奖赏预期对面孔情绪加工的影响：一项事件相关电位研究

采用事件相关电位(ERPs)技术考察了奖赏预期对人类面孔情绪识别的影响。实验采用线索-目标范式, 分别记录了被试在奖赏预期条件下以及无奖赏预期条件下对正性、中性和负性面孔进行情绪辨别任务的ERP数据。行为结果显示, 被试在奖赏预期条件下的反应时快于无奖赏预期条件下的反应时, 对情绪面孔的反应时快于对中性面孔的反应时。ERPs数据显示, 奖赏线索比无奖赏线索诱发了更正的P1、P2和P300成分。目标刺激诱发的P1、N170波幅以及N300均受到奖赏预期的调节, 在奖赏预期条件下目标诱发了更正的ERPs。P1、N170、VPP等成分没有受到面孔情绪的影响, 而额中央位置的N300波幅显示情绪(正性与负性)面孔与中性面孔加工的差异。重要的是, N300波幅出现奖赏预期与情绪的交互作用, 正、负情绪加工效应以及负性偏向效应受奖赏预期的差异性影响。正性情绪加工效应不受奖赏预期的影响, 而负性情绪加工效应和负性偏向效应在奖赏预期条件下显著大于无奖赏预期条件下。这些结果说明, 奖赏预期能够调节对面孔情绪的加工, 且不同加工进程中奖赏对情绪加工的调节作用不同。动机性信息调节注意资源的分配, 促进了个体在加工面孔情绪时的负性偏向。     

场景的不同空间频率信息对面部表情加工的影响:来自ERP的证据

使用事件相关电位(event-related potentials,ERPs)技术考察场景(scene)的不同空间频率信息对面部表情加工的影响。结果发现:对于完整频谱的正常场景来说,中性场景中的恐惧面孔所诱发的N170波幅显著大于消极场景中的恐惧面孔,但该场景效应并未出现在高、低空间频率场景中;另外,中性场景中的中性面孔所诱发的N170波幅显著大于消极场景中的中性面孔,该效应发生于三类不同空间频率的场景中。该研究结果表明,场景对恐惧面孔早期知觉编码加工的影响依赖于场景完整频谱信息。相对于恐惧面孔,中性情绪面孔的结构化编码加工更容易受到消极情绪场景的干扰,而且这种干扰能够发生在场景仅有粗略轮廓信息以及细节线条信息的情况下。     

自动化情绪调节中存在积极效应吗:来自ERPs的证据

采用线索Go/Nogo任务,运用ERPs技术考察了老年人和青年人在自动化情绪调节上的差异。ERPs结果显示:⑴愉快面孔比中性面孔诱发的Go-N2波幅较小,潜伏期较短;Nogo-P3波幅较大,潜伏期较短,表明情绪面孔比中性面孔更能吸引注意;⑵在愉快面孔上,老年组比青年组的Go/Nogo-P3波幅大、潜伏期差异不显著;在悲伤面孔上,老年组比青年组的Go/Nogo-P3波幅大,Nogo-P3潜伏期长,说明老年组比青年组更加抑制对悲伤面孔的反应,老年人在自动化情绪调节中表现出一定程度的积极效应。     

知觉负载对负性分心面孔的知觉加工和记忆的影响

本研究采用视觉搜索和意外再认记忆任务,结合事件相关电位技术,考察知觉负载对负性分心面孔的知觉加工和记忆的影响。在视觉搜索任务中,行为上恐惧分心面孔在高负载下干扰任务。ERP结果上,恐惧比中性分心面孔诱发更大的N170和N250;在低负载下恐惧比中性分心面孔诱发更大的N700,在高负载下没有差异。在意外再认记忆中,个体对低负载下的恐惧分心面孔表现出记忆。这些结果说明负性分心物在早期是自动化加工;晚期加工受知觉负载的调节,负载越低对负性分心物的过滤越少,存在对负性分心物的记忆偏向。     

羞怯与非羞怯大学生在早期面孔加工中的差异——来自ERP的电生理学证据

羞怯与社会认知密切相关,而面孔识别是人们社会生活中的一项重要的社会认知功能。目前关于羞怯的电生理学研究大多关注表情的效价效应和面孔的新旧效应对羞怯个体面孔加工的影响,却忽视了羞怯个体在基本的面孔识别能力——面孔-物体识别中可能存在的认知神经差异。因此,本研究采用ERP技术,使用GO/Nogo范式的面孔-物体识别任务,对17名羞怯大学生和17名非羞怯大学生在面孔结构编码中的N170成分进行考察,以期发现不同羞怯水平大学生在早期面孔加工中的认知神经差异。本研究发现,非羞怯大学生对面孔结构具有加工优势,识别面孔时,非羞怯大学生的N170波幅显著大于羞怯大学生的N170波幅,识别物体时则不存在组间差异;N170是面孔识别的特异性成分,面孔诱发的N170波幅显著大于物体诱发的N170波幅;识别面孔时,N170表现出大脑右半球的加工优势。     

语境信息对面部表情加工的影响

为检验语境信息在面部表情加工和识别中的作用,通过两个实验考察语境信息的情绪性和自我相关性对中性以及不同强度恐惧面孔情绪加工的影响。结果发现,积极语境下中性情绪面孔效价的评分更高,自我相关语境下中性面孔唤醒度的评分更高;消极语境下面孔的恐惧情绪更容易被察觉。因此,面部表情加工中的语境效应表现为对中性情绪面孔的情绪诱发和增强作用,以及在情绪一致情况下对不同情绪强度面孔判断的促进作用。     

场景主旨对恐惧刺激加工影响的ERP研究

背景的情绪属性对恐惧面孔早期加工产生影响,但场景主旨的含义属性与恐惧刺激加工的关系并不清楚。以门和蛇的合成图片探讨不同任务的场景主旨加工及与其中恐惧刺激加工相互影响的脑机制,结果发现场景主旨信息对恐惧刺激加工存在影响。P1波幅的恐惧主效应显著,场景主旨的早期加工受到刺激图片恐惧属性的影响。N2在场景上主效应显著,即N2受到刺激图片情绪属性和实验任务的共同影响。     

内隐情绪加工对返回抑制效应的调节

为探讨内隐情绪加工是否会对返回抑制产生影响,采用线索靶子范式,以情绪性面孔图片作为目标,要求被试完成定位任务。结果发现,行为数据和脑电数据均显示了显著的返回抑制效应;N1成分上情绪效价和线索有效性的主效应及交互作用均显著,有效线索条件下情绪目标诱发的波幅显著大于中性目标;N170成分上线索有效性主效应显著,相较于N1成分,N170成分在有效线索上波幅更小,在无效线索上波幅更大。实验结果表明返回抑制效应受到内隐情绪加工的调节,提示该效应来源于早期的知觉抑制,支持知觉抑制理论。     

面孔加工的结构编码阶段异族效应的加工方式： ERPs研究

实验采用事件相关电位（ERPs）技术,以大学生为被试,运用非洲、欧洲、亚洲三个不同种族的面孔照片,探究异族效应与加工方式的关系。行为实验结果显示,被试对非洲面孔的反应时快于欧洲面孔,且两者均快于亚洲面孔。ERP研究结果显示,亚洲面孔的N170波幅显著小于非洲和欧洲面孔的波幅,后两者的N170波幅没有差异,而且亚洲面孔的倒置效应最大。研究结果说明相对于异族面孔,本族面孔更多地使用构型编码的加工方式,且N170成分表现出右半球优势。     

内隐/外显不同水平攻击者的注意偏向：行为和ERP证据

通过行为实验（点探测）和ERP实验（情绪Stroop）两个实验任务,考察了内隐/外显不同水平攻击者的注意偏向及其脑机制。结果表明：高外显攻击者对愤怒面孔存在注意偏向;高外显攻击者在愤怒面孔上的N100波幅显著低于中性面孔,表明其注意分配和调节能力较弱;高外显攻击者较之低外显攻击者的P300波幅更小表明其存在注意等方面的认知加工缺陷,N400波幅更小表明其对愤怒面孔进行语义编码时加工更为流畅;外显攻击组与内隐攻击组在FCz和Cz电极点上不同。这为内隐/外显攻击二者有着独立结构提供了行为与认知神经科学的证据。     

The Role of Emotional Content and Perceptual Saliency During the Programming of Saccades Toward Faces

Previous studies have shown that the human visual system can detect a face and elicit a saccadic eye movement toward it very efficiently compared to other categories of visual stimuli. In the first experiment, we tested the influence of facial expressions on fast face detection using a saccadic choice task. Face-vehicle pairs were simultaneously presented and participants were asked to saccade toward the target (the face or the vehicle). We observed that saccades toward faces were initiated faster, and more often in the correct direction, than saccades toward vehicles, regardless of the facial expressions (happy, fearful, or neutral). We also observed that saccade endpoints on face images were lower when the face was happy and higher when it was neutral. In the second experiment, we explicitly tested the detection of facial expressions. We used a saccadic choice task with emotional-neutral pairs of faces and participants were asked to saccade toward the emotional (happy or fearful) or the neutral face. Participants were faster when they were asked to saccade toward the emotional face. They also made fewer errors, especially when the emotional face was happy. Using computational modeling, we showed that this happy face advantage can, at least partly, be explained by perceptual factors. Also, saccade endpoints were lower when the target was happy than when it was fearful. Overall, we suggest that there is no automatic prioritization of emotional faces, at least for saccades with short latencies, but that salient local face features can automatically attract attention.     

Processing emotional facial expressions: The role of anxiety and awareness

In this paper, the role of self-reported anxiety and degree of conscious awareness as determinants of the selective processing of affective facial expressions is investigated. In two experiments, an attentional bias toward fearful facial expressions was observed, although this bias was apparent only for those reporting high levels of trait anxiety and only when the emotional face was presented in the left visual field. This pattern was especially strong when the participants were unaware of the presence of the facial stimuli. In Experiment 3, a patient with right-hemisphere brain damage and visual extinction was presented with photographs of faces and fruits on unilateral and bilateral trials. On bilateral trials, it was found that faces produced less extinction than did fruits. Moreover, faces portraying a fearful or a happy expression tended to produce less extinction than did neutral expressions. This suggests that emotional facial expressions may be less dependent on attention to achieve awareness. The implications of these results for understanding the relations between attention, emotion, and anxiety are discussed.     

Anxiety and sensitivity to gaze direction in emotionally expressive faces

This study investigated the role of neutral, happy, fearful, and angry facial expressions in enhancing orienting to the direction of eye gaze. Photographs of faces with either direct or averted gaze were presented. A target letter (T or L) appeared unpredictably to the left or the right of the face, either 300 ms or 700 ms after gaze direction changed. Response times were faster in congruent conditions (i.e., when the eyes gazed toward the target) relative to incongruent conditions (when the eyes gazed away from the target letter). Facial expression did influence reaction times, but these effects were qualified by individual differences in self-reported anxiety. High trait-anxious participants showed an enhanced orienting to the eye gaze of faces with fearful expressions relative to all other expressions. In contrast, when the eyes stared straight ahead, trait anxiety was associated with slower responding when the facial expressions depicted anger. Thus, in anxiety-prone people attention is more likely to be held by an expression of anger, whereas attention is guided more potently by fearful facial expressions.     

Anxiety and sensitivity to eye gaze in emotional faces

This paper reports three studies in which stronger orienting to perceived eye gaze direction was revealed when observers viewed faces showing fearful or angry, compared with happy or neutral, emotional expressions. Gaze-related spatial cueing effects to laterally presented fearful faces and centrally presented angry faces were also modulated by the anxiety level of participants, with high- but not low-state anxious individuals revealing enhanced shifts of attention. In contrast, both high- and low-state anxious individuals demonstrated enhanced orienting to averted gaze when viewing laterally presented angry faces. These results provide novel evidence for the rapid integration of facial expression and gaze direction information, and for the regulation of gaze-cued attention by both the emotion conveyed in the perceived face and the degree of anxiety experienced by the observer.     

A robust method for measuring an individual’s sensitivity to facial expressions

This paper describes a method to measure the sensitivity of an individual to different facial expressions. It shows that individual participants are more sensitive to happy than to fearful expressions and that the differences are statistically significant using the model-comparison approach. Sensitivity is measured by asking participants to discriminate between an emotional facial expression and a neutral expression of the same face. The expression was diluted to different degrees by combining it in different proportions with the neutral expression using morphing software. Sensitivity is defined as measurement of the proportion of neutral expression in a stimulus required for participants to discriminate the emotional expression on 75% of presentations. Individuals could reliably discriminate happy expressions diluted with a greater proportion of the neutral expression compared with that required for discrimination of fearful expressions. This tells us that individual participants are more sensitive to happy compared with fearful expressions. Sensitivity is equivalent when measured on two different testing sessions, and greater sensitivity to happy expressions is maintained with short stimulus durations and stimuli generated using different morphing software. Increased sensitivity to happy compared with fear expressions was affected at smaller image sizes for some participants. Application of the approach for use with clinical populations, as well as understanding the relative contribution of perceptual processing and affective processing in facial expression recognition, is discussed.

     

Probing the attentional control theory in social anxiety: An emotional saccade task

Volitional attentional control has been found to rely on prefrontal neuronal circuits. According to the attentional control theory of anxiety, impairment in the volitional control of attention is a prominent feature in anxiety disorders. The present study investigated this assumption in socially anxious individuals using an emotional saccade task with facial expressions (happy, angry, fearful, sad, neutral). The gaze behavior of participants was recorded during the emotional saccade task, in which participants performed either pro- or antisaccades in response to peripherally presented facial expressions. The results show that socially anxious persons have difficulties in inhibiting themselves to reflexively attend to facial expressions: They made more erratic prosaccades to all facial expressions when an antisaccade was required. Thus, these findings indicate impaired attentional control in social anxiety. Overall, the present study shows a deficit of socially anxious individuals in attentional control—for example, in inhibiting the reflexive orienting to neutral as well as to emotional facial expressions. This result may be due to a dysfunction in the prefrontal areas being involved in attentional control.     

特质焦虑在面部表情前注意加工阶段的影响：来自ERP的证据

为探讨高特质焦虑者在前注意阶段对情绪刺激的加工模式以明确其情绪偏向性特点, 本研究采用偏差-标准反转Oddball范式探讨了特质焦虑对面部表情前注意加工的影响。结果发现: 对于低特质焦虑组, 悲伤面孔所诱发的早期EMMN显著大于快乐面孔, 而对于高特质焦虑组, 快乐和悲伤面孔所诱发的早期EMMN差异不显著。并且, 高特质焦虑组的快乐面孔EMMN波幅显著大于低特质焦虑组。结果表明, 人格特质是影响面部表情前注意加工的重要因素。不同于普通被试, 高特质焦虑者在前注意阶段对快乐和悲伤面孔存在相类似的加工模式, 可能难以有效区分快乐和悲伤情绪面孔。     

Recognition and evaluation of emotional prosody in individuals with generalized social phobia: a pilot study

Studies using facial emotional expressions as stimuli partially support the assumption of biased processing of social signals in social phobia. This pilot study explored for the first time whether individuals with social phobia display a processing bias towards emotional prosody. Fifteen individuals with generalized social phobia and fifteen healthy controls (HC) matched for gender, age, and education completed a recognition test consisting of meaningless utterances spoken in a neutral, angry, sad, fearful, disgusted or happy tone of voice. Participants also evaluated the stimuli with regard to valence and arousal. While these ratings did not differ significantly between groups, analysis of the recognition test revealed enhanced identification of sad and fearful voices and decreased identification of happy voices in individuals with social phobia compared with HC. The two groups did not differ in their processing of neutral, disgust, and anger prosody.     

Stimulus properties of facial expressions and their influence on the classical conditioning of fear

The influence of particular stimulus properties of facial expressions of emotion upon associative learning to a neutral cue was examined in the present investigation. A compound stimulus, composed of either a fearful, happy, or neutral facial expression paired with a neutral cue (tone), signaled an aversive event (mild electric shock). Phasic change in skin conductance (SC) was used as the measure of associative learning. Analyses of variance revealed that subjects who saw a fearful expression paired with the tone gave larger SC responses to the fearful expression than to the tone. The opposite pattern was obtained for subjects who had a happy expression paired with the tone. Subjects who had the neutral expression paired with the tone showed no significant difference in their responses to the two stimuli. Results of the present investigation were consistent with those of an earlier study by Lanzetta and Orr (1980), and extend the earlier theoretical interpretations by suggesting that fear expressions function as excitatory stimuli and happy expressions act as inhibitory stimuli. Methodological changes in the present study, which include a shorter CS interval and asynchronous stimulus onsets, also extend the previous findings.This research was supported by National Science Foundation Grant No. 7912422-AO1 and by funds from the Lincoln Filene endowment to Dartmouth College.     

The effects of emotion priming on visual search in socially anxious adults

This study examined the effects of emotion priming on visual search in participants characterised for different levels of social anxiety. Participants were primed with five facial emotions (angry, fear, happy, neutral, and surprised) and one scrambled face immediately prior to visual search trials involving finding a slanted coloured line amongst distractors, as reaction times and accuracy to target detection were recorded. Results suggest that for individuals low in social anxiety, being primed with an angry, surprised, or fearful face facilitated visual search compared to being primed with scrambled, neutral or happy faces. However, these same emotions degraded visual search in participants with high levels of social anxiety. This study expands on previous research on the impact of emotion on attention, finding that amongst socially anxious individuals, the effects of priming with threat extend beyond initial attention capture or disengagement, degrading later visual search.