Second-order relational properties and the inversion effect: testing a theory of face perception.

Recognition of faces is more severely impaired by inversion than is recognition of other types of objects. This was originally interpreted as evidence for the existence of special face-recognition mechanisms. Recently, Diamond and Carey (1986) attributed the inversion effect to the use of second-order relational properties that are important for, but not unique to, face recognition. According to their hypothesis, face recognition differs from the recognition of most other objects in its dependence on second-order relational properties. This hypothesis was tested in two experiments by comparing the effects of inversion on the identification of dot patterns that differed in the extent to which they required the encoding of second-order relational properties. Identification of the second-order relational patterns was not more disrupted by inversion than was identification of first-order patterns. These results fail to support the hypothesis that second-order relational properties are responsible for the inversion effect.     

Early maturity of face processing in children: Local and relational distinctiveness effects in 7-year-olds

It is still often claimed that face recognition in children matures relatively late (e.g., 10 years), supporting an “expertise” rather than an “innate” interpretation. However, a review indicates that many adult properties of face processing (inversion effects, first-order relational processing, second-order relational processing, race effects, distinctiveness effects on perception) are present at 6-7 years. A new experiment investigates distinctiveness effects on memory. We manipulated distinctiveness via both local alterations to an original face (thicker lips, bushier eyebrows), and second-order relational alterations (eyes closer together, mouth moved down; Leder & Bruce, 1998). We also varied orientation (upright, inverted). Seven-year-olds' memory showed adult patterns of sensitivity to all these manipulations. We conclude that face recognition matures relatively early, and that the focus of future studies must shift to much younger age groups.     

The face inversion effect—Parts and wholes: Individual features and their configuration

The face inversion effect (FIE) is a reduction in recognition performance for inverted faces (compared to upright faces) that is greater than that typically observed with other stimulus types (e.g., houses). The work of Diamond and Carey, suggests that a special type of configural information, “second-order relational information” is critical in generating this inversion effect. However, Tanaka and Farah concluded that greater reliance on second-order relational information did not directly result in greater sensitivity to inversion, and they suggested that the FIE is not entirely due to a reliance on this type of configural information. A more recent review by McKone and Yovel provides a meta-analysis that makes a similar point. In this paper, we investigated the contributions made by configural and featural information to the FIE. Experiments 1a and1b investigated the link between configural information and the FIE. Remarkably, Experiment 1b showed that disruption of all configural information of the type considered in Diamond and Carey's analysis (both first and second order) was effective in reducing recognition performance, but did not significantly impact on the FIE. Experiments 2 and 3 revealed that face processing is affected by the orientation of individual features and that this plays a major role in producing the FIE. The FIE was only completely eliminated when we disrupted the single feature orientation information in addition to the configural information, by using a new type of transformation similar to Thatcherizing our sets of scrambled faces. We conclude by noting that our results for scrambled faces are consistent with an account that has recognition performance entirely determined by the proportion of upright facial features within a stimulus, and that any ability to make use of the spatial configuration of these features seems to benefit upright and inverted normal faces alike.     

Recognition of faces and complex objects in younger and older adults

We examined whether (1) age-associated impairments in face recognition are specific to faces or also apply to within-category recognition of other objects and (2) age-related face recognition deficits are related to impairments in encoding second-order relations and holistic information. In Experiments 1 and 2, we found reliable age differences for recognition of faces, but not of objects. Moreover, older adults (OAs) and younger adults (YAs) displayed similar face inversion effects. In Experiment 3, unlike YAs, OAs did not show the expected decline in performance for recognition of composites (Young, Hellawell, and Hay, 1987). In Experiment 4, both OAs and YAs showed a whole/part advantage (Tanaka and Farah, 1993). Our results suggest that OAs have spared function for processing of second-order relations and holistic information. Possible explanations for the finding that OAs have greater difficulty recognizing faces than recognizing other objects are proposed.     

The face inversion effect is not a consequence of aberrant eye movements

The face inversion effect is the finding that inverted faces are more difficult to recognize than other inverted objects. The present study explored the possibility that eye movements have a role in producing the face inversion effect. In Experiment 1, we demonstrated that the faces used here produce a robust face inversion effect when compared with another homogenous set of objects (antique radios). In Experiment 2, participants' eye movements were monitored while they learned a set of faces and during a recognition test. Although we clearly found a face inversion effect, the same features of a face were fixated during the learning and recognition test faces, whether the face was right side up or upside down. Thus, the face inversion effect is not a result of a different pattern of eye movements during the viewing of the face.     

Upright versus upside-down faces: How interface attractiveness varies with orientation

A choice experiment is reported in which all pairs and triples of faces from a set of eight moderately attractive faces were presented, both upright and upside down, to 103 subjects. In each orientation, the subjects had to select the face that appeared more (pairs) or most (triples) attractive to them. For each orientation, the preference probabilities that arose from the pair and triple comparisons could be described by the BTL rule (Luce, 1959). Thus, each face was represented by two scores, one reflecting its attractiveness in the upright orientation and the other reflecting its attractiveness in the inverted orientation. Orientation affected the preference probabilities. Qualitatively, score ratios between faces decreased from upright to inverted orientation, suggesting that the faces became less discriminable by inversion. Quantitatively, the effect of inversion could be described by a simple rule that assumes a face’s two attractiveness scores to be affinely related across orientations. This result indicates that inversion affected all faces about equally. The present findings are discussed with respect to faces’ first- and second-order relational properties, a distinction emphasized in current theories of face perception. They suggest that the processing of first- and secondorder relational properties is impaired by inversion to roughly the same degree.     

面孔倒置效应的研究与理论述评

面孔倒置效应是指, 个体对倒置面孔的再认成绩显著低于对正立面孔的再认成绩, 而且, 与普通物体的倒置效应相比, 面孔的倒置效应更大。研究者们针对面孔倒置效应提出了多种理论假说, 两种主要的理论解释是：第一, 倒置面孔破坏了面孔的结构特征, 影响了面孔的整体加工, 所以, 个体对倒置面孔的再认成绩较差; 第二, 眼睛在面孔加工中起重要作用, 尤其在倒置面孔中的作用更明显, 使得倒置面孔N170波幅较高。ERP和fMRI研究提示, 未来研究需要进一步明确眼睛、注意等在面孔倒置效应中的作用。     

The Thatcher illusion and face processing in infancy

Adults readily detect changes in face patterns brought about by the inversion of eyes and mouth when the faces are viewed upright but not when they are viewed upside down. Research suggests that this illusion (the Thatcher illusion) is caused by the interfering effects of face inversion on the processing of second-order relational information (fine spatial information such as the distance between the eyes). In the current study, 6-month-olds discriminated 'thatcherized' faces when they were viewed upright but not when they were viewed upside down. These results are consistent with the notion that 6-month-olds are sensitive to second-order relational information while processing faces.     

The body-inversion effect

Researchers argue that faces are recognized via the configuration of their parts. An important behavioral finding supporting this claim is the face-inversion effect, in which inversion impairs recognition of faces more than nonface objects. Until recently, faces were the only class of objects producing the inversion effect for untrained individuals. This study investigated whether the inversion effect extends to human body positions, a class of objects whose exemplars are structurally similar to each other. Three experiments compared the recognition of upright and inverted faces, houses, and body positions using a forced-choice, same/different paradigm. For both reaction time and error data, the recognition of possible human body postures was more affected by inversion than the recognition of houses. Further, the recognition of possible human body postures and recognition of faces showed similar effects of inversion. The inversion effect was diminished for impossible body positions that violated the biomechanical constraints of human bodies. These data suggest that human body positions, like faces, may be processed configurally by untrained viewers.     

When inverted faces are recognized: The role of configural information in face recognition

The identification of upright faces seems to involve a special sensitivity to "configural" information, the processing of which is less effective when the face is inverted. However the precise meaning of "configural" remains unclear. Five experiments are presented, which showed that the disruption of the processing of relational, rather than holistic, information largely determines the occurrence as well as the size of the face-inversion effect. In Experiment 1, faces could be identified either by unique combinations of local information (e.g. a specific eye colour plus hair colour) or by unique relational information (e.g. nose-mouth distance). The former showed no inversion effect, whereas the latter did. A combination of local and relational information (Experiment 2) again produced an inversion effect, although this effect was smaller than that found when only relational information was used. The results were replicated in Experiment 3 when differences in the brightness of local features were used instead of specific colour combinations. Experiment 4 used different retrieval conditions to distinguish relational from holistic processing, and demonstrated again that spatial relations between single features appeared to provide crucial information for face recognition. In Experiment 5, the importance of relational information was confirmed using faces that also varied in the shapes of local features.     

Are faces perceived as configurations more by adults than by children?

Abstract

Adult face recognition is severely hampered by stimulus inversion. Several investigators have attributed this vulnerability to the effect of orientation on encoding relational aspects of faces. Previous work has also demonstrated that children are less sensitive to orientation of faces than are adults. This has been interpreted as reflecting an increasing reliance on configural aspects of faces with increasing age and expertise.

Young, Hellawell, and Hay (1987) demonstrated that for adults the encoding of relations among facial parts is, indeed, sensitive to orientation. When chimeric faces are upright, the top half of one face fuses with the bottom half of the other, making the person depicted in the top half difficult to recognize. This effect (the composite effect) is not seen when the faces are inverted. The present study obtained the composite effect for 6-year-old and 10-year-old children, just as for adults. The composite effect was found to an equal degree at all ages tested and was seen both in tasks involving highly familiar faces and in those involving newly learned, previously unfamiliar faces. Thus, these data provided no support for the hypothesis of increasing reliance on configural aspects of faces with increasing age, at least in the sense tapped by this procedure.

However, the data did confirm an Age X Orientation interaction. In recognizing both familiar and previously unfamiliar faces, 6-year-olds were less affected by inversion than were 10-year-olds, who, in turn, were less affected than were adults. Increasing vulnerability to inversion of faces with age was independent of the composite effect. Apparently, there are two distinct sources to the large effect of inversion that characterizes adult face encoding: one seen throughout development and one acquired only with expertise.     

Three studies on configural face processing by chimpanzees

Previous studies have demonstrated the sensitivity of chimpanzees to facial configurations. Three studies further these findings by showing this sensitivity to be specific to second-order relational properties. In humans, this type of configural processing requires prolonged experience and enables subordinate-level discriminations of many individuals. Chimpanzees showed evidence of a composite-like effect for conspecific but not human faces despite extensive experience with humans. Chimpanzee face recognition was impaired only when manipulations targeted second-order properties. Finally, face processing was impaired when individual features were blurred through pixelation. Results confirm that chimpanzee face discrimination, like humans, depends on the integrity of second-order relational properties.     

Compensation of neural delays in visual‐motor behaviour: No evidence for shorter afferent delays for visual motion

Abstract

Faces and other objects that share a configuration present a special problem to the visual system. Two components of the visual system's solution to this homogeneity problem have been identified. Inversion studies have identified the use of relational features (Diamond &; Carey, 1986; Rhodes, Brake, &; Atkinson, 1993), and caricature studies have identified norm-based coding (Carey, Rhodes, Diamond, &; Hamilton, in preparation; Rhodes, Brennan, &; Carey, 1987; Rhodes &; McLean, 1990). Here we explore a possible link between these two components, asking whether caricature effects depend selectively on exaggeration of relational features. If so, then inversion, which makes relational features particularly difficult to code (compared with isolated features), should reduce caricature effects. In three experiments we found a caricature equivalence effect (caricatures identified as accurately as undistorted images and both better than anticaricatures) that was unaffected by orientation, suggesting that relational feature coding is not necessary for caricatures to be effective. Therefore, caricature and inversion effects reflect distinct components of face recognition. Caricature level and orientation also interacted differently with other factors, as would be expected if their effects depend upon different underlying processes. For one set of faces there was a caricature advantage in accuracy (Experiments 1 and 3). This superportrait effect occurred even for subjects who were unfamiliar with the faces prior to the experiment (Experiment 3), a result with important forensic implications. Furthermore, the effect was restricted to upright faces. Therefm, although caricatures can be recognized as well as undistorted images whatever features are exaggerated, exaggeration of relational features may be needed for a superportrait effect.     

Mental rotation of faces

The effect of orientation upon face recognition was explored in two experiments, which used a procedure adapted from the mental rotation literature. In the first experiment, a linear increase in the RT of same-different judgments was found as the second of a pair of sequentially presented faces was rotated away from the vertical. Also, it was found that the effect of changing facial expression did not interact with orientation. In the second experiment, a linear relationship between RT and orientation was found in a task involving the recognition of famous faces. This recognition task was found to be more affected by inversion than was an expression classification task. These results are interpreted as evidence against the view that inverted faces are processed in a qualitatively different manner from upright faces, and are also inconsistent with the hypothesis that inversion makes faces difficult to recognize because facial expression cannot be extracted from an inverted face.     

The development of expert face processing: are infants sensitive to normal differences in second-order relational information?

Sensitivity to second-order relational information (i.e., spatial relations among features such as the distance between eyes) is a vital part of achieving expertise with face processing. Prior research is unclear on whether infants are sensitive to second-order differences seen in typical human populations. In the current experiments, we examined whether infants are sensitive to changes in the space between the eyes and between the nose and the mouth that are within the normal range of variability in Caucasian female faces. In Experiment 1, 7-month-olds detected these changes in second-order relational information. Experiment 2 extended this finding to 5-month-olds and also found that infants detect second-order relations in upright faces but not in inverted faces, thereby exhibiting an inversion effect that has been considered to be a hallmark of second-order relational processing during adulthood. These results suggest that infants as young as 5 months are sensitive to second-order relational changes that are within the normal range of human variability. They also indicate that at least rudimentary aspects of face processing expertise are available early in life.     

An inversion effect modified by expertise in capuchin monkeys

The face inversion effect may be defined as the general impairment in recognition that occurs when faces are rotated 180°. This phenomenon seems particularly strong for faces as opposed to other objects and is often used as a marker of a specialized face-processing mechanism. Four brown capuchin monkeys (Cebus apella) were tested on their ability to discriminate several classes of facial and non-facial stimuli presented in both their upright and inverted orientations in an oddity task. Results revealed significantly better performance on upright than inverted presentations of capuchin and human face stimuli, but not on chimpanzee faces or automobiles. These data support previous studies in humans and other primates suggesting that the inversion effect occurs for stimuli for which subjects have developed an expertise.     

Explaining the face-inversion effect: the face–scheme incompatibility (FSI) model

The face-inversion effect (FIE) can be viewed as being based on two kinds of findings. According to the face(UI) effect, perception and recognition are better for faces presented upright (U) than for faces presented inverted (I). According to the face/object(UI) effect, inversion impairs the processing of faces more than the processing of nonfacial objects (e.g., buildings or cars). Part I of this article focuses on the face(UI) effect and the configural-processing hypothesis, which is considered the most popular explanatory hypothesis of the FIE. In this hypothesis, it is proposed that inversion impairs the processing of configural information (the spatial relations between features) but hardly (if at all) impairs the processing of featural information (e.g., eyes, nose, and mouth). Part II of the article starts from the conclusion reached in part I, that the configural-processing hypothesis has not succeeded in explaining a substantial number of the findings and in resolving certain theoretical problems. The part then goes on to outline a new alternative model, the face–scheme incompatibility (FSI) model, which contends with these theoretical problems, accounts for the configural-processing hypothesis, succeeds in explaining a considerable portion of the empirical findings related to the face(UI) effect, and proposes a relatively new research program on the concept of the face scheme. The basic assumption of the FSI model is that schemes and prototypes are involved in processing a visual stimulus of a face and in transforming it to a “meaning-bearing” face, and that different schemes are involved if the face is presented upright or inverted.     

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.     

Older adults' configural processing of faces: role of second-order information

Problems with face recognition are frequent in older adults. However, the mechanisms involved have only been partially discovered. In particular, it is unknown to what extent these problems may be related to changes in configural face processing. Here, we investigated the face inversion effect (FIE) together with the ability to detect modifications in the vertical or horizontal second-order relations between facial features. We used a same/different unfamiliar face discrimination task with 33 young and 33 older adults. The results showed dissociations in the performances of older versus younger adults. There was a lack of inversion effect during the recognition of original faces by older adults. However, for modified faces, older adults showed a pattern of performance similar to that of young participants, with preserved FIE for vertically modified faces and no detectable FIE for horizontally modified faces. Most importantly, the detection of vertical modifications was preserved in older relative to young adults whereas the detection of horizontal modifications was markedly diminished. We conclude that age has dissociable effects on configural face-encoding processes, with a relative preservation of vertical compared to horizontal second-order relations processing. These results help to understand some divergent results in the literature and may explain the spared familiar face identification abilities in the daily lives of older adults.