs of men and women but not children. In women, pupillary responses also correlated poorly with sexual appeal ratings of the stimuli. These experiments provide initial evidence that eye-tracking could be used as a measure of sex-specific interest in male observers, and as an age-specific index in male and female observers

The role of attention in face processing

Selective attention is widely regarded as a crucial component of human perception. In the visual domain, attentional mechanisms have been implicated in stimulus encoding, implicit recognition, conscious perception and goal-directed behaviour. To date, however, the role of attention in face processing has been largely overlooked. This is remarkable given the social and biological importance of faces, and the wealth of psychological research that has focused on faces as stimuli. Moreover, if we are to better understand how the human brain processes faces, then this would also require an insight into the interaction between attention and face processing. The experiments in this thesis addressed the relation of attention and face processing directly by assessing the consequences of various attentional manipulations in response-competition and repetition priming tasks. The first line of enquiry examined observers’ ability to attend selectively to facial expression and identity, and whether attention is required for the integration of these types of information into a multi-dimensional face percept. Subsequent experiments examined capacity limits in face processing and attention biases to faces and nonface comparisons. The main findings indicated that face processing is capacity limited, such that only a single face can be processed at a time, and that faces are particularly efficient at retaining and engaging visual attention in comparison to nonface objects. However, while face processing limits appear to proceed independent of a general capacity, attention biases to faces may reflect processing stages that are shared with other stimuli. These findings are discussed in relation to existing research on faces and attention

Matching faces against the clock

This study examined the effect of time pressure on face matching accuracy. Across two experiments, observers decided whether pairs of faces depict one person or different people. Time pressure was exerted via two additional displays, which were constantly updated to inform observers on whether they were on track to meet or miss a time target. In this paradigm, faces were matched under increasing or decreasing (Experiment 1) and constant time pressure (Experiment 2), which varied from ten to two seconds. In both experiments, time pressure reduced accuracy, but the point at which this declined varied from eight to two seconds. A separate match response bias was found, which developed over the course of the experiments. These results indicate that both time pressure and the repetitive nature of face matching are detrimental to performance

Understanding face identification through within-person variability in appearance: Introduction to a virtual special issue

In the effort to determine the cognitive processes underlying the identification of faces, the dissimilarities between images of different people have long been studied. In contrast, the inherent variability between different images of the same face has either been treated as a nuisance variable that should be eliminated from psychological experiments or it has not been considered at all. Over the past decade, research efforts have increased substantially to demonstrate that this within-person variation is meaningful and can give insight into various processes of face identification, such as identity matching, face learning, and familiar face recognition. In this virtual special issue of the Quarterly Journal of Experimental Psychology, we explain the importance of within-person variability for face identification and bring together recent relevant articles published in the journal

Heterosexual, Homosexual, and Bisexual Men's Pupillary Responses to Persons at Different Stages of Sexual Development.

This study investigated whether pupil size during the viewing of images of adults and children reflects the sexual orientation of heterosexual, homosexual, and bisexual men (n = 100, Mage = 22). More specifically, we explored whether this measure corresponds with sexual age preferences for adults over children in nonpedophilic men. In general, results across three experiments, in which observers freely viewed or rated the sexual appeal of person images, suggest that pupil dilation to sexual stimuli is an indicator of sexual orientation toward adults. Heterosexual men's pupils dilated most strongly to adults of the other sex, homosexual men dilated most strongly to adults of the same sex, and bisexual men showed an intermediate pattern. Dilation to adults was substantially stronger than dilation to younger age groups. Sexual appeal ratings for images of adults and children also correlated with pupil responses, suggesting a direct link between pupil dilation and sexual interest. These findings provide support for pupil dilation as a measure of sex- and age-specific sexual preferences

Viewers base estimates of face matching accuracy on their own familiarity: Explaining the photo-ID paradox

Matching two different images of a face is a very easy task for familiar viewers, but much harder for unfamiliar viewers. Despite this, use of photo-ID is widespread, and people appear not to know how unreliable it is. We present a series of experiments investigating bias both when performing a matching task and when predicting other people’s performance. Participants saw pairs of faces and were asked to make a same/different judgement, after which they were asked to predict how well other people, unfamiliar with these faces, would perform. In four experiments we show different groups of participants familiar and unfamiliar faces, manipulating this in different ways: celebrities in experiments 1 to 3 and personally familiar faces in experiment 4. The results consistently show that people match images of familiar faces more accurately than unfamiliar faces. However, people also reliably predict that the faces they themselves know will be more accurately matched by different viewers. This bias is discussed in the context of current theoretical debates about face recognition, and we suggest that it may underlie the continued use of photo-ID, despite the availability of evidence about its unreliability

Searching for faces differs from categorization: Evidence from scenes and eye movements

This study examined whether the detection of frontal, ¾ and profile face views differs from their categorization as faces. Experiment 1 compared three tasks that required observers to determine the presence or absence of a face but varied in the extent to which they had to search for faces in simple displays and small or large scenes to make this decision. Performance was equivalent for all face views in simple displays and small scenes, but was notably slower for profile views when this required the search for faces in extended scene displays. This search effect was confirmed in Experiment 2, which compared observers’ eye movements with their response times to faces in visual scenes. These results demonstrate that the categorization of faces at fixation is dissociable from the detection of faces in space. Consequently, we suggest that face detection should be studied with extended visual displays, such as natural scenes