New Developments in Understanding Emotional Facial Signals in Chimpanzees

ABSTRACT— There has been little research over the past few decades focusing on similarities and differences in the form and function of emotional signals in nonhuman primates, or whether these communication systems are homologous with those of humans. This is, in part, due to the fact that detailed and objective measurement tools to answer such questions have not been systematically developed for nonhuman primate research. Despite this, emotion research in humans has benefited for over 30 years from an objective, anatomically based facial-measurement tool: the Facial Action Coding System (FACS). In collaboration with other researchers, we have now developed a similar system for chimpanzees (ChimpFACS) and, in the process, have made exciting new discoveries regarding chimpanzees' perception and categorization of emotional facial expressions and similarities in the facial anatomy of chimpanzees and humans, and we have identified homologous facial movements in the two species. Investigating similarities and differences in primate emotional communication systems is essential if we are to understand unique evolutionary specializations among different species.     

Blushing during social interactions in people with a fear of blushing

Changes in facial blood flow were investigated during an introductory conversation, delivering a speech, and listening to the speech afterwards in 16 people with a fear of blushing and 16 controls. It was hypothesized that fear of blushing would be associated with high ratings of self-reported blushing intensity and embarrassment during the tasks, and with persistence of the blushing reaction between tasks. Embarrassment and self-reported blushing intensity were greater in the fear-of-blushing group than in controls throughout the experiment. Increases in facial blood flow were similar in the two groups during each of the tasks. However, blushing dissipated more slowly after each task in the fear-of-blushing group than in controls, resulting in an incremental increase in facial blood flow over the course of the experiment. The slow recovery after an episode of blushing might result in physiological or social cues that help to maintain a fear of blushing.     

Jumping to interpretations: social anxiety disorder and the identification of emotional facial expressions

A small body of research suggests that socially anxious individuals show biases in interpreting the facial expressions of others. The current study included a clinically anxious sample in a speeded emotional card-sorting task in two conditions (baseline and threat) to investigate several hypothesized biases in interpretation. Following the threat manipulation, participants with generalized social anxiety disorders (GSADs) sorted angry cards with greater accuracy, but also evidenced a greater rate of neutral cards misclassified as angry, as compared to nonanxious controls. The controls showed the opposite pattern, sorting neutral cards with greater accuracy but also misclassifying a greater proportion of angry cards as neutral, as compared to GSADs. These effects were accounted for primarily by low-intensity angry cards. Results are consistent with previous studies showing a negative interpretive bias, and can be applied to the improvement of clinical interventions.     

Detection of emotional expressions in rapidly changing facial displays in high- and low-socially anxious women

Facial information and attention to facial displays are distributed over spatial as well as temporal domains. Thus far, research on selective attention to (dis)approving faces in the context of social anxiety has concentrated primarily on the spatial domain. Using a rapid serial visual presentation (RSVP) paradigm, the present study examined the temporal characteristics of visual attention for happy and angry faces in high- (n=16) and low-socially anxious individuals (n=17), to test whether also in the temporal domain socially anxious individuals are characterized by threat-confirming attentional biases. Results indicated that presenting angry faces as the first target (T1) did not aggravate the detection of the emotional expression of the second target (T2). Yet, participants generally showed superior detection of the emotional expression of T2, if T2 was an angry face. Casting doubt on the role of such attenuated attentional blink for angry faces in social anxiety, no evidence emerged to indicate that this effect was relatively strong in high-socially anxious individuals. Finally, the presentation of an angry face as T2 resulted in a relatively hampered identification of a happy-T1. Again, this "backward blink" was not especially pronounced in high-socially anxious individuals. The present anger superiority effects are consistent with evolutionary models stressing the importance of being especially vigilant for signals of dominance. Since the effects were not especially pronounced in high-anxious individuals, the present study adds to previous findings indicating that socially anxious individuals are not characterized by a bias in the (explicit) detection of emotional expressions [Philippot, P., & Douilliez, C. (2005). Social phobics do not misinterpret facial expression of emotion. Behaviour Research and Therapy, 43, 639-652].     

Anxiety-related biases in children's avoidant responses to a masked angry face

While anxious children often show escape and withdrawal behaviours towards threats, few studies have experimentally assessed avoidance. The present study examined whether children with high levels of anxiety showed more avoidant responses to a neutral conditioned cue (CS+) that was paired with an unconditioned threat stimulus (UCS), a masked angry facial expression. Thirty-six 10 and 11 year-olds participated in a task, which involved choosing between two CS card stimuli of different colours to win points. Whilst both cards awarded the same number of points, one colour was systematically paired with a masked angry face (CS+), whilst the other colour was paired with a masked neutral face (CS-). Children with higher anxiety scores had an overall tendency to choose the card associated with the neutral face, with some evidence suggesting that this tendency emerged gradually across trials. These results suggest a relationship between anxiety and stimulus-response learning for CS+-UCS associations that support behavioural avoidance.     

Infants perceive human point-light displays as solid forms

While five-month-old infants show orientation-specific sensitivity to changes in the motion and occlusion patterns of human point-light displays, it is not known whether infants are capable of binding a human representation to these displays. Furthermore, it has been suggested that infants do not encode the same physical properties for humans and material objects. To explore these issues we tested whether infants would selectively apply the principle of solidity to upright human displays. In the first experiment infants aged six and nine months were repeatedly shown a human point-light display walking across a computer screen up to 10 times or until habituated. Next, they were repeatedly shown the walking display passing behind an in-depth representation of a table, and finally they were shown the human display appearing to pass through the table top in violation of the solidity of the hidden human form. Both six- and nine-month-old infants showed significantly greater recovery of attention to this final phase. This suggests that infants are able to bind a solid vertical form to human motion. In two further control experiments we presented displays that contained similar patterns of motion but were not perceived by adults as human. Six- and nine-month-old infants did not show recovery of attention when a scrambled display or an inverted human display passed through the table. Thus, the binding of a solid human form to a display in only seems to occur for upright human motion. The paper considers the implications of these findings in relation to theories of infants' developing conceptions of objects, humans and animals.     

客体的视觉工作记忆研究进展

近年来,客体信息的视觉工作记忆问题引发了大量研究,并获得不少成果。本文对视觉工作记忆的研究范式,客体在视觉工作记忆中的存储方式、容量及保持时间等相关研究进行了概述,重点介绍关于视觉工作记忆存储单元和容量问题的"强客体"假设、"弱客体"假设和双重存储机制假设,并提出进一步的研究思路。     

面孔识别动态增益效应研究综述

近年来,研究者围绕动态面孔识别中的动态增益效应开展了一系列的研究。本文围绕面孔熟悉程度和面孔的活动类型两个方面对与动态增益效应有关的一系列动态面孔认知研究进行了总结,并对不同研究的差异进行了比较和分析。最后,对动态面孔认知规律、眼动模式和脑机制等研究方向上的发展进行了展望。     

Anticipating intentional actions: The effect of eye gaze direction on the judgment of head rotation

Using a representational momentum paradigm, this study investigated the hypothesis that judgments of how far another agent’s head has rotated are influenced by the perceived gaze direction of the head. Participants observed a video-clip of a face rotating 60° towards them starting from the left or right profile view. The gaze direction of the face was either congruent with, ahead of, or lagging behind the angle of rotation. Following this, two static faces, at varying angles of rotation with respect to the end-point angle of the face in the video-clip, were presented simultaneously. The task of the participants was to decide which of the two heads was at an angle best resembling the angle of the end-point of the moving face. The critical test condition consisted of one test face oriented at 10° before, and the other at 10° after the end-point. The ‘lagging behind’ gaze condition elicited a significant underestimation of the rotation compared to the ‘congruent’ and ‘ahead’ gaze conditions. Participants did not exhibit similar biases when judging the rotation of several non-face control stimuli with visual features that mimicked different aspects of gaze direction. The findings suggest that when the gaze direction of a perceived agent is incongruent with the direction of the agent’s head motion observers automatically utilise this discrepancy to adjust their inferences about the agent’s intended heading direction.