A comparative case study of face recognition: The contribution of configural and part-based recognition systems, and their interaction

Understanding the interaction between the configural and part-based systems in face recognition is the major aim of this study. Specifically, we established whether configural representation of faces contribute to aspects of face recognition that depend on part-based processes, such as identifying inverted or fractured faces. Using face recognition tasks that require part-based or configural processing, we compared the results of CK—a man who has object agnosia and alexia [Moscovitch, M., Winocur, G., & Behrmann, M. (1997). What is special about face recognition? Nineteen experiments on a person with visual object agnosia and dyslexia but normal face recognition. Journal of Cognitive Neuroscience, 9(5), 555–604] but normal upright face recognition, to those of DC—a man who has prosopagnosia but normal object recognition. CK was normal at recognizing faces if configural processing was sufficient, but poor at recognizing faces that were modified so as to alter their gestalt, and require part-based processing (Moscovitch et al.). DC was impaired at recognizing upright faces and his performance declined in all tasks involving recognition of modified faces, including those that depend on part-based and on configural processing. Nevertheless, DC was normal on tasks involving perception of generic faces and face imagery. These results show that although configural face perception can proceed without part-based processing, the reverse is not the case. Our results suggest that the configural system is always necessary for face recognition, and appears to support what remains of face identification even in prosopagnosic people who have an intact part-based system.     

Developmental prosopagnosia with normal configural processing

The configural processing hypothesis proposes that prosopagnosia results from a domain-general impairment in configural processing, and so predicted that all prosopagnosics would have impaired configural processing. In order to test this prediction, tests of face recognition and configural processing were presented to a developmental prosopagnosic. He was severely impaired in face recognition, but his normal performance on three tests of configural processing disconfirmed the configural processing hypothesis. Additional tests of low-level vision and object recognition found no evidence of impairments with material other than faces. The pattern of spared and impaired face recognition indicates that this case of developmental prosopagnosia is caused by a domain-specific inability to match novel views of faces with previously derived representations.     

Impaired holistic processing of unfamiliar individual faces in acquired prosopagnosia

Prosopagnosia is an impairment at individualizing faces that classically follows brain damage. Several studies have reported observations supporting an impairment of holistic/configural face processing in acquired prosopagnosia. However, this issue may require more compelling evidence as the cases reported were generally patients suffering from integrative visual agnosia, and the sensitivity of the paradigms used to measure holistic/configural face processing in normal individuals remains unclear. Here we tested a well-characterized case of acquired prosopagnosia (PS) with no object recognition impairment, in five behavioral experiments (whole/part and composite face paradigms with unfamiliar faces). In all experiments, for normal observers we found that processing of a given facial feature was affected by the location and identity of the other features in a whole face configuration. In contrast, the patient's results over these experiments indicate that she encodes local facial information independently of the other features embedded in the whole facial context. These observations and a survey of the literature indicate that abnormal holistic processing of the individual face may be a characteristic hallmark of prosopagnosia following brain damage, perhaps with various degrees of severity.     

The right place at the right time: priming facial expressions with emotional face components in developmental visual agnosia

The current study examined the nature of deficits in emotion recognition from facial expressions in case LG, an individual with a rare form of developmental visual agnosia (DVA). LG presents with profoundly impaired recognition of facial expressions, yet the underlying nature of his deficit remains unknown. During typical face processing, normal sighted individuals extract information about expressed emotions from face regions with activity diagnostic for specific emotion categories. Given LG's impairment, we sought to shed light on his emotion perception by examining if priming facial expressions with diagnostic emotional face components would facilitate his recognition of the emotion expressed by the face. LG and control participants matched isolated face components with components appearing in a subsequently presented full-face and then categorized the face's emotion. Critically, the matched components were from regions which were diagnostic or non-diagnostic of the emotion portrayed by the full face. In experiment 1, when the full faces were briefly presented (150 ms), LG's performance was strongly influenced by the diagnosticity of the components: his emotion recognition was boosted within normal limits when diagnostic components were used and was obliterated when non-diagnostic components were used. By contrast, in experiment 2, when the face-exposure duration was extended (2000 ms), the beneficial effect of the diagnostic matching was diminished as was the detrimental effect of the non-diagnostic matching. These data highlight the impact of diagnostic facial features in normal expression recognition and suggest that impaired emotion recognition in DVA results from deficient visual integration across diagnostic face components.     

The influence of left and right hemisphere brain damage on configural and featural processing of affective faces

The literature about the lateralization of facial emotion perception according to valence (positive, negative) is conflicting; investigating the underlying processes may shed light on why some studies show right-hemisphere dominance across valence and other studies demonstrate hemispheric differences according to valence. This is the first clinical study to examine whether the use of configural and featural cues underlies hemispheric differences in affective face perception. Right brain-damaged (RBD; n = 17), left brain-damaged (LBD; n = 17) and healthy control (HC; n = 34) participants completed an affective face discrimination task that tested configural processing using whole faces and featural processing using partial faces. No group differences in expression perception according to valence or processing strategy were found. Across emotions, the RBD group was less accurate than the HC group in discriminating whole faces, whilst the RBD and LBD groups were less accurate than HCs in discriminating partial faces. This suggests that the right hemisphere processes facial expressions from configural and featural information, whereas the left hemisphere relies more heavily on featural facial information.     

Understanding memory for faces in Parkinson's disease: the role of configural processing

It has previously been reported that unfamiliar face recognition memory is impaired in Parkinson's disease (PD) [(Dewick, H. C., Hanley, J. R., Davies, A. D. M., Playfer, J. R. & Turnbull, C. J., Perception and memory for faces in Parkinson's disease. Neuropsychologia, 1991, 29, 785-802), (Haeske-Dewick, H. C., Are perception and memory for faces influenced by a specific age at onset factor in Parkinson's disease? Neuropsychologia, 1996, 34, 315-320), (Levin, B. E., Llabre, M. M. & Weiner, W. J., Cognitive impairments associated with early Parkinson's disease. Neurology, 1989, 39, 557-561)]. In the work reported here, we consider the possible mechanisms that might underlie this impairment. 28 PD patients and 28 controls were given a two-part test of recognition memory for words and faces, and two perceptual tests to measure their configural and componential processing ability. We found that PD patients were significantly worse than controls on the recognition memory test for faces, but not when the stimuli were words. In addition, PD patients were significantly impaired relative to controls on the closure test (FCT) used to measure configural processing, but there was no difference between the two groups on a test of componential processing ability. Multiple regression analyses revealed that even after accounting for the influence of age, intelligence and level of depression, configural processing ability was the important predictor of unfamiliar face recognition memory in Parkinson's disease. There was no effect of Parkinson's disease specific variables on either face recognition or FCT performance. In addition, some recently diagnosed patients were poor at face recognition. It is suggested that face configuration skills may be affected very early in the course of Parkinson's disease, and that this may be connected to the fact that considerable nigrostriatal degeneration and alteration in brain neurotransmitter levels occur before the clinical symptoms of PD appear.     

Perceptual expertise effects are not all or none: spatially limited perceptual expertise for faces in a case of prosopagnosia

We document a seemingly unique case of severe prosopagnosia, L. R., who suffered damage to his anterior and inferior right temporal lobe as a result of a motor vehicle accident. We systematically investigated each of three factors associated with expert face recognition: fine-level discrimination, holistic processing, and configural processing (Experiments 1-3). Surprisingly, L. R. shows preservation of all three of these processes; that is, his performance in these experiments is comparable to that of normal controls. However, L. R. is only able to apply these processes over a limited spatial extent to the fine-level detail within faces. Thus, when the location of a given change is unpredictable (Experiment 3), L. R. exhibits normal detection of features and spatial configurations only for the lower half of each face. Similarly, when required to divide his attention over multiple face features, L. R. is able to determine the identity of only a single feature (Experiment 4). We discuss these results in the context of forming a better understanding of prosopagnosia and the mechanisms used in face recognition and visual expertise. We conclude that these mechanisms are not "all-or-none," but rather can be impaired incrementally, such that they may remain functional over a restricted spatial area. This conclusion is consistent with previous research suggesting that perceptual expertise is acquired in a spatially incremental manner [Gauthier, I., & Tarr, M. J. Unraveling mechanisms for expert object recognition: Bridging brain activity and behavior. Journal of Experimental Psychology: Human Perception & Performance, 28, 431-446, 2002].     

Discriminating Thatcherised from typical faces in a case of prosopagnosia

We report data from a prosopagnosic patient (PHD), and aged-matched control participants, from experiments where participants categorised individually presented emotional faces (Experiment 1) and Thatcherised (from typical) faces (Experiment 2). In Experiment 2 participants also discriminated between simultaneously presented Thatcherised and typical faces. PHD was at chance categorising Thatcherised from typical faces. He was, however, able to discriminate between Thatcherised and typical faces, and partially able to categorise emotional faces. The results are discussed in terms of a loss of configural processing but preserved feature processing in PHD. The loss of configural processing impacts his categorisation of Thatcherised and typical faces, and his emotion processing, while his preserved feature processing supports his ability to categorise some emotional faces and his ability to discriminate between Thatcherised and typical faces.     

Haptic face recognition and prosopagnosia

Cases of cross-modal influence have been observed since the beginning of psychological science. Yet some abilities like face recognition are traditionally only investigated in the visual domain. People with normal visual face-recognition capacities identify inverted faces more poorly than upright faces. An abnormal pattern of performance with inverted faces by prosopagnosic individuals is characteristically interpreted as evidence for a deficit in configural processing essential for normal face recognition. We investigated whether such problems are unique to vision by examining face processing by hand in a prosopagnosic individual. We used the haptic equivalent of the visual-inversion paradigm to investigate haptic face recognition. If face processing is specific to vision, our participant should not show difficulty processing faces haptically and should perform with the same ease as normal controls. Instead, we show that a prosopagnosic individual cannot haptically recognize faces. Moreover, he shows similar abnormal inversion effects by hand and eye. These results suggest that face-processing deficits can be found across different input modalities. Our findings also extend the notion of configural processing to haptic face and object recognition.     

Understanding facial emotion perception in Parkinson's disease: the role of configural processing

Parkinson's disease (PD) has been frequently associated with facial emotion recognition impairments, which could adversely affect the social functioning of those patients. Facial emotion recognition requires processing of the spatial relations between facial features, known as the facial configuration. Few studies, however, have investigated this ability in people with PD. We hypothesized that facial emotion recognition impairments in patients with PD could be accounted for by a deficit in configural processing. To assess this hypothesis, three tasks were proposed to 10 patients with PD and 10 healthy controls (HC): (i) a facial emotion recognition task with upright faces, (ii) a similar task with upside-down faces, to explore the face inversion effect, and (iii) a configural task to assess participants’ abilities to detect configural modifications made on a horizontal or vertical axis. The results showed that when compared with the HC group, the PD group had impaired facial emotion recognition, in particular for faces expressing anger and fear, and exhibited reduced face inversion effect for these emotions. More importantly, the PD group's performance on the configural task to detect vertical modifications was lower than the HC group's. Taken together, these results suggest the presence of a configural processing alteration in patients with PD, especially for vertical, second-order information. Furthermore, configural performance was positively correlated with emotion recognition for anger, disgust, and fear, suggesting that facial emotion recognition could be related, at least partially, to configural processing.     

Dysfunction in configural face processing in patients with schizophrenia

BACKGROUND: Face recognition has important implications for patients with schizophrenia, who exhibit poor interpersonal and social skills. Previous reports have suggested that patients with schizophrenia have deficits in their ability to recognize faces, and because face recognition relies heavily on information about the configuration of faces, we hypothesized that patients with schizophrenia would have specific problems in processing configural information. METHODS: We measured the performance of 20 patients with schizophrenia and 20 normal subjects in a face-discrimination task, using upright and inverted pairs of face photographs that differed in featural or configural information. RESULTS: The patients with schizophrenia showed disproportionately poorer performance in discriminating configural compared with featural face sets. CONCLUSION: The result suggests that the face-recognition deficit in schizophrenic patients is due to specific impairments in configural processing of faces.     

Typical Emotion Processing for Cartoon but not for Real Faces in Children with Autistic Spectrum Disorders

This study evaluated whether atypical face processing in autism extends from human to cartoon faces for which they show a greater interest. Twenty children with autistic spectrum disorders (ASD) were compared to two groups of typically developing children, matched on chronological and mental age. They processed the emotional expressions of real faces, human cartoon and nonhuman cartoon faces. Children with ASD were as capable as controls in processing emotional expressions, but strategies differed according to the type of face. Controls relied on a configural strategy with all faces. By contrast, ASD children exploited this typical configural strategy with cartoons but used a local strategy with real faces. This atypical visual processing style is discussed in the context of face expertise.     

Training with own-race faces can improve processing of other-race faces: evidence from developmental prosopagnosia

Faces of one's own race are discriminated and recognized more accurately than faces of an other race (other-race effect - ORE). Studies have employed several methods to enhance individuation and recognition of other-race faces and reduce the ORE, including intensive perceptual training with other-race faces and explicitly instructing participants to individuate other-race faces. Unfortunately, intensive perceptual training has shown to be specific to the race trained and the use of explicit individuation strategies, though applicable to all races, can be demanding of attention and difficult to consistently employ. It has not yet been demonstrated that a training procedure can foster the automatic individuation of all other-race faces, not just faces from the race trained. Anecdotal evidence from a training procedure used with developmental prosopagnosics (DPs) in our lab, individuals with lifelong face recognition impairments, suggests that this may be possible. To further test this idea, we had five Caucasian DPs perform ten days of configural face training (i.e. attending to small spacing differences between facial features) with own-race (Caucasian) faces to see if training would generalize to improvements with other-race (Korean) faces. To assess training effects and localize potential effects to parts-based or holistic processing, we used the part-whole task using Caucasian and Korean faces (Tanaka, J. W., Kiefer, M., & Bukach, C. M. (2004). A holistic account of the own-race effect in face recognition: evidence from a cross-cultural study. Cognition, 93(1), B1-9). Results demonstrated that after training, DPs showed a disproportionate improvement in holistic processing of other-race faces compared to own-race faces, reducing their ORE. This suggests that configural training with own-race faces boosted DPs’ general configural/holistic attentional resources, which they were able to apply to other-race faces. This provides a novel method to reduce the ORE and supports more of an attentional/social-cognitive model of the ORE rather than a strictly expertise model.     

Joie, tristesse ou colère ? Quelles stratégies utilisent les enfants porteurs du syndrome de Williams pour reconnaître des expressions émotionnelles faciales ?

Children with Williams syndrome (WS) show an uneven cognitive profile with relatively spared face-processing skills contrasting with impaired visuospatial cognition. More precisely, deficits to process spatial relationships between elements of a visual pattern (that is, configural processing) have been found in children with WS. The present study aimed at determining whether this configural-processing deficit affects facial-emotion recognition. To this aim, 15 children with WS were asked to recognize emotional expressions displayed in upright and inverted faces and their performance was compared to that of 15 mental and 15 chronological age-matched controls. Results revealed that children with WS, as typically developing controls, were more accurate to recognize emotions displayed in upright than in inverted faces. This indicates that children with WS are able to use a typical perceptual strategy, that is., a configural strategy, to process facial expressions of emotion. Findings of this study are interpreted in relation to the hallmark feature of WS-hypersociability.     

An evaluation of two commonly used tests of unfamiliar face recognition

The Warrington Recognition Memory for Faces (RMF) and the Benton Facial Recognition Test (BFRT) are commercially available tests that are commonly used by clinicians and cognitive neuropsychologists to evaluate unfamiliar face recognition. Yet, it is not clear that a normal score on either instrument demonstrates normal unfamiliar face recognition. Because the RMFs stimuli contain abundant non-internal facial feature information, subjects may be able to score in the normal range without using internal facial features. On the BFRT, subjects commonly rely on feature matching strategies using the hairline and eyebrows rather than recognizing the facial configuration. To test whether these routes to recognition can support normal performance, normal subjects were tested with versions of the RMF and the BFRT in which the faces had been painted over in a way that prevented the operation of some of the procedures normally involved with face recognition. Even though these modifications removed all of the internal feature information in the RMF, many subjects scored in the normal range, and despite precluding the use of configural processing in the BFRT, many of the scores were in the normal range. As a result, it is apparent that normal scores on these tests do not demonstrate normal unfamiliar face recognition and so clinicians should be cautious in interpreting scores in the normal range. Finally, these results place in question models supported by dissociations involving normal performance on these tests.     

Differential amygdala response to lower face in patients with autistic spectrum disorders: An fMRI study

Much functional neuroimaging evidence indicates that autistic spectrum disorders (ASD) demonstrate marked brain abnormalities in face processing. Most of these findings were obtained from studies using tasks related to whole faces. However, individuals with ASD tend to rely more on individual parts of the face for identification than on the overall configuration. Therefore, this neuroimaging evidence might reflect differential visual attention systems in face recognition. It was hypothesized that differential brain function is shown between ASD and control participants with face recognition tasks presenting parts of faces separately. Nine adults with high-functioning ASD and 24 age-matched normal comparison participants were studied using a 3T-MR scanner. We investigated brain activation when processing whole faces and parts of faces displaying positive or negative expressions. The control group showed bilateral amygdalae activation to the whole face, but not to parts of the face. The ASD group showed bilateral amygdalae activation to the lower face (mainly mouth region), but not to the whole face and upper face (mainly eye region). These findings suggest that differential amygdala function for face processing exists in ASD. This aberrant amygdala function might cause abnormalities in gaze processing or recognition of emotional expressions, shown clinically in ASD.     

Face and body perception in schizophrenia: A configural processing deficit?

Face and body perception rely on common processing mechanisms and activate similar but not identical brain networks. Patients with schizophrenia show impaired face perception, and the present study addressed for the first time body perception in this group. Seventeen patients diagnosed with schizophrenia or schizoaffective disorder were compared to 17 healthy controls on standardized tests assessing basic face perception skills (identity discrimination, memory for faces, recognition of facial affect). A matching-to-sample task including emotional and neutral faces, bodies and cars either in an upright or in an inverted position was administered to assess potential category-specific performance deficits and impairments of configural processing. Relative to healthy controls, schizophrenia patients showed poorer performance on the tasks assessing face perception skills. In the matching-to-sample task, they also responded more slowly and less accurately than controls, regardless of the stimulus category. Accuracy analysis showed significant inversion effects for faces and bodies across groups, reflecting configural processing mechanisms; however reaction time analysis indicated evidence of reduced inversion effects regardless of category in schizophrenia patients. The magnitude of the inversion effects was not related to clinical symptoms. Overall, the data point towards reduced configural processing, not only for faces but also for bodies and cars in individuals with schizophrenia.     

Facial expression recognition in Williams syndrome

Individuals with Williams syndrome (WS) excel in face recognition and show both a remarkable concern for social stimuli and a linguistic capacity for, in particular, emotionally referenced language. The animated full facial expression comprehension test (AFFECT), a new test of emotional expression perception, was used to compare participants with WS with both chronological and mental age-matched controls. It was found that expression recognition in WS was worse than that of chronologically age-matched controls but indistinguishable from that of mental age controls. Different processing strategies are thought to underlie the similar performance of individuals with WS and mental age controls. The expression recognition performance of individuals with WS did not correlate with age, but was instead found to correlate with IQ. This is compared to earlier findings, replicated here, that face recognition performance on the Benton test correlates with age and not IQ. The results of the Benton test have been explained in terms of individuals with WS being good at face recognition; since a piecemeal strategy can be used, this strategy is improved with practice which would explain the correlation with age. We propose that poor expression recognition of the individuals with WS is due to a lack of configural ability since changes in the configuration of the face are an important part of expressions. Furthermore, these reduced configural abilities may be due to abnormal neuronal development and are thus fixed from an early age.     

Paradoxical configuration effects for faces and objects in prosopagnosia

Selective impairment in recognition of faces (prosopagnosia) has been advanced as an argument for a brain module dedicated to face processing and focusing on the specific configural properties of faces. Loss of the inversion effect supposedly strengthened the argument ([10]: de Gelder B, Bachoud-Levi AC, Degos JD. Inversion superiority in visual agnosia may be common to a variety of orientation polarised objects besides faces. Vision Research, 1998;38:2855-61; [20]: Farah MJ, Wilson K, Drain H, Tanaka J. The inverted face inversion effect in prosopagnosia: Evidence for mandatory, face-specific perceptual mechanisms. Vision Research 1995b;35:2089-93). The present study of prosopagnosic patient LH reports that he has lost the normal pattern of superior performance with upright faces and objects and shows instead paradoxical inversion effect for faces but also for objects. Experiment 2 investigated whether LH's use of features based route for processing upright objects would be hindered by the whole-based encoding when processing upright objects. The data show the same context effect for objects as was found for faces. Therefore the inversion effect does not present decisive evidence for the existence of a face module. Moreover, the importance of configuration-based recognition known to be crucial for face processing, must also be taken seriously for object recognition.