The distribution of attention within objects in multiple-object scenes: prioritization by spatial probabilities and a center bias

This study investigates how the attentional distribution within objects is affected by spatial probabilities, bias toward objects' centers (Alvarez & Scholl, 2005), and object motion. In a multiple-object tracking task, observers tracked line objects while simultaneously detecting probes appearing on the objects. Experiments 1 and 2 manipulated the probabilities of probes appearing at the centers and ends of objects. Overall, probe detection was better at centers than at ends, but it was also affected by probe location probabilities; when probe locations were 100% certain, the center advantage was eliminated. Experiment 3 manipulated rotational, translational, and size-change components of object motion. The center advantage still occurred with stationary objects, and its magnitude was not affected by different motion types. These results indicate that attention is biased toward the centers of objects in multiple-object scenes, both for stationary and moving objects. They also imply that attentional prioritizations based on spatial probabilities can accompany moving objects.     

Oculomotion mediates attentional guidance toward temporarily close objects

Previous research has identified multiple features of individual objects that are capable of guiding visual attention. However, in dynamic multi-element displays not only individual object features but also changing spatial relations between two or more objects might signal relevance. Here we report a series of experiments that investigated the hypothesis that reduced inter-object spacing guides visual attention toward the corresponding objects. Our participants discriminated between different probes that appeared on moving objects while we manipulated spatial proximity between the objects at the moment of probe onset. Indeed, our results confirm that there is a bias toward temporarily close objects, which persists even when such a bias is harmful for the actual task (Experiments 1a and 1b). Remarkably, this bias is mediated by oculomotor processes. Controlling for eye-movements reverses the pattern of results (Experiment 2a), whereas the location of the gaze tends toward the temporarily close objects under free viewing conditions (Experiment 2b). Taken together, our results provide insights into the interplay of attentional and oculomotor processes during dynamic scene processing. Thereby, they also add to the growing body of evidence showing that within dynamic perception, attentional and oculomotor processes act conjointly and are hardly separable.     

Action relations, semantic relations, and familiarity of spatial position in Balint’s syndrome: Crossover effects on perceptual report and on localization

We contrasted effects of the action relationship between objects, relative to effects of semantic relation and familiarity of spatial location, in a patient with Balint’s syndrome. We found enhanced perceptual report of objects placed in the correct colocations for action in comparison with when the objects (1) were placed in incorrect locations for action (Experiment 1), (2) were associatively related (Experiment 2), or (3) fell in familiar locations but were not action related (Experiment 4). In contrast, the ability to localize the objects was affected by whether the objects were in familiar as opposed to unfamiliar locations with respect to one another. Action relations between objects facilitate joint attention to both objects but do not facilitate binding to location. Familiar spatial relations facilitate spatial binding, but do not cue joint attention to the stimuli. Effects of action relation on attention and localization can be dissociated from effects of semantic relationship and familiarity of spatial location on attention and localization.     

The impact of monetary stimuli on object-based attention

Previous research has implied that monetary reward to target location (a reward for spatial properties) can affect object-based attention, but no study has directly investigated the influence of monetary objects (a reward for object properties) on object-based attention. Thus, it is unclear whether and how monetary objects can affect object-based attention. To experimentally investigate this problem, this study adapted the well-established two-rectangle paradigm. In Experiment 1, either two 100-yuan notes or two 1-yuan notes were presented to participants. We found an object-based effect with faster responses to targets at an uncued position on the cued object compared to those at an equidistant position on the uncued object; the effect was similar in 100-yuan and 1-yuan note trials. In Experiment 2, two notes (one 100-yuan and one 1-yuan) were simultaneously presented to participants, and cue location (100-yuan, 1-yuan) was manipulated. We found a greater object-based effect when the cue appeared on the 100-yuan note than on the 1-yuan note. These results suggest that the rewarding property of objects can affect object-based attention by means of altering object salience.     

Binding facilitates attention switching within working memory

The authors investigated the units of selective attention within working memory. In Experiment 1, a group of participants kept 1 count and 1 location in working memory and updated them repeatedly in random order. Another group of participants were instructed to achieve the same goal by memorizing the verbal and spatial information in an integrative way as a moving digit. The behavioral data showed that switching attention between properties of an integrated working-memory item was faster than switching between respective properties of different items. Experiment 2 demonstrated that this switching facilitation cannot be simply ascribed to the different amount of working-memory items maintained by the two groups of participants. Finally, by adopting a pure verbal task in Experiment 3, the authors observed the same binding facilitation, with the possibility of "location-based selection" excluded. They summarize the observations of all 3 experiments in the study and suggest both a location- and object-based mechanism for attention selection in working memory.     

Inhibitory guidance in visual search: The case of movement–form conjunctions

We used a probe-dot procedure to examine the roles of excitatory attentional guidance and distractor suppression in search for movement-form conjunctions. Participants in Experiment?1 completed a conjunction (moving X amongst moving Os and static Xs) and two single-feature (moving X amongst moving Os, and static X amongst static Os) conditions. "Active" participants searched for the target, whereas "passive" participants viewed the displays without responding. Subsequently, both groups located (left or right) a probe dot appearing in either an occupied or an unoccupied location. In the conjunction condition, the active group located probes presented on static distractors more slowly than probes presented on moving distractors, reversing the direction of the difference found within the passive group. This disadvantage for probes on static items was much stronger in conjunction than in single-feature search. The same pattern of results was replicated in Experiment?2, which used a go/no-go procedure. Experiment?3 extended the go/no-go procedure to the case of search for a static target and revealed increased probe localisation times as a consequence of active search, primarily for probes on moving distractor items. The results demonstrated attentional guidance by inhibition of distractors in conjunction search.     

Launching at a distance: The effect of spatial markers

It has been widely reported that spatial contiguity is important to judgements of causality involving one object launching another [Michotte's “launching effect” (1963, 1991)]. The present study examined the impact of different types of spatial markers on causal judgements of a distal launch (one object approaching other, stopping short of it, and the second object subsequently moving along the same trajectory). The spatial markers were objects that either partially or completely bridged the spatial gap between two objects (Experiment 1), or they were dashed lines that marked the stopping location of the first object or the starting location of the second object (Experiment 2). The presence of either objects or dashed lines could produce higher causal ratings, but the location of the marker mattered. The results suggest that altering a cause's ability to predict when the effect would occur (via a spatial marker) and the presence of a conduit for energy transmission have independent effects on causal judgements of object interaction.     

运动轨迹和方向对视觉空间关系加工的影响

视觉空间关系分为类别与数量两种表征。研究通过控制起参照作用的运动客体消失状态与定位客体出现时间,分析客体运动信息对两种关系判断的影响。结果发现:运动信息在各间隔时间对类别任务影响呈序列排列,运动方向较轨迹信息有优势,轨迹较法线信息有优势;数量表征仅在0ms间隔受运动方向促进,在其他间隔下,三种位置上的判断均无差异。结果表明运动客体类别表征比数量表征更持久;且相对类别表征,数量判断作为精确距离表征不易受运动方向和轨迹信息影响。     

The role of attention for the Simon effect

Summary It has been claimed that spatial attention plays a decisive role in the effect of irrelevant spatial stimulus-response correspondence (i. e., the Simon effect), especially the way the attentional focus is moved onto the stimulus (lateral shifting rather than zooming). This attentional-movement hypothesis is contrasted with a referential-coding hypothesis, according to which spatial stimulus coding depends on the availability of frames or objects of reference rather than on certain attentional movements. In six experiments, reference objects were made available to aid spatial coding, which either appeared simultaneously with the stimulus (Experiments 1–3), or were continuously visible (Experiments 4–6). In contrast to previous experiments and to the attentional predictions, the Simon effect occurred even though the stimuli were precued by large frames surrounding both possible stimulus positions (Experiment 1), even when the reference object's salience was markedly reduced (Experiment 2), or when the precueing frames were made more informative (Experiment 3). Furthermore, it was found that the Simon effect is not reduced by spatial correspondence between an uninformative spatial precue and the stimulus (Experiment 4), and it does not depend on the location of spatial precues appearing to the left or right of both possible stimulus locations (Experiment 5). This was true even when the precue was made task-relevant in order to ensure attentional focusing (Experiment 6). In sum, it is shown that the Simon effect does not depend on the kind of attentional operation presumably performed to focus onto the stimulus. It is argued that the available data are consistent with a coding approach to the Simon effect which, however, needs to be developed to be more precise as to the conditions for spatial stimulus coding.     

Selection can be performed effectively without temporal binding,but could be even more effective with it

Experiments using spatial cues and spatial probes provide strong evidence for an attention mechanism that chooses a location and selects all information at that location. This selection process can work very quickly; so quickly that selection probably begins before segmentation and grouping. It can be implemented in a neural network simply and efficiently without temporal binding. In conjunction with this spatial attention, however, temporal binding can potentially enhance visual selection in complex scenes. First, it would allow a target object to be selected without also selecting a superimposed distractor. Second, it could maintain representations of objects after attention has moved to another object. Third, it could allow multiple parts of an object or scene to be selected, segmented, and analysed simultaneously. Thus, temporal synchrony should be more likely to appear during tasks with overlapping targets and distractors, and tasks that require that multiple objects or multipart objects be analysed and remembered simultaneously.     

Selective learning of spatial configuration and object identity in visual search

To conduct an efficient visual search, visual attention must be guided to a target appropriately. Previous studies have suggested that attention can be quickly guided to a target when the spatial configurations of search objects or the object identities have been repeated. This phenomenon is termed contextual cuing. In this study, we investigated the effect of learning spatial configurations, object identities, and a combination of both configurations and identities on visual search. The results indicated that participants could learn the contexts of spatial configurations, but not of object identities, even when both configurations and identities were completely correlated (Experiment 1). On the other hand, when only object identities were repeated, an effect of identity learning could be observed (Experiment 2). Furthermore, an additive effect of configuration learning and identity learning was observed when, in some trials, each context was the relevant cue for predicting the target (Experiment 3). Participants could learn only the context that was associated with target location (Experiment 4). These findings indicate that when multiple contexts are redundant, contextual learning occurs selectively, depending on the predictability of the target location.     

The effects of location cuing on redundant-target processing

The present study is concerned with the redundany gain: the observation that subjects respond faster to simultaneously presented redundant targets than to single targets. This finding is usually interpreted as evidence for parallel, self-terminating, unlimited-capacity processing. Alternatively, it has been claimed that the reaction-time advantage with redundant targets is simply due to spatial uncertainty under single-target conditions. The present study tested this hypothesis. In Experiment 1, subjects responded when one, two, or three letters E were presented, and refrained from responding when one, two, or three letters F were presented. In half of the trials, location uncertainty was eliminated by presentation of a line segment at one of the locations of the subsequently appearing target letters. The results reject the alternative spatial-uncertainty explanation: even when the location of the impending target is cued in advance, there is no attenuation of the redundancy gain. Experiment 2 served as a control experiment and showed a clear redundancy gain, even in conditions in which it was ensured that, before display onset, attention was directed to a location of one of the impending targets.     

靶刺激变换与情景信息属性对真实情景再认的影响

采用眼动研究范式,通过两个实验考察靶刺激变换与情景信息属性对情景再认的影响。实验一结果显示,靶刺激变换对情景再认、靶刺激所属兴趣区的凝视时间均有显著影响,这表明在情景再认过程中,观察者会有意识地搜索靶刺激,靶刺激具有诊断效应;实验二应用了知觉信息与语义信息重合和分离两种情景材料。结果显示,观察者对语义信息的首次注视次数显著多于知觉信息;观察者对知觉信息和语义信息分离条件下语义信息的首次注视时间显著长于重合条件下。这一结果提示,在情景识别过程中,语义信息具有注意优先性,但其优先性会受到知觉信息启动的干扰。     

Asymmetric mislocalization of a visual flash ahead of and behind a moving objectt

When subjects localize a flash relative to another stationary stimulus, the flash appears displaced in the direction of nearby motion signals (position capture; Whitney and Cavanagh, 2000 Nature Neuroscience 3 954-959). Our previous study had suggested that the position capture is larger for a flash presented ahead of a moving stimulus than for a flash behind it (Watanabe et al, 2003 Perception 32 545-559). In the present study, I investigated the spatial asymmetry of position capture. Experiment 1 demonstrated that asymmetric position capture occurs primarily in a moving-object-centered coordinate. Experiment 2 showed evidence that the asymmetric position capture operates after individuation of single visual objects. Finally, experiment 3 demonstrated that, when attention was reduced with a dual-task procedure, the asymmetric position capture increased. These results suggest that the spatial asymmetry of position capture occurs without attention but the spatial bias can be reduced by attention. Therefore, the underlying mechanism for the asymmetric spatial bias may be different from attentive tracking (Cavanagh, 1992 Science 257 1563-1565) and mislocalization during smooth pursuit (Brenner et al, 2001 Vision Research 41 2253-2259).     

Spatio-temporal working-memory and short-term object-location tasks use different memory mechanisms

Spatial short-term memory for objects' locations was investigated in a spatial relocation task. During maintenance, dynamic visual noise or spatial tapping were administered as visual or spatial secondary tasks, respectively. Because memory for location should tap the visual component of working memory, a visual but not a spatial secondary task should impair location memory. In fact, neither of the tasks impaired memory (Experiment 1), although the expected dissociation between visual and spatial components was clearly confirmed for a spatio-temporal main task (Corsi test) (Experiment 2). We then contrasted location memory for pictures of objects and of nonsense figures under visual interference. Real objects were relocated much better than nonsense figures, and visual noise was again ineffective (Experiment 3). When spatial tapping was combined with the same material (Experiment 3a), again no influence on memory for locations of objects was observed and only a small influence on remembering nonsense figures. We suggest that the Corsi and the relocation VSWM-tasks use different memory mechanisms. The configuration of objects is reconstructed from perceptual records in an episodic buffer, provided by the same structures that enable visual memory after longer intervals. Rehearsal is not necessary for the persistence of these traces. In contrast, in the Corsi task remembering, a temporal sequence across homogeneous locations needs spatio-temporal marking and therefore active rehearsal of the locations by shifting spatial attention. A spatially demanding secondary task during retention interrupts this rehearsal.     

How does attention select and track spatially extended objects? New effects of attentional concentration and amplification

Real-world situations involve attending to spatially extended objects, often under conditions of motion and high processing load. The present experiments investigated such processing by requiring observers to attentionally track a number of long, moving lines. Concurrently, observers responded to sporadic probes as a measure of the distribution of attention across the lines. The results revealed that attention is concentrated at the centers of lines during tracking, despite their uniformity, and that this center advantage grew as the lines became longer: Not only did observers get worse near the endpoints, but they became better at the lines' centers, as if attention became more concentrated as the objects became more extended. These results begin to show how attention is flexibly allocated in online visual processing to extended dynamic objects.     

Location perception: the X-Files parable

Three aspects of visual object location were investigated: (1) how the visual system integrates information for locating objects, (2) how attention operates to affect location perception, and (3) how the visual system deals with locating an object when multiple objects are present. The theories were described in terms of a parable (the X-Files parable). Then, computer simulations were developed. Finally, predictions derived from the simulations were tested. In the scenario described in the parable, we ask how a system of detectors might locate an alien spaceship, how attention might be implemented in such a spaceship detection system, and how the presence of one spaceship might influence the location perception of another alien spaceship. Experiment 1 demonstrated that location information is integrated with a spatial average rule. In Experiment 2, this rule was applied to a more-samples theory of attention. Experiment 3 demonstrated how the integration rule could account for various visual illusions.     

Location perception: TheX-Files parable

Three aspects of visual object location were investigated: (1) how the visual system integrates information for locating objects, (2) how attention operates to affect location perception, and (3) how the visual system deals with locating an object when multiple objects are present. The theories were described in terms of a parable (theX-Files parable). Then, computer simulations were developed. Finally, predictions derived from the simulations were tested. In the scenario described in the parable, we ask how a system of detectors might locate an alien spaceship, how attention might be implemented in such a spaceship detection system, and how the presence of one spaceship might influence the location perception of another alien spaceship. Experiment 1 demonstrated that location information is integrated with a spatial average rule. In Experiment 2, this rule was applied to a more-samples theory of attention. Experiment 3 demonstrated how the integration rule could account for various visual illusions.     

Spatial representation by young infants: Categorization of spatial relations or sensitivity to a crossing primitive?

The spatial representation abilities of 3- to 4-month-old infants were examined in four experiments. Experiments 1 and 2 showed that infants familiarized with a diamond appearing in distinct locations to the left or right of a vertical bar subsequently preferred a stimulus depicting the diamond on the opposite side of the bar over a stimulus depicting the diamond in a novel location on the same side of the bar. Experiment 3 was a replication of Experiment 1, except that the bar was oriented at 45 degrees. In this instance, infants divided their attention between the stimulus depicting the diamond on the opposite side of the bar and the stimulus depicting the diamond in a novel location on the same side of the bar. Experiment 4 demonstrated that the results of Experiment 3 were not a consequence of a failure to process the diagonal bar. When considered with previous reports that infants can represent the categories of above and below (Quinn, 1994), the present results suggest that (1) infants can also represent the categories of left and right, and (2) performance cannot be interpreted as a response to an arbitrary crossing of one object relative to another. Although recent discussions of the relation between language and cognition have pointed to the ways in which spatial language influences spatial cognition (Bowerman & Levinson, 2001), the present findings are consistent with an influence in the opposite direction: Spatial cognition may in some instances shape spatial language.     

相对到达时间任务中飞行员对客体特征与运动特征的分离

相对到达时间任务(RAT)是判断两个运动客体哪个先到达指定目标, 可用来评估个体动态空间能力。采用RAT任务对飞行员与普通被试进行对照研究, 寻求发现两组在运动客体特征和视觉空间运动特征及其相互关系上的处理差异。设计了3个实验分别考察客体颜色、客体大小、运动方向、速率大小、视线方向以及背景特征对判断的影响。结果显示：(1)客体颜色不影响运动客体的相对时间判断, 客体大小、运动方向、速率大小、视线方向以及背景特征影响判断; (2)控制组对显示屏上从左到右的运动客体的相对时间判断好于从右到左任务, 大速率任务判断更好, 对大客体快速行驶而小客体低速行驶时的相对到达时间更易区分, 且与两眼视线方向不一致的运动方向会使控制组判断更难, 运动背景中的目标线特征改变使控制组判断绩效降低; (3)和控制组比, 飞行员反应快正确率高, 其快速判断优势集中体现在从右到左运动以及小速率任务上, 且在不同运动方向和不同速率上的反应时均无差异, 飞行员的处理优势还表现在不受客体大小、视线方向改变和目标线特征改变的影响。结论：飞行员能在变化的空间中准确处理相对速度、相对距离、相对时间等运动信息, 能分离客体大小、背景、运动方向等因素对相对到达时间判断的影响, 在运动空间中飞行员具有较高场独立性认知特征和动态空间处理能力。