Typicality effects in face and object perception: further evidence for the attractor field model

In a previous study, it was shown that a 50/50 morph of a typical and an atypical parent face was perceived to be more similar to the atypical parent face than to the typical parent face (Tanaka, Giles, Kremen, & Simon, 1998). Experiments 1 and 2 examine face typicality effects in a same/different discrimination task in which typical or atypical faces and their 80%, 70%, 60%, and 50% morphs were presented sequentially (Experiment 1) or simultaneously (Experiment 2). The main finding was that in both modes of presentation, atypical morphs were more poorly discriminated than their corresponding typical morphs. In Experiment 3, typicality effects were extended to the perception of nonface objects; in this instance, it was found that 50/50 morphs of birds and cars were judged to be more similar to their atypical parents than to their typical parents. These results are consistent with an attractor field model, in which it is proposed that the perception of a face or object stimulus depends not only on its fit to an underlying representation, but also on the representation's location in the similarity space.     

Atypical updating of face representations with experience in children with autism

Face identity aftereffects are significantly diminished in children with autism relative to typical children, which may reflect reduced perceptual updating with experience. Here, we investigated whether this atypicality also extends to non‐face stimulus categories, which might signal a pervasive visual processing difference in individuals with autism. We used a figural aftereffect task to measure directly perceptual updating following exposure to distorted upright faces, inverted faces and cars, in typical children and children with autism. A size‐change between study and test stimuli limited the likelihood that any processing atypicalities reflected group differences in adaptation to low‐level features of the stimuli. Results indicated that, relative to typical children, figural aftereffects for upright faces, but not inverted faces or cars, were significantly attenuated in children with autism. Moreover, the group difference was amplified when we isolated the ‘face‐selective’ component of the aftereffect, by partialling out the mid‐level shape adaptation common to upright and inverted face stimuli. Notably, the aftereffects of typical children were disproportionately larger for upright faces than for inverted faces and cars, but the magnitude of aftereffects of autistic children was not similarly modulated according to stimulus category. These findings are inconsistent with a pervasive adaptive coding atypicality relative to typical children, and suggest that reduced perceptual updating may constitute a high‐level, and possibly face‐selective, visual processing difference in children with autism.     

Sensitivity to spacing changes in faces and nonface objects in preschool-aged children and adults

Sensitivity to variations in the spacing of features in faces and a class of nonface objects (i.e., frontal images of cars) was tested in 3- and 4-year-old children and adults using a delayed or simultaneous two-alternative forced choice matching-to-sample task. In the adults, detection of spacing information was robust against exemplar differences for faces but varied across exemplars for cars (Experiment 1A). The 4-year-olds performed above chance in both face and car discrimination even when differences in spacing were very small (within ±1.6 standard deviations [SDs]) and the task involved memory components (Experiment 1B), and the same was true for the 3-year-olds when tested with larger spacing changes (within ±2.5 SDs) in a task that posed no memory demands (Experiment 2). An advantage in the discrimination of faces over cars was found at 4 years of age, but only when spacing cues were made more readily available (within ±2.5 SDs). Results demonstrate that the ability to discriminate objects based on feature spacing (i.e., sensitivity to second-order information) is present at 3 years of age and becomes more pronounced for faces than cars by 4 years of age.     

Expertise increases the functional overlap between face and object perception

Recent studies indicate that expertise with objects can interfere with face processing. Although competition occurs between faces and objects of expertise, it remains unclear whether this reflects an expertise-specific bottleneck or the fact that objects of expertise grab attention and thereby consume more central resources. We investigated the perceptual costs of expertise by measuring visual thresholds for identifying targets embedded within RSVP sequences presented at varying temporal rates. Car experts and novices searched for face targets among face and car distractors, or watch targets among watch and car distractors. Remarkably, car experts were slower than novices at identifying faces among task-irrelevant cars, yet faster than novices at identifying watches among cars. This suggests that car expertise leads to greater functional overlap between cars and faces while reducing the functional overlap between cars and objects, a result incompatible with the notion of an encapsulated module for exclusive processing of faces.     

知觉场理论对面孔知觉年龄偏差效应的解释

使用融合面孔范式和倒置面孔范式来研究面孔知觉的年龄偏差效应,检验知觉场能否作为面孔整体加工的指标,并以此发展年龄偏差的整体加工解释。结果发现：（1）成人和儿童在加工正立面孔时的知觉场均大于加工倒置面孔时的知觉场;（2）在加工正立面孔时,成人加工本年龄面孔比加工他年龄面孔的知觉场更大。上述结果表明：（1）知觉场大小可以作为面孔整体加工的指标,且受面孔朝向的影响;（2）知觉场假设可以解释面孔的年龄偏差效应。     

知觉场理论对面孔知觉年龄偏差效应的解释

使用融合面孔范式和倒置面孔范式来研究面孔知觉的年龄偏差效应,检验知觉场能否作为面孔整体加工的指标,并以此发展年龄偏差的整体加工解释。结果发现：（1）成人和儿童在加工正立面孔时的知觉场均大于加工倒置面孔时的知觉场;（2）在加工正立面孔时,成人加工本年龄面孔比加工他年龄面孔的知觉场更大。上述结果表明：（1）知觉场大小可以作为面孔整体加工的指标,且受面孔朝向的影响;（2）知觉场假设可以解释面孔的年龄偏差效应。     

Irrelevant objects of expertise compete with faces during visual search

Prior work suggests that nonface objects of expertise can interfere with the perception of faces when the two categories are alternately presented, suggesting competition for shared perceptual resources. Here, we ask whether task-irrelevant distractors from a category of expertise compete when faces are presented in a standard visual search task. Participants searched for a target (face or sofa) in an array containing both relevant and irrelevant distractors. The number of distractors from the target category (face or sofa) remained constant, whereas the number of distractors from the irrelevant category (cars) varied. Search slopes, calculated as a function of the number of irrelevant cars, were correlated with car expertise. The effect was not due to car distractors grabbing attention, because they did not compete with sofa targets. Objects of expertise interfere with face perception even when they are task irrelevant, visually distinct, and separated in space from faces.     

Developmental plateau in visual object processing from adolescence to adulthood in autism

A lack of typical age-related improvement from adolescence to adulthood contributes to face recognition deficits in adults with autism on the Cambridge Face Memory Test (CFMT). The current studies examine if this atypical developmental trajectory generalizes to other tasks and objects, including parts of the face. The CFMT tests recognition of whole faces, often with a substantial delay. The current studies used the immediate memory (IM) task and the parts-whole face task from the Let’s Face It! battery, which examines whole faces, face parts, and cars, without a delay between memorization and test trials. In the IM task, participants memorize a face or car. Immediately after the target disappears, participants identify the target from two similar distractors. In the part-whole task, participants memorize a whole face. Immediately after the face disappears, participants identify the target from a distractor with different eyes or mouth, either as a face part or a whole face.Results indicate that recognition deficits in autism become more robust by adulthood, consistent with previous work, and also become more general, including cars. In the IM task, deficits in autism were specific to faces in childhood, but included cars by adulthood. In the part-whole task, deficits in autism became more robust by adulthood, including both eyes and mouths as parts and in whole faces. Across tasks, the deficit in autism increased between adolescence and adulthood, reflecting a lack of typical improvement, leading to deficits with non-face stimuli and on a task without a memory delay. These results suggest that brain maturation continues to be affected into adulthood in autism, and that the transition from adolescence to adulthood is a vulnerable stage for those with autism.     

The Cambridge Car Memory Test: A task matched in format to the Cambridge Face Memory Test, with norms, reliability, sex differences, dissociations from face memory, and expertise effects

Many research questions require a within-class object recognition task matched for general cognitive requirements with a face recognition task. If the object task also has high internal reliability, it can improve accuracy and power in group analyses (e.g., mean inversion effects for faces vs. objects), individual-difference studies (e.g., correlations between certain perceptual abilities and face/object recognition), and case studies in neuropsychology (e.g., whether a prosopagnosic shows a face-specific or object-general deficit). Here, we present such a task. Our Cambridge Car Memory Test (CCMT) was matched in format to the established Cambridge Face Memory Test, requiring recognition of exemplars across view and lighting change. We tested 153 young adults (93 female). Results showed high reliability (Cronbach's alpha = .84) and a range of scores suitable both for normal-range individual-difference studies and, potentially, for diagnosis of impairment. The mean for males was much higher than the mean for females. We demonstrate independence between face memory and car memory (dissociation based on sex, plus a modest correlation between the two), including where participants have high relative expertise with cars. We also show that expertise with real car makes and models of the era used in the test significantly predicts CCMT performance. Surprisingly, however, regression analyses imply that there is an effect of sex per se on the CCMT that is not attributable to a stereotypical male advantage in car expertise.     

Association and dissociation between detection and discrimination of objects of expertise: Evidence from visual search

Expertise in face recognition is characterized by high proficiency in distinguishing between individual faces. However, faces also enjoy an advantage at the early stage of basic-level detection, as demonstrated by efficient visual search for faces among nonface objects. In the present study, we asked (1) whether the face advantage in detection is a unique signature of face expertise, or whether it generalizes to other objects of expertise, and (2) whether expertise in face detection is intrinsically linked to expertise in face individuation. We compared how groups with varying degrees of object and face expertise (typical adults, developmental prosopagnosics [DP], and car experts) search for objects within and outside their domains of expertise (faces, cars, airplanes, and butterflies) among a variable set of object distractors. Across all three groups, search efficiency (indexed by reaction time slopes) was higher for faces and airplanes than for cars and butterflies. Notably, the search slope for car targets was considerably shallower in the car experts than in nonexperts. Although the mean face slope was slightly steeper among the DPs than in the other two groups, most of the DPs’ search slopes were well within the normative range. This pattern of results suggests that expertise in object detection is indeed associated with expertise at the subordinate level, that it is not specific to faces, and that the two types of expertise are distinct facilities. We discuss the potential role of experience in bridging between low-level discriminative features and high-level naturalistic categories.     

Experts’ memory: an ERP study of perceptual expertise effects on encoding and recognition

This study examined how perceptual expertise facilitates encoding and recognition. The electroencephalogram of car experts and car novices was recorded in the study as well as test phases of a remember/know task with car and bird stimuli. Car expertise influenced performance and event-related potentials (ERPs) for cars but not birds. Experts recognized and “recollected” cars more accurately, while novices had more false alarms. The ERPs provided neural evidence for theoretical assumptions about expert memory. Memory encoding in the study phase was less effortful and more elaborate for experts than novices, as indicated by lower mean amplitudes for subsequently “recollected” cars and by indistinguishable differences due to memory for recollection and familiarity. The parietal old/new effect, a correlate of recollection measured during recognition testing, was only found for experts. The results show that refined perceptual and semantic processing, characteristics of perceptual expertise, facilitate both memory encoding and recognition memory.     

The development of norm-based coding and race-specific face prototypes: An examination of 5- and 8-year-olds’ face space

The current research investigated the organization of children’s face space by examining whether 5- and 8-year-olds show race-contingent aftereffects. Participants read a storybook in which Caucasian and Chinese children’s faces were distorted in opposite directions. Before and after adaptation, participants judged the normality/attractiveness of expanded, compressed, and undistorted Caucasian and Chinese faces. The method was validated with adults and then refined to test 8- and 5-year-olds. The 5-year-olds were also tested in a simple aftereffects paradigm. The current research provides the first evidence for simple attractiveness aftereffects in 5-year-olds and for race-contingent aftereffects in both 5- and 8-year-olds. Evidence that adults and 5-year-olds may possess only a weak prototype for Chinese children’s faces suggests that Caucasian adults’ prototype for Chinese adult faces does not generalize to child faces and that children’s face space undergoes a period of increasing differentiation between 5 and 8 years of age.     

知觉和概念加工范式对内隐与外显记忆发展的影响

控制知觉材料的熟悉性和概念范例的典型性,以考察它们对内隐与外显记忆发展的影响。结果表明：（1）知觉内隐记忆的启动效应不存在年龄和熟悉性效应,而知觉外显记忆成绩则具有明显的年龄和熟悉性效应;（2）在概念内隐记忆任务上,典型范例的启动效应不存在年龄差异,非典型范例的启动效应则存在随年龄而增长的启动效应：无论是典型范例还是非典型范例的外显记忆成绩均随年龄增长而提高。     

Individuation training with other‐race faces reduces preschoolers’ implicit racial bias: a link between perceptual and social representation of faces in children

The present study examined whether perceptual individuation training with other‐race faces could reduce preschool children's implicit racial bias. We used an ‘angry = outgroup’ paradigm to measure Chinese children's implicit racial bias against African individuals before and after training. In Experiment 1, children between 4 and 6 years were presented with angry or happy racially ambiguous faces that were morphed between Chinese and African faces. Initially, Chinese children demonstrated implicit racial bias: they categorized happy racially ambiguous faces as own‐race (Chinese) and angry racially ambiguous faces as other‐race (African). Then, the children participated in a training session where they learned to individuate African faces. Children's implicit racial bias was significantly reduced after training relative to that before training. Experiment 2 used the same procedure as Experiment 1, except that Chinese children were trained with own‐race Chinese faces. These children did not display a significant reduction in implicit racial bias. Our results demonstrate that early implicit racial bias can be reduced by presenting children with other‐race face individuation training, and support a linkage between perceptual and social representations of face information in children.     

The training and transfer of real-world perceptual expertise

A hallmark of perceptual expertise is that experts classify objects at a more specific, subordinate level of abstraction than novices. To what extent does subordinate-level learning contribute to the transfer of perceptual expertise to novel exemplars and novel categories? In this study, participants learned to classify 10 varieties of wading birds and 10 varieties of owls at either the subordinate, species (e.g., "great blue crown heron,"eastern screech owl") or the family ("wading bird,"owl") level of abstraction. During training, the amount of visual exposure was equated such that participants received an equal number of learning trials for wading birds and owls. Pre- and posttraining performance was measured in a same/different discrimination task in which participants judged whether pairs of bird stimuli belonged to the same or different species. Participants trained in species-level discrimination demonstrated greater transfer to novel exemplars and novel species categories than participants trained in family-level discrimination. These findings suggest that perceptual categorization, not perceptual exposure per se, is important for the development and generalization of visual expertise.     

On facial expertise: processing strategies of twins' parents

Parents of monozygotic twins typically learn to recognise their own children and also to tell them apart on photographs. However, it is unknown whether such exemplar expertise can be generalised to unfamiliar faces of equal similarity (ie other twins). In the present study, parents of monozygotic twins were compared to 'control' parents whose children were non-twin siblings. In a same/different task with familiar and unfamiliar twin faces as stimuli, twins' parents were faster than control parents in distinguishing their own children, but slower when distinguishing unfamiliar twin faces. These unexpected findings can be interpreted as a generalisation of a habitual perceptual strategy that is efficient only with familiar face exemplars. When pictures of the twins' faces were inverted by 180degrees, the typical inversion costs for familiar faces were observed, but the twins' parents recognised unfamiliar twins' faces better when these were inverted than when upright. This inverted inversion effect could be caused by the high similarity of the face pairs as well as by experience with familiar faces of equally high similarity. We conclude that the facial expertise of twins' parents is idiosyncratic to their own children and not based on an enhanced general facial expertise.     

Insights into the development of face recognition mechanisms revealed by face aftereffects

An important question in person perception is how we acquire the perceptual/cognitive mechanisms that characterize adult expertise. Children's performance on face recognition tests improves dramatically between age 4 and adolescence suggesting that our face recognition system may change during childhood. Yet, the source of this improvement is controversial. In this review, we consider whether changes in the way identity is represented/coded in face space could contribute to this age-related improvement. Face aftereffects have been extensively applied to studying face coding in adults and more recently they have been applied to studying the mechanisms of face coding in children. Face aftereffects are temporary distortions of perception induced by exposure to faces and are thought to reflect the mechanisms underlying face perception. Face aftereffect techniques have revealed that children as young as 4 years of age show evidence of adult-like face space organization, with opponent coding of face dimensions. These findings are consistent with an emerging picture that the key mechanisms of face perception are present early in childhood.     

Perceptual asymmetries in normal children and children with attention deficit/hyperactivity disorder

Perceptual asymmetries in normal right-handed children (7-12 years of age) and children with attention deficit/hyperactivity disorder (ADHD), combined type, were investigated using various chimeric stimuli in free-viewing conditions. In the face-matching task, participants indicated which of two symmetrical face chimeras more closely resembled the original; in the chimeric faces task, participants indicated which of a pair of faces appeared happier; and in the grey scales task participants indicated which of two shaded rectangles appeared to be darker overall. Leftward biases were found for normal children with no effects of age. Contrary to expectations, normal leftward biases were also found for ADHD children in the face-matching and the chimeric faces tasks; however, a significant leftward bias was not observed in the grey scales task. The absence of anomalous perceptual bias in ADHD children on these purely perceptual tasks, suggests that anomalous perceptual asymmetries observed in other tasks (line bisection and cancellation tasks) may have been confounded by the motor response, and/or the explicit spatial components of those tasks.     

面孔加工特异性的事件相关电位研究

采用事件相关电位方法,以面孔、汽车、鸟和椅子为刺激,在汽车搜索作业及分类判断作业两种条件下考察了N170面孔特异性效应。结果发现,面孔在两种条件下均引起明显不同于其余三类物体的N170。实验任务对汽车刺激有明显的影响,具体表现为：在搜索作业下,汽车N170有接近面孔N170的趋势,其波幅显著大于鸟、椅子N170的波幅;在分类作业中,则没有这种显著的差异。从而为证明存在面孔识别的特异性神经机制提供了证据。     

The development of spatial frequency biases in face recognition

Previous research has suggested that a mid-band of spatial frequencies is critical to face recognition in adults, but few studies have explored the development of this bias in children. We present a paradigm adapted from the adult literature to test spatial frequency biases throughout development. Faces were presented on a screen with particular spatial frequencies blocked out by noise masks. A mid-band bias was found in adults and 9- and 10-year-olds for upright faces but not for inverted faces, suggesting a face-sensitive effect. However, 7- and 8-year-olds did not demonstrate the mid-band bias for upright faces but rather processed upright and inverted faces similarly. This suggests that specialization toward the mid-band for upright face recognition develops gradually during childhood and may relate to an advanced level of face expertise.