Of snakes and faces: An evolutionary perspective on the psychology of fear

Snakes and faces are unique stimuli because they are deeply grounded in evolutionarily shaped behavior systems. Snakes are the prototypical stimulus in a predatory defense system promoting escape from predators, which prepares primates for efficient processing, attentional priority, and rapid fear acquisition to snakes and other stimuli related to predation. The social submissiveness system plays a similar role on the social arena by promoting yielding to dominant individuals without jeopardizing the protection of the group. Supporting these theoretical propositions, empirical data from a research program spanning four decades demonstrate enhanced fear conditioning to snakes and threatening faces compared to neutral stimuli, as well as fast nonconscious processing of, and prioritized attention to, snakes and threatening faces. Human brain‐imaging data show that these effects are mediated by an extensive fear‐network centering on the amygdala.     

The reduction of anxiety in children: a comparison of the effects of 'systematic desensitization in vitro' and 'systematic desensitization in vivo'

Twenty-four children between the ages of 5 and 10. selected on the basis of fear of water, as determined by parents and swimming teachers, were divided into two experimental groups and one control group. One of the experimental groups was treated with four sessions of in vitro desensitization (gradual imaginal exposure to fear evoking stimuli plus relaxation), followed by four sessions of in vivo desensitization (real-life exposure to fear evoking stimuli plus relaxation). The other group received eight sessions of in vivo desensitization. The control group took part only in the tests, which were administered at the commencement of treatment, after four sessions, and at the end of the course of treatments. In testing, a behavior observation record was used to score the subject's behavior in the given situation; in addition, two teacher's records were used, in which swimming teachers recorded their evaluation of the subject's anxiety in each situation.Better results were achieved by desensitization in vivo than by desensitizalion in vitro or by the control procedure. No differences were found between the latter two groups. It could not be demonstrated that desensitization in vitro increased the effectiveness of subsequent desensitization in vivo     

对威胁刺激的碰撞时间估计

对靠近运动刺激的碰撞时间(time-to-collision, TTC)估计具有重要的进化意义。为了解释个体如何进行TTC估计, 研究者提出了结构主义理论、生态光学理论和tau理论等, 也考察了影响TTC估计的部分因素。近年的研究通过比较个体对威胁刺激和非威胁刺激的TTC估计, 考察了刺激的情绪相关属性对TTC估计的影响。结果表明, 相比于自然非威胁刺激(如兔子等图片), 个体会低估自然威胁刺激(如蛇等图片)的TTC, 但这种TTC的低估在社会威胁刺激(如愤怒面孔图片)上有时很小甚至不显著。个体低估TTC可能存在三种原因：(1)个体对威胁刺激具有特异性反应; (2)威胁刺激具有较高的情绪唤醒度; (3)个体对威胁刺激具有心理距离更近和运动速度更快的知觉偏差。未来研究可以进一步考察在社会威胁刺激上表现出的TTC低估效应不稳定的原因; 探索威胁刺激TTC估计中的自主生理反应和神经机制; 采用虚拟现实技术进行威胁刺激TTC估计的研究; 在实验设计中考虑性别和人格特质等个体因素的影响。     

Stimulus hierarchy generalization in systematic desensitization

A group of snake phobic Ss were desensitized to the first 5 items of a standard 7 item snake fear hierarchy in which the items were ordered on the basis of distance from a snake. This group and a no-treatment control group (which did not receive the desensitization) were treated for fear of all the hierarchy stimuli in terms of ratings both before and after the desensitization. The Ss rated their fear responses to all the stimuli as presented to them in (1) real form (2) by slide, and (3) in imaginal form. The results verified all four experimental hypotheses: (1) The experimental Ss showed greater fear reduction than the control Ss to both the training stimuli (the stimuli on which desensitization done) and the generalization stimuli (the other two stimuli), (2) The systematic desensitization (SD) group showed (a) more fear reduction to the last training stimuli than to the lower generalization stimulus and (b) more to the latter than to the higher generalization stimulus, (3) The SD group showed less fear reduction to the generalization stimuli in their real form than in both the slide and imaginai modalities (in the desensitization each stimulus presentation was done first in slide form and then in imaginal form), and (4) There were significant overall individual differences in generalization of fear reduction to the generalization stimuli.     

高焦虑个体对威胁性刺激的注意偏向特点*

采用点探测实验范式,将图片按照威胁性分为高威胁性和一般威胁性,探讨焦虑程度不同的个体对不同威胁性刺激的注意特点。采用状态-特质焦虑问卷从265个大学生中选取了33名高焦虑被试和31名对照组被试。结果发现：（1）高焦虑组个体对一般威胁性刺激有显著注意偏向,对高威胁性刺激有注意回避趋势;（2）对照组个体对一般威胁性刺激没有表现出注意偏向,对高威胁刺激有注意偏向趋势。结论：（1）即使是一般威胁性图片也能引起高焦虑被试的注意偏向 （2）高威胁性图片才能引起对照组个体产生注意偏向的趋势。     

Cognitive functioning and anxiety

Summary Various possible differences in cognitive functioning between those high and low in trait anxiety are considered. Particular emphasis is paid to the hypothesis that individuals high in trait anxiety tend to approach threatening stimuli, whereas those low in trait anxiety tend to avoid such stimuli. The evidence indicates that there are such differences in the processing of threatening stimuli as a function of trait anxiety. However, these differences are found only under certain conditions, for example, when threatening and nonthreatening stimuli are presented concurrently, and when minor rather than major threat is involved.The differences between those high and low in trait anxiety encompass pre-attentive, attentional, and interpretative mechanisms. As a consequence, any adequate theory of trait anxiety must take proper account of cognitive mechanisms and functioning.     

Context learning for threat detection

It is hypothesised that threatening stimuli are detected better due to their salience or physical properties. However, these stimuli are typically embedded in a rich context, motivating the question whether threat detection is facilitated via learning of contexts in which threat stimuli appear. To address this question, we presented threatening face targets in new or old spatial configurations consisting of schematic faces and found that detection of threatening targets was faster in old configurations. This indicates that individuals are able to learn regularities within visual contexts and use this contextual information to guide detection of threatening targets. Next, we presented threatening and non-threatening face targets embedded in new or old spatial configurations. Detection of threatening targets was facilitated in old configurations, and this effect was reversed for non-threatening targets. Present findings show that detection of threatening targets is driven not only by stimulus properties as theorised traditionally but also by learning of contexts in which threatening stimuli appear. Further, results show that context learning for threatening targets obstructs context learning for non-threatening targets. Overall, in addition to typically emphasised bottom-up factors, our findings highlight the importance of top-down factors such as context and learning in detection of salient, threatening stimuli.     

Affective states leak into movement execution: Automatic avoidance of threatening stimuli in fear of spider is visible in reach trajectories

Approach-like actions are initiated faster with stimuli of positive valence. Conversely, avoidance-like actions are initiated faster with threatening stimuli of negative valence. We went beyond reaction time measures and investigated whether threatening stimuli also affect the way in which an action is carried out. Participants moved their hand either away from the picture of a spider (avoidance) or they moved their hand toward the picture of a spider (approach). We compared spider-fearful participants to non-anxious participants. When reaching away from the threatening spider picture, spider-fearful participants moved more directly to the target than controls. When reaching toward the threatening spider, spider-fearful participants moved less directly to the target than controls. Some conditions that showed clear differences in movement trajectories between spider-fearful and control participants were devoid of differences in reaction time. The deviation away from threatening stimuli provides evidence for the claim that affective states like fear leak into movement programming and produce deviations away from threatening stimuli in movement execution. Avoidance of threatening stimuli is rapidly integrated into ongoing motor behaviour in order to increase the distance between the participant's body and the threatening stimulus.     

The presence of threat affects saccade trajectories

In everyday life, fast identification and processing of threat-related stimuli is of critical importance for survival. Previous studies suggested that spatial attention is automatically allocated to threatening stimuli, such as angry faces. However, in the previous studies the threatening stimuli were not completely irrelevant for the task. In the present study we used saccadic curvature to investigate whether attention is automatically allocated to threatening emotional information. Participants had to make an endogenous saccade up or down while an irrelevant face paired with an object was present in the periphery. The eyes curved away more from the angry faces than from either neutral or happy faces. This effect was not observed when the faces were inverted, excluding the possible role of low-level differences. Since the angry faces were completely irrelevant to the task, the results suggest that attention is automatically allocated to the threatening stimuli, which generates activity in the oculomotor system, and biases behaviour.     

Anxiety and retrieval inhibition: support for an enhanced inhibition account

Retrieval inhibition of negative associations is important for exposure therapy for anxiety, but the relationship between memory inhibition and anxiety is not well understood—anxiety could either be associated with enhanced or deficient inhibition. The present study tested these two competing hypotheses by measuring retrieval inhibition of negative stimuli by related neutral stimuli. Non-clinically anxious undergraduates completed measures of trait and state anxiety and completed a retrieval induced forgetting task. Adaptive forgetting varied with state anxiety. Low levels of state anxiety were associated with no evidence for retrieval inhibition for either threatening or non-threatening categories. Participants in the middle tertile of state anxiety scores exhibited retrieval inhibition for non-threatening categories but not for threatening categories. Participants in the highest tertile of state anxiety, however, exhibited retrieval inhibition for both threatening and non-threatening categories with the magnitude of retrieval inhibition being greater for threatening than non-threatening categories. The data are in line with the avoidance aspect of the vigilance–avoidance theory of anxiety and inhibition. Implications for cognitive behavioural therapy practices are discussed.     

Coherence and specificity of information-processing biases in depression and social phobia

Research has not resolved whether depression is associated with a distinct information-processing bias, whether the content of the information-processing bias in depression is specific to themes of loss and sadness, or whether biases are consistent across the tasks most commonly used to assess attention and memory processing. In the present study, participants diagnosed with major depression, social phobia, or no Axis I disorder, completed several information-processing tasks assessing attention and memory for sad, socially threatening, physically threatening, and positive stimuli. As predicted, depressed participants exhibited specific biases for stimuli connoting sadness; social phobic participants did not evidence such specificity for threat stimuli. It is important to note that the different measures of bias in memory and attention were not systematically intercorrelated. Implications for the study of cognitive bias in depression, and for cognitive theory more broadly, are discussed.     

关于IN结合论的十对命题

本文首先概述IN结合论的基本内涵,指出它是智力(I)与非智力因素(N)结合论的简称;然后从三个维度考察了IN结合论的十对命题。这三个维度是：(1)区别维度。即从智力与非智力因素二者的区别看,有3对命题;(2)影响学习维度。即从二者对学习的影响看,有4对命题;(3)联系维度。即从二者的联系看,有3对命题。     

情绪对认知加工的影响：事件相关脑电位系列研究

为探讨情绪与认知的相互作用关系及其脑机制,建立了情境图片、面孔、汉字和声音四个系列组成的中国情感刺激材料库,并通过ERP实验对情绪与注意、工作记忆的关系以及特质焦虑者的认知特点进行了研究。结果发现：⑴ 负性情绪刺激在信息加工过程中至少在注意、评价及反应准备这几个阶段具有某种优先权,注意偏向也可在内隐任务下发生,负性刺激对注意资源不足具有某种补偿作用;⑵ 威胁性视觉提示对其后的视觉加工具有调节作用,高焦虑个体对这类性刺激投入了更多的视觉加工资源,而且威胁性刺激对注意的影响可以跨通道进行,威胁性的视觉刺激可以影响触觉注意;⑶ 在情绪对工作记忆的影响方面,负性情绪下空间工作记忆任务引起的P300波幅减小,这种效应可能是基于情绪对顶叶注意系统的调节作用,而在词语工作记忆任务中这种效应消失     

Distracted by danger: Temporal and spatial dynamics of visual selection in the presence of threat

Threatening stimuli are known to influence attentional and visual processes in order to prioritize selection. For example, previous research showed faster detection of threatening relative to nonthreatening stimuli. This has led to the proposal that threatening stimuli are prioritized automatically via a rapid subcortical route. However, in most studies, the threatening stimulus is always to some extent task relevant. Therefore, it is still unclear if threatening stimuli are automatically prioritized by the visual system. We used the additional singleton paradigm with task-irrelevant fear-conditioned distractors (CS+ and CS-) and indexed the time course of eye movement behavior. The results demonstrate automatic prioritization of threat. First, mean latency of saccades directed to the neutral target was increased in the presence of a threatening (CS+) relative to a nonthreatening distractor (CS-), indicating exogenous attentional capture and delayed disengagement of covert attention. Second, more error saccades were directed to the threatening than to the nonthreatening distractor, indicating a modulation of automatically driven saccades. Nevertheless, cumulative distributions of the saccade latencies showed no modulation of threat for the fastest goal-driven saccades, and threat did not affect the latency of the error saccades to the distractors. Together these results suggest that threatening stimuli are automatically prioritized in attentional and visual selection but not via faster processing. Rather, we suggest that prioritization results from an enhanced representation of the threatening stimulus in the oculomotor system, which drives attentional and visual selection. The current findings are interpreted in terms of a neurobiological model of saccade programming.     

Eye movements reveal mechanisms underlying attentional biases towards threat

Mechanisms underlying attentional biases towards threat (ABTs), such as attentional avoidance and difficulty of disengagement, are still unclear. To address this issue, we recorded participants' eye movements during a dot detection task in which threatening or neutral stimuli served as peripheral cues. We evaluated response times (RTs) in trials where participants looked at the central fixation cross (not at the cues), as they were required, and number and duration of (unwanted) fixations towards threatening or neutral cues; in all analyses trait anxiety was treated as a covariate. Difficulty in attentional disengagement (longer RTs) was found when peripheral threatening stimuli were presented for 100?ms. Moreover, we observed significantly shorter (unwanted) fixations on threatening than on neutral peripheral stimuli, compatible with an avoidance bias, for longer presentation times. These findings demonstrate that, independent of trait anxiety levels, disengagement bias occurs without eye movements, whereas eye movements are implied in threat avoidance.     

Conserved evolutionary history for quick detection of threatening faces

Humans quickly recognize threats such as snakes and threatening faces, suggesting that human ancestors evolved specialized visual systems to detect biologically relevant threat stimuli. Although non-human primates also detect snakes quickly, it is unclear whether primates share the efficient visual systems to process the threatening faces of their conspecifics. Primates may not necessarily process conspecific threats by facial expressions, because threats from conspecifics in natural situations are often accompanied by other cues such as threatening actions (or attacks) and vocal calls. Here, we show a similar threat superiority effect in both humans and macaque Japanese monkeys. In visual search tasks, monkeys and humans both responded to pictures of a threatening face of an unfamiliar adult male monkey among neutral faces faster than to pictures of a neutral face among threatening faces. However, the monkeys’ response times to detect deviant pictures of a non-face stimulus were not slower when it was shown among threat faces than when it was shown among neutral faces. These results provide the first evidence that monkeys have an attentional bias toward the threatening faces of conspecifics and suggest that threatening faces are evolutionarily relevant fear stimuli. The subcortical visual systems in primates likely process not only snakes, but also more general biological threat-relevant stimuli, including threatening conspecific faces.     

Effect of negative emotion on visual attention: Automatic capture by fear‐related stimuli1

Abstract: In this study, we examined the effect of threatening pictures (e.g., snakes and spiders) on control of spatial attention using a probe detection task. In addition to attentional capture by the threatening stimuli (Unpredictable task), the effects of affective valence of the pictures on the voluntary control of attention were explored (Predictable task). Results showed that reaction time (RT) was facilitated to the probe that appeared at the location of threatening stimuli when it occurred in the right visual field (but not in the left visual field), indicating that attention was captured automatically, at least in this visual field. However, when participants were able to predict the probe location, the attentional gains increased similarly for all the conditions (composed of visual field by picture type combinations) relative to those of Unpredictable task, with no indication of deferred deployment of attention to threatening stimuli. The results of this study suggested that the emotional valence, particularly negative valence, affected the automatic control of attention. This effect differed between the two visual fields in which emotional stimuli occurred.     

Contrasting two accounts of anxiety-linked attentional bias: selective attention to varying levels of stimulus threat intensity

Previous research has established that clinical anxiety patients and nonclinical populations with high levels of anxiety vulnerability characteristically orient attention toward moderately threatening stimuli. In contrast, populations with low levels of anxiety vulnerability typically orient attention away from such stimuli. The differing experimental predictions generated by 2 classes of hypothetical explanation for this anxiety-linked attentional discrepancy were tested, using attentional probe methodology to compare the attentional responses of high and low trait anxious individuals to facial stimuli of differing threat intensities. The results support the view that all individuals orient attention away from mildly threatening stimuli and toward strongly threatening stimuli, with differences in anxiety vulnerability reflecting the intensity of stimulus threat required to elicit the attentional vigilance response.     

A time-course analysis of attentional cueing by threatening scenes

Models of attention and emotion have assigned a special status to the processing of threatening information: Facilitated attentional capture by threat and its prioritized processing would allow for swift and adequate action to potentially dangerous stimuli. In four experiments, we examined the time-course of facilitated orienting of attention to threatening scenes in the exogenous cueing paradigm. Threat value and presentation duration of the cues were systematically varied. Facilitated attentional capture by threat was limited to highly threatening pictures presented for 100 ms. No attentional effects were observed with a 28 ms cue presentation duration. At slightly longer cue presentations, 200 ms and 500 ms, results indicated no and even reduced attentional capture by threat compared with neutral information. The present results provide support for the idea that threat facilitates fast attentional orienting to its location, followed by the inhibition of attention to threat.     

Coping with threat and memory for ambiguous information: testing the repressive discontinuity hypothesis

Two studies examined the influence of coping dispositions (repression, sensitization, and nondefensiveness) and anxiety on the encoding and memory representation of ambiguous threat-related stimuli. In Study 1, memory was tested shortly after encoding. Study 2 contrasted immediate and delayed testing. Repressers showed evidence of "mixed" affective reactions to ambiguous stimuli at encoding, accompanied by weak memory representation of potentially threatening implications of these stimuli. In contrast, sensitizers and anxious individuals manifested a processing bias in favor of threatening implications of ambiguous stimuli. Influences of coping on memory were most pronounced for delayed testing. Anxiety influences on memory were weak. An expectancy-based account of individual differences in processing ambiguous stimuli is discussed.