Contextual cueing in multiple object tracking

In this study, we examined whether visual context can be learned through a dynamic display and whether it can facilitate sustained attentional tracking by combining a multiple object tracking (MOT) task and a contextual cueing procedure. The trajectories of the targets and distractors in the MOT task were made invariant by repeatedly presenting them. The results revealed that when the targets were repeatedly displayed, tracking performance implicitly improved, and this effect was enhanced when the unattended distractors in the displays were also repeated. However, the repetition of the distractors alone did not produce any effect. Interestingly, when the targets and distractors were switched in a display in which the distractors had been previously repeated, the tracking performance was impaired as compared with that in the case of nonrepeated displays. We concluded that the contextual information in a dynamic display facilitates attentional tracking and that different types of contextual modulations occurred in MOT processes, such as facilitation for attended targets and inhibition for ignored distractors.     

多目标视觉追踪中物体属性加工的眼动研究*

采用多目标视觉追踪任务(MOT),探讨物体颜色特征对视觉追踪的影响,同时记录被试的眼动情况,探讨追踪过程中颜色特征对眼动模式的影响。结果发现,视觉追踪机制能够对物体的颜色特征进行加工,但加工程度受制于目标物与分心物之间的特征竞争关系。在物体颜色特征条件下,视觉系统采用知觉组织加工策略,以被追踪目标构成的多边形中心为注意中心。在对物体颜色特征的加工中,内源性注意与外源性注意相互影响。     

多目标追踪中基于运动信息的分组效应

本研究旨在探讨运动信息对多目标追踪的影响, 具体为考察多目标追踪中是否存在基于运动信息的分组效应, 以及不同类型表面特征(颜色和形状)对这一效应的影响。实验1发现多目标追踪中存在基于运动信息的分组效应, 并且这一分组效应是自动化的。实验2和实验3分别在不同颜色和不同形状组合条件下考察了基于运动信息的分组效应的稳定性, 结果都表明不同表面特征的组合不会干扰基于运动信息的分组效应的形成, 但其效应量都因表面特征的出现而缩减。整体而言, 多目标追踪中存在基于运动信息的自动化分组效应, 并且这一效应是格式塔法则中共同命运律的具体表现, 能稳定存在于不同表面特征组合之间。     

动态非注意盲中的分心物加工机制：是否存在抑制

系统考察在控制目标与非目标颜色特征属性的条件下, 动态非注意盲中视觉系统是否存在对分心物的抑制机制。实验一为基线实验, 将目标与非目标设置为相同的白色圆形, 考察被试对不同颜色特征(白色或者黑色)新异刺激的觉察情况; 实验二和实验三通过改变目标与非目标的颜色特征, 进一步探讨视觉系统对分心物(包括非目标和新异刺激)的抑制机制。结果发现, 视觉系统对干扰目标追踪(并计数)任务的分心物均产生抑制作用, 并且不同颜色特征的分心物受到的抑制作用不同, 与目标颜色特征相同的分心物受到的抑制作用较大, 相应新异刺激的觉察率低; 与目标颜色特征区分明显的分心物受到的抑制作用较小, 相应新异刺激的觉察率较高。     

The role of visual attention in multiple object tracking: Evidence from ERPs

We examined the role of visual attention in the multiple object tracking (MOT) task by measuring the amplitude of the N1 component of the event-related potential to probe flashes presented on targets, distractors, or empty background areas. We found evidence that visual attention enhances targets and suppresses distractors (Experiments 1 and 3). However, we also found that when tracking load was light (two targets and two distractors), accurate tracking could be carried out without any apparent contribution from the visual attention system (Experiment 2). Our results suggest that attentional selection during MOT is flexibly determined by task demands, as well as tracking load, and that visual attention may not always be necessary for accurate tracking.     

The semantic category-based grouping in the Multiple Identity Tracking task

In the Multiple Identity Tracking (MIT) task, categorical distinctions between targets and distractors have been found to facilitate tracking (Wei, Zhang, Lyu, & Li in Frontiers in Psychology, 7, 589, 2016). The purpose of this study was to further investigate the reasons for the facilitation effect, through six experiments. The results of Experiments 1–3 excluded the potential explanations of visual distinctiveness, attentional distribution strategy, and a working memory mechanism, respectively. When objects’ visual information was preserved and categorical information was removed, the facilitation effect disappeared, suggesting that the visual distinctiveness between targets and distractors was not the main reason for the facilitation effect. Moreover, the facilitation effect was not the result of strategically shifting the attentional distribution, because the targets received more attention than the distractors in all conditions. Additionally, the facilitation effect did not come about because the identities of targets were encoded and stored in visual working memory to assist in the recovery from tracking errors; when working memory was disturbed by the object identities changing during tracking, the facilitation effect still existed. Experiments 4 and 5 showed that observers grouped targets together and segregated them from distractors on the basis of their categorical information. By doing this, observers could largely avoid distractor interference with tracking and improve tracking performance. Finally, Experiment 6 indicated that category-based grouping is not an automatic, but a goal-directed and effortful, strategy. In summary, the present findings show that a semantic category-based target-grouping mechanism exists in the MIT task, which is likely to be the major reason for the tracking facilitation effect.     

The effects of distractors in multiple object tracking are modulated by the similarity of distractor and target features

Is the effect of distractors in multiple object tracking dependent on the distractors sharing the features of the targets? In experiment 1, observers tracked five targets among five distractors that were identical to the targets and a number of additional distractors that were either identical to or featurally distinct from the targets. Results showed that distractors that are distinct from the targets in shape or color, or are stationary, impair tracking less than distractors that are identical to the targets. However, tracking performance declined as the number of distractors increased, even for featurally distinct distractors. Experiment 2 showed that distractors that differ from the targets on two features impair tracking less than distractors that differ from the targets on only one feature, but only when target tracking load is low. These results indicate that shape, color, and motion information about distractors can be used to distinguish them from targets during tracking, although even distractors with a different feature from the targets produce some interference with tracking. These findings suggest that the effect of distractors on tracking is dependent on top-down settings for target features.     

Efficient visual search without top-down or bottom-up guidance

Two types of mechanisms have dominated theoretical accounts of efficient visual search. The first are bottom-up processes related to the characteristics of retinotopic feature maps. The second are top-down mechanisms related to feature selection. To expose the potential involvement of other mechanisms, we introduce a new search paradigm whereby a target is defined only in a context-dependent manner by multiple conjunctions of feature dimensions. Because targets in a multiconjunction task cannot be distinguished from distractors either by bottom-up guidance or top-down guidance, current theories of visual search predict inefficient search. While inefficient search does occur for the multiple conjunctions of orientation with color or luminance, we find efficient search for multiple conjunctions of luminance/size, luminance/shape, and luminance/topology. We also show that repeated presentations of either targets or a set of distractors result in much faster performance and that bottom-up feature extraction and top-down selection cannot account for efficient search on their own. In light of this, we discuss the possible role of perceptual organization in visual search. Furthermore, multiconjunction search could provide a new method for investigating perceptual grouping in visual search.     

Higher visuo-Attentional Demands of Multiple Object Tracking (MOT) Lead to A Lower Precision in Pointing Movements

Multiple object tracking (MOT) requires visually attending to dynamically moving targets and distractors. This cognitive ability is based on perceptual-attentional processes that are also involved in goal-directed movements. This study aimed to test the hypothesis that MOT affects the motor performance of aiming movements. Therefore, the participants performed pointing movements using their fingers or a computer mouse that controlled the movements of a cursor directed at the targets in the MOT task. The precision of the pointing movements was measured, and it was predicted that a higher number of targets and distractors in the MOT task would result in a lower pointing precision. The results confirmed this hypothesis, indicating that MOT might influence the performance of motor actions. The potential factors underlying this influence are discussed.     

目标大小变化对多目标视觉追踪的影响

采用多目标追踪任务（MOT）对追踪过程中被试（16名）的眼动进行记录,探讨目标特征变化对视觉追踪的影响。结果表明：视觉追踪机制能够对物体的特征属性进行编码加工,但加工程度受制于目标物与分心物之间的特征竞争关系;追踪过程中,视觉系统采用知觉组织加工策略,以被追踪目标构成的多边形中心为注意中心;物体大小特征没有引起较多的外源性注意,在物体大小特征的变化条件下,视觉追踪主要是内源性的注意控制加工过程。     

Attentional signatures of perception: multiple object tracking reveals the automaticity of contour interpolation

Multiple object tracking (MOT) is an attentional task wherein observers attempt to track multiple targets among moving distractors. Contour interpolation is a perceptual process that fills-in nonvisible edges on the basis of how surrounding edges (inducers) are spatiotemporally related. In five experiments, we explored the automaticity of interpolation through its influences on tracking. We found that (1) when the edges of targets and distractors jointly formed dynamic illusory or occluded contours, tracking accuracy worsened; (2) when interpolation bound all four targets together, performance improved; (3) when interpolation strength was weakened (by altering the size or relative orientation of inducing edges), tracking effects disappeared; and (4) real and interpolated contours influenced tracking comparably, except that real contours could more effectively shift attention toward distractors. These results suggest that interpolation's characteristics-and, in particular, its automaticity-can be revealed through its attentional influences or "signatures" within tracking. Our results also imply that relatively detailed object representations are formed in parallel, and that such representations can affect tracking when they become relevant to scene segmentation.     

多身份追踪中基于表情特征的分组效应

探讨了表情因素作为身份特征对多身份追踪中分组效应的影响。采用多身份追踪范式, 8个客体为表情图片(正性、负性、中性)其中4个为目标, 对45名被试进行了有无眉毛线索对追踪表现影响的测查。实验条件分别为：目标表情与非目标表情完全不相同组(4水平, 简称分组)、目标表情与非目标表情都由两种相同数量的表情混合组成(3水平, 简称配对)与基线组(8个客体表情相同)。发现分组水平的成绩显著优于基线组, 配对水平的成绩显著低于基线组, 并表现出了负性表情的追踪优势; 另外, 有无眉毛线索对追踪表现无显著影响。这一结果说明多身份追踪中存在基于表情特征的分组效应, 负性表情的分组知觉高于正性表情。     

Color categories and color appearance

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue-green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses.     

多目标追踪的神经机制

多目标追踪任务是研究动态场景中视觉注意加工机制常用的范式。自1998年开始对多目标追踪神经机制的影像学研究以来, 研究者采用ERP和fMRI等技术对多目标注意追踪所涉及的神经电生理活动和脑功能区激活方面开展了大量研究。ERP研究发现, 追踪过程持续的ERP脑电成分如N2pc、CDA的波幅与注意追踪负荷有关, 并且出现在目标与非目标上的探测刺激诱发的脑电成分如N1、P1波幅的差异可反映注意资源的分配, 具体为目标在追踪过程中得到了激活, 而非目标受到了抑制。fMRI研究比较一致地发现了顶叶(包括前顶内沟、后顶内沟、顶上小叶)、背外侧额叶皮层等在注意追踪中的强烈激活。其中顶内沟主要与注意负荷有关, 顶内沟的活动水平直接决定了观察者注意追踪的行为表现。而顶上小叶可能更多的负责注意转移。背外侧额叶皮层可能负责追踪时的感觉运动预测过程。     

知觉加工中存在颜色类别知觉效应的证据

对于颜色的辨别具有类别知觉效应：类间两种颜色的辨别能力比同等颜色空间距离的类内两种颜色的辨别能力更高。对于类别知觉效应的产生机制存在两种观点：知觉特性假设、语言标签假设。以往的研究范式由于实验任务涉及到工作记忆成分,被试在完成任务时会自动地对颜色命名以利于记忆,因此所得证据大多支持语言标签假设,而对知觉特性假设的支持证据则很少。本文利用目标觉察范式最大限度去掉了工作记忆成分,通过测量被试辨别两种颜色的反应时,得到了类别知觉效应。并通过语言干扰任务进一步证实在该实验范式下类别知觉效应与语言的无关性。从而,为知觉特性假设提供了证据     

Automatization and training in visual search.

In several search tasks, the amount of practice on particular combinations of targets and distractors was equated in varied-mapping (VM) and consistent-mapping (CM) conditions. The results indicate the importance of distinguishing between memory and visual search tasks, and implicate a number of factors that play important roles in visual search and its learning. Visual search was studied in Experiment 1. VM and CM performance were almost equal, and slope reductions occurred during practice for both, suggesting the learning of efficient attentive search based on features, and no important role for automatic attention attraction. However, positive transfer effects occurred when previous CM targets were re-paired with previous CM distractors, even though these targets and distractors had not been trained together. Also, the introduction of a demanding simultaneous task produced advantages of CM over VM. These latter two results demonstrated the operation of automatic attention attraction. Visual search was further studied in Experiment 2, using novel characters for which feature overlap and similarity were controlled. The design and many of the findings paralleled Experiment 1. In addition, enormous search improvement was seen over 35 sessions of training, suggesting the operation of perceptual unitization for the novel characters. Experiment 3 showed a large, persistent advantage for CM over VM performance in memory search, even when practice on particular combinations of targets and distractors was equated in the two training conditions. A multifactor theory of automatization and attention is put forth to account for these findings and others in the literature.     

Language is not necessary for color categories

The origin of color categories is under debate. Some researchers argue that color categories are linguistically constructed, while others claim they have a pre‐linguistic, and possibly even innate, basis. Although there is some evidence that 4–6‐month‐old infants respond categorically to color, these empirical results have been challenged in recent years. First, it has been claimed that previous demonstrations of color categories in infants may reflect color preferences instead. Second, and more seriously, other labs have reported failing to replicate the basic findings at all. In the current study we used eye‐tracking to test 8‐month‐old infants’ categorical perception of a previously attested color boundary (green–blue) and an additional color boundary (blue–purple). Our results show that infants are faster and more accurate at fixating targets when they come from a different color category than when from the same category (even though the chromatic separation sizes were equated). This is the case for both blue–green and blue–purple. Our findings provide independent evidence for the existence of color categories in pre‐linguistic infants, and suggest that categorical perception of color can occur without color language.     

Object property encoding and change blindness in multiple object tracking

The paradigm of multiple object tracking (MOT) is an established tool for investigating human performance under conditions of divided attention to several objects. We studied change detection ability for colour and shape information in the setting of MOT. Subjects had to detect colour and shape changes during an MOT task. These changes occurred either openly (with nothing to hide them) or with a mud splash in the background to hide the change transient signal. Our experiment demonstrated that (1) when hidden by mud splashes, we fail to perceive a considerable number of colour changes even in the attended objects (i.e., targets) and (2) the visual system is significantly more likely to miss colour and shape changes in distractors than in target. We conclude that a colour change will be detected a lot more efficiently if attention is drawn to its transient. When a simultaneous mud splash hides the transient signal, subjects are significantly less efficient in detecting the change.     

威胁性刺激蛇一定会被更快觉察吗?蛇与蜥蜴的对比

大量运用视觉搜索范式的研究发现,在进化过程中对人类生存具有威胁的蛇会被人们更快地觉察。但已有研究采用动物（蛇）植物（花）配对搜索的方式,而很少直接采用近似的动物配对搜索。本研究选取成人大学生被试,通过视觉搜索范式和眼动追踪,对比了蛇和同为爬行类动物、却不具有进化上威胁性的蜥蜴的视觉搜索过程,以探究蛇的威胁性和动物特征相似性在威胁性刺激注意偏向中的作用。实验1采用蛇和蜥蜴互为目标物和干扰物,发现相对于蛇,被试对蜥蜴的行为反应时更短;首次注视到达时间也更短。实验2-4分别采用黑白和线画刺激、恒定干扰物（花和青蛙）、使用自然背景材料对比蛇和蜥蜴的觉察,发现了一致的结果,即被试对蜥蜴的视觉搜索时间和行为反应时间都要快于蛇。在视觉搜索任务中当两种视觉刺激材料的属性接近时,蛇在进化上的威胁性不一定导致更快的搜索时间,而刺激物的视觉特征对目标物的觉察会产生重要的影响。     

Tracking objects that move where they are headed

Previous work has demonstrated that the ability to keep track of moving objects is improved when the objects have unique visual features, such as color or shape. In the present study, we investigated how orientation information is used during the tracking of objects. Orientation is an interesting feature to explore in moving objects because it is directional and is often informative of the direction of motion. Most objects move forward, in the direction they are oriented. In the present experiments, participants tracked a subset of moving isosceles triangles whose orientations were constant, related, or unrelated to the direction of motion. In the standard multiple object tracking (MOT) task, tracking performance improved when orientations were unique and remained constant, but not when orientation and direction of motion were aligned. In the target recovery task, in which MOT was interrupted by a brief blanking of the display, performance did improve when orientation and direction were aligned. In the final experiment, results showed that orientation was not used before the blank to predict future target locations, but was instead used after the blank. We concluded that people use orientation to compare a stored representation to target position for recovery of lost targets.