The role of high spatial frequencies in face perception

The relevance of low and high spatial-frequency information for the recognition of photographs of faces has been investigated by testing recognition of faces that have been either low-pass (LP) or high-pass (HP) filtered in the spatial-frequency domain. The highest resolvable spatial frequency was set at 15 cycles per face width (cycles fw-1). Recognition was much less accurate for images that contained only the low spatial frequencies (up to 5 cycles fw-1) than for images that contained only spatial frequencies higher than 5 cycles fw-1. For faces HP filtered above 8 cycles fw-1, recognition was almost as accurate as for faces LP filtered below 8 cycles fw-1, although the energy content of the latter greatly exceeded that of the former. These findings show that information conveyed by the higher spatial frequencies is not redundant. Rather, it is sufficient by itself to ensure recognition.     

The perception of face gender: The role of stimulus structure in recognition and classification

The perception of face gender was examined in the context of extending “face space” models of human face representations to include the perceptual categories defined by male and female faces. We collected data on the recognizability, gender classifiability (reaction time to classify a face as male/female), attractiveness, and masculinity/femininity of individual male and female faces. Factor analyses applied separately to the data for male and female faces yielded the following results. First, for both male and female faces, the recognizability and gender classifiability of faces were independent—a result inconsistent with the hypothesis that both recognizability and gender classifiability depend on a face’s “distance” from the subcategory gender prototype. Instead, caricatured aspects of gender (femininity/masculinity ratings) related to the gender classifiability of the faces. Second, facial attractiveness related inversely to face recognizability for male, but not for female, faces—a result that resolves inconsistencies in previous studies. Third, attractiveness and femininity for female faces were nearly equivalent, but attractiveness and masculinity for male faces were not equivalent. Finally, we applied principal component analysis to the pixel-coded face images with the aim of extracting measures related to the gender classifiability and recognizability of individual faces. We incorporated these model-derived measures into the factor analysis with the human rating and performance measures.     

The role of the amygdala in visual awareness

Pessoa and colleagues recently reported the novel finding that objective awareness of a negative stimulus is associated with coactivation of the amygdala and fusiform gyrus. Based on the neuroanatomical connections of the amygdala, we suggest that the amygdala is acting to increase neural activity in the fusiform gyrus, thereby increasing the likelihood that visual representations that have affective value reach awareness. The psychological consequence is that a person's momentary affective state might help to select the contents of conscious experience.     

The role of the amygdala in the appraising brain

Lindquist et al. convincingly argue that the brain implements psychological operations that are constitutive of emotion rather than modules subserving discrete emotions. However, the nature of such psychological operations is open to debate. I argue that considering appraisal theories may provide alternative interpretations of the neuroimaging data with respect to the psychological operations involved.     

The role of the amygdala in conditioned flavor preference

Long-Evans rats with control or amygdala lesions were tested in a conditioned flavor preference task. Half of the rats in each lesion group received an unsweetened grape-flavored solution on odd-numbered days and a sweetened cherry-flavored solution on even-numbered days. The remaining rats received a sweetened grape-flavored solution on odd-numbered days and an unsweetened cherry-flavored solution on even-numbered days. The appropriate solution was presented once a day for 15 min to each rat in the homecage. After six days of testing, each rat received unsweetened cherry and grape flavored solutions simultaneously for 15 min daily across four days. When the two unsweetened flavored solutions were presented simultaneously control rats showed a significant preference for the flavor that was sweetened during training compared to the unsweetened solution. However, amygdala-lesioned rats did not show a preference. The data suggest that the amygdala may be critically involved in mediating reward-based conditioned flavor preference.     

The role of the mother's voice in developing mother's face preference: Evidence for intermodal perception at birth

Four experiments are described which investigated the role of the mother's voice in facilitating recognition of the mother's face at birth. Experiment 1 replicated our previous findings (Br. J. Dev. Psychol. 1989; 7: 3–15; The origins of human face perception by very young infants. Ph.D. Thesis, University of Glasgow, Scotland, UK, 1990) indicating a preference for the mother's face when a control for the mother's voice and odours was used only during the testing. A second experiment adopted the same procedures, but controlled for the mother's voice from birth through testing. The neonates were at no time exposed to their mother's voice. Under these conditions, no preference was found. Further, neonates showed only few head turns towards both the mother and the stranger during the testing. Experiment 3 looked at the number of head turns under conditions where the newborn infants were exposed to both the mother's voice and face from birth to 5 to 15 min prior to testing. Again, a strong preference for the mother's face was demonstrated. Such preference, however, vanished in Experiment 4, when neonates had no previous exposure to the mother's voice–face combination. The conclusion drawn is that a prior experience with both the mother's voice and face is necessary for the development of face recognition, and that intermodal perception is evident at birth. The neonates' ability to recognize the face of the mother is most likely to be rooted in prenatal learning of the mother's voice. Copyright © 2004 John Wiley & Sons, Ltd.     

The electrophysiological correlates of integrated face and body-part perception

Previous studies have suggested that the human visual system processes faces and bodies holistically—that is, the different body parts are integrated into a unified representation. However, the time course of this integrative process is less known. In the present study, we investigated this issue by recording event-related potentials evoked by a face and two hands presented simultaneously and in different configurations. When the hands were rotated to obtain a biologically implausible configuration, a reduction of the P2 amplitude was observed relative to the condition in which the face and hands were retained in their veridical configuration and were supplemented with visual cues to highlight further the overall body posture. Our results show that the P2 component is sensitive to manipulations affecting the configuration of face and hand stimuli and suggest that the P2 reflects the operation of perceptual mechanisms responsible for the integrated processing of visually presented body parts.     

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.     

Integrating face and voice in person perception

Integration of information from face and voice plays a central role in our social interactions. It has been mostly studied in the context of audiovisual speech perception: integration of affective or identity information has received comparatively little scientific attention. Here, we review behavioural and neuroimaging studies of face-voice integration in the context of person perception. Clear evidence for interference between facial and vocal information has been observed during affect recognition or identity processing. Integration effects on cerebral activity are apparent both at the level of heteromodal cortical regions of convergence, particularly bilateral posterior superior temporal sulcus (pSTS), and at 'unimodal' levels of sensory processing. Whether the latter reflects feedback mechanisms or direct crosstalk between auditory and visual cortices is as yet unclear.     

What's in a face: Individual differences in face perception

White and black females judged the similarity of all pairs of white and black male faces. An individual difference multidimensional scaling analysis of the similarity judgments indicated that most of the dimensions underlying the perceptions of male faces involved affective (honest, tense, attractive) characteristics rather than simple physical features (eye width, mouth height). The major physical dimension was face shape (long vs. wide). The dimensions were similar for black and white subjects. An individual difference hypothesis that we pay attention to those characteristics that we possess was partially confirmed.     

The distributed human neural system for face perception

Face perception, perhaps the most highly developed visual skill in humans, is mediated by a distributed neural system in humans that is comprised of multiple, bilateral regions. We propose a model for the organization of this system that emphasizes a distinction between the representation of invariant and changeable aspects of faces. The representation of invariant aspects of faces underlies the recognition of individuals, whereas the representation of changeable aspects of faces, such as eye gaze, expression, and lip movement, underlies the perception of information that facilitates social communication. The model is also hierarchical insofar as it is divided into a core system and an extended system. The core system is comprised of occipitotemporal regions in extrastriate visual cortex that mediate the visual analysis of faces. In the core system, the representation of invariant aspects is mediated more by the face-responsive region in the fusiform gyrus, whereas the representation of changeable aspects is mediated more by the face-responsive region in the superior temporal sulcus. The extended system is comprised of regions from neural systems for other cognitive functions that can be recruited to act in concert with the regions in the core system to extract meaning from faces.     

Environmental inversion effects in face perception

Visual processing is highly sensitive to stimulus orientation; for example, face perception is drastically worse when faces are oriented inverted vs. upright. However, stimulus orientation must be established in relation to a particular reference frame, and in most studies, several reference frames are conflated. Which reference frame(s) matter in the perception of faces? Here we describe a simple, novel method for dissociating effects of egocentric and environmental orientation on face processing. Participants performed one of two face-processing tasks (expression classification and recognition memory) as they lay horizontally, which served to disassociate the egocentric and environmental frames. We found large effects of egocentric orientation on performance and smaller but reliable effects of environmental orientation. In a follow-up control experiment, we ruled out the possibility that the latter could be explained by compensatory ocular counterroll. We argue that environmental orientation influences face processing, which is revealed when egocentric orientation is fixed.     

The role of eyebrows in face recognition

A fundamental challenge in face recognition lies in determining which facial characteristics are important in the identification of faces. Several studies have indicated the significance of certain facial features in this regard, particularly internal ones such as the eyes and mouth. Surprisingly, however, one rather prominent facial feature has received little attention in this domain: the eyebrows. Past work has examined the role of eyebrows in emotional expression and nonverbal communication, as well as in facial aesthetics and sexual dimorphism. However, it has not been made clear whether the eyebrows play an important role in the identification of faces. Here, we report experimental results which suggest that for face recognition the eyebrows may be at least as influential as the eyes. Specifically, we find that the absence of eyebrows in familiar faces leads to a very large and significant disruption in recognition performance. In fact, a significantly greater decrement in face recognition is observed in the absence of eyebrows than in the absence of eyes. These results may have important implications for our understanding of the mechanisms of face recognition in humans as well as for the development of artificial face-recognition systems.     

The face and person perception: insights from social cognition

Social-cognitive investigations of face perception have tended to be motivated by different goals than cognitive and neuropsychological studies-namely, to understand the dynamics of social categorization rather than identity recognition-and the result has been a lack of cross-pollination of insights and ideas between the disciplines. We review the evidence from social cognition, with an eye to discussing how this work aligns with the Bruce and Young (1986) model of face recognition. Acknowledging the invaluable impact the model has exerted on our understanding of face recognition, we suggest that considering the bottom-up constraints of visual processing and the top-down influences of semantic knowledge will contribute to a more comprehensive understanding of face perception.     

情绪概念加工与情绪面孔知觉的相互影响

通过3个实验探讨情绪概念加工与情绪面孔知觉是否存在相互影响, 以及加工深度对两者关系的影响。实验1采用情绪面孔启动范式, 探讨较深的情绪概念加工层面对情绪概念与情绪面孔的关系的影响。实验2更改概念任务, 探讨较浅的概念加工层面对两者关系的影响。实验3缩短启动面孔呈现时间, 探讨较浅的面孔知觉层面对两者关系的影响。通过研究主要得出以下结论：(1)情绪概念加工与情绪面孔知觉确实存在相互影响; (2)概念加工深度影响两者关系的方向性, 在较深的概念加工层面, 两者的关系是双向的, 在较浅的概念加工层面, 两者的关系是单向的; (3)知觉加工深度也影响两者关系的方向性, 在较深的知觉加工层面, 两者的关系是双向的, 在较浅的知觉加工层面, 没有发现两者的相互影响。本研究为抽象概念的具身表征提供了实证支持。     

Interference resolution in face perception and name retrieval

Selective retrieval is a rather difficult task, and especially so when one attempts to retrieve personal representations such as faces or names. Retrieval of memories under strong competition conditions is pervasive in human memory and some have suggested that inhibitory control is used to overcome interference between competing stimuli. In the present study, we used the retrieval practice paradigm to investigate if competition among personal representations (such as facial features and names) is also resolved by inhibitory mechanisms. This question is theoretically relevant, since personal representations have been said to have a special status on cognition. Moreover, some models of face recognition assume that interference can arise between different representations, but that this interference would be automatically and rapidly solved, with no need for a controlled inhibitory mechanism to act. In two experiments we showed RIF for facial features and familiar names, but only when participants had to actively retrieve some information. This suggests that personal information is subject to mechanisms of inhibitory control, which could help explain everyday life difficulties in processes such as face feature recognition or name retrieval.     

The role of attention and familiarity in face identification

How is attention allocated during face identification? Previous work using famous and unfamiliar faces suggests that either no attention or a special attentional mechanism is required. We used a conventional attentional blink (AB) procedure to measure face identification with temporarily reduced attention. The participants viewed a rapid series of face images with one embedded nonface abstract pattern (T1). They judged the texture of T1 and then detected a prespecified face (T2) presented at varying lags after T1. T2 was either famous or unfamiliar, as were distractor faces. Regardless of distractor type, detection of an unfamiliar T2 face was significantly impaired at short versus long T1-T2 lags, indicating an attentional requirement for face identification. Detection of a famous T2 face was unaffected by lag, suggesting that familiarity protects against atemporal attentional bottleneck These findings do not support propositions that face identification is "special" in its need for attentional control