The Effects of Scene Inversion on Change Blindness

In two experiments, participants searched for a difference between two views of a scene. In Experiment 1, the authors extended the change-blindness findings from previous work by R. A. Rensink, J. K. O'Regan, and J. J. Clark (1997), which used an experimenter-induced global transient, to a less artificial situation in which participants searched for a difference in a pair of photographic images presented simultaneously. To examine the idea that meaning-driven endogenous orienting was responsible for the previously observed advantage for changes in center-of-interest items, the authors inverted half of the image pairs. The advantage for center-of-interest items was replicated with upright displays, but it was completely eliminated by inversion, strongly supporting the role of meaning-driven endogenous orienting in this task. With flickering displays (Experiment 2), the center-of-interest effect was completely unaffected by inversion. The authors suggest that when change blindness is induced via flicker, scene modifications are typically found by stimulus-driven rather than by meaning-driven processes.     

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.     

The spatial correspondence hypothesis and orienting in response to central and peripheral spatial cues

Two experiments examined visual orienting in response to spatial precues. In Experiment 1A participants were informed that targets usually (p =.8) appeared on the same side as cues in a particular colour (e.g., red). Rapid orienting was observed, with both central and peripherally presented cues. In Experiment IB cue displays were spatially symmetric. Participants were informed that target location (left or right) was usually predicted (p =.8) by cue colour (red or green). Orienting effects were observed, but these were slower to develop and much weaker than in Experiment 1 A. In Experiment 2A and 2B the cue was a single, centrally presented letter. We compared effects of spatially symmetric (T, X, v, o) and asymmetric (d, b) letter cues. Validity effects were present for asymmetric cues, but entirely absent for symmetric cues. These finding are discussed in terms of Lambert and Duddy's (2002) proposal that spatial correspondence learning plays a critical role in spatial precueing. Implications of the results for the distinction between endogenous and exogenous orienting are also considered.     

视觉工作记忆对前注意阶段注意定向的调节

在注意阶段,视觉工作记忆与注意共享某些特征时,视觉工作记忆内容会引导注意定向。在前注意阶段的影响又是如何？对此问题的研究却很少见,本研究采用工作记忆与基于特征的视觉搜索相结合的任务深入探讨了此问题。研究结果发现：即使在前注意阶段,注意定向也会受到视觉工作记忆自上而下的调节。然而与注意阶段不同的是：当视觉工作记忆内容与随后视觉搜索任务的目标相关时,与记忆内容匹配的搜索项目会引导注意定向到该项目所在的位置,但只有此项目作为分心物时,才会明显地延迟对靶子的加工,而此项目作为靶子时,这种影响并不明显;当视觉工作记忆中保持的项目与随后视觉搜索任务的目标无关时,注意会忽略视觉工作记忆中保持的项目,有效地检测靶子     

Influence of recall procedures on the modality effect with numbers and enumerated stimuli

Experiment 1 extended J. S. Nairne and W. L. McNabb's (1985) counting procedure for presenting numerical stimuli to examine the modality effect. The present authors presented participants with dots and beeps and instructed participants to count the items to derive to-be-remembered numbers. In addition, the authors presented numbers as visual and auditory symbols, and participants recalled items by using free-serial written recall. Experiment 1 demonstrated primacy effects, recency effects, and modality effects for visual and auditory symbols and for counts of dots and beeps. Experiment 2 replicated the procedure in Experiment 1 using strict-serial written recall instead of free-serial written recall. The authors demonstrated primacy and recency effects across all 4 presentation conditions and found a modality effect for numbers that the authors presented as symbols. However, the authors found no modality effect when they presented numbers as counts of beeps and dots. The authors discuss the implications of the results in terms of methods for testing modality effects.     

Awareness of the continuously visible: information acquisition during preview

What can we learn about a scene while we stare at it, but before we know what we will be looking for? Three experiments were performed to investigate whether previewing a search array prior to knowing the target allows search to operate more quickly (lower reaction time [RT]), more efficiently (reduced set size slope), and/or by consulting abstract mental representations. Experiment 1 compared RTs for previewed and nonpreviewed arrays, some of which were highly degraded with visual noise. Preview reduced RTs for the noisy displays but did not affect search efficiency. Limited interactions of visual quality and preview suggested that prior exposure allowed the extraction and maintenance of about three abstract identities. If the target was one of those items, the observer responded without searching; if not, the observer searched the remaining items as if there had been no preview. Experiment 2 replicated these findings with less extreme noise. In Experiment 3, subjects previewed 0-6 items of a 12-item display. RTs decreased linearly as the number of previewed items increased from 0 to 3 and then reached a plateau, confirming that the capacity of the representation was about 3 items. Implications for visual awareness are discussed.     

Now you see it, now you don't: repetition blindness for nonwords

Repetition blindness (RB) for nonwords has been found in some studies, but not in others. The authors propose that the discrepancy in results is fueled by participant strategy; specifically, when rapid serial visual presentation lists are short and participants are explicitly informed that some trials will contain repetitions, participants are able to use partial orthographic information to correctly guess repetitions on repetition trials while avoiding spurious repetition reports on control trials. The authors first replicated V. Coltheart and R. Langdon's (2003) finding of RB for words but repetition advantage for nonwords (Experiment 1). When all participants were encouraged to utilize partial information in a same/different matching task along with an identification task, a repetition advantage was observed for both words and nonwords (Experiment 2). When guessing of repetitions was made detectable by including non-identical but orthographically similar items in the experiments, the repetition advantage disappeared; instead, RB was found for both words and nonwords (Experiments 3 and 4). Finally, when experiments did not contain any identical items, participants almost never reported repetitions, and reliable RB was found for orthographically similar words and nonwords (Experiments 5 and 6).     

The phenomenology of endogenous orienting

Can we build endogenous expectations about the locus of occurrence of a target without being able to describe them? Participants performed cue-target detection tasks with different proportions of valid and invalid trials, without being informed of these proportions, and demonstrated typical endogenous effects. About half were subsequently able to correctly describe the cue-target relationships ('verbalizers'). However, even non-verbalizer participants showed endogenous orienting with peripheral cues (Experiments 1 and 3), not depending solely on practice (Experiment 2). Explicit instructions did not bring about dramatic advantages in performance (Experiment 4). With central symbolic cues, only verbalizers showed reliable endogenous effects (Experiment 5). We concluded that endogenous orienting with peripheral cues can occur independently of participants developing explicit hypotheses about the cue-target relationships.     

Developmental changes in self-corrected elaboration effects on incidental memory

Abstract:  Two experiments were carried out to investigate the changes across age groups in the effects of self-corrected elaboration on incidental memory. Each participant performed an orienting task involving three conditions: self-corrected, self-generated and experimenter-provided elaboration. The orienting task was followed by free recall tests. In Experiment 1, the participants were sixth-grade and second-grade students. For sixth-grade students the self-corrected elaboration led to a better free recall than the other two elaborations, whereas for the second-grade students, no difference was observed between any of the three elaborations. In Experiment 2, using a longer word list than that in Experiment 1, the participants were undergraduates. The self-corrected and self-generated elaborations led to a better free recall than the experimenter-provided elaboration, and no difference between the former two elaborations was observed. The results obtained from these two experiments were interpreted as showing that the effectiveness of a self-corrected elaboration depends on the participants' age.     

Contextual cueing in 3D layouts defined by binocular disparity

Under incidental learning conditions, a spatial layout can be acquired implicitly and facilitates visual search (the contextual cueing effect; Chun & Jiang, 1998). We investigated two aspects of this effect: Whether spatial layouts of a 3D display are encoded automatically or require selective processing (Experiment 1), and whether the learned layouts are limited to 2D configurations or can encompass three dimensions (Experiment 2). In Experiment 1, participants searched for a target presented only in a specific depth plane. Contextual cueing effect was obtained only when the location of the items in the attended plane was invariant and consistently paired with a target location. In contrast, repeating and pairing the layout of the ignored items with the target location did not produce a contextual cueing effect. In Experiment 2, we found that reaction times for the repeated condition increased significantly when the disparity of the repeated distractors was reversed in the last block of trials. These results indicate that contextual cueing in 3D displays occurs when the layout is relevant and selectively attended, and that 3D layouts can be preserved as an implicit visual spatial context.     

Improvement, learning and retention of skill at visual search

Three experiments examined factors responsible for improvement in visual search. In Experiment I three groups of subjects were each trained for 3000 trials to search for a particular set of target letters among a particular set of background letters. After intervals of 2, 4, or 6 weeks without further practice they were re-tested, either with the same displays or on new displays which they searched for the same target items among new background items. Negative transfer suggested that memory for specific cue-systems distinguishing target from background letters is retained for as long as 4 weeks.

Experiment II examined performance of three very highly practised subjects. After 25 days practice, variations in the size of the target set no longer affected search time. This could not be explained by learning of specific cue systems, since after this amount of practice subjects showed perfect transfer to displays which they searched for the same target items among new background items. Experiment III suggested that practised subjects achieve this high level of competence by learning to make two independent successive decisions, first to locate any member of the target set on the display and next to identify which particular member of the target set has been located.     

Visual search in a multi-element asynchronous dynamic (MAD) world

In visual search tasks participants search for a target among distractors in strictly controlled displays. We show that visual search principles observed in these tasks do not necessarily apply in more ecologically valid search conditions, using dynamic and complex displays. A multi-element asynchronous dynamic (MAD) visual search was developed in which the stimuli could either be moving, stationary, and/or changing in luminance. The set sizes were high and participants did not know the specific target template. Experiments 1 through 4 showed that, contrary to previous studies, search for moving items was less efficient than search for static items and targets were missed a high percentage of the time. However, error rates were reduced when participants knew the exact target template (Experiment 5) and the difference in search efficiency for moving and stationary targets disappeared when lower set sizes were used (Experiment 6). In all experiments there was no benefit to finding targets defined by a luminance change. The data show that visual search principles previously shown in the literature do not apply to these more complex and "realistically" driven displays.     

Processing level and recognition: A search method for inducing alternative encodings of unrelated words

Twenty-four subjects viewed cards containing four words. In synonym orienting, half of the cards contained a synonym pair and half did not; in homophone orienting, half of the displays contained a homophone pair. The remaining two words in each display were used to index retention. During presentation of displays, subjects responded “yes” or “no” to indicate the presence or absence of a matching pair. Following presentation, a recognition test was administered. Half the items were tested early and half were tested late; within each test order, half the items appeared with context cues during testing and half appeared without. Results showed superior recognition (1) following semantic orienting, (2) for items tested early, (3) for items tested with context, and (4) for nonmatch displays requiring exhaustive item comparison. An Orienting by Test Cuing interaction showed that the presence of test cues improved recognition for homophone orienting items only. The interaction may have resulted from the lack of cuetarget associations and the reinstatement of the phonemic orienting set during the test.     

An analysis of the time course of attention in preview search

We used a probe dot procedure to examine the time course of attention in preview search (Watson & Humphreys, 1997). Participants searched for an outline red vertical bar among other new red horizontal bars and old green vertical bars, superimposed on a blue background grid. Following the reaction time response for search, the participants had to decide whether a probe dot had briefly been presented. Previews appeared for 1,000 msec and were immediately followed by search displays. In Experiment 1, we demonstrated a standard preview benefit relative to a conjunction search baseline. In Experiment 2, search was combined with the probe task. Probes were more difficult to detect when they were presented 1,200 msec, relative to 800 msec, after the preview, but at both intervals detection of probes at the locations of old distractors was harder than detection on new distractors or at neutral locations. Experiment 3A demonstrated that there was no difference in the detection of probes at old, neutral, and new locations when probe detection was the primary task and there was also no difference when all of the shapes appeared simultaneously in conjunction search (Experiment 3B). In a final experiment (Experiment 4), we demonstrated that detection on old items was facilitated (relative to neutral locations and probes at the locations of new distractors) when the probes appeared 200 msec after previews, whereas there was worse detection on old items when the probes followed 800 msec after previews. We discuss the results in terms of visual marking and attention capture processes in visual search.     

Remembering parts and wholes: Configural processing in face recollection

In two experiments, we examined the role of configural processing on states of awareness in face recognition. Configural processing was manipulated by presenting upright and inverted faces during study and test. After studying facial photographs of humans (Experiment 1) and horses (Experiment 2), participants provided a remember/know judgement for each recognised test face. In both experiments, disrupted configural processing had selective effects on states of awareness, so that inversion reduced remember, but not know, responses. Experiment 2 revealed disproportionate inversion effects in that the difference in remember responses between upright and inverted items was significant for human faces but not horses. These findings suggest that configural processing facilitates explicit recollection by providing a distinctive combination of nonsalient event attributes.     

Searching for threat

In a series of experiments, a visual search task was used to test the idea that biologically relevant threatening stimuli might be recognized very quickly or capture visuo-spatial attention. In Experiment 1, there was evidence for both faster detection and faster search rates for threatening animals than for plants. However, examination of the basis of this effect in Experiment 2 showed that it was not due to threat per se, as detection and search rate advantages were found for pleasant rather than threatening animals compared to plants. In Experiment 3, participants searched for the plants and pleasant and threatening animals used in Experiments 1 and 2, among a fixed heterogeneous selection of non-target items. There was no search rate or detection advantage for threatening animals compared to pleasant animals or plants. The same targets and non-targets as those used in Experiment 3 were also used in Experiment 4. In Experiment 4, participants searched for targets that were presented either close to or distant from an initial fixation point. There was no evidence for a "threat" detection advantage either close to or distant from the cross. Finally, an experiment was conducted in which target categories (fruit, flowers, and animals) were not pre-specified prior to each trial block. There were no differences in reaction times to detect pleasant animals, threatening animals, or fruit. We conclude that the visual search paradigm does not readily reveal any biases that might exist for threatening stimuli in the general population.     

两亚型注意缺陷多动障碍(ADHD)儿童的内隐注意定向

研究探讨注意缺陷障碍儿童与正常儿童之间,混合型与注意缺陷型ADHD儿童之间在内源与外源注意定向功能的差异。ADHD儿童及与之匹配的正常儿童对照组分别参与了两个实验,实验一采用了内源性内隐注意定向任务,实验二采用了外源性内隐注意定向任务。研究表明：（1）ADHD儿童与正常儿童相比,在注意定向过程（注意解除、转移与施加）上有一定缺陷。（2）ADHD儿童注意定向网络功能有缺陷,与反应水平上动作准备有关的注意功能可能受损。（3）两种亚类型儿童注意定向功能缺陷模式不同。在内原定向上,混合型与注意缺陷型相比较,混合型ADHD儿童表现为有较强的反应冲动性;注意缺陷型儿童,主要表现为注意加工过程比较缓慢,注意更易涣散。在外源定向上,混合型儿童在反应的运动准备及运动控制方面的缺陷要大于注意缺陷型儿童     

Inhibition of Return Is a Foraging Facilitator in Visual Search

Using overt orienting, participants searched a complex visual scene for a camouflaged target (Waldo from the "Where's Waldo?™" books). After several saccades, we presented an uncamouflaged probe (black disk) while removing or maintaining the scene, and participants were required to locate this probe by foveating it. Inhibition of return was observed as a relative increase in the time required to locate these probes when they were in the general region of a previous fixation, but only when the search array remained present. Perhaps also reflecting inhibition of return, preprobe saccades showed a strong directional bias away from a previously fixated region. Together with recent studies that replicate the finding of inhibition at distractor locations following serial but not parallel visual search—so long as the search array remains visible—these data strongly support the proposal that inhibition of return functions to facilitate visual search by inhibiting orienting to previously examined locations.     

Information search in the laboratory and on the Web: With or without an experimenter

The focus of this study is the effect of the location (laboratory vs. Web) of experiments on active information searchin decision-making tasks. In two experiments, participants were confronted with two different search method versions (list vs. keyword) for acquiring information about a task from a database. The amount and type of information gathered and the time required for task completion were measured. In Experiment 1, significantly more information was searched for in the laboratory than on the Web when the list version was employed, whereas there was no difference between locations in the keyword version. In Experiment 2, the participants were assigned randomly to the Web or the laboratory condition. The results of Experiment 1 were replicated. Whereas location (and the presence or absence of an experimenter) had an effect on the absolute amount of information gathered in both experiments, the relative distribution and type of information items did not differ.     

Exogenous and endogenous spatial attention effects on visuospatial working memory

In this study, we investigate how exogenous and endogenous orienting of spatial attention affect visuospatial working memory (VSWM). Specifically, we focused on two attentional effects and their consequences on storage in VSWM, when exogenous (Experiment 1) or endogenous (Experiment 2) orienting cues were used. The first effect, known as the meridian effect, is given by a decrement in behavioural performance when spatial cues and targets are presented in locations separated by vertical and/or horizontal meridians. The second effect, known as the distance effect, is given by a decrement in the orienting effects as a function of the spatial distance between cues and targets. Our results revealed a dissociation between exogenous and endogenous orienting mechanisms in terms of both meridian and distance effects. We found that meridian crossing affects performance only when endogenous cues were used. Specifically, VSWM performance with endogenous cueing depended more on the number of meridian crossings than on distance between cue and target. By contrast, a U-shaped distance dependency was observed using exogenous cues. Our findings therefore suggest that exogenous and endogenous orienting mechanisms lead to different forms of attentional bias for storage in VSWM.