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.     

Task difficulty and response complexity modulate affective priming by emotional facial expressions

In this study we used an affective priming task to address the issue of whether the processing of emotional facial expressions occurs automatically independent of attention or attentional resources. Participants had to attend to the emotion expression of the prime face, or to a nonemotional feature of the prime face, the glasses. When participants attended to glasses (emotion unattended), they had to report whether the face wore glasses or not (the glasses easy condition) or whether the glasses were rounded or squared (the shape difficult condition). Affective priming, measured on valence decisions on target words, was mainly defined as interference from incongruent rather than facilitation from congruent trials. Significant priming effects were observed just in the emotion and glasses tasks but not in the shape task. When the key–response mapping increased in complexity, taxing working memory load, affective priming effects were reduced equally for the three types of tasks. Thus, attentional load and working memory load affected additively to the observed reduction in affective priming. These results cast some doubts on the automaticity of processing emotional facial expressions.     

Facial identity and facial expression matching in 5–12‐year‐old children and adults

Facial identity and facial expression matching tasks were completed by 5–12‐year‐old children and adults using stimuli extracted from the same set of normalized faces. Configural and feature processing were examined using speed and accuracy of responding and facial feature selection, respectively. Facial identity matching was slower than face expression matching for all age groups. Large age effects were found on both speed and accuracy of responding and feature use in both identity and expression matching tasks. Eye region preference was found on the facial identity task and mouth region preference on the facial expression task. Use of mouth region information for facial expression matching increased with age, whereas use of eye region information for facial identity matching peaked early. The feature use information suggests that the specific use of primary facial features to arrive at identity and emotion matching judgments matures across middle childhood. Copyright © 2009 John Wiley & Sons, Ltd.     

The role of dynamic information in the recognition of unfamiliar faces

The effects of movement on unfamiliar face recognition were investigated. In an incidental learning task, faces were studied either as computer-animated (moving) displays or as a series of static images, with identical numbers of frames shown for each. The movements were either nonrigid transformations (changes in expression) or rigid rotations in depth (nodding or shaking). At test, participants saw either single, static images or moving sequences. Only one experiment showed a significant effect of study type, in favor of static instances. There was no additional advantage from studying faces in motion in these experiments, in which both study types showed the same amounts of information. Recognition memory was relatively unaffected by changes in expression between study and test. Effects of viewpoint change were large when expressive transformations had been studied but much smaller when rigid rotations in depth had been studied. The series of experiments did reveal a slight advantage for testing memory with moving compared with static faces, consistent with recent findings using familiar faces. Future work will need to examine whether such effects may also be due to the additional information provided by an animated sequence.     

Exploring the role of characteristic motion when learning new faces

Previous research has shown that it is easier to recognize familiar faces when shown moving, rather than static, especially when viewing conditions are difficult (Knight & Johnston, 1997; Lander, Christie, & Bruce, 1999). One possible theoretical reason for the moving-face advantage is that we learn "characteristic motion signatures" for familiar faces, associated with the face representation in memory. To examine this idea we investigated the role of motion at test when learning faces from either static images or moving sequences (Experiment 1). Results suggest that there is only an advantage for motion at test when the face is learned moving. In Experiment 2 we map the importance of facial motion as a face becomes increasingly familiar, on a television drama. We demonstrate that the beneficial effect of motion is not dependent on the amount of time the face is viewed. Results from both experiments support the idea of rapidly learned characteristic motion patterns.     

Interactive processes in matching identity and expressions of unfamiliar faces: evidence for mutual facilitation effects

We investigated the interactions between matching identity and expressions of unfamiliar faces. In experiment 1, participants matched expressions in frontal and in oblique views, while we manipulated facial identity. In experiment 2, participants matched identity in frontal and in oblique views, while facial expressions were manipulated. Labeling of expressions was not required. Results showed mutual facilitation between matching facial identity and facial expressions, in accuracy as well as in reaction times. Thus, matching expressions was better and faster for same-identity images in oblique as well as in frontal views (experiment 1), and matching identity was better and faster for same-expression images in oblique as well as in frontal views (experiment 2). The discussion focuses on the implications of these results for the structural encoding of facial identity and facial expressions.     

The interference effect of emotional expressions on facial identity recognition in preschool-aged children

The present study aims to explore the influence of facial emotional expressions on pre-scholars' identity recognition was analyzed using a two-alternative forced-choice matching task. A decrement was observed in children's performance with emotional faces compared with neutral faces, both when a happy emotional expression remained unchanged between the target face and the test faces and when the expression changed from happy to neutral or from neutral to happy between the target and the test faces (Experiment 1). Negative emotional expressions (i.e. fear and anger) also interfered with children's identity recognition (Experiment 2). Obtained evidence suggests that in preschool-age children, facial emotional expressions are processed in interaction with, rather than independently from, the encoding of facial identity information. The results are discussed in relationship with relevant research conducted with adults and children.     

Why are moving faces easier to recognize?

Previous work has suggested that seeing a famous face move aids the recognition of identity, especially when viewing conditions are degraded (Knight & Johnston, ; Lander, Christie, & Bruce, ). Experiment 1 investigated whether the beneficial effects of motion are related to a particular type of facial motion (expressing, talking, or rigid motion). Results showed a significant beneficial effect of both expressive and talking movements, but no advantage for rigid motion, compared with a single static image. Experiment 2 investigated whether the advantage for motion is uniform across identity. Participants rated moving famous faces for distinctiveness of motion. The famous faces (moving and static freeze frame) were then used as stimuli in a recognition task. The advantage for face motion was significant only when the motion displayed was distinctive. Results suggest that a reason why moving faces are easier to recognize is because some familiar faces have characteristic motion patterns, which act as an additional cue to identity.     

Dynamic properties influence the perception of facial expressions

Two experiments were conducted to investigate the role played by dynamic information in identifying facial expressions of emotion. Dynamic expression sequences were created by generating and displaying morph sequences which changed the face from neutral to a peak expression in different numbers of intervening intermediate stages, to create fast (6 frames), medium (26 frames), and slow (101 frames) sequences. In experiment 1, participants were asked to describe what the person shown in each sequence was feeling. Sadness was more accurately identified when slow sequences were shown. Happiness, and to some extent surprise, was better from faster sequences, while anger was most accurately detected from the sequences of medium pace. In experiment 2 we used an intensity-rating task and static images as well as dynamic ones to examine whether effects were due to total time of the displays or to the speed of sequence. Accuracies of expression judgments were derived from the rated intensities and the results were similar to those of experiment 1 for angry and sad expressions (surprised and happy were close to ceiling). Moreover, the effect of display time was found only for dynamic expressions and not for static ones, suggesting that it was speed, not time, which was responsible for these effects. These results suggest that representations of basic expressions of emotion encode information about dynamic as well as static properties.     

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.     

Dynamic facial expressions are processed holistically,but not more holistically than static facial expressions

There is evidence that facial expressions are perceived holistically and featurally. The composite task is a direct measure of holistic processing (although the absence of a composite effect implies the use of other types of processing). Most composite task studies have used static images, despite the fact that movement is an important aspect of facial expressions and there is some evidence that movement may facilitate recognition. We created static and dynamic composites, in which emotions were reliably identified from each half of the face. The magnitude of the composite effect was similar for static and dynamic expressions identified from the top half (anger, sadness and surprise) but was reduced in dynamic as compared to static expressions identified from the bottom half (fear, disgust and joy). Thus, any advantage in recognising dynamic over static expressions is not likely to stem from enhanced holistic processing, rather motion may emphasise or disambiguate diagnostic featural information.     

Developmental changes in face processing skills

Expertise in processing differences among faces in the spacing among facial features (second-order relations) is slower to develop than expertise in processing the shape of individual features or the shape of the external contour. To determine the impact of the slow development of sensitivity to second-order relations on various face-processing skills, we developed five computerized tasks that require matching faces on the basis of identity (with changed facial expression or head orientation), facial expression, gaze direction, and sound being spoken. In Experiment 1, we evaluated the influence of second-order relations on performance on each task by presenting them to adults (N=48) who viewed the faces either upright or inverted. Previous studies have shown that inversion has a larger effect on tasks that require processing the spacing among features than it does on tasks that can be solved by processing the shape of individual features. Adults showed an inversion effect for only one task: matching facial identity when there was a change in head orientation. In Experiment 2, we administered the same tasks to children aged 6, 8, and 10 years (N=72). Compared to adults, 6-year-olds made more errors on every task and 8-year-olds made more errors on three of the five tasks: matching direction of gaze and the two facial identity tasks. Ten-year-olds made more errors than adults on only one task: matching facial identity when there was a change in head orientation (e.g., from frontal to tilted up). Together, the results indicate that the slow development of sensitivity to second-order relations causes children to be especially poor at recognizing the identity of a face when it is seen in a new orientation.     

Super‐recognisers in Action: Evidence from Face‐matching and Face Memory Tasks

Individuals employed in forensic or security settings are often required to compare faces of ID holders to document photographs, or to recognise the faces of suspects in closed‐circuit television footage. It has long been established that both tasks produce a high error rate amongst typical perceivers. This study sought to determine the performance of individuals with exceptionally good face memory (‘super‐recognisers’) on applied facial identity matching and memory tasks. In experiment 1, super‐recognisers were significantly better than controls when matching target faces to simultaneously presented line‐ups. In experiment 2, super‐recognisers were also better at recognising faces from video footage. These findings suggest that super‐recognisers are more accurate at face matching and face memory tasks than typical perceivers, and they could be valuable expert employees in national security and forensic settings. © 2015 The Authors Applied Cognitive Psychology Published by John Wiley & Sons Ltd.     

Getting to know you: How we learn new faces

Previous work has shown an advantage for matching the internal features of familiar faces in contrast to an advantage for the external features of unfamiliar faces. In the current experiment, we tracked this shift towards an internal feature advantage as subjects were familiarized with a set of initially unfamiliar faces. They were asked to learn a set of 24 faces from video images and complete a face matching task on 3 consecutive days. Half of the faces were learned from moving images while the others were learned from static images to determine whether movement was necessary to produce the internal advantage found when matching familiar faces. We found that by the end of the 3 days, performance on the internal features had improved and was equivalent to performance on the external features. In contrast, matching of the external features remained at a relatively constant level across the experiment. Faces were learned equally well from moving and static images suggesting that movement is not necessary to promote learning of the internal features.     

The Role of Emotional Content and Perceptual Saliency During the Programming of Saccades Toward Faces

Previous studies have shown that the human visual system can detect a face and elicit a saccadic eye movement toward it very efficiently compared to other categories of visual stimuli. In the first experiment, we tested the influence of facial expressions on fast face detection using a saccadic choice task. Face-vehicle pairs were simultaneously presented and participants were asked to saccade toward the target (the face or the vehicle). We observed that saccades toward faces were initiated faster, and more often in the correct direction, than saccades toward vehicles, regardless of the facial expressions (happy, fearful, or neutral). We also observed that saccade endpoints on face images were lower when the face was happy and higher when it was neutral. In the second experiment, we explicitly tested the detection of facial expressions. We used a saccadic choice task with emotional-neutral pairs of faces and participants were asked to saccade toward the emotional (happy or fearful) or the neutral face. Participants were faster when they were asked to saccade toward the emotional face. They also made fewer errors, especially when the emotional face was happy. Using computational modeling, we showed that this happy face advantage can, at least partly, be explained by perceptual factors. Also, saccade endpoints were lower when the target was happy than when it was fearful. Overall, we suggest that there is no automatic prioritization of emotional faces, at least for saccades with short latencies, but that salient local face features can automatically attract attention.     

Visual speech information for face recognition

Two experiments test whether isolated visible speech movements can be used for face matching. Visible speech information was isolated with a point-light methodology. Participants were asked to match articulating point-light faces to a fully illuminated articulating face in an XAB task. The first experiment tested single-frame static face stimuli as a control. The results revealed that the participants were significantly better at matching the dynamic face stimuli than the static ones. Experiment 2 tested whether the observed dynamic advantage was based on the movement itself or on the fact that the dynamic stimuli consisted of many more static and ordered frames. For this purpose, frame rate was reduced, and the frames were shown in a random order, a correct order with incorrect relative timing, or a correct order with correct relative timing. The results revealed better matching performance with the correctly ordered and timed frame stimuli, suggesting that matches were based on the actual movement itself. These findings suggest that speaker-specific visible articulatory style can provide information for face matching.     

空间工作记忆负载对真实场景情境提示效应的影响

重复的画面布局能够促进观察者对目标项的搜索 (情境提示效应)。本研究采用双任务范式,分别在视觉搜索任务的学习阶段 (实验2a) 和测验阶段 (实验2b) 加入空间工作记忆任务, 并与单任务基线 (实验1)进行比较, 考察空间工作记忆负载对真实场景搜索中情境线索学习和情境提示效应表达的影响。结果发现: 空间负载会增大学习阶段的情境提示效应量, 同时削弱测验阶段的情境提示效应量, 而不影响情境线索的外显提取。由此可见, 真实场景中情境线索的学习和提示效应的表达均会受到有限的工作记忆资源的影响, 但情境线索提取的外显性不变。     

Learning the moves: the effect of familiarity and facial motion on person recognition across large changes in viewing format

Familiarity with a face or person can support recognition in tasks that require generalization to novel viewing contexts. Using naturalistic viewing conditions requiring recognition of people from face or whole body gait stimuli, we investigated the effects of familiarity, facial motion, and direction of learning/test transfer on person recognition. Participants were familiarized with previously unknown people from gait videos and were tested on faces (experiment 1a) or were familiarized with faces and were tested with gait videos (experiment 1b). Recognition was more accurate when learning from the face and testing with the gait videos, than when learning from the gait videos and testing with the face. The repetition of a single stimulus, either the face or gait, produced strong recognition gains across transfer conditions. Also, the presentation of moving faces resulted in better performance than that of static faces. In experiment 2, we investigated the role of facial motion further by testing recognition with static profile images. Motion provided no benefit for recognition, indicating that structure-from-motion is an unlikely source of the motion advantage found in the first set of experiments.     

The role of motion in learning new faces

Four experiments are reported that investigate the usefulness of rigid (head nodding, shaking) and nonrigid (talking, expressions) motion for establishing new face representations of previously unfamiliar faces. Results show that viewing a face in motion leads to more accurate face learning, compared with viewing a single static image (Experiment 1). The advantage for viewing the face moving rigidly seems to be due to the different angles of view contained in these sequences (Experiment 2). However, the advantage for nonrigid motion is not simply due to multiple images (Experiment 3) and is not specifically linked to forwards motion but extends to reversed sequences (Experiment 4). Thus, although we have demonstrated beneficial effects of motion for face learning, they do not seem to be due to the specific dynamic properties of the sequences shown. Instead, the advantage for nonrigid motion may reflect increased attention to faces moving in a socially important manner.