Effect of inversion on the recognition of external and internal facial features

The purpose of the present study was to find out whether inversion affects recognition of external and internal facial features. 24 participants matched, under two experimental conditions (pair and multiple-choice matchings), upright target faces with three categories of facial test stimuli: full faces, external features and internal features, which were presented in either upright or inverted orientations. Data analysis showed that matching of facial stimuli was faster, more accurate and more consistent under upright than under inverted orientations for all stimulus categories; mostly for full faces, and least for internal features. As a rule, there were no speed-accuracy trade-offs. Implications of the data for accounts of the inversion effect in face recognition in terms of a shift from configurational to componential processing were discussed.     

The inversion effect in infancy: the role of internal and external features

The present work examined the changing role of inner and outer facial features in the recognition of upright and inverted faces in 5-, 7-, and 9-month-olds. Study 1 established that the “inversion effect” (impaired recognition of an inverted face) was present in infants as young as 5 months. In Study 2, internal and external features were inverted separately. Disrupting the internal configuration by inversion impaired recognition at all ages; disrupting the external configuration impaired recognition only at 5-months. In Study 3, an upright familiar face was paired with one having either novel internal or novel external features. The results confirmed that the 5-month-olds used only the external features to recognize faces, whereas older infants were as adept at using internal features as external ones. These findings suggest a shift, after 5 months, away from dependence on external features for face recognition and toward greater reliance on internal ones.     

The contribution of external and internal features to the matching of unfamiliar faces

The relative efficacy of external and internal features in matching unfamiliar faces was studied in three experiments in which the subjects matched target and test faces differing in terms of external or internal features, or both. In Experiment 1 only full congruency between target and test faces was considered a match; in Experiments 2 and 3 faces sharing the same external and internal features were also considered to be matches. A total of 100 subjects matched 192 pairs of target and test faces in a same-different task. Reaction times and matching errors were recorded for analyses of variance. In all three experiments performance was best when either all features matched or all features mismatched, with mismatches having a slight edge. When matches of external and internal features with the target faces were inconsistent with each other, mismatches of external features led to faster responses in Experiments 1 and 2, and mismatches of internal features led to faster responses in Experiment 3. The results suggest that since faces are configurational stimuli, face matching is influenced by the non-relevant set of features; and that mismatches, especially of external features, influence face matching more than matches do.     

Does matching of internal and external facial features depend on orientation and viewpoint?

Although it is recognized that external (hair, head and face outline, ears) and internal (eyes, eyebrows, nose, mouth) features contribute differently to face recognition it is unclear whether both feature classes predominately stimulate different sensory pathways. We employed a sequential speed-matching task to study face perception with internal and external features in the context of intact faces, and at two levels of contextual congruency. Both internal and external features were matched faster and more accurately in the context of totally congruent/incongruent facial stimuli compared to just featurally congruent/incongruent faces. Matching of totally congruent/incongruent faces was not affected by the matching criteria, but was strongly modulated by orientation and viewpoint. On the contrary, matching of just featurally congruent/incongruent faces was found to depend on the feature class to be attended, with strong effects of orientation and viewpoint only for matching of internal features, but not of external features. The data support the notion that different processing mechanisms are involved for both feature types, with internal features being handled by configuration sensitive mechanisms whereas featural processing modes dominate when external features are the focus.     

Holistic processing and reliance on global viewing strategies in older adults' face perception

There is increasing evidence that face recognition might be impaired in older adults, but it is unclear whether the impairment is truly perceptual, and face specific. In order to address this question we compared performance in same/different matching tasks with face and non-face objects (watches) among young (mean age 23.7) and older adults (mean age 70.4) using a context congruency paradigm (Meinhardt-Injac, Persike & Meinhardt, 2010, Meinhardt-Injac, Persike and Meinhardt, 2011a). Older adults were less accurate than young adults with both object classes, while face matching was notably impaired. Effects of context congruency and inversion, measured as the hallmarks of holistic processing, were equally strong in both age groups, and were found only for faces, but not for watches. The face specific decline in older adults revealed deficits in handling internal facial features, while young adults matched external and internal features equally well. Comparison with non-face stimuli showed that this decline was face specific, and did not concern processing of object features in general. Taken together, the results indicate no age-related decline in the capabilities to process faces holistically. Rather, strong holistic effects, combined with a loss of precision in handling internal features indicate that older adults rely on global viewing strategies for faces. At the same time, access to the exact properties of inner face details becomes restricted.     

The relative importance of external and internal features of facial composites

Three experiments are reported that compare the quality of external with internal regions within a set of facial composites using two matching‐type tasks. Composites are constructed with the aim of triggering recognition from people familiar with the targets, and past research suggests internal face features dominate representations of familiar faces in memory. However the experiments reported here show that the internal regions of composites are very poorly matched against the faces they purport to represent, while external feature regions alone were matched almost as well as complete composites. In Experiments 1 and 2 the composites used were constructed by participant‐witnesses who were unfamiliar with the targets and therefore were predicted to demonstrate a bias towards the external parts of a face. In Experiment 3 we compared witnesses who were familiar or unfamiliar with the target items, but for both groups the external features were much better reproduced in the composites, suggesting it is the process of composite construction itself which is responsible for the poverty of the internal features. Practical implications of these results are discussed.     

Integration of internal and external facial features in 8- to 10-year-old children and adults

Investigation of whole-part and composite effects in 4- to 6-year-old children gave rise to claims that face perception is fully mature within the first decade of life (Crookes & McKone, 2009). However, only internal features were tested, and the role of external features was not addressed, although external features are highly relevant for holistic face perception (Sinha & Poggio, 1996; Axelrod & Yovel, 2010, 2011). In this study, 8- to 10-year-old children and adults performed a same–different matching task with faces and watches. In this task participants attended to either internal or external features. Holistic face perception was tested using a congruency paradigm, in which face and non-face stimuli either agreed or disagreed in both features (congruent contexts) or just in the attended ones (incongruent contexts). In both age groups, pronounced context congruency and inversion effects were found for faces, but not for watches. These findings indicate holistic feature integration for faces. While inversion effects were highly similar in both age groups, context congruency effects were stronger for children. Moreover, children's face matching performance was generally better when attending to external compared to internal features. Adults tended to perform better when attending to internal features. Our results indicate that both adults and 8- to 10-year-old children integrate external and internal facial features into holistic face representations. However, in children's face representations external features are much more relevant. These findings suggest that face perception is holistic but still not adult-like at the end of the first decade of life.     

Beyond U-Shaped Development in Infants' Processing of Faces: An Information-Processing Account

The development of the "inversion" effect in face processing was examined in infants 3 to 6 months of age by testing their integration of the internal and external features of upright and inverted faces using a variation of the "switch" visual habituation paradigm. When combined with previous findings showing that 7-month-olds use integrative processing of an upright face, but featural processing of an inverted face (Cohen & Cashon, 2001a), the present findings suggest that from 3 to 7 months, infants' ability to integrate facial features follows an N-shaped developmental pattern for upright faces and an inverted U-shaped pattern for inverted faces. We discuss these results in terms of a set of domain-general information-processing principles.     

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.     

The ups and downs of face perception: evidence for holistic encoding of upright and inverted faces

A visual-search task was used to investigate the influence of facial organisation on discrimination of an internal facial feature. Participants searched for a downturned mouth in arrays of one to six faces that differed only in the target feature, with distractor faces containing an upturned mouth. Feature search was tested in four different face contexts: upright unaltered faces, inverted unaltered faces, upright faces in which the internal features were scrambled, or inverted scrambled faces. Normal face organisation facilitated feature search in upright faces, but slowed it in inverted faces. These findings demonstrate an interdependence of features and their configuration in the perceptual analysis of both upright and inverted faces.     

Matching familiar and unfamiliar faces on internal and external features

Two experiments are reported in which subjects were asked to match a photograph of a complete face and a simultaneously presented photograph of internal or external features of a face, deciding whether or not the two photographs were pictures of the same person. In experiment 1 'same' pairs were derived from different pictures of the same face, so that subjects had to match the faces and not the particular photographs used. Matches based on internal features were found to be faster for familiar than for unfamiliar faces, whereas there was no difference in reaction time between matches based on the external features of familiar and unfamiliar faces. Faster matching of internal features of familiar faces was found to hold equally for pairs of photographs that differed in orientation of the face or in facial expression. In experiment 2 'same' pairs were derived from the same photographs, which gave subjects the choice of matching on the basis of the features of the depicted faces or matching the photographs. Reaction times were faster than in experiment 1, and there were no differences between familiar and unfamiliar faces. The study confirms reports of differential saliency of the internal features of familiar faces, and shows that this only holds when stimuli are treated as faces. The finding thus reflects properties of structural rather than pictorial codes.     

An inner face advantage in children's recognition of familiar peers

Children’s recognition of familiar own-age peers was investigated. Chinese children (4-, 8-, and 14-year-olds) were asked to identify their classmates from photographs showing the entire face, the internal facial features only, the external facial features only, or the eyes, nose, or mouth only. Participants from all age groups were familiar with the faces used as stimuli for 1 academic year. The results showed that children from all age groups demonstrated an advantage for recognition of the internal facial features relative to their recognition of the external facial features. Thus, previous observations of a shift in reliance from external to internal facial features can be attributed to experience with faces rather than to age-related changes in face processing.     

No evidence for subliminal affective priming with emotional facial expression primes

The present study investigated whether facial expressions of emotion presented outside consciousness awareness will elicit evaluative responses as assessed in affective priming. Participants were asked to evaluate pleasant and unpleasant target words that were preceded by masked or unmasked schematic (Experiment 1) or photographic faces (Experiments 1 and 2) with happy or angry expressions. They were either required to perform the target evaluation only or to perform the target evaluation and to name the emotion expressed by the face prime. Prime-target interval was 300 ms in Experiment 1 and 80 ms in Experiment 2. Naming performance confirmed the effectiveness of the masking procedure. Affective priming was evident after unmasked primes in tasks that required naming of the facial expressions for schematic and photographic faces and after unmasked primes in tasks that did not require naming for photographic faces. No affective priming was found after masked primes. The present study failed to provide evidence for affective priming with masked face primes, however, it indicates that voluntary attention to the primes enhances affective priming.     

7-11-year-old children show an advantage for matching and recognizing the internal features of familiar faces: Evidence against a developmental shift

Adults are better at recognizing familiar faces from the internal facial features (eyes, nose, mouth) than from the external facial features (hair, face outline). However, previous research suggests that this “internal advantage” does not appear until relatively late in childhood, and some studies suggest that children rely on external features to recognize all faces, whether familiar or not. We use a matching task to examine face processing in 7-8- and 10-11-year-old children. We use a design in which all face stimuli can be used as familiar items (for participants who are classmates) and unfamiliar items (for participants from a different school). Using this design, we find an internal feature advantage for matching familiar faces, for both groups of children. The same children were then shown the external and internal features of their classmates and were asked to name or otherwise identify them. Again, both age groups identified more of their classmates correctly from the internal than the external features. This is the first time an internal advantage has been reported in this age group. Results suggest that children as young as 7 process faces in the same way as do adults, and that once procedural difficulties are overcome, the standard effects of familiarity are observed.     

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.     

Face recognition memory: The effects of exposure duration and encoding instruction

Two experiments test the effects of exposure duration and encoding instruction on the relative memory for five facial features. Participants viewed slides of Identi-kit faces and were later given a recognition test with same or changed versions of each face. Each changed test face involved a change in one facial feature: hair, eyes, chin, nose or mouth. In both experiments the upper-face features of hair and eyes were better recognized than the lower-face features of nose, mouth, and chin, as measured by false alarm rates. In Experiment 1, participants in the 20-second exposure duration condition remembered faces significantly better than participants in the 3-second exposure duration condition; however, memory for all five facial features improved at a similar rate with the increased duration. In Experiment 2, participants directed to use feature scanning encoding instructions remembered faces significantly better than participants following age judgement instructions; however, the size of the memory advantage for upper facial features was less with feature scanning instructions than with age judgement instructions. The results are discussed in terms of a quantitative difference in processing faces with longer exposure duration, versus a qualitative difference in processing faces with various encoding instructions. These results are related to conditions that affect the accuracy of eyewitness identification.     

Attention to internal face features in unfamiliar face matching

Accurate matching of unfamiliar faces is vital in security and forensic applications, yet previous research has suggested that humans often perform poorly when matching unfamiliar faces. Hairstyle and facial hair can strongly influence unfamiliar face matching but are potentially unreliable cues. This study investigated whether increased attention to the more stable internal face features of eyes, nose, and mouth was associated with more accurate face‐matching performance. Forty‐three first‐year psychology students decided whether two simultaneously presented faces were of the same person or not. The faces were displayed for either 2 or 6 seconds, and had either similar or dissimilar hairstyles. The level of attention to internal features was measured by the proportion of fixation time spent on the internal face features and the sensitivity of discrimination to changes in external feature similarity. Increased attention to internal features was associated with increased discrimination in the 2‐second display‐time condition, but no significant relationship was found in the 6‐second condition. Individual differences in eye‐movements were highly stable across the experimental conditions.     

Exploring levels of face familiarity by using an indirect face-matching measure

An experiment is reported in which participants matched complete images of unfamiliar, moderately familiar, and highly familiar faces with simultaneously presented images of internal and external features. Participants had to decide if the two images depicted same or different individuals. Matches to internal features were made faster to highly familiar faces than both to moderately familiar and to unfamiliar faces, and matches to moderately familiar faces were made faster than to unfamiliar faces. For external feature matches, this advantage was only found for "different" decision matches to highly familiar faces compared to unfamiliar faces. The results indicate that the differences in familiar and unfamiliar face processing are not the result of all-or-none effects, but seem to have a graded impact on matching performance. These findings extend the earlier work of Young et al (1985 Perception 14 737-746), and we discuss the possibility of using the matching task as an indirect measure of face familiarity.     

Configurational information in face perception

A new facial composites technique is demonstrated, in which photographs of the top and bottom halves of different familiar faces fuse to form unfamiliar faces when aligned with each other. The perception of a novel configuration in such composite stimuli is sufficiently convincing to interfere with identification of the constituent parts (experiment 1), but this effect disappears when stimuli are inverted (experiment 2). Difficulty in identifying the parts of upright composites is found even for stimuli made from parts of unfamiliar faces that have only ever been encountered as face fragments (experiment 3). An equivalent effect is found for composites made from internal and external facial features of well-known people (experiment 4). These findings demonstrate the importance of configurational information in face perception, and that configurations are only properly perceived in upright faces.     

任务类型对面孔联合效应和特征效应的调节

采用特征-联合范式的研究发现, 面孔再认阶段可记录到明显的联合效应和特征效应; 然而, 与再认同属情景记忆的另一任务(来源提取)条件的相应效应尚未报道, 背景信息一致性对联合面孔和特征面孔提取的调节作用以及面孔不同特征对特征效应的影响也未考察。为澄清上述问题, 本文采用特征-联合范式, 并以位置为背景展开研究。实验含一个学习任务和两个测验任务(再认和来源提取)。结果显示, 再认和来源提取阶段均记录到显著的联合效应和特征效应, 且两类效应均在来源提取阶段更强; 任务类型与位置背景一致性交互影响提取绩效; 面孔外部特征和内部特征对特征效应的影响相似。表明联合效应和特征效应具有显著的任务类型敏感性, 这些效应是联合面孔和特征面孔的熟悉性较强且对源面孔的回忆加工相对较弱的结果, 且这两类面孔的提取为背景一致性所调节; 任务类型对两类效应的调节与双重加工理论模型相吻合。