注意定势和刺激特征对无意视盲的影响

研究采用动态无意视盲范式,呈现3个2×2的被试间实验,考察注意定势和刺激特征对无意视盲的影响.研究结果显示,非预期刺激与注意项目的特征显著性独立于注意定势,非预期刺激与注意项目的特征相似性则基于注意定势.显著的刺激容易被觉察,但它不会总是自动地捕获注意,最重要的影响因素是观察者的注意定势.     

注意定势对基于空间位置的返回抑制的影响

将研究注意定势的比例控制范式与基于空间位置的返回抑制范式相结合。系统地探讨了与空间位置相关的注意定势对基于空间位置的返回抑制的影响。结果表明。在20％和50％有效条件下均出现了显著的返回抑制。但由于注意定势的作用。20％有效条件下的返回抑制量要明显高于50％有效条件;而在80％有效条件下．没有出现返回抑制。并且外显地形成相关注意定势的被试显示出显著的返回抑制的反转。而没有外显地形成相关注意定势的被试则显示出了返回抑制效应。这表明,内源性的注意定势对返回抑制的质和量都有重要影响。适当的注意定势可以在任意方向上改变返回抑制。     

语义关联的注意捕获——来自线索化范式的证据

采用线索化范式, 操作性地建立线索和靶子的语义关联, 考察语义关联对注意捕获的影响。实验1采用特征线索意义靶子的形式, 建立某一特定语义水平的注意控制定势, 发现线索靶子语义一致时线索捕获注意, 线索靶子语义不一致时同样的线索失去捕获注意的能力。实验2随机呈现线索颜色和靶子汉字, 建立两种语义概念的注意控制定势, 发现所有的线索都出现了捕获效应, 而不论其在某一具体试次中是否与靶子意义一致。实验3交换了线索与靶子的属性及概念, 采用意义线索特征靶子的形式, 结果与实验1一致。这些结果表明, (1)语义关联的注意捕获符合关联性的无意注意定向假说, 刺激的捕获能力受当前的注意控制定势调节; (2)由语义概念激活的知觉表征在调节空间注意分配上与其自身相比形式相同, 但程度有所下降; (3)知觉特征水平的注意控制定势能够激活与其相应的语义概念, 使其吸引注意并调节空间注意分配; (4)知觉表征和语义概念的激活可能是双向的, 激活后在指导注意转移上表现出相同的特性。     

类别注意控制定势在注意捕获中的加工机制

注意捕获是指注意定向的过程中刺激不自觉地捕获注意的现象。在复杂的视觉搜索任务中, 类别注意控制定势(cACS)能够帮助我们将注意引导到与目标定义类别匹配的刺激上, 并对其进行优先加工。探讨cACS在注意捕获中的加工机制, 不仅能够扩展注意捕获领域的理论研究, 还能对实际生活提供指导。通过文献梳理, 从cACS的作用阶段、cACS的加工强度及cACS作用时的激活脑区三个方面总结了注意捕获中的cACS的加工机制。未来研究可以就抑制分心物的ACS、不同类型的cACS加工差异和人工类别ACS加工过程等进行探讨。     

自上而下任务定势影响基于关系的注意捕获

采用空间线索化范式,考察在有无任务定势的强化下对涉及关系信息的注意捕获的影响。实验一在线索呈现和目标呈现中分别设置线索颜色关系和靶刺激颜色关系,要求被试在二者关系一致与否两种情况下对目标呈现中颜色奇异的靶刺激进行辨别。实验二在原有的颜色关系的基础上,要求被试忽略目标呈现中某一颜色关系条件下的靶刺激,限定只对另一颜色关系下的目标呈现进行任务反应。实验一结果显示无论颜色关系一致与否,颜色奇异项都优先捕获注意,注意捕获以自动化的形式呈现。实验二结果表明注意会选择性的指向与线索呈现中颜色关系相同的靶刺激而非单纯地捕获奇异颜色项。注意捕获可以基于"关系"模式而非具体的特征。总的来说,基于关系信息的注意捕获只有在建立很强的自上而下注意控制定势的条件下才能产生。     

刺激类型及表征关系对无意视盲的影响

通过考察刺激类型以及重叠呈现的图片流和词语流的表征关系对非注意刺激的捕获差异,试图考察刺激类型和表征关系对无意视盲（Inattentional Blindness）的影响。分别有20名中学生参加了词和图片基线水平测试,52名中学生参与了无意视盲实验。研究结果表明：（1）当词与图片重叠呈现时,不管注意刺激是词还是图片,也不管词与图片的表征是否一致,与基线水平相比,被试都出现了显著的无意视盲现象。（2）当词与图片的表征意义一致时,如果注意刺激是图片,而非注意刺激是词,那么被试更容易觉察到非注意刺激。（3）非注意刺激与注意刺激表征意义一致时更容易捕获观察者的注意     

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。     

特征关联的类别间面孔适应

研究通过系列实验探讨了面孔适应不仅仅发生在形状选择性上, 也能发生在任务相关的特征上有内在关联的两个不同类别的物体间。实验1以带有明显性别倾向的物品图片作为适应刺激, 让被试对男女之间morphing程度不同的图片面孔进行性别辨别, 考察了不同适应刺激呈现时间的类别间面孔适应。结果表明适应刺激呈现时间大于50 ms时均存在类别间面孔适应效应。实验2评估了“性别”这一特征以及适应刺激形式在类别间面孔适应中所起的作用, 结果发现带有性别倾向的物品图片、相应的物品名称和性别文字(“男性”、“女性”) 3种适应刺激类型均能产生类别间适应。实验3通过操纵适应刺激上的注意负荷(高负荷、低负荷和无负荷), 探究了注意对类别间面孔适应的影响。结果表明随着注意负荷的增加, 类别间面孔适应效应减小。3个实验报告了一个新异的类别间适应后效, 证明了适应也能发生于在任务相关特征上有内在关联的两个不同类别的物体间。     

网络成瘾倾向者在视觉工作记忆引导下的注意捕获

采用工作记忆任务和视觉搜索任务相结合的双任务范式, 探讨网络成瘾倾向者在视觉工作记忆引导下的注意捕获。实验1考察了单一分心刺激视场中分心刺激的性质对网络成瘾倾向者选择性注意的影响, 实验2通过控制匹配试验出现的概率来诱发不同的抑制动机, 探讨多分心刺激视场中两种抑制动机下网络成瘾倾向者的注意表现。结果发现：(1)无论在单一分心刺激还是多分心刺激视场中, 网络成瘾倾向被试的目标搜索反应时均显著短于正常组被试, 且两组的搜索正确率没有差异。(2)在单一分心刺激视场中, 无论是与工作记忆项目匹配还是不匹配的分心刺激都会捕获正常组被试的注意, 但不会捕获网络成瘾倾向被试的注意。(3)在多分心刺激视场中, 当抑制动机水平较低时, 两组被试均对匹配分心物产生注意捕获效应, 且网络成瘾倾向被试受工作记忆引导的注意捕获效应小于正常组被试; 当抑制动机较高时, 两组被试均对匹配分心物产生注意抑制效应, 且没有差异。研究结果表明, 面对非网络相关视觉刺激时, 网络成瘾倾向者受工作记忆引导的注意捕获效应小于正常组, 并表现出了知觉加工上的优势。     

高强迫症状个体对图片刺激的注意偏向

以往强迫症注意偏向研究呈现出不一致的结果。为探索研究结果的不一致性是否由于被试取样和刺激选择所导致,当前研究改用非临床强迫症状个体作为研究对象,采用图片作为刺激来引发被试的反应和脑电波的变化。研究采用2(高强迫症状组、低强迫症状组)×3(中性图片、一般威胁图片和强迫相关图片)的混合实验设计,因变量为反应时和相关的脑电成分,结果显示:高强迫症状组较低强迫症状组对强迫相关图片表现出了更大幅度的P2波幅的变化。从而可以推断出,高强迫症状个体对强迫相关图片表现出了明显的注意偏向,其成分为注意脱困,主要发生在早期自动化加工阶段。     

Perception without attention: results of a new method.

Having found by the use of a new method for examining perception without attention that grouping and texture segregation do not seem to occur (see Mack, Tang, Tuma, Kahn, & Rock (1992) Cognitive Psychology, 24, we go on to ask what is perceived without attention using this new method. Our subjects receive only one inattention trial in a sequence of trials involving a visual distraction task. In addition to the distraction task in the inattention trial, subjects received a stimulus of which they had no prior knowledge or expectation and were questioned or tested directly afterward for their perception of that stimulus. Two subsequent trials containing test stimuli serve as within-subject controls. The results of a series of experiments indicate that the presence of one or more stimulus objects and their locations are preattentively perceived, as is their color, but shape is not. Because individual items are detected without attention, we conclude that perceptual organization is initially based on a principle in which connected regions of uniform stimulation are inferred to be discrete units (the principle of uniform connectedness). One striking, unexpected finding is that without attention many subjects have no awareness at all of the stimulus object, an effect we call inattentional blindness.     

非预想刺激的运动速率对无意视盲的影响

无意视盲是指由于对某些事物的专注而导致的眼前对象被忽视的现象。它受到诸如非预想刺激的位置、大小、颜色; 非预想刺激与注意刺激之间的关系; 被试的年龄、专业知识、加工能力等诸多因素的影响。本文通过改进的MR范式考察了“等时”和“等距”条件下非预想刺激的运动速率对无意视盲的影响。实验结果显示: (1)非预想刺激的运动速率和其呈现时间对无意视盲的比率有显著影响; (2)在一定的呈现时间范围内, 视盲率随运动速率的升高而降低, 但当维持相等的运动距离时, 视盲率没有显著变化; (3)当呈现时间超出一定范围时, 运动速率对无意视盲的影响急剧减小, 即呈现时间制约着运动速率对无意视盲的影响, 两者间呈倒U型曲线关系。文末就实验结果进行了详细分析和讨论。     

Gist perception requires attention

Four experiments (240 subjects) explored gist perception without attention using the Mack and Rock (1998) cross task. Twelve scenes were flashed under conditions of inattention, divided, and full attention. Subjects described what they saw on critical trials in which a scene was flashed with the cross. In Experiments 3 and 4 subjects also chose the scene from a four scene array. In Experiment 4 the critical scenes were shown twice in the inattention condition. Overall, only 17% reported gist in the inattention condition, 65% did so with divided, and 82% did so with full attention. In Experiment 4 most subjects remained inattentionally blind to the scenes even though they were shown twice, conditions which fostered repetition priming, and we found a suggestion of negative priming. The results of all 4 experiments indicate that gist requires attention.     

Location and attention

A discrepancy exists in the literature concerning attention and visual localization accuracy. Prinzmetal, Amiri, Allen, and Edwards (1998), and Tsal and Bareket (1999a) found that localization accuracy increases with attention. Using an inattention paradigm, Rock, Linnett, Grant, and Mack (1992) found no difference between localization accuracy in three attention conditions: inattention, divided attention, and control. Using a similar inattention paradigm, the current study addressed this discrepancy. Subjects were instructed to perform a line judgement task, and attention for an additional location task was manipulated. In Experiment 1, location accuracy was worse in the inattention condition than in either the dividedattention or the control condition. There was no difference between the divided-attention and control conditions. Experiment 2 controlled for the possibility that improved location accuracy in the divided and control conditions was due to the expectation of performing a location response, rather than the manipulation of attention. Our results are in agreement with previous findings (Prinzmetal et al., 1998; Tsal & Bareket, 1999a) and suggest that the apparent discrepancy is due to coarse coding of the location responses in the study by Rock et al. (1992).     

New indirect measures of "inattentive" visual grouping in a change-detection task

It has often been suggested that Gestalt-like visual grouping processes may operate preattentively, but Mack and Rock (1998) suggested that no visual grouping takes place under "inattention." We introduced a new method to assess this. While participants performed a demanding change-detection task on a small matrix at fixation, task-irrelevant background elements were arranged by color sinilarity into columns, rows, or pseudorandomly. Independent of any change in the target matrix, background grouping could also change or remain the same on each trial. This influenced accuracy of change judgments for the central task, even though background grouping or its change usually could not be explicitly reported when probed with surprise questions as in Mack and Rock. This suggests that visual grouping may arise implicitly under inattention and provides a new method for testing the boundaries of this processing. Here we extended the initial result to changes in background grouping remote from the target and to those occurring across an intervening saccade.     

New indirect measures of “inattentive” visual grouping in a change-detection task

It has often been suggested that Gestalt-like visual grouping processes may operate preattentively, but Mack and Rock (1998) suggested that no visual grouping takes place under “inattention.” We introduced a new method to assess this. While participants performed a demanding change-detection task on a small matrix at fixation, task-irrelevant background elements were arranged by color similarity into columns, rows, or pseudorandomly. Independent of any change in the target matrix, background grouping could also change or remain the same on each trial. This influenced accuracy of change judgments for the central task, even though background grouping or its change usually could not be explicitly reported when probed with surprise questions as in Mack and Rock. This suggests that visual grouping may arise implicitly under inattention and provides a new method for testing the boundaries of this processing. Here we extended the initial result to changes in background grouping remote from the target and to those occurring across an intervening saccade.     

Visual mental imagery influences attentional guidance in a visual-search task

Visual mental imagery resembles visual working memory (VWM). Because both visual mental imagery and VWM involve the representation and manipulation of visual information, it was hypothesized that they would exert similar effects on visual attention. Several previous studies have demonstrated that working-memory representations guide attention toward a memory-matching task-irrelevant stimulus during visual-search tasks. Therefore, mental imagery may also guide attention toward imagery-matching stimuli. In the present study, five experiments were conducted to investigate the effects of visual mental imagery on visual attention during a visual-search task. Participants were instructed to visualize a color or an object clearly associated with a specific color, after which they were asked to detect a colored target in the visual-search task. Reaction times for target detection were shorter when the color of the target matched the imagined color, and when the color of the target was similar to that strongly associated with the imagined object, than when the color of the target did not match that of the mental representation. This effect was not observed when participants were not instructed to imagine a color. These results suggest that similar to VWM, visual mental imagery guides attention toward imagery-matching stimuli.     

Contrast and assimilation in categorization and exemplar production

We studied contrast and assimilation in three tasks: an exemplar-production task, a categorization task, and a combined categorization-then-production task. On each trial of the first task, subjects produced a circle when prompted with a category label. In the second task, they classified lines that differed in length into one of four categories. On each trial of the combined task, they classified two lines and then produced a line when prompted by a category label. All three tasks converged on the same conclusion: subjects' representation of the categories (measured in pixels in the production tasks and by the direction of errors in classification) shifted systematically from trial to trial. When successive stimuli were from the same category, the representation of that category was pulled toward the exemplar from the previous trial. When successive stimuli were from different categories, the representations of the neighbouring categories were pushed from the category of the initial stimulus. We conclude that accounts of categorization and identification must accommodate both assimilation and contrast as a function of trial-to-trial shifts in representation.     

Effects of relaxation response training on attentional deficits in schizophrenics

Four groups of six male patients each (12 = schizophrenic; 12 = antisocial personality) volunteered. One group from each diagnostic category were instructed in the Relaxation Response while the other two groups were instructed with a placebo exercise. After training, subjects were exposed to an attentional task involving manual responding to visual stimuli. Analyses of several dependent measures including mean correct responses yielded no significant group differences.     

Grouping does not require attention

Many theories of visual perception stipulate that Gestalt grouping occurs preattentively. Subjects' failure to report perceiving even salient grouping patterns under conditions of inattention challenges this assumption (see, e.g., Mack, Tang, Tuma, Kahn, & Rock, 1992), but Moore and Egeth (1997) showed that although subjects are indeed unable to identify grouping patterns outside the focus of attention, effects of these patterns on visual perception can be observed when they are assessed using implicit, rather than explicit, measures. However, this finding, which is the only one to date demonstrating grouping effects without attention, is open to an alternative account. In the present study, we eliminated this confound and replicated Moore and Egeth's findings, using the Müller-Lyer illusion (Experiments 1 and 2). Moreover, we found converging evidence for these findings with a variant of the flanker task (Experiment 3), when the amount of available attentional resources was varied (Experiments 4 and 5). The results reinforce the idea that, although grouping outside the focus of attention cannot be the object of overt report, grouping processes can occur without attention.