知觉与行为分离现象在二维铁钦纳错觉实验中的验

利用二维铁钦纳错觉图片对单手及双手抓握情境下的知觉与行为分离现象进行实验验证,并探讨注意引导等因素对分离现象的影响。实验包括知觉任务和行为任务两项内容,前者主要测量被试的主观错觉量,后者则探讨分离现象是否存在及其影响因素。在行为任务中,记录被试在中心（目标）圆尺寸“实际相同”和“知觉相同”等不同情境下的行为,以拇指和食指抓握图片中心圆的最大抓握孔径为行为指标。结果发现：单手抓握时,左、右手的行为虽然在一定程度上受到了错觉的影响,但均显示出分离现象;双手抓握时,右手受错觉影响的程度减少,分离现象增强,而左手的结果则比较混淆。因此,分离现象是存在的,但它的出现可能受到注意引导、注意分配倾向或双手协调能力等因素的影响。     

从视觉知觉与行为的分离看行为的计划-控制模型

知觉与行为的分离现象最早是从临床病例中发现的,以后研究者在正常人身上利用错觉实验范式继续探索该现象,并由此发展了4个模型进行解释。其中,计划-控制模型得到了众多实验事实的支持。该模型认为：行为分为计划和控制两个阶段,每个阶段都有独立的加工模块,每个模块使用不同的视觉表征;错觉影响计划阶段,但是不影响在线控制阶段。本文重点回顾了动态错觉效应对计划-控制模型的实验验证,并进行了评价和展望     

知觉与行为的分离假设和注意引导

许多支持知觉和行为分离的研究存在知觉任务与行为任务对注意对象要求不一致的现象,知觉任务要求注意整体而行为任务只注意局部。因此本研究提出假设:如果把知觉实验中的注意引导向局部,两类任务没有显著差异。本研究分别设计了把被试的注意引向局部条件下的知觉任务和抓握任务,通过判断不同长度水平下木块的宽度来研究木块的长度对宽度判断有无影响。结果表明:不同的长度水平对木块宽度的知觉判断和最大抓握孔径都没有影响。因此本研究认为前人支持知觉行为分离假说的研究结论与注意引导有关。     

视错觉产生的神经机制

传统认知心理学对视觉错觉的解释存在局限性。认知神经科学在移动错觉、轮廓错觉、颜色错觉研究中的一批新发现,可以综合并概括为一种视错觉发生的神经关联重叠机制。该重叠性表现为错觉与相应的真实知觉具有本质上相同的神经活动,即错觉与真实知觉享有共同的神经关联,没有只对错觉反应而不对真实知觉反应的特定神经关联物,而错觉神经活动的特别之处是在真实知觉发生的相同脑区有更强烈的激活     

错觉研究:从狭义到广义的演进

心理学家对错觉现象的关注由来已久,以往的错觉研究大部分关注与知觉过程相联系的错觉。近十几年来,当代错觉研究呈现出新的热点,并从狭义向广义演进。这一研究对象扩展的基础,是错觉现象的本质特征,即认知过程的一致性偏差。广义错觉研究的对象涉及知觉、记忆、思维、推理等各种心理过程。     

词汇听觉使用频率在两类记忆测验中的比较研究

讨论了词语使用过程中视觉使用频率和听觉使用频率的区分。通过两个实验对听觉使用频率进行了探讨。实验一通过量表评定法得到了两组视觉使用频率相同,但听觉使用频率不同的双字词,实验二利用实验一得到的两组双字词对被试进行了记忆测验,在单一的听觉条件下,发现在自由回忆,听觉再认和模糊辨听这两类不同的记忆测验中出现了实验性分离现象;反映了听觉使用频率自身的一些特征。     

规范错觉对外出就餐中食物浪费的影响：心理机制与应对策略

规范错觉是指个体的规范感知与实际存在于群体中的社会规范之间存在差异, 规范错觉影响了社会生活的方方面面。对957份问卷调查的分析显示, 人们普遍高估了他人的食物浪费(行为错觉)以及对浪费的赞同程度(态度错觉), 而这两种错觉又加剧了人们自身的浪费行为。中介效应检验显示, 印象管理中的社交性维度部分中介了两种错觉与浪费行为间的关系。两个随机对照实验进一步检验了描述性(命令性)规范信息对行为(态度)错觉的影响, 结果发现, 描述性规范信息降低了行为错觉, 并通过社交性减少了浪费行为; 而命令性规范信息并不改变态度错觉本身, 但通过降低态度错觉对浪费的影响而减少了浪费行为。上述结果意味着两种规范信息尽管高度相似, 但其作用机制却可能不同, 同时这一发现也为政策制定者提出了两种干预途径。     

大小错觉视角下的眼妆研究

视错觉是一种视觉认知,是在某种知觉条件下产生的对外界事物特性的扭曲。视错觉的产生原因,不仅有脑认知活动导致的生理因素,又有主观线索和经验引起的心理因素。视错觉可以按照不同的现象和成因分为尺寸错觉、轮廓错觉、运动错觉、细胞群错觉、扭曲错觉和不可能图形等六大类。     

图形结构对直线知觉长度的影响

问题图形对它所包含的线条的知觉长度有极重要的影响,可使两个有相同的物埋长度的线条看起来不一样长。这构成一些著名的几何错觉,在心理学中已提出各种不同的解释。与此有关,Künnapas(1955)曾经研究正方形框架的大小对其中直线的知觉长度的影响。在他的实验中,作为标准刺激和变异刺激的直线均置于正方形之中,结果发现,变异刺激的正方形     

坡度知觉及其影响因素的研究进展

人们对于地表斜坡的知觉是非常不准确的,通常表现为对坡度估计过高。但是,研究发现,在以行为的方式对坡度进行模拟时,所模拟的坡度值却与实际坡度基本一致。这种面对同一视觉线索出现的视知觉与行为不一致的现象即为坡度知觉中的“知觉-行为分离”。本文回顾了影响坡度知觉的各种因素,涉及视觉线索、认知判断、感觉通道、生理状态以及报告方式等方面的研究,并对坡度知觉的未来研究进行了展望。     

A double dissociation between action and perception in the context of visual illusions: opposite effects of real and illusory size

The idea that there are two distinct cortical visual pathways, a dorsal action stream and a ventral perception stream, is supported by neuroimaging and neuropsychological evidence. Yet there is an ongoing debate as to whether or not the action system is resistant to pictorial illusions in healthy participants. In the present study, we disentangled the effects of real and illusory object size on action and perception by pitting real size against illusory size. In our task, two objects that differed slightly in length were placed within a version of the Ponzo illusion. Even though participants erroneously perceived the physically longer object as the shorter one (or vice versa), their grasping was remarkably tuned to the real size difference between the objects. These results provide the first demonstration of a double dissociation between action and perception in the context of visual illusions and together with previous findings converge on the idea that visually guided action and visual perception make use of different metrics and frames of reference.     

Grasping visual illusions: no evidence for a dissociation between perception and action

Neuropsychological studies prompted the theory that the primate visual system might be organized into two parallel pathways, one for conscious perception and one for guiding action. Supporting evidence in healthy subjects seemed to come from a dissociation in visual illusions: In previous studies, the Ebbinghaus (or Titchener) illusion deceived perceptual judgments of size, but only marginally influenced the size estimates used in grasping. Contrary to those results, the findings from the present study show that there is no difference in the sizes of the perceptual and grasp illusions if the perceptual and grasping tasks are appropriately matched. We show that the differences found previously can be accounted for by a hitherto unknown, nonadditive effect in the illusion. We conclude that the illusion does not provide evidence for the existence of two distinct pathways for perception and action in the visual system.     

Age-related differences in the visual processes implied in perception and action: distance and location parameters

The aim of the two present experiments was to examine the ontogenetic development of the dissociation between perception and action in children using the Duncker illusion. In this illusion, a moving background alters the perceived direction of target motion. Targets were held stationary while appearing to move in an induced displacement. In Experiment 1, 30 children aged 7, 9, and 12 years and 10 adults made a perceptual judgment or pointed as accurately as possible, with their index finger, to the last position of the target. The 7-year-old children were more perceptually deceived than the others by the Duncker illusion but there were no differences for the goal-directed pointing movements. In Experiment 2, 50 children aged 7, 8, 9, 10, and 11 years made a perceptual judgment or reproduced as accurately as possible, with a handle, the distance traveled by the target. Participants were perceptually deceived by the illusion, judging the target as moving although it was stationary. When reproducing the distance covered by the target, children were unaffected by the Duncker illusion. Our results suggest that the separation of the allocentric visual perception pathway from the egocentric action pathway occurs before 7 years of age.     

Effects of visual illusions on grasping

In 2 experiments, the Muller-Lyer illusion (F. C. Muller-Lyer, 1889; N = 16) and the parallel-lines illusion (W. Wundt, 1898; N = 26) clearly affected maximum preshape aperture in grasping (both ps < .001). The grasping effects were similar but not perfectly equal to the perceptual effects. Control experiments show that these differences can be attributed to problems in matching the perceptual task and the grasping task. A model is described stating the assumptions that are needed to compare the grasping effects and the perceptual effects of visual illusions. Further studies on the relationship between perception and grasping are reviewed. These studies provide no clear evidence for a dissociation between perception and grasping and therefore do not support the action versus perception hypothesis (A. D. Milner & M. A. Goodale, 1995).     

Dissociations between vision for perception and vision for action depend on the relative availability of egocentric and allocentric information

In three experiments, we scrutinized the dissociation between perception and action, as reflected by the contributions of egocentric and allocentric information. In Experiment 1, participants stood at the base of a large-scale one-tailed version of a Müller-Lyer illusion (with a hoop) and either threw a beanbag to the endpoint of the shaft or verbally estimated the egocentric distance to that location. The results confirmed an effect of the illusion on verbal estimates, but not on throwing, providing evidence for a dissociation between perception and action. In Experiment 2, participants observed a two-tailed version of the Müller-Lyer illusion from a distance of 1.5 m and performed the same tasks as in Experiment 1, yet neither the typical illusion effects nor a dissociation became apparent. Experiment 3 was a replication of Experiment 1, with the difference that participants stood at a distance of 1.5 m from the base of the one-tailed illusion. The results indicated an illusion effect on both the verbal estimate task and the throwing task; hence, there was no dissociation between perception and action. The presence (Exp. 1) and absence (Exp. 3) of a dissociation between perception and action may indicate that dissociations are a function of the relative availability of egocentric and allocentric information. When distance estimates are purely egocentric, dissociations between perception and action occur. However, when egocentric distance estimates have a (complementary) exocentric component, the use of allocentric information is promoted, and dissociations between perception and action are reduced or absent.     

Conscious Vision for Action Versus Unconscious Vision for Action?

David Milner and Melvyn Goodale’s dissociation hypothesis is commonly taken to state that there are two functionally specialized cortical streams of visual processing originating in striate (V1) cortex: a dorsal, action‐related “unconscious” stream and a ventral, perception‐related “conscious” stream. As Milner and Goodale acknowledge, findings from blindsight studies suggest a more sophisticated picture that replaces the distinction between unconscious vision for action and conscious vision for perception with a tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. The combination excluded by the tripartite division is the possibility of conscious vision for action. But are there good grounds for concluding that there is no conscious vision for action? There is now overwhelming evidence that illusions and perceived size can have a significant effect on action ( Bruno & Franz, 2009 ; Dassonville & Bala, 2004 ; Franz & Gegenfurtner, 2008 ; McIntosh & Lashley, 2008 ). There is also suggestive evidence that any sophisticated visual behavior requires collaboration between the two visual streams at every stage of the process ( Schenk & McIntosh, 2010 ). I nonetheless want to make a case for the tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. My aim here is not to refute the evidence showing that conscious vision can affect action but rather to argue (a) that we cannot gain cognitive access to action‐guiding dorsal stream representations, and (b) that these representations do not correlate with phenomenal consciousness. This vindicates the semi‐conservative view that the dissociation hypothesis is best understood as a tripartite division.     

Wagon-wheel illusion under steady illumination: real or illusory?

Wheels turning in the movies sometimes appear to rotate backwards. This is called the wagon-wheel illusion (WWI). The mechanism of this illusion is based on the intermittent nature of light in films and other stroboscopic presentations, which renders them as a series of snapshots rather than a continuous visual data stream. However, there have been claims that this illusion is seen even in continuous light, which would suggest that the visual system itself may sample a continuous visual data stream. We examined the rate of this putative sampling and its variations across individuals while in different psychological states. We obtained two results: (i) WWI occurred in stroboscopic lights as expected, (ii) WWI was never reported by our subjects under continuous lights, such as sunlight and lamps with DC power source. Thus, WWI cannot be taken as evidence for discreteness of conscious visual perception.     

Visual illusions affect both movement planning and on-line control: a multiple cue position on bias and goal-directed action

Over the last decade, there has been an interest in the impact of visual illusions on the control of action. Much of this work has been motivated by Milner and Goodale's two visual system model of visual processing. This model is based on a hypothesized dissociation between cognitive judgments and the visual control of action. It holds that action is immune to the visual context that provides the basis for the illusion-induced bias associated with cognitive judgments. Recently, Glover has challenged this position and has suggested that movement planning, but not movement execution is susceptible to visual illusions. Research from our lab is inconsistent with both models of visual-motor processing. With respect to the planning and control model, kinematic evidence shows that the impact of an illusion on manual aiming increases as the limb approaches the target. For the Ebbinghaus illusion, this involved a decrease in the time after peak velocity to accommodate the 'perceived' size of the target. For the Müller-Lyer illusion, the influence of the figure's tails increased from peak velocity to the end of the movement. Although our findings contradict a strong version of the two visual systems hypothesis, we did find dissociations between perception and action in another experiment. In this Müller-Lyer study, perceptual decisions were influenced by misjudgment of extent, while action was influenced by misjudgment of target position. Overall, our findings are consistent with the idea that it is often necessary to use visual context to make adjustments to ongoing movements.