双通路理论视角下孤独症谱系障碍者的视线加工障碍

临床行为观察发现, 孤独症谱系障碍个体普遍存在不能与他人建立视线接触, 不能追随他人视线看向目标物体等视线加工(gaze processing)障碍。然而已有实验研究发现该群体在实验情境中普遍存在视线接触(eye contact)异常, 但其视线追随行为(gaze following)则存在正常与异常并存的现象。基于视线加工双通路理论的启示, 该障碍可能是由于视线加工皮下通路先天功能异常而皮层通路后天发展异常所致。然而, 该理论尚缺乏皮下通路先天功能异常是视线接触障碍潜在神经机制的直接证据, 还需进一步考察皮下通路先天功能异常对视线追随障碍的影响作用, 以及皮层通路后天发展异常即其补偿机制的神经回路及早期形成过程。     

孤独症者的预测编码缺陷：前馈联结异常还是反馈联结异常？

依据预测编码理论,研究者提出预测缺陷是孤独症谱系障碍(Autism Spectrum Disorder, ASD)个体感知运动、认知学习和社交言语等多领域缺陷的基础,即孤独症的预测缺陷假说(Predictive Impairment in Autism,PIA)。在PIA中,研究者基于贝叶斯和层级性推理分别提出“低先验”和“高且不灵活的预测误差精度”两个假说,然而上述假说并未得到一致证据支持。ASD个体在不同领域中不同先验的相对权重并非普遍降低,而是具有广泛的任务或情境敏感性。关于ASD个体是否具备基于环境波动调节预测误差精度的能力,也尚存分歧。此外,关于其潜在机制,是神经调节系统异常导致的自下而上前馈联结异常,还是预测脑区功能异常导致的自上而下反馈联结异常,尚无定论。由此可见,虽然该理论为ASD提供了统一的解释框架,但仍需更多研究证据进行修正和完善,以期为早期筛查和诊断、治疗和教育实践提供指导。     

孤独症者面孔加工中眼部注视不足,是回避还是忽视?

临床行为观察发现,孤独症谱系障碍(Autism Spectrum Disorder,简称ASD)个体在社会交往中较少注视他人眼部。近年的眼动研究发现,ASD个体面孔加工中的眼部注视不足随年龄增长而逐渐显现,与脑电技术相结合的眼动研究进一步发现ASD个体的面孔认知加工障碍与眼部注视不足存在关联。该障碍的潜在认知神经机制可能既源于原生性的杏仁核激活异常,也源于次生性的社会脑发展异常。然而,ASD个体的杏仁核是过度激活主动回避眼部还是激活不足被动忽视眼部尚无定论。今后研究者应横跨不同年龄阶段和不同研究层次,同时搜集眼动与神经生理数据,开展横向比较与纵向追踪相结合的相关研究。     

发展性计算障碍的最新研究进展

发展性计算障碍是一种影响算术技能获得的特定的学习障碍。截至目前,有关发展性计算障碍的认知与神经机制的理论尚存分歧,有关诊断与鉴别标准也未统一。近年来,对于发展性计算障碍的理论假设有从一般认知因素取向到数学特定因素取向发展的趋势。而随着脑成像技术的不断发展,对于发展性计算障碍神经机制的研究也从针对单个脑区的特异性功能发展到从功能连接网络角度进行研究。并且研究者们开始尝试开发基于数学认知基本理论的干预方法,并采用了利用生物技术手段的新方法。基因-脑-行为的整合研究将有助于全面揭示发展性计算障碍的发生机制,而建立在系统理论基础上经过科学评估的干预手段将可能有效促进障碍者的计算能力。     

发展性阅读障碍与知觉加工

近年来许多行为实验和神经生理学实验都发现 ,发展性阅读障碍与基本知觉障碍有关。在视觉领域研究者提出了巨细胞障碍假设 ,这种假设认为阅读障碍者视觉神经系统中的巨细胞障碍导致他们对某种类型的视觉刺激加工存在困难 ,进而影响阅读。在听觉领域研究发现阅读障碍者加工快速、系列、短暂呈现的声音刺激存在障碍。研究者认为阅读障碍者加工快速刺激输入障碍反映了普遍的时间知觉障碍。这方面的研究发展非常迅速 ,理论观点非常明确 ,并且直接与内在的神经机制相联系 ,形成了与传统的“语言障碍”理论迥然不同的“知觉障碍”理论。“知觉障碍”理论综合了行为、认知和神经等多个层次的研究 ,反映了神经科学发展所带来的巨大影响和认知加工模块化理论的渐渐衰退。     

发展性口吃的脑机制

口吃是一种常见的言语障碍,对此曾提出过大脑半球言语功能偏侧化异常假设。近期,发展性口吃的神经成像研究在支持这一经典假设的同时,还发现负责言语监控的颞叶系统和负责言语运动控制的额叶系统与皮层下脑结构存在功能失调,这可能损害言语产生时的精确时间控制。据此,研究者开始用神经网络的观点来解释发展性口吃产生的脑机制,认为患者可能存在由多个言语产生相关脑区构成的“双通路”网络的功能障碍     

孤独症儿童动作发展障碍的神经机制

动作发展障碍(Developmental motor disorders)是孤独症谱系障碍的常见特征。通过系统回顾孤独症儿童动作发展障碍的神经科学研究, 发现γ-氨基丁酸和5-羟色胺浓度的改变及γ-氨基丁酸相关蛋白和Shank蛋白的表达异常不仅会损害中枢神经系统的发育, 而且还能导致突触兴奋性与抑制性失衡, 进而改变孤独症儿童小脑和大脑皮层运动区的功能连接。孤独症儿童小脑、基底神经节和胼胝体结构的改变对全脑的连通性产生了负面影响。神经生化机制和脑结构的异常共同导致了脑功能的异常, 最终造成孤独症儿童的动作发展障碍。此外, 动作发展障碍与孤独症核心症状共同的神经基础主要包括镜像神经元系统紊乱, 丘脑、基底神经节和小脑异常以及SLC7A5和PTEN 基因突变。未来研究需要关注与运动密切相关的其他神经递质, 如乙酰胆碱和多巴胺; 探索动作发展障碍神经网络的动态机制及其形成; 剖析该障碍的神经机制和自闭症核心症状神经机制的相互作用。     

自闭症谱系障碍个体的共情及其理论与神经机制

自闭症谱系障碍(autism spectrum disorders,ASD)个体的社会性功能存在严重缺陷。研究者曾认为共情能力的损害是ASD的核心因素,但实证研究发现ASD个体倾向于在任务复杂或内隐的实验条件下共情受损,而在任务简单或外显的条件下则倾向于共情完整。这可能与他们难以自发、主动地注意并加工社会信息有关。心灵盲假设、极端男性脑理论、共情失衡假设、SOME模型等理论假设,以及碎镜理论、社会脑理论等神经机制对ASD个体的共情特点进行了解释和分析。最后就该领域存在的问题进行了反思与展望。     

威胁对创造力的影响：认知与情绪双加工路径

威胁对创造力的影响颇具热点性与争议性, 总体来看, 当前存在威胁对创造力的阻碍、促进以及两者间呈倒U型关系三种观点。但三种观点分歧的原因与内在机制尚不清楚。本文从认知与情绪角度对相关研究进行了梳理, 认为以上分歧来自于威胁等级的不同, 创造力机制的差异及相关的中介/调节变量。未来研究可从认知与情绪干预的角度, 系统验证观点分歧的原因, 深入分析威胁与创造力的认知神经和基因等内在机制。     

抑郁症认知功能障碍的神经生物学研究进展

作为严重的精神疾病之一,认知功能障碍可能是抑郁症(MDD)的核心症状和重要发病原因之一,严重影响着MDD的临床治愈和心理社会功能的恢复,目前已经受到广泛的关注。MDD患者的认知功能障碍主要表现在注意力不集中、信息处理和工作记忆能力减弱以及控制执行功能的严重不足等。神经影像学与生物学标志物等研究结果已经证实MDD认知功能的异常。了解MDD的认知功能障碍及其神经生物学标志物,对于了解MDD发病机制以及制定个性化治疗方案具有重要意义。     

孤独症谱系障碍者基于运动线索的生命知觉

生命知觉是人们将客体自动加工为可以相互作用的生命体的认知过程。ASD者基于运动线索的生命知觉的研究方法包括追逐检测范式、运动特性参数化范式和因果知觉范例。其生命知觉的异常主要表现为运动信息整合能力不足、社会因果知觉缺陷以及对高复杂度运动的神经追踪较弱。相关理论假设从神经病理、认知加工及脑结构和功能障碍层面进行解释。未来应提升研究方法的生态效度,推进追踪与系统化研究,促进相关干预方案的开发。     

视觉正常的自闭症儿童双眼注视点间距的特点及其意义

视网膜上物象对应的外在注视点之间的距离, 即双眼注视点间距(distance of binoculars point of regard, DBPR)在自闭症谱系障碍(autism spectrum disorders, ASD)个体上存在异常的表现, 而ASD个体伴随较高的斜视发病率, 可能会对其双眼注视点间距产生影响。研究采用正弦曲线平滑追踪任务范式, 探索视觉正常的ASD儿童在动态刺激加工过程中DBPR的鉴别意义。结果发现, ASD儿童DBPR过大且具有跨任务类型的稳定性, 且与斜视无关。DBPR在大振幅、快速度的条件下具有优良的鉴别力, 并与自闭症行为量表总分以及感知觉维度显著正相关。结果表明, 双眼注视点间距具有良好的鉴别价值。     

The perception of biological and mechanical motion in female fragile X premutation carriers

Previous studies reported impaired visual information processing in patients with fragile X syndrome and in premutation carriers. In this study, we assessed the perception of biological motion (a walking point-light character) and mechanical motion (a rotating shape) in 25 female fragile X premutation carriers and in 20 healthy non-carrier controls. Stimuli were moving stimulus dots embedded among a cloud of noise dots. Sensitivity (d′) for motion detection was determined. Emotional symptoms were assessed by Hamilton’s depression and anxiety rating scales. Results revealed that the premutation carriers displayed lower sensitivities for biological and mechanical motion relative to the non-carriers. This deficit was more pronounced in the case of biological stimuli. The premutation carriers displayed higher depression and anxiety scores relative to the non-carriers. Higher depression, but not anxiety, scores were associated with decreased sensitivity for biological, but not mechanical, motion in the carrier group. These results suggest that motion perception deficits are detectable in fragile X premutation carriers, and that the impairment of biological motion perception is associated with depressive symptoms.     

生物运动及其在社会认知障碍研究中的应用

人类对生物运动具有较强的视觉敏感性,即使在视觉线索有限的情况下,仍能提取其中的社会性信息。本研究系统梳理了当前生物运动视知觉实验研究涉及的各类社会性信息,并归纳分析社会认知缺陷与生物运动视知觉加工之间的内在联系,以期促进对生物运动视知觉加工心理机制问题的深入探讨     

Anorexia nervosa and autism spectrum disorders: guided investigation of social cognitive endophenotypes

Death by suicide occurs in a disproportionate percentage of individuals with anorexia nervosa (AN), with a standardized mortality ratio indicating a 57-fold greater risk of death from suicide relative to an age-matched cohort. Longitudinal studies indicate impaired social functioning increases risk for fatal outcomes, while social impairment persists following recovery. Study of social cognition in AN may elucidate impaired processes that may influence therapeutic efficacy. Symptoms of autism spectrum disorders (ASD) are overrepresented in those who evidence a chronic course. Relative to that in AN, social information processing in ASD is well characterized and may inform systematic study in AN. This article (a) reviews impaired interpersonal processes in AN, (b) compares the phenotype of AN with that of ASD, (c) highlights deficits of social cognitive disturbance in ASD relative to AN, and (d) proposes a new framework to understand the interaction of individuals with AN with their social context.     

自闭症谱系障碍个体的社会动机缺陷

自闭症谱系障碍(ASD)是一种源于儿童期的神经发育障碍, 社会交往障碍是其核心特征, 与社会动机缺陷密切相关。社会动机是引导个体社会行为的强大动力, 主要表现为社会定向、社会奖赏和社会维持。现有研究表明, ASD个体的社会动机发展存在缺陷, 他们对社会刺激的注意偏向减少, 不能主动寻求和体会社会互动带来的快乐, 且缺乏维持社会关系的行为策略等。然而, 相关研究结果受到个体特征、环境和实验设计等因素的影响。研究者未来应综合考虑这些影响因素, 加强对ASD个体社会动机理论的整合研究, 以便全面系统地了解ASD个体的社会动机缺陷。     

Seeing it differently: visual processing in autism

Several recent behavioral and neuroimaging studies have documented an impairment in face processing in individuals with Autism Spectrum Disorder (ASD). It remains unknown, however, what underlying mechanism gives rise to this face processing difficulty. One theory suggests that the difficulty derives from a pervasive problem in social interaction and/or motivation. An alternative view proposes that the face-processing problem is not entirely social in nature and that a visual perceptual impairment might also contribute. The focus of this review is on this latter, perceptual perspective, documenting the psychological and neural alterations that might account for the face processing impairment. The available evidence suggests that perceptual alterations are present in ASD, independent of social function.     

Neural correlates of coherent and biological motion perception in autism

Recent evidence suggests those with autism may be generally impaired in visual motion perception. To examine this, we investigated both coherent and biological motion processing in adolescents with autism employing both psychophysical and fMRI methods. Those with autism performed as well as matched controls during coherent motion perception but had significantly higher thresholds for biological motion perception. The autism group showed reduced posterior Superior Temporal Sulcus (pSTS), parietal and frontal activity during a biological motion task while showing similar levels of activity in MT+/V5 during both coherent and biological motion trials. Activity in MT+/V5 was predictive of individual coherent motion thresholds in both groups. Activity in dorsolateral prefrontal cortex (DLPFC) and pSTS was predictive of biological motion thresholds in control participants but not in those with autism. Notably, however, activity in DLPFC was negatively related to autism symptom severity. These results suggest that impairments in higher-order social or attentional networks may underlie visual motion deficits observed in autism.     

Relating the perception of visual ensemble statistics to individual levels of autistic traits

Integrating information across the visual field into an ensemble (e.g., seeing the forest from the trees) is an effective strategy to efficiently process the visual world, and one that is often impaired in autism spectrum disorder. Individual differences in sensory processing predict ensemble encoding, providing a potential mechanism for differing perceptual strategies across individuals, and possibly across diagnostic groups exhibiting atypical sensory processing. Here, we explore whether ensemble encoding is associated with traits associated with autism spectrum disorder (ASD). Participants (N=68) were presented with an ensemble display consisting of circles of varying sizes and colors, and were asked to remember the size of the red and blue circles, while ignoring the green circles. Participants were then cued to a target location after a brief delay, and instructed to report the remembered size of the circle they had previously viewed in that location, as ensemble information commonly biases memory for individual objects toward the probed mean of a set of similar objects. The Autism-spectrum Quotient (AQ) was completed to measure each individual’s level of autistic traits. We found that an individual’s level of ensemble perception, measured as their bias toward the probed mean, was negatively associated with a higher level of ASD traits. These results suggest that individuals with higher levels of ASD traits are less likely to integrate perceptual information. These findings may shed light on different perceptual processing within the autism spectrum, and provide insight into the relationship between individual differences and ensemble encoding.