间距和语义对阅读障碍儿童拥挤效应的影响

以14名阅读障碍儿童以及与其年龄和阅读水平相匹配的儿童为实验对象,考察了间距和语义对阅读障碍儿童拥挤效应的影响。结果发现阅读障碍儿童受拥挤效应的影响显著大于正常儿童,表明阅读障碍存在视觉加工缺陷;间距和语义均影响阅读障碍儿童的拥挤效应,表明影响阅读障碍儿童拥挤效应的因素既有刺激的低水平视觉特征,也有高水平语言信息;间距与阅读障碍儿童拥挤效应的关系呈U型。     

多感觉整合测量范式中存在的影响因素探讨

已有的多感觉整合研究范式多采用不同单通道刺激和双通道刺激随机呈现的方式进行测量。在这种范式中混有通道转换效应, 该效应可能导致多感觉整合的测量结果不准确。因此, 分析清楚实验范式中通道转换效应的影响因素, 并以此为依据设计合理的整合测量范式, 是进行多感觉整合研究的一个必要前提。本文首先通过实验一验证了在经典的整合测量范式中通道转换效应的影响方式; 进而, 在实验二中通过控制前后刺激的信号强度的一致性, 分析了通道转换效应的特点。综合分析显示, 通道转换效应是由前一刺激差异所造成的对当前刺激通道加工的注意资源分配和警觉水平的变化所导致。该结果表明, 在多感觉行为测量中, 需先根据前一刺激通道分类后再进行分析。     

McGurk效应的影响因素与神经基础

McGurk效应(麦格克效应)是典型的视听整合现象, 该效应受到刺激的物理特征、注意分配、个体视听信息依赖程度、视听整合能力、语言文化差异的影响。引发McGurk效应的关键视觉信息主要来自说话者的嘴部区域。产生McGurk效应的认知过程包含早期的视听整合(与颞上皮层有关)以及晚期的视听不一致冲突(与额下皮层有关)。未来研究应关注面孔社会信息对McGurk效应的影响, McGurk效应中单通道信息加工与视听整合的关系, 结合计算模型探讨其认知神经机制等。     

内源性空间线索有效性对视听觉整合的影响

采用内源性线索-靶子范式, 操纵线索类型(有效线索、无效线索)和靶刺激通道类型(视觉刺激、听觉刺激、视听觉刺激)两个自变量, 通过两个实验, 分别设置50%和80%两种内源性空间线索有效性来考察不同空间线索有效性条件下内源性空间注意对视听觉整合的影响。结果发现, 当线索有效性为50%时(实验1), 有效线索位置和无效线索位置的视听觉整合效应没有显著差异; 当线索有效性为80%时(实验2), 有效线索位置的视听觉整合效应显著大于无效线索位置的视听觉整合效应。结果表明, 线索有效性不同时, 内源性空间注意对视听觉整合产生了不同的影响, 高线索有效性条件下内源性空间注意能够促进视听觉整合效应。     

社会拥挤对消费者感官刺激偏好的影响及机制研究

本研究通过1个田野实验和2个实验室实验探讨了社会拥挤对消费者感官刺激偏好的影响及内在机制。相比于不拥挤,社会拥挤会增加消费者对强(vs.弱)感官刺激的偏好(实验1),这一效应受感知控制缺失驱动(实验2)。权力感对社会拥挤与消费者感官刺激偏好的关系起到调节作用(实验3),即当个体的权力感较高时,社会拥挤对强感官刺激偏好的促进作用才成立;反之,这种效应便会消失。     

汉字、拼音、英文Stroop干扰效应的比较研究

本研究通过比较汉字、拼音和英文的Stroop干扰效应,考察文字系统的差异能否影响Stroop干扰效应。结果表明汉字、拼音、英文在Stroop任务中的干扰效应依次降低。组块之间的比较表明随着刺激的重复呈现,汉字、拼音、英文的Stroop干扰效应都逐渐变小且趋于相同。对Stroop效应更加合理的理论解释是整合了文字加工过程的平行分布加工模型。     

社会性预期优势效应的神经机制

社会性预期优势效应是指个体在预期条件下的信息加工能力显著优于非预期条件。探讨社会性预期优势效应的神经机制, 是心理学家和认知神经科学家关注的一项重要课题。社会性预期编码模型可以为预期静默效应(预期刺激引起的神经活动减弱)提供理论解释, 但该模型不能解释社会性预期刺激诱发的增强神经活动。因此, 研究1和研究2将考察无意识和意识社会性注意在社会性预期编码模型中的作用, 从而将它们整合到该模型中。研究3不再局限于对社会性预期编码模型的考察, 而是扩展到对预期转换机制的探讨, 最终将社会性预期编码模型和预期转换机制整合在预期节俭化框架之下。对于社会性预期优势效应神经机制的研究不仅能够完善社会性预期编码模型, 还有助于拓宽社会性预期研究的视角。     

注意对视听语义整合加工的影响

采用2×3的被试内实验设计,将注意条件和目标刺激类型作为实验变量,考察了指向不同感觉通道的注意对视听语义整合加工的不同影响。结果发现,只有在同时注意视觉和听觉刺激时,被试对语义一致的视听刺激反应最快,即产生冗余信号效应。而在选择性注意一个感觉通道时,语义一致的视听刺激并不具有加工优势。进一步分析发现,在同时注意视觉和听觉时语义一致视听刺激的加工优势源自于其视觉和听觉成分产生了整合。也就是说,只有在同时注意视觉和听觉时,语义一致视听刺激才会产生整合,语义不一致视听刺激不会产生整合。而在选择性注意一个感觉通道时,不论语义是否一致,视听刺激均不会产生整合。     

时距估计中的重复刺激效应

Treisman及其同事最早发现人类对时距的判断很容易受到重复刺激的影响而发生扭曲或偏离,并认为时距估计中的重复刺激具有两种效应。着重介绍了时距估计中重复刺激效应产生的机制及其理论模型、重复刺激效应的影响因素。提出了时距估计中重复刺激效应未来研究中值得关注的几个主要问题。     

纵向数据的中介效应分析

目前中介效应检验主要是基于截面数据,但许多时候截面数据的中介分析不适合进行因果推断,因而需要收集历时性的纵向数据,进行纵向数据的中介分析。评介了基于交叉滞后面板模型、多层线性模型和潜变量增长模型的纵向数据的中介分析方法及其四个发展。第一,中介效应随时间变化,如连续时间模型、多层时变系数模型。第二,中介效应随个体变化,如随机效应的交叉滞后面板模型和多层自回归模型。第三,中介模型的整合,如交叉滞后面板模型与多层线性模型整合为多层自回归模型。第四,中介检验方法的发展,建议使用Monte Carlo、Bootstrap和贝叶斯法进行纵向数据的中介分析。总结出一个纵向数据的中介分析流程并给出相应的Mplus程序。随后展望了纵向数据的中介分析的拓展方向。     

Task set determines the amount of crowding

The present study deals with the question of how crowding effects, which are interactions among adjacent features or characters, emerges automatically or by so-called higher level controlled processing. Two experiments are presented comparing performances during detecting, localizing, and identifying a flanked target in same strings when the target was defined on the basis of either its form or its category. Detection and localization performances were better for form- relative to category-defined targets whereas the reverse was observed for identification performance. This shows that the interacting information is indeed high level in that it is affected by task settings like the defining target feature and the observers’ task set. The results suggest that crowding effects do not emerge due to processes depending on the parameters of stimulus presentation, but due to processes activated by certain task sets.     

Object substitution masking and its relationship with visual crowding

Object substitution masking (OSM) occurs when the perceptibility of a brief target is reduced by a trailing surround mask typically composed of four dots. Camp et al. (Journal of Experimental Psychology: Human Perception and Performance, 41, 940–957, 2015) found that crowding a target by adding adjacent flankers, in addition to OSM, had a more deleterious effect on performance than expected based on the combined individual effects of crowding and masking alone. The current experiments test why OSM and crowding interact in this way. In three experiments, target-flanker distance is manipulated whilst also varying mask duration in a digit identification task. The OSM effect—as indexed by the performance difference between unmasked and masked conditions—had a quadratic function with respect to target-flanker distance. Results suggest it is OSM affecting crowding rather than the converse: Masking seems to amplify crowding at intermediate target-distractor distances at the edge of the crowding interference zone. These results indicate that OSM and crowding share common mechanisms. The effect of OSM is possibly a consequence of changes to the types of feature detectors which are pooled together for target identification when that target must compete for processing with a trailing mask in addition to competition from adjacent flankers.     

Semantic processing of crowded stimuli?

Effects of semantic processing of crowded characters were investigated using numbers as stimuli. In an identification task, typical spacing effects in crowding were replicated. Using the same stimuli in a magnitude comparison task, a smaller effect of spacing was observed as well as an effect of response congruency. These effects were replicated in a second experiment with varying stimulus-onset asynchronies. In addition, decreasing performance with increasing onset-asynchrony (so-called type-B masking) for incongruent flankers indicates semantic processing of target and flankers. The data show that semantic processing takes place even in crowded stimuli. This argues strongly against common accounts of crowding in terms of early stimulus-driven impairments of processing.     

Semantic priming from crowded words

Vision in a cluttered scene is extremely inefficient. This damaging effect of clutter, known as crowding, affects many aspects of visual processing (e.g., reading speed). We examined observers' processing of crowded targets in a lexical decision task, using single-character Chinese words that are compact but carry semantic meaning. Despite being unrecognizable and indistinguishable from matched nonwords, crowded prime words still generated robust semantic-priming effects on lexical decisions for test words presented in isolation. Indeed, the semantic-priming effect of crowded primes was similar to that of uncrowded primes. These findings show that the meanings of words survive crowding even when the identities of the words do not, suggesting that crowding does not prevent semantic activation, a process that may have evolved in the context of a cluttered visual environment.     

Reexamining the possible benefits of visual crowding: dissociating crowding from ensemble percepts

Peripheral objects and their features become indistinct when closely surrounding but nonoverlapping objects are present. Most models suggest that this phenomenon, called crowding, reflects limitations of visual processing, but an intriguing idea is that it may be, in part, adaptive. Specifically, the mechanism generating crowding may simultaneously facilitate ensemble representations of features, leaving meaningful information about clusters of objects. In two experiments, we tested whether visual crowding and the perception of ensemble features share a common mechanism. Observers judged the orientation of a crowded bar, or the ensemble orientation of all bars in the upper and lower visual fields. While crowding was predictably stronger in the upper relative to the lower visual field, the ensemble percept did not vary between the visual fields. Featural averaging within the crowded region does not always scale with the resolution limit defined by crowding, suggesting that dissociable processes contribute to visual crowding and ensemble percepts.     

发展性阅读障碍的视觉拥挤效应

发展性阅读障碍的核心缺陷一直是研究者关注的焦点。近年来,国内外大量研究发现视觉加工缺陷可能是导致阅读障碍的一个重要原因,其中视觉拥挤效应与阅读障碍密切相关。本文将回顾视觉拥挤效应的概念及其理论基础、拼音文字和汉语阅读障碍者视觉拥挤效应的相关研究,提出汉语阅读障碍视觉拥挤效应研究的未来发展方向,以便更好地了解汉语阅读障碍与视觉拥挤效应之间的关系。     

发展性阅读障碍的视觉拥挤效应

发展性阅读障碍的核心缺陷一直是研究者关注的焦点。近年来,国内外大量研究发现视觉加工缺陷可能是导致阅读障碍的一个重要原因,其中视觉拥挤效应与阅读障碍密切相关。本文将回顾视觉拥挤效应的概念及其理论基础、拼音文字和汉语阅读障碍者视觉拥挤效应的相关研究,提出汉语阅读障碍视觉拥挤效应研究的未来发展方向,以便更好地了解汉语阅读障碍与视觉拥挤效应之间的关系。     

Psychophysical magic: rendering the visible 'invisible'

What are the neural correlates of conscious visual awareness? Tackling this question requires contrasting neural correlates of stimulus processing culminating in visual awareness with neural correlates of stimulus processing unaccompanied by awareness. To produce these two neural states, one must be able to erase an otherwise visible stimulus from awareness. This article describes and assesses visual phenomena involving dissociation of physical stimulation and conscious awareness: degraded stimulation, visual masking, visual crowding, bistable figures, binocular rivalry, motion-induced blindness, inattentional blindness, change blindness and attentional blink. No single approach stands above the others, but those producing changing visual awareness despite invariant physical stimulation are clearly preferable. Such phenomena can help lead us ultimately to a comprehensive account of the neural correlates of conscious awareness.     

The role of crowding in parallel search: Peripheral pooling is not responsible for logarithmic efficiency in parallel search

Recent results from our laboratory showed that, in fixed-target parallel search tasks, reaction times increase in a logarithmic fashion with set size, and the slope of this logarithmic function is modulated by lure-target similarity. These results were interpreted as being consistent with a processing architecture where early vision (stage one) processes elements in the display in exhaustive fashion with unlimited capacity and with a limitation in resolution. Here, we evaluate the contribution of crowding to our recent logarithmic search slope findings, considering the possibility that peripheral pooling of features (as observed in crowding) may be responsible for logarithmic efficiency. Factors known to affect the strength of crowding were varied, specifically: item spacing and similarity. The results from three experiments converge on the same pattern of results: reaction times increased logarithmically with set size and were modulated by lure-target similarity even when crowding was minimized within displays through an inter-item spacing manipulation. Furthermore, we found logarithmic search efficiencies were overall improved in displays where crowding was minimized compared to displays where crowding was possible. The findings from these three experiments suggest logarithmic efficiency in efficient search is not the result peripheral pooling of features. That said, the presence of crowding does tend to reduce search efficiency, even in “pop-out” search situations.