Holistic processing of faces in preschool children and adults

Contrary to the encoding-switch hypothesis, recent research demonstrates that 6-year-olds do not rely solely on parts-based encoding to recognize upright faces. This research shows better recognition of face parts presented in the whole face than in isolation, indicating use of holistic encoding. The present study examined whether children younger than 6 years also recognize faces holistically. Four-year-olds, 5-year-olds, and adults were administered a part-whole face recognition task. Children below the age of 6 remembered parts from upright faces better when tested in the whole-face context than in isolation. This whole-face advantage did not occur when faces were inverted. Although children showed a smaller inversion decrement than adults and generally performed more poorly than adults, the different age groups showed similar patterns of performance, indicating that young preschoolers, like older children and adults, are able to recognize faces holistically.     

A sideways look at configural encoding: two different effects of face rotation

Inversion has a disproportionate disruptive effect on the recognition of faces. This may be due to the disruption of holistic or configural encoding employed to recognise upright faces. The paradigm developed by Tanaka and Farah (1993 Quarterly Journal of Experimental Psychology, Section A 46 225-246) was used to investigate the effect of 90 degrees (or orthogonal) rotation on configural encoding. Faces learnt in the orthogonal condition were not recognised as well as upright faces, but a whole-face advantage was found in both cases. This whole-face advantage did not occur for inverted faces. It appears that 90 degrees rotation affects recognition but not specifically configural encoding. It is concluded that rotating a face can have at least two different effects on face processing depending on the range of rotation. Implications for the nature of facial dimensions and the expertise account of the inversion effect are considered.     

Face Recognition in Young Children: When the Whole is Greater than the Sum of Its Parts

Do young children recognize faces differently than older children and adults? Previous research (Carey & Diamond, 1977) has suggested that, before the age of 8, children recognize a face by its individual features; after the age of 8, they switch to a whole-face (holistic) recognition strategy. The part-whole paradigm provides a suitable test for the encoding switch hypothesis. In this paradigm, memory for a face part is probed when the part is presented in isolation and in the whole face. The difference in performance between the two test conditions serves as an index of holistic processing. Results from such studies reveal that even 6-year-olds remember parts from upright faces better when tested in the whole-face context than in isolation. When faces are inverted, the holistic processes of young children and older children are disrupted. These results indicate that counter to the encoding switch hypothesis, children recognize faces holistically by 6 years of age.     

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。     

Configural and local processing of faces in children with Williams syndrome

Three experiments investigated face processing in children with Williams syndrome (WS). In Experiment 1, the ability to discriminate different aspects of faces was compared between WS subjects and a group of children individually matched for chronological age (CA-matches) and another group matched for mental age (MA-matches). In Experiments 2 and 3, the ability to process the local and configural aspects of geometrical patterns and faces was assessed within the same groups of subjects. The results indicated that the WSs' overall performance on face recognition was below that of the CA-matches, but similar to that of the MA-matches. This study revealed in addition that the CA- and MA-matches showed a bias toward a configural mode of face and geometrical shape processing, whereas children with WS did not show any bias. These findings suggest that face processing undergoes an abnormal developmental course in WS.     

Perceptual learning and acquired face familiarity: Evidence from inversion,use of internal features,and generalization between viewpoints

Pairs of similar faces were created from photographs of different people using morphing software. The ability of participants to discriminate between novel pairs of faces and between those to which they had received brief, unsupervised, exposure (5×2 s each) was assessed. In all experiments exposure improved discrimination performance. Overall, discrimination was better when the faces were upright, but exposure produced improved discrimination for both upright and inverted faces (Experiment 1). The improvement produced by exposure was selective to internal face features (Experiment 2) and was evident when there was a change in orientation (three-quarter to full face or vice versa) between exposure and test (Experiment 3). These findings indicate that perceptual learning observed following brief exposure to faces exhibit well-established hallmarks of familiar face processing (i.e., internal feature advantage and insensitivity to a change of viewpoint). Considered in combination with previous studies using the same type of stimuli (Mundy, Honey, & Dwyer, 2007), the current results imply that general perceptual learning mechanisms contribute to the acquisition of face familiarity.     

The eyes or the mouth? Feature salience and unfamiliar face processing in Williams syndrome and autism

Using traditional face perception paradigms the current study explores unfamiliar face processing in two neurodevelopmental disorders. Previous research indicates that autism and Williams syndrome (WS) are both associated with atypical face processing strategies. The current research involves these groups in an exploration of feature salience for processing the eye and mouth regions of unfamiliar faces. The tasks specifically probe unfamiliar face matching by using (a) upper or lower face features, (b) the Thatcher illusion, and (c) featural and configural face modifications to the eye and mouth regions. Across tasks, individuals with WS mirror the typical pattern of performance, with greater accuracy for matching faces using the upper than using the lower features, susceptibility to the Thatcher illusion, and greater detection of eye than mouth modifications. Participants with autism show a generalized performance decrement alongside atypicalities, deficits for utilizing the eye region, and configural face cues to match unfamiliar faces. The results are discussed in terms of feature salience, structural encoding, and the phenotypes typically associated with these neurodevelopmental disorders.     

The eyes or the mouth? Feature salience and unfamiliar face processing in Williams syndrome and autism

Using traditional face perception paradigms the current study explores unfamiliar face processing in two neurodevelopmental disorders. Previous research indicates that autism and Williams syndrome (WS) are both associated with atypical face processing strategies. The current research involves these groups in an exploration of feature salience for processing the eye and mouth regions of unfamiliar faces. The tasks specifically probe unfamiliar face matching by using (a) upper or lower face features, (b) the Thatcher illusion, and (c) featural and configural face modifications to the eye and mouth regions. Across tasks, individuals with WS mirror the typical pattern of performance, with greater accuracy for matching faces using the upper than using the lower features, susceptibility to the Thatcher illusion, and greater detection of eye than mouth modifications. Participants with autism show a generalized performance decrement alongside atypicalities, deficits for utilizing the eye region, and configural face cues to match unfamiliar faces. The results are discussed in terms of feature salience, structural encoding, and the phenotypes typically associated with these neurodevelopmental disorders.     

Understanding the role of configural processing in face emotion recognition in Parkinson’s disease

This investigation examined whether impairment in configural processing could explain deficits in face emotion recognition in people with Parkinson’s disease (PD). Stimuli from the Radboud Faces Database were used to compare recognition of four negative emotion expressions by older adults with PD (n = 16) and matched controls (n = 17). Participants were tasked with categorizing emotional expressions from upright and inverted whole faces and facial composites; it is difficult to derive configural information from these two types of stimuli so featural processing should play a larger than usual role in accurate recognition of emotional expressions. We found that the PD group were impaired relative to controls in recognizing anger, disgust and fearful expressions in upright faces. Then, consistent with a configural processing deficit, participants with PD showed no composite effect when attempting to identify facial expressions of anger, disgust and fear. A face inversion effect, however, was observed in the performance of all participants in both the whole faces and facial composites tasks. These findings can be explained in terms of a configural processing deficit if it is assumed that the disruption caused by facial composites was specific to configural processing, whereas inversion reduced performance by making it difficult to derive both featural and configural information from faces.     

The “parts and wholes” of face recognition: A review of the literature

It has been claimed that faces are recognized as a “whole” rather than by the recognition of individual parts. In a paper published in the Quarterly Journal of Experimental Psychology in 1993, Martha Farah and I attempted to operationalize the holistic claim using the part/whole task. In this task, participants studied a face and then their memory presented in isolation and in the whole face. Consistent with the holistic view, recognition of the part was superior when tested in the whole-face condition compared to when it was tested in isolation. The “whole face” or holistic advantage was not found for faces that were inverted, or scrambled, nor for non-face objects, suggesting that holistic encoding was specific to normal, intact faces. In this paper, we reflect on the part/whole paradigm and how it has contributed to our understanding of what it means to recognize a face as a “whole” stimulus. We describe the value of part/whole task for developing theories of holistic and non-holistic recognition of faces and objects. We discuss the research that has probed the neural substrates of holistic processing in healthy adults and people with prosopagnosia and autism. Finally, we examine how experience shapes holistic face recognition in children and recognition of own- and other-race faces in adults. The goal of this article is to summarize the research on the part/whole task and speculate on how it has informed our understanding of holistic face processing.     

Local and Relational Aspects of Face Distinctiveness

Distinctiveness contributes strongly to the recognition and rejection of faces in memory tasks. In four experiments we examine the role played by local and relational information in the distinctiveness of upright and inverted faces. In all experiments subjects saw one of three versions of a face: original faces, which had been rated as average in distinctiveness in a previous study (Hancock, Burton, & Bruce, 1996), a more distinctive version in which local features had been changed ( D-local ), and a more distinctive version in which relational features had been changed ( D-rel ). An increase in distinctiveness was found for D-local and D-rel faces in Experiment 1 (complete faces) and 3 and 4 (face internals only) when the faces had to be rated in upright presentation, but the distinctiveness of the D-rel faces was reduced much more than that of the D-local versions when the ratings were given to the faces presented upside-down (Experiments 1 and 3). Recognition performance showed a similar pattern: presented upright, both D-local and D-rel revealed higher performance compared to the originals, but in upside-down presentation the D-local versions showed a much stronger distinctiveness advantage. When only internal features of faces were used (Experiments 3 and 4), the D-rel faces lost their advantage over the Original versions in inverted presentation. The results suggest that at least two dimensions of facial information contribute to a face's apparent distinctiveness, but that these sources of information are differentially affected by turning the face upside-down. These findings are in accordance with a face processing model in which face inversion effects occur because a specific type of information processing is disrupted, rather than because of a general disruption of performance.     

Regional variation in the inversion effect for faces: differential effects for feature shape, feature configuration, and external contour

Faces are perceived via an orientation-dependent expert mechanism. We previously showed that inversion impaired perception of the spatial relations of features more in the lower face than in the (more salient) upper face, suggests a failure to rapidly process this type of structural data from the entire face. In this study we wished to determine if this interaction between inversion and regional salience, which we consider a marker for efficient whole-face processing, was specific to second-order (coordinate) spatial relations or also affected other types of structural information in faces. We used an oddity paradigm to test the ability of seventeen subjects to discriminate changes in feature size, feature spatial relations, and external contour in both the upper and lower face. We also tested fourteen subjects on perception of two different types of spatial relations: second-order changes that create plausible alternative faces, and illegal spatial changes that transgress normal rules of facial geometry. In both experiments we examined for asymmetries between upper-face and lower-face perceptual accuracy with brief stimulus presentations. While all structural changes were less easily discerned in inverted faces, only changes to spatial relations showed a marked asymmetry between the upper and lower face, with far worse performance in the mouth region. Furthermore, this asymmetry was found only for second-order spatial relations and not illegal spatial changes. These results suggest that the orientation-dependent face mechanism has a rapid whole-face processing capacity specific to the internal second-order (coordinate) spatial relations of facial features.     

Face inversion disproportionately impairs the perception of vertical but not horizontal relations between features

Upside-down inversion disrupts the processing of spatial relations between the features of a face, while largely preserving local feature analysis. However, recent studies on face inversion failed to observe a clear dissociation between relational and featural processing. To resolve these discrepancies and clarify how inversion affects face perception, the authors monitored inversion effects separately for vertical and horizontal distances between features. Inversion dramatically declined performance in the vertical-relational condition, but it impaired featural and horizontal-relational performance only moderately. Identical observations were made whether upright and inverted trials were blocked or randomly interleaved. The largest performance decrement was found for vertical relations even when faces were rotated by 90 degrees. Evidence that inversion dramatically disrupts the ability to extract vertical but not horizontal feature relations supports the view that inversion qualitatively changes face perception by rendering some of the processes activated by upright faces largely ineffective.     

Short-Term Memory Deficits Are Not Uniform in Down and Williams Syndromes

Neuropsychological investigation of the development of the mnesic function in mental retardation has primarily focused on evaluating short-term memory (STM). Studies have often documented a reduced verbal short-term memory span in individuals with mental retardation and with Down syndrome in particular, compared to groups of mental age-matched controls. However, recent evidence suggests that verbal short-term memory is not equally impaired in all individuals with mental retardation. Findings in children with Williams syndrome are particularly relevant in this regard. Also, data concerning STM for visual information suggest that visual-object and visual-spatial working memory may be differently compromised in people with mental retardation. In particular, individuals with Williams syndrome exhibit specific difficulties in visual-spatial but not in visual-object working memory tasks compared to typically-developing children matched for mental age. Instead, people with Down syndrome show reduced performance in both visual-spatial and visual-object tests. Taken together, these results reinforce the view that intellectual disability is not a unitary condition characterized by homogeneous slowness of cognitive development but a variety of conditions in which some cognitive functions may be more disrupted than others. The finding that the working memory deficit in individuals with Williams and Down syndrome may be qualitatively differentiated also supports the hypothesis that it is not simply a manifestation of general cognitive impairment but, rather, the expression of a specific deficit of a discrete cognitive ability.     

Combined effects of inversion and feature removal on N170 responses elicited by faces and car fronts

The face-sensitive N170 is typically enhanced for inverted compared to upright faces. Itier, Alain, Sedore, and McIntosh (2007) recently suggested that this N170 inversion effect is mainly driven by the eye region which becomes salient when the face configuration is disrupted. Here we tested whether similar effects could be observed with non-face objects that are structurally similar to faces in terms of possessing a homogeneous within-class first-order feature configuration. We presented upright and inverted pictures of intact car fronts, car fronts without lights, and isolated lights, in addition to analogous face conditions. Upright cars elicited substantial N170 responses of similar amplitude to those evoked by upright faces. In strong contrast to face conditions however, the car-elicited N170 was mainly driven by the global shape rather than the presence or absence of lights, and was dramatically reduced for isolated lights. Overall, our data confirm a differential influence of the eye region in upright and inverted faces. Results for car fronts do not suggest similar interactive encoding of eye-like features and configuration for non-face objects, even when these objects possess a similar feature configuration as faces.     

Temporal integration in face perception: evidence of configural processing of temporally separated face parts

Temporal integration is the process by which temporally separated visual components are combined into a unified representation. Although this process has been studied in object recognition, little is known about temporal integration in face perception and recognition. In the present study, the authors investigated the characteristics and time boundaries of facial temporal integration. Whole faces of nonfamous and famous people were segmented horizontally into 3 parts and presented in sequence, with varying interval lengths between parts. Inversion and misalignment effects were found at short intervals (0-200 ms). Moreover, their magnitude was comparable to those found with whole-face presentations. These effects were eliminated, or substantially reduced, when the delay interval was 700 ms. Order of parts presentation did not influence the pattern of inversion effects obtained within each temporal delay condition. These results demonstrate that temporal integration of faces occurs in a temporary and limited visual buffer. Moreover, they indicate that only integrated faces can undergo configural processing.     

The effect of inversion on the encoding of normal and “thatcherized” faces

In the “Thatcher illusion” a face, in which the eyes and mouth are inverted relative to the rest of the face, looks grotesque when shown upright but not when inverted. In four experiments we investigated the contribution of local and global processing to this illusion in normal observers. We examined inversion effects (i.e., better performance for upright than for inverted faces) in a task requiring discrimination of whether faces were or were not “thatcherized”. Observers made same/different judgements to isolated face parts (Experiments 1-2) and to whole faces (Experiments 3-4). Face pairs had the same or different identity, allowing for different process- ing strategies using feature-based or configural information, respectively. In Experiment 1, feature-based matching of same-person face parts yielded only a small inversion effect for normal face parts. However, when feature-based matching was prevented by using the face parts of different people on all trials (Experiment 2) an inversion effect occurred for normal but not for thatcherized parts. In Experiments 3 and 4, inversion effects occurred with normal but not with thatcherized whole faces, on both same- and different-person matching tasks. This suggests that a common configural strategy was used with whole (normal) faces. Face context facilitated attention to misoriented parts in same-person but not in different-person matching. The results indicate that (1) face inversion disrupts local configural processing, but not the processing of image features, and (2) thatcherization disrupts local configural processing in upright faces.     

Impaired face recognition does not preclude intact whole face perception

We studied intact and impaired processes in a prosopagnosic patient (RP). In Experiment 1, RP showed an inversion superiority effect with both faces and objects, with better performance when stimuli were presented upside down than in normal upright orientation. In Experiment 2, we studied the effect of face configuration directly by comparing matching performance with normal vs. scrambled faces. RP was worse with normal than with scrambled faces, whereas normal controls showed an advantage of a good face context. In Experiment 3, RP showed interference from external face features on the evaluation of internal face features. These results indicate, first, that although RP is impaired in face recognition and face matching, he does still encode the whole face rather than relying completely on parts-based procedures. Second, RP has a deficit at the level of the configural processes involved in finding subtle differences between individual faces, as his performance is worse when presented with a normal face configuration than with scrambled or inverted faces.     

Neural evidence for the contribution of holistic processing but not attention allocation to the other-race effect on face memory

Multiple mechanisms have been suggested to contribute to the other-race effect on face memory, the phenomenon of better memory performance for own-race than other-race faces. Here, two of these mechanisms, increased attention allocation and greater holistic processing during memory encoding for own-race than other-race faces, were tested in two separate experiments. In these experiments event-related potentials were measured during study (the difference due to memory, Dm) and test phase (old/new effects) to examine brain activation related to memory encoding and retrieval, allowing for selective investigations of these memory sub-processes. In Experiment 1, participants studied own-race (Caucasian) and other-race (Chinese) faces under focused or divided attention. In Experiment 2, participants studied own-race (Caucasian) and other-race (African American) faces presented upright or upside down (i.e., inverted). Both experiments showed decreases in memory performance when attention allocation or holistic processing was reduced, but these effects were similar for own-race and other-race faces. Manipulations of holistic processing, but not attention allocation, influenced the neural other-race effects during memory encoding. Inverted own-race faces showed similar neural patterns as upright other-race faces, indicating that when holistic processing of own-race faces was reduced, these faces were encoded similarly as upright other-race faces. No influences of the experimental manipulations on other-race effects during memory retrieval were found. The present study provides the first neural evidence that increased holistic processing during memory encoding contributes to the other-race effect on face memory.