Social cognition and the human brain

Humans are exceedingly social animals, but the neural underpinnings of social cognition and behavior are not well understood. Studies in humans and other primates have pointed to several structures that play a key role in guiding social behaviors: the amygdala, ventromedial frontal cortices, and right somatosensory-related cortex, among others. These structures appear to mediate between perceptual representations of socially relevant stimuli, such as the sight of conspecifics, and retrieval of knowledge (or elicitation of behaviors) that such stimuli can trigger. Current debates concern the extent to which social cognition draws upon processing specialized for social information, and the relative contributions made to social cognition by innate and acquired knowledge.     

Infants' ability to match dynamic phonetic and gender information in the face and voice.

Six experiments tested young infants' sensitivity to vowel and gender information in dynamic faces and voices. Infants were presented with side-by-side displays of two faces articulating the vowels /a/ or /i/ in synchrony. The heard voice matched the gender of one face in some studies and the vowel of one face in other studies and, in some studies, vowel and gender were placed in conflict. Infants of age 4.5 months showed no evidence of matching face and voice on the basis of gender, but were able to ignore irrelevant gender information and match on the basis of the vowel. Robust evidence of the ability to match on the basis of gender was not evident until 8 months of age. This set of findings suggests that, when identical stimuli are used, gender matching does not emerge until a later age than does phonetic matching. Results are discussed in relation to key theories of intermodal development.     

识别名人与陌生人面孔的功能磁共振成像

探讨名人与陌生人身份判断的脑功能。6名被试参加实验,运用功能磁共振技术采集数据,AFNI软件进行统计处理。实验结果显示,名人面孔身份识别主要激活了额颞区和梭状回等,陌生人面孔识别主要激活了脑岛和梭状回。实验表明,熟悉名人面孔与陌生人面孔识别有其不同的区域;都有梭状回的视觉加工,但是激活的程度不同。     

情绪面孔搜索不对称性：情绪观与知觉观的争议

情绪面孔搜索不对称性是指当负性情绪面孔作为目标, 正性情绪面孔作为分心物时, 其搜索速度比正性情绪面孔作为目标时(负性情绪面孔作为分心物)更快。对于这一现象的解释存在争议, 研究者主要从不同情绪面孔在情绪因素和知觉因素两个方面的差异进行解释。来自行为研究和认知神经科学的证据对情绪面孔搜索不对称性效应的解释主要有威胁性刺激捕获假设和情绪摆脱假设的情绪观, 以及嘴部差异说、闭合结构说、知觉组群说以及其他面部特征假设的知觉观。经过对比评价两类观点的理论异同和实验证据认为未来的研究可以整合情绪因素和知觉因素来解释该效应。     

Research on face recognition: The Aberdeen influence

The review of ‘Recognizing faces’ by Hadyn Ellis, published in the British Journal of Psychology in 1975, marked the genesis of a distinct field of research. This seminal review sprang from a broader programme of research on face recognition conducted at the University of Aberdeen, whose influence continues to be felt in what has become an internationally important research area. We discuss the background to the Aberdeen research, summarize some of its achievements, and offer reasons why it proved so successful. These reasons include the synergy between theory and practice‐based studies, the value of combining different perspectives and sources of evidence, sound techniques that led to easily reproducible findings, and the emphasis on testing even the most ‘common sense’ assumptions.     

Angry faces are more resistant to forgetting than are happy faces: directed forgetting effects on the identity of emotional faces

Using the item-method directed forgetting paradigm (i.e. intentionally forgetting specified information), we examined directed forgetting of facial identity as a function of facial expression and the sex of the expresser and perceiver. Participants were presented with happy and angry male and female faces cued for either forgetting or remembering, and were then asked to recognise previously studied faces from among a series of neutral faces. For each recognised test face, participants also recalled the face’s previously displayed emotional expression. We found that angry faces were more resistant to forgetting than were happy faces. Furthermore, angry expressions on male faces and happy expressions on female faces were recognised and recalled better than vice versa. Signal detection analyses revealed that male faces gave rise to a greater sensitivity than female faces did, and male participants, but not female participants, showed greater sensitivity to male faces than to female faces. Several theoretical implications are discussed.     

Can holistic processing be learned for inverted faces?

The origin of "special" processing for upright faces has been a matter of ongoing debate. If it is due to generic expertise, as opposed to having some innate component, holistic processing should be learnable for stimuli other than upright faces. Here we assess inverted faces. We trained subjects to discriminate identical twins using up to 1100 exposures to each twin in different poses and images. In the upright orientation, twin discrimination was supported by holistic processing. Removal of a single face feature had no effect on performance, and a composite effect (Young, A. W., Hellawell, D., & Hay, D.C. (1987). Configurational information in face perception. Perception 16 (6), 747-759) was obtained. In the inverted orientation, however, above chance identification ability relied on (a) image specific learning, or (b) tiny local feature differences not noticed in the upright faces. The failure to learn holistic processing for inverted faces indicates that, in contrast to the situation for objects (Tarr, M.J., & Pinker, S. (1989). Mental rotation and orientation-dependence in shape recognition. Cognitive Psychology 21 (2), 233-282), orientation specificity of face processing is highly stable against practice.     

Domain specificity versus expertise: factors influencing distinct processing of faces

To explore face specificity in visual processing, we compared the role of task-associated strategies and expertise on the N170 event-related potential (ERP) component elicited by human faces with the ERPs elicited by cars, birds, items of furniture, and ape faces. In Experiment 1, participants performed a car monitoring task and an animacy decision task. In Experiment 2, participants monitored human faces while faces of apes were the distracters. Faces elicited an equally conspicuous N170, significantly larger than the ERPs elicited by non-face categories regardless of whether they were ignored or had an equal status with other categories (Experiment 1), or were the targets (in Experiment 2). In contrast, the negative component elicited by cars during the same time range was larger if they were targets than if they were not. Furthermore, unlike the posterior-temporal distribution of the N170, the negative component elicited by cars and its modulation by task were more conspicuous at occipital sites. Faces of apes elicited an N170 that was similar in amplitude to that elicited by the human face targets, albeit peaking 10 ms later. As our participants were not ape experts, this pattern indicates that the N170 is face-specific, but not specie-specific, i.e. it is elicited by particular face features regardless of expertise. Overall, these results demonstrate the domain specificity of the visual mechanism implicated in processing faces, a mechanism which is not influenced by either task or expertise. The processing of other objects is probably accomplished by a more general visual processor, which is sensitive to strategic manipulations and attention.     

Vigilance for threat: effects of anxiety and defensiveness

Eysenck’s (1997) theory that attentional biases for threat vary as an interactive function of trait anxiety and defensiveness was tested using a visual probe task. Two stimulus exposure conditions were used to explore a secondary issue concerning attentional allocation over time. Results indicated that, among high trait anxious participants, only those with low levels of defensiveness showed vigilance for threatening faces presented for 500 ms. They also showed an attentional preference for neutral faces, relative to happy faces, irrespective of exposure condition. This pattern was reversed in high trait anxious participants with high levels of defensiveness, who showed an attentional bias towards happy faces (relative to neutral faces) under both exposure conditions. The findings are discussed in relation to their implications for (a) the significance of measures of defensiveness for the conceptualization of high trait anxious individuals, and (b) the status of anxiety-related biases at different stages of information processing.     

Sex differences in face processing: Are women less lateralized and faster than men?

The aim of this study was to determine the influence of sex on hemispheric asymmetry and cooperation in a face recognition task. We used a masked priming paradigm in which the prime stimulus was centrally presented; it could be a bisymmetric face or a hemi-face in which facial information was presented in the left or the right visual field and projected to the right or the left hemisphere. The target stimulus was always a bisymmetric face presented centrally. Faces were selected from Minear and Park’s (2004) database. Fifty-two right-handed students (26 men, 26 women) participated in this experiment, in which accuracy (percentage of correct responses) and reaction times (RTs in ms) were measured. Although accuracy data showed that the percentage of correct recognition – when prime and target matched – was equivalent in men and women, men’s RTs were longer than women’s in all conditions. Accuracy and RTs showed that men are more strongly lateralized than women, with right hemispheric dominance. These results suggest that men are as good at face recognition as women, but there are functional differences in the two sexes. The findings are discussed in terms of functional cerebral networks distributed over both hemispheres and of interhemispheric transmission.