视知觉无意识对局部形状和颜色特征加工的注意调节

研究了视知觉无意识对局部几何特征加工中的整体优势效应.被试为天津师范大学本科生60名.仪器为pentium III高分辨率计算机,程序用E-prime心理实验软件系统编制而成.被试的任务是判断靶图形中央线条的方向或颜色.用MANOVA分析了启动图形对靶图形局部特征加工的启动效应,发现了视知觉对无意识呈现的图形加工具有形状优势效应,启动图形与靶图形的整体形状相同可以抑制对靶图形局部形状特征的判断.当被试的任务变成判断靶线条的颜色或启动图形的边由连通状态变成不连通时,视知觉无意识对启动图形加工的整体优势效应消失.该结果提示整体优势效应很可能与任务涉及的信息通道密切相关,对局部形状特征的注意很可能涉及对周围整体形状信息加工自动抑制的过程.     

大学生中文独体字知觉加工效应

采用Navon型复合刺激识别任务，考察中文独体字知觉加工的优先效应。结果表明：构形关系上独体字识别有笔画数效应，呈局部优先性，受练习、认知组块影响。定向关系中复合独体字识别呈整体优先性，慢于单体字和复合图的识别，不受笔画、局部性质影响，当局部构件有独立语义或构形意义时，优先效应反转，局部优先性增强。结论认为局部与整体构形优先关系，局部意义负载影响视知觉加工模式，独体字识别由局部和整体加工合力完成。     

视知觉无意识加工中的形状优势效应

研究了视知觉无意识加工中是否存在形状优势效应。被试为天津师范大学本科生60名。仪器为pentium lll高分辨率计算机．程序用E-prime心理实验软件系统编制而成。在实验1中,用信号检测论技术发现．当启动图形呈现时间为20ms时．被试是不能觉知到该图形的。在实验2和3中．被试的任务分别是判断图形的形状和颜色,用MANOVA分析启动图形对靶图形的启动效应时发现．启动图形的颜色线索不会影响靶图形的形状判断,但启动图形的形状线索却能抑制或促进靶图形的颜色判断。实验证据提示．在判断物体整体特征时,无意识知觉具有形状优势效应。     

封闭性知觉在大范围优先性中的特殊性

本文研究当封闭性作为被试分辨的图形性质时,空间位置不确定性和视野位置对大范围优先性有何影响。实验发现：（１）无论复合刺激呈现在视野的中央或外周．分辨复合刺激的整体性质的反应时（ＲＴ）比分辨局部性质的ＲＴ短,整体性质对分辨局部性质的反应有较强的干扰作用。相反,局部性质对分辨整体性质的反应的影响较小;（２）刺激位置的不确定对大范围优先性没有显著影响;（３）与周边刺激相比,分辨视野中央的复合刺激的ＲＴ较短,但整体性质的ＲＴ优势和对局部性质的干扰作用,不受刺激在视野中的位置的影响。这些实验结果揭示了封闭性知觉在大范围优先性中的特殊性。     

知觉组织对时序知觉的双重影响:同时判断任务的证据

本研究探讨知觉组织对时序知觉的双重影响。实验采用三条线段构成的C形为实验材料,操纵图形朝向和SOA水平(实验1和实验2)、图形颜色(实验3)以及反应限制(实验4),要求被试完成同时判断任务。结果发现,在不同的SOA条件下,图形对向条件的同时判断频率均显著高于图形反向条件(实验1),即使在知觉组织线索弱化时这种现象仍然存在(实验2和实验3),而且知觉组织对时序知觉的影响不是由于被试的反应偏向导致的(实验4)。结果说明知觉组织对时序知觉存在双重影响:当两个刺激同时出现时,知觉组织能够提高时序知觉表现; 而当两个刺激非同时出现时,知觉组织显著降低时序知觉表现。     

自我信息对知觉选择中整体优先性的调控作用

已有研究表明个人重要信息调控高级认知加工过程, 如面孔识别、记忆、思维等。本研究的三项实验系统地测量了个人重要信息对知觉选择的影响。采用最近发展的自我连接学习范式, 让中性几何图形与不同人(自我、朋友、陌生人)建立联系; 图形-标签连接完成后, 以复合图形(局部小图形组成整体大图形)作为实验刺激, 被试完成整体/局部图形判断任务, 通过评估个体对具有不同社会意义图形(目标vs.分心物水平)的感知差异, 测量个人重要信息对知觉选择的调控作用。结果发现, 与他人相关图形相比, 自我相关图形作为分心物调控整体优先效应, 这种效应一致地发生在整体和局部水平上, 并且不受注意任务的影响。这些结果提示社会信息对认知的调控作用发生在视觉选择水平上。     

刺激材料的整体性知觉对类别建构的影响

采用标准－匹配的实验程序,操纵刺激材料的空间整合性和知觉的整体性水平,探讨逐个呈现刺激材料时影响被试类别建构策略的根本原因。报告了3个实验,结果证明：逐个呈现并不一定会导致被试倾向于家族相似性归类;刺激材料的空间整合性不一定会影响被试的类别建构策略,空间整合和空间分离都可能出现家族相似性和单维归类倾向;刺激材料的整体性知觉水平对类别建构影响明显：知觉为分离则倾向于家族相似性分类;知觉为整体则倾向于单维分类。被试在实验可能采用分析性策略,然而材料的整体性知觉影响了分析的侧重点,从而对类别建构产生了非常重要的影响     

注意和非注意条件下的整体和局部性质加工

以往关于整体和局部知觉的研究通常要求被试直接对出现在复合刺激整体或局部水平上的靶目标做反应,因此复合刺激与任务相关并被注意。该研究通过测量复合字母的整体和局部性质对随后出现的探测刺激的启动效应来研究在非注意条件下整体和局部性质加工的差异。实验一发现复合刺激的整体和局部性质对探测刺激产生负启动效应,但二者没有显著差异。实验二缩短了启动刺激与探测刺激之间的时间间隔,复合刺激的整体和局部性质对探测刺激都不再产生启动效应。在实验一、二中,当要求被试直接对复合刺激做反应时,其分辨局部性质的错误率都比分辨整体性质的错误率高。根据这些结果,讨论了在注意和非注意下的整体和局部性质加工的差异。     

内侧颞叶系统在知觉启动中的作用及其机制

以ll例内侧颞叶(MTL)损伤病人为被试,探讨MTL与知觉启动的关系及其内在机制。被试依次完成学习颜色词、快速词命名和再认任务。在实验l的词命名中包括旧词、重组颜色词和新词,结果表明,MTL损伤病人没有表现出旧词的命名时间短于重组颜色词的现象,颜色启动效应受损,其再认成绩也低于正常被试。但是当用新颜色词代替重组颜色词后(实验2),MTL损伤病人读旧词的时间明显短于新颜色词,颜色启动与正常对照组之间没有明显差别,但他们的再认成绩仍比对照组低。这表明,当任务要求被试加工项目与其特性之间的关系时(词与颜色),MTL损伤对启动效应会有影响,提示MTL在一些形式的知觉启动中起重要作用。     

汉字的视知觉——知觉任务效应和汉字属性效应

本研究通过三个实验发现:1.在三种非速示的特定知觉任务下,认知汉字反应时的长短依次是;识别汉字两个部件的反应时>识别整体字的反应时>辨认字的结构方式的反应时,在错误率指标上也获得了同样的结果模式。这表明,在汉字的视知觉中存在知觉任务效应,而这些任务标志着不同复杂程度的加工水平。2.对于左右和上下结构的字,在辨认其结构方式上无差异。3.在命名整体字中,汉字的表层属性,如结构方式和表音特点对整体字的识别没有影响,这表明整体字是正常阅读条件下的知觉单位。4.在知觉分解整体字和命名识别其部件中,(1)字的结构方式有相当大的影响:上下结构字的反应时远远长于左右结构字的反应时。(2)字的表音特点对部件识别也极有影响,如形声字的反应时和错误率都远远短于和少于非形声字。(3)在误操作中,存在着大量整体字的命名现象。以上表明的汉字属性效应,都是发生在汉字知觉的分解过程中,它们反映了整体对部分的强烈影响。     

Interactions between perceptual organization based on Gestalt laws and those based on hierarchical processing

Our recent research with compound stimuli (Han, Humphreys, & Chen, 1999a) suggests that grouping between local elements facilitates the perception of global structure, whereas encoding closure in local elements enhances their segmentation. The present study presents further evidence supporting this assertion. Experiment 1 first developed a new paradigm in which grouping between local elements was manipulated. Subjects responded to the orientations of perceptual groups consisting of local arrows or triangles embedded in background crosses. Responses to the orientations of the groups were slowed as a function of the increased contrast of the crosses, indicating that the strength of grouping between local arrows or triangles was gradually weakened by increasing the contrast of the crosses. Using a similar paradigm, Experiments 2 and 3 investigated the role of Gestalt factors in hierarchical analysis. Global arrows or triangles made up of local arrows, or triangles were embedded in background crosses. Subjects responded to global or local stimuli in terms of orientation or closure. Increasing the contrast of the background crosses produced stronger effects on global responses than on local responses and resulted in elimination of the global precedence effect and emerging of a local precedence effect, which was stronger for closure discrimination than for orientation discrimination. These results provide new evidence supporting our previous claim about the role of Gestalt factors in hierarchical analysis.     

影响视觉复合刺激中整体和局部性质加工的几种因素

文章研究了视知觉组织,空间位置不确定性和视野位置等因素对复合刺激中整体和局部性质加工的影响。实验发现,（１）当复合刺激呈现在白背景上时,反应时和干扰作用都表明复复合刺激中大图的加工优于小图,刺激位置的不确定削弱大图对小图的干扰作用;而当复合刺激呈现在由“＋”组成的背影或时,小图的加工优于大图,刺激位置的不确定延长分辩小图的ＲＴ;（２）与周国刺激相比,分辨视野中央的复合刺激的ＲＴ较短,这种影响对分辨     

Perceptual grouping in space and time: Evidence from the Ternus display

We report three experiments investigating the effect of perceptual grouping on the appearance of a bistable apparent-motion (Ternus) display. Subjects viewed a Ternus display embedded in an array of context elements that could potentially group with the Ternus elements. In contrast to several previous findings, we found that grouping influenced apparent motion perception. In Experiment 1, apparent motion perception was significantly affected via grouping by shape similarity, even when the visible persistence of the elements was controlled. In Experiment 2, elements perceived as moving without context were perceived as stationary when grouped with stationary context elements. In Experiment 3, elements perceived as stationary without context were perceived as moving when grouped with moving context elements. We argue that grouping in the spatial and temporal domains interact to yield perceptual experience of apparent-motion displays.     

The effects of global grouping laws on surface lightness perception

Previous studies of lightness perception have shown that local surface grouping laws such as proximity and T junction were powerful determinants of target surface lightness. Recent lightness theories also emphasize the importance of local grouping of surfaces. In this study, we further examined the effects of three global grouping laws--symmetry, repetition, and alternation--on lightness perception. Local surface grouping laws such as proximity and good continuation were controlled across all of our stimulus displays. Participants' lightness perception consistently depended on a given surface's belongingness as determined by these laws--that is, global grouping laws affected a target surface's lightness perception. Our results indicate that global grouping laws determine a target surface's lightness when local surface grouping does not produce any distinct surface belongingness. Implications of our basic results are discussed in terms of a recent lightness theory.     

Induced perceptual grouping

ABSTRACT— The term perceptual grouping is associated with classical principles such as similarity and proximity. This article reports induced perceptual grouping, a phenomenon that occurs when placement of a uniform set of items near a structured set induces grouping within the otherwise uniform set. For example, when items grouped pair-wise by similarity are placed near another set of unstructured items, an analogous pair-wise grouping links elements of the second set. Induced grouping affected reaction times in two different visual search tasks, with reaction times depending on whether the target properties were contained within a group or crossed group boundaries as defined by induced grouping due to similarity, proximity, or common fate. Induced grouping was reduced when grouping between the structured and unstructured sets was weakened by means of a common-region cue or decreased similarity. Induced grouping appears to reflect the computation of hierarchical structure in visual images.     

Perceptual grouping and attention: Not all groupings are equal

We examined grouping under inattention using Driver, Davis, Russell, Turatto, & Freeman’s (2001) method. On each trial, two successive displays were briefly presented, each comprising a central target square surrounded by elements. The task was to judge whether the two targets were the same or different. The organization of the background elements stayed the same or changed, independently of the targets. In different conditions, background elements grouped into columns/rows by color similarity, a shape (a triangle/arrow, a square/cross, or a vertical/horizontal line) by color similarity, and a shape with no other elements in the background. We measured the influence of the background on the target same-different judgments. The results imply that background elements grouped into columns/rows by color similarity and into a shape when no segregation from other elements was involved and the shape was relatively “good.” In contrast, no background grouping was observed when resolving figure-ground relations for segregated units was required, as in grouping into a shape by color similarity. These results suggest that grouping is a multiplicity of processes that vary in their attentional demands. Regardless of attentional demands, the products of grouping are not available to awareness without attention.     

Parallel and competitive processes in hierarchical analysis: perceptual grouping and encoding of closure.

The role of perceptual grouping and the encoding of closure of local elements in the processing of hierarchical patterns was studied. Experiments 1 and 2 showed a global advantage over the local level for 2 tasks involving the discrimination of orientation and closure, but there was a local advantage for the closure discrimination task relative to the orientation discrimination task. Experiment 3 showed a local precedence effect for the closure discrimination task when local element grouping was weakened by embedding the stimuli from Experiment 1 in a background made up of cross patterns. Experiments 4A and 4B found that dissimilarity of closure between the local elements of hierarchical stimuli and the background figures could facilitate the grouping of closed local elements and enhanced the perception of global structure. Experiment 5 showed that the advantage for detecting the closure of local elements in hierarchical analysis also held under divided- and selective-attention conditions. Results are consistent with the idea that grouping between local elements takes place in parallel and competes with the computation of closure of local elements in determining the selection between global and local levels of hierarchical patterns for response.     

Perceptual grouping and distance estimates in typical and atypical development: comparing performance across perception, drawing and construction tasks

Perceptual grouping is a pre-attentive process which serves to group local elements into global wholes, based on shared properties. One effect of perceptual grouping is to distort the ability to estimate the distance between two elements. In this study, biases in distance estimates, caused by four types of perceptual grouping, were measured across three tasks, a perception, a drawing and a construction task in both typical development (TD: Experiment 1) and in individuals with Williams syndrome (WS: Experiment 2). In Experiment 1, perceptual grouping distorted distance estimates across all three tasks. Interestingly, the effect of grouping by luminance was in the opposite direction to the effects of the remaining grouping types. We relate this to differences in the ability to inhibit perceptual grouping effects on distance estimates. Additive distorting influences were also observed in the drawing and the construction task, which are explained in terms of the points of reference employed in each task. Experiment 2 demonstrated that the above distortion effects are also observed in WS. Given the known deficit in the ability to use perceptual grouping in WS, this suggests a dissociation between the pre-attentive influence of and the attentive deployment of perceptual grouping in WS. The typical distortion in relation to drawing and construction points towards the presence of some typical location coding strategies in WS. The performance of the WS group differed from the TD participants on two counts. First, the pattern of overall distance estimates (averaged across interior and exterior distances) across the four perceptual grouping types, differed between groups. Second, the distorting influence of perceptual grouping was strongest for grouping by shape similarity in WS, which contrasts to a strength in grouping by proximity observed in the TD participants.     

Hierarchical attention in discriminating objects at different levels of specificity

An implicit assumption of studies in the attentional literature has been that global and local levels of attention are involved in object recognition. To investigate this assumption, a divided attention task was used in which hierarchical figures were presented to prime the subsequent discrimination of target objects at different levels of category identity (basic and subordinate). Target objects were identified among distractor objects that varied in their degree of visual similarity to the targets. Hierarchical figures were also presented at different sizes and as individual global and local elements in order to investigate whether attention-priming effects on object discrimination were due to grouping/parsing operations or spatial extent. The results showed that local processing primed subordinate object discriminations when the objects were visually similar. Global processing primed basic object discriminations, regardless of the similarity of the distractors, and subordinate object discriminations when the objects were visually dissimilar. It was proposed that global and local processing aids the selection of perceptual attributes of objects that are diagnostic for recognition and that selection is based on two mechanisms: spatial extent and grouping/parsing operations.