不同抑郁状态个体对情绪面孔的评价研究

目的:为探讨不同抑郁状态个体对情绪面孔的效价评价情况。方法:以BDI、SDS、CCMD-3和汉密顿抑郁量表为工具筛选出42名正常对照组、54名抑郁情绪组、17名抑郁康复组和24名抑郁患者组成员,所有被试完成情绪面孔的效价评价任务。结果:发现抑郁患者组和抑郁情绪组对高兴面孔的评价分数显著低于其他两组(F=7.427,p=0.000);抑郁患者组和抑郁康复组对悲伤面孔的评价分数显著低于其他两组(F=4.956,p=0.003);抑郁患者组和抑郁康复组在情绪评价任务中对高兴和中性面孔的反应时显著长于其他两组(F=13.735,p=0.000;F=18.008,p=0.000),对悲伤面孔的反应时与其他两组无显著差异(p>0.05),抑郁患者组对中性面孔的反应时显著长于悲伤面孔(F=4.240,p=0.018)。结论:抑郁个体对正性刺激存在感知缺陷,对负性刺激存在夸大加工倾向和加工易化效应,其中前者是抑郁的状态特征,后两者是抑郁的特质特征。     

人类面孔早期加工特异性神经机制

在面孔识别研究领域中,大量研究探讨人类对这一类刺激的加工是否具有与其他刺激不同的认知神经机制,即面孔的加工具有领域特异性还是过程特异性？由于各类研究使用的方法各不相同,导致对这一问题的回答尚缺乏一致性。本研究假设,如果面孔刺激具有特异性,无论在何种任务被试采用何种加工方式下,人类面孔N170反应在统计值上均显著高于其他类别的N170反应;相反,面孔与其他刺激在N170上则没有统计上的差异。研究将人类面孔、动物面孔、水果／蔬菜、房屋4类刺激呈现在不同任务设置下,测量人类面孔在不同任务中与各类刺激间的早期反应差异。当前研究结果发现,人类面孔在不同任务中始终保持着比其他刺激更为显著的ERPs（Event-Related Potentials,ERPs）反应优势,表现在额中部的早期正成分VPP和右侧颞枕部负成分N170对人类面孔反应幅度显著高于其他三类刺激的。人类面孔与其他刺激的ERP间差异反应模式在不同任务下相对稳定,并末发现动物面孔有类似效应。研究结果支持人类面孔加工的领域特异性说法。     

Abnormalities in visual processing amongst students with body image concerns

Individuals with body dysmorphic disorder (BDD) appear to possess abnormalities in the way they observe and discriminate visual information. A pre-occupation with perceived defects in appearance has been attributed to a local visual processing bias. We studied the nature of visual bias in individuals who may be at risk of developing BDD – those with high body image concerns (BICs) – by using inverted stimulus discrimination. Inversion disrupts global, configural information in favor of local, feature-based processing. 40 individuals with high BIC and 40 low BIC controls performed a discrimination task with upright and inverted faces, bodies, and scenes. Individuals with high BIC discriminated inverted faces and bodies faster than controls, and were also more accurate when discriminating inverted bodies and scenes. This reduction in inversion effect for high BIC individuals may be due to a stimulus-general local, detail-focused processing bias, which may be associated with maladaptive fixation on small features in their appearance.     

Conscious and unconscious processing of facial expressions: Evidence from two split‐brain patients

We investigated how the brain's hemispheres process explicit and implicit facial expressions in two ‘split‐brain’ patients (one with a complete and one with a partial anterior resection). Photographs of faces expressing positive, negative or neutral emotions were shown either centrally or bilaterally. The task consisted in judging the friendliness of each person in the photographs. Half of the photograph stimuli were ‘hybrid faces’, that is an amalgamation of filtered images which contained emotional information only in the low range of spatial frequency, blended to a neutral expression of the same individual in the rest of the spatial frequencies. The other half of the images contained unfiltered faces. With the hybrid faces the patients and a matched control group were more influenced in their social judgements by the emotional expression of the face shown in the left visual field (LVF). When the expressions were shown explicitly, that is without filtering, the control group and the partially callosotomized patient based their judgement on the face shown in the LVF, whereas the complete split‐brain patient based his ratings mainly on the face presented in the right visual field. We conclude that the processing of implicit emotions does not require the integrity of callosal fibres and can take place within subcortical routes lateralized in the right hemisphere.     

情绪面孔的意识神经相关物及其无意识自动加工：来自事件相关电位的证据

意识的神经相关物尚有争议, 且个体能否无意识自动检测视觉环境变化尚不清楚。本研究采用非注意视盲范式操控视觉意识, 并引入具有社会信息的情绪面孔, 探讨意识的神经相关物以及视觉意识与自动检测变化机制的关系。在A阶段, 部分被试对任务无关的情绪面孔处于无意识水平; 在B阶段, 所有被试对任务无关的情绪面孔处于意识水平; 在C阶段, 所有被试对任务相关的情绪面孔处于意识水平。结果显示, 任务无关的情绪面孔的意识过程诱发视觉意识负波(visual awareness negativity, VAN)、晚期正成分(late positivity, LP)和晚期枕区正成分(late occipital positivity, LOP)。此外, 无意识的情绪面孔能诱发视觉失匹配负波(visual mismatch negativity, vMMN), 且其幅值不受意识影响, 但是受任务相关性调制。这些结果提示对情绪面孔的视觉意识在不同的时间进程上有不同的ERP指标——VAN反映早期知觉经验, 而LP和LOP反映晚期意识过程, 而且面孔情绪信息的自动加工独立于视觉意识, 但是受视觉注意调制。     

Fast face detection using a unified architecture for unconstrained and infrared face images

Human face detection along with its localization is a difficult task when the face is presented in the cluttered scene in an unconstrained scenario that might be with arbitrary pose variations, occlusions, random backgrounds and infrared (IR) environment. This paper proposes a novel face detection method which can address some of these issues and challenges quite successfully during face detection in unconstrained as well as infrared environments. It makes use of Fast Successive Mean Quantization Transform (FastSMQT) features for image enhancement and feature representation to deal with illumination and sensor insensitiveness. A split up Sparse Network of Winnows (SNoW) with Winnow updating rule is then exploited to speed up the original SNoW classifier. Finally, the features and classifiers are combined together with skin detection algorithm for face detection in crowd image and head orientation correction of near infrared faces. The proposed face detector is robust in handling pose, occlusion, illumination, blur and low image resolution. The experiment is performed on six challenging and publicly available databases, viz. BIOID, LFW, FDDB, UFI, WIDER FACE and IIT Delhi near infrared. The experimental results depict that the proposed method outperforms traditional as well as some advanced methods in detecting unconstrained and infrared faces under challenging situations.     

背景性质对7-10岁自闭症谱系障碍儿童面孔搜索与加工的作用

为了考察背景性质对ASD者搜索面孔的影响,设计两个眼动实验任务,要求14名7~10岁ASD儿童和20名同年龄正常儿童观看图片。实验一采用将面孔嵌入风景图片中引起语义不一致的刺激;实验二采用含有面孔的无意义背景乱序图片刺激。结果发现：（1）面孔与背景语义不一致并不能促进ASD儿童对面孔的搜索;（2）乱序背景对ASD儿童面孔搜索与加工没有产生干扰作用,但使正常儿童的搜索时间变长;（3）一旦觉察到面孔后,ASD儿童对面孔的注视时间少于正常儿童。表明正常儿童对面孔的搜索与加工受背景性质的影响,而ASD儿童不受背景性质的影响;一旦发现面孔,ASD儿童的注意维持较短,但面孔加工模式与正常儿童相似。     

Delayed reconfiguration of a non-emotional task set through reactivation of an emotional task set in task switching: an ageing study

ABSTRACT

In our everyday life, we frequently switch between different tasks, a faculty that changes with age. However, it is still not understood how emotion impacts on age-related changes in task switching. Using faces with emotional and neutral expressions, Experiment 1 investigated younger (n?=?29; 18–38 years old) and older adults’ (n?=?32; 61–80 years old) ability to switch between an emotional and a non-emotional task (i.e. responding to the face's expression vs. age). In Experiment 2, younger and older adults also viewed emotional and neutral faces, but switched between two non-emotional tasks (i.e. responding to the face's age vs. gender). Data from Experiment 1 demonstrated that switching from an emotional to a non-emotional task was slower when the expression of the new face was emotional rather than neutral. This impairment was observed in both age groups. In contrast, Experiment 2 revealed that neither younger nor older adults were affected by block-wise irrelevant emotion when switching between two non-emotional tasks. Overall, the findings suggest that task-irrelevant emotion can impair task switching through reactivation of the competing emotional task set. They also suggest that this effect and the ability to shield task-switching performance from block-wise irrelevant emotion are preserved in ageing.     

Exogenous attention to angry faces in social anxiety: A perceptual accuracy approach

We investigated the interaction between endogenous and exogenous attention for the processing of emotional stimuli in individuals with high social anxiety using accuracy rates. Following the presentation of an endogenous cue at the centre, exogenous cues (i.e., angry and neutral faces) were presented at peripheral locations. Subsequently, non-emotional masked targets were presented, and the participants were instructed to discriminate between the targets. With respect to exogenous attention, high socially anxious people exhibited higher accuracy when the angry face and target appeared on the same side than when they appeared on different sides, whereas low socially anxious people did not exhibit such effects. On the other hand, different abilities of endogenous attention were not observed between high and low socially anxious people. These results suggest that exogenous attention is biased towards threat in high socially anxious people.     

Investigation of effects of face rotation on race processing: An ERPs study

Recent ERP research has indicated that the processing of faces of other races (OR) and same race (SR) as the perceiver differs at the perceptual level, more precisely for the N170 component. The purpose of the present study was to continue the investigation of the race-of-face processing across multiple orientations. Event-related brain potentials (ERPs) and performance were recorded when Caucasian participants were required to categorize by race Caucasian and African faces presented in eight different angles of orientation. Three main observations were made: (1) the face-sensitive N170 is modulated by the race of faces, being larger in response to OR compared to SR faces; (2) face rotation affected this component in the same pattern for both racial groups; (3) the N170-ORE progressively disappeared as the faces moved away from their canonical orientation at the right hemisphere only. Thus, the current findings suggest that configural/holisitic information is extracted from faces of both racial groups, but that upright OR faces require increased demands.