Visual working memory load disrupts the space‐based attentional guidance of target selection

During visual search, the selection of target objects is guided by stored representations of target‐defining features (attentional templates). It is commonly believed that such templates are maintained in visual working memory (WM), but empirical evidence for this assumption remains inconclusive. Here, we tested whether retaining non‐spatial object features (shapes) in WM interferes with attentional target selection processes in a concurrent search task that required spatial templates for target locations. Participants memorized one shape (low WM load) or four shapes (high WM load) in a sample display during a retention period. On some trials, they matched them to a subsequent memory test display. On other trials, a search display including two lateral bars in the upper or lower visual field was presented instead, and participants reported the orientation of target bars that were defined by their location (e.g., upper left or lower right). To assess the efficiency of attentional control under low and high WM load, EEG was recorded and the N2pc was measured as a marker of attentional target selection. Target N2pc components were strongly delayed when concurrent WM load was high, indicating that holding multiple object shapes in WM competes with the simultaneous retention of spatial attentional templates for target locations. These observations provide new electrophysiological evidence that such templates are maintained in WM, and also challenge suggestions that spatial and non‐spatial contents are represented in separate independent visual WM stores.     

Spatial separation between targets constrains maintenance of attention on multiple objects

Humans are limited in their ability to maintain multiple attentional foci. In attentive tracking of moving objects, performance declines as the number of tracked targets increases. Previous studies have interpreted such reduction in terms of a limit in the number of attentional foci. However, increasing the number of targets usually reduces spatial separation among different targets. In this study, we examine the role of target spatial separation in maintaining multiple attentional foci. Results from a multiple-object tracking task show that tracking accuracy deteriorates as the spatial separation between targets decreases. We propose that local interaction between nearby attentional foci modulates the resolution of attention, and that capacity limitation from attentive tracking originates in part from limitations in maintaining critical spacing among multiple attentional foci. These findings are consistent with the hypothesis that tracking performance is limited not primarily by a number of locations, but by factors such as the spacing and speed of the targets and distractors.     

All set! Evidence of simultaneous attentional control settings for multiple target colors

Although models of visual search have often assumed that attention can only be set for a single feature or property at a time, recent studies have suggested that it may be possible to maintain more than one attentional control setting. The aim of the present study was to investigate whether spatial attention could be guided by multiple attentional control settings for color. In a standard spatial cueing task, participants searched for either of two colored targets accompanied by an irrelevantly colored distractor. Across five experiments, results consistently showed that nonpredictive cues matching either target color produced a significant spatial cueing effect, while irrelevantly colored cues did not. This was the case even when the target colors could not be linearly separated from irrelevantly cue colors in color space, suggesting that participants were not simply adopting one general color set that included both target colors. The results could not be explained by intertrial priming by previous targets, nor could they be explained by a single inhibitory set for the distractor color. Overall, the results are most consistent with the maintenance of multiple attentional control settings.     

Evidence for a fixed capacity limit in attending multiple locations

A classic question concerns whether humans can attend multiple locations or objects at once. Although it is generally agreed that the answer to this question is “yes,” the limits on this ability are subject to extensive debate. According to one view, attentional resources can be flexibly allocated to a variable number of locations, with an inverse relationship between the number of selected locations and the quality of information processing at each location. Alternatively, these resources might be quantized in a “discrete” fashion that enables concurrent access to a small number of locations. Here, we report a series of experiments comparing these alternatives. In each experiment, we cued participants to attend a variable number of spatial locations and asked them to report the orientation of a single, briefly presented target. In all experiments, participants’ orientation report errors were well-described by a model that assumes a fixed upper limit in the number of locations that can be attended. Conversely, report errors were poorly described by a flexible-resource model that assumes no fixed limit on the number of locations that can be attended. Critically, we showed that these discrete limits were predicted by cue-evoked neural activity elicited before the onset of the target array, suggesting that performance was limited by selection processes that began prior to subsequent encoding and memory storage. Together, these findings constitute novel evidence supporting the hypothesis that human observers can attend only a small number of discrete locations at an instant.     

On the modularity of implicit sequence learning: independent acquisition of spatial, symbolic, and manual sequences

Learning sequential structures is of fundamental importance for a wide variety of human skills. While it has long been debated whether implicit sequence learning is perceptual or response-based, here we propose an alternative framework that cuts across this dichotomy and assumes that sequence learning rests on associative changes that can occur concurrently in distinct processing systems and support the parallel acquisition of multiple uncorrelated sequences. In three experiments we used a serial search task to test critical predictions of this framework. Experiments 1 and 2 showed that participants learnt uncorrelated sequences of auditory letters and manual responses, as well as sequences of visual letters, spatial locations, and manual responses simultaneously, as indicated by a reliable response time (RT) cost incurred by occasional deviants violating either of the sequences. This RT cost was reliable even when participants showing explicit knowledge were excluded. In Experiment 3 learning of spatial and nonspatial sequences was functionally dissociated: whereas a spatio-motor distractor task disrupted learning of location but not of letter sequences, a phonological distractor task had the reverse effect. The distractor tasks thus did not reduce unspecific attentional resources, but selectively disrupted the formation of sequential associations within spatial and nonspatial processing dimensions. These results support the view that implicit sequence learning rests on experience-dependent changes that can occur in parallel in multiple processing systems involved in spatial attention, object recognition, phonological processing, and manual response selection. The resulting dimension-specific sequence representations support independent predictions of what will appear next, where it will appear, and how one will have to respond to it.     

Multiple attentional sets while monitoring rapid serial visual presentations

The present study examined whether observers are able to establish multiple attentional sets to concurrently monitor two different spatial locations. Observers identified a target letter in red or cyan among nontarget letters of other heterogeneous colours during a temporal feature search. A peripheral distractor display consisted of one item of either the same colour as the current target, and the other potential target colour, or an irrelevant colour that could never be the target. They identified an odd-ball colour letter among homogenous colours during a singleton search. The results revealed that observers maintained multiple attentional sets for detecting two singletons or for targets involving two (or three) features. However, they were unable to maintain a mixture of sets. Moreover, exposure to a distractor containing feature that corresponded to a feature of the current target was advantageous for target identification. The presence or absence of this set-specific capture depended on top-down knowledge and did not occur automatically in the singleton-detection stream. These results demonstrate a limitation in the flexibility of attentional sets. Although two singleton detections were possible, multiple attentional templates for a more complex attentional set could not be maintained concurrently when monitoring multiple rapid serial visual presentations.     

Putting action in perspective

Embodied approaches to cognition propose that our own actions influence our understanding of the world. Do other people's actions also have this influence? The present studies show that perceiving another person's actions changes the way people think about objects in a scene. In Study 1, participants viewed a photograph and answered a question about the location of one object relative to another. The question either did or did not call attention to an action being performed in the scene. Studies 2 and 3 focused on whether depicting an action in a scene influenced perspective choice. Across all studies, drawing attention to action, whether verbally or pictorially, led observers to encode object locations from the actor's spatial perspective. Study 4 demonstrated that the tendency to adopt the actor's perspective might be mediated by motor experience.     

Attentional inhibition mediates inattentional blindness

Salient stimuli presented at unattended locations are not always perceived, a phenomenon termed inattentional blindness. We hypothesized that inattentional blindness may be mediated by attentional inhibition. It has been shown that attentional inhibition effects are maximal near an attended location. If our hypothesis is correct, inattentional blindness effects should similarly be maximal near an attended location. During central fixation, participants viewed rapidly presented colored digits at a peripheral location. An unexpected black circle (the critical stimulus) was concurrently presented. Participants were instructed to maintain central fixation and name each color/digit, requiring focused attention to that location. For each participant, the critical stimulus was presented either near to or far from the attended location (at the same eccentricity). In support of our hypothesis, inattentional blindness effects were maximal near the attended location, but only at intermediate task accuracy.     

Reduced habituation to angry faces: increased attentional capture as to override inhibition of return

The aim of this paper was to study whether real angry faces do capture attention to the extent of overcoming the inhibition of return (IOR) effect and whether the anxiety level of participants modulates this effect by stressing biases toward threatening stimuli. With this purpose, participants categorized the emotional valence of face targets in a standard spatial cueing procedure suitable to measure IOR. In Experiment 1, participants were selected according to their high vs. low-trait anxiety, whereas in Experiment 2 participants were induced a positive vs. anxiety mood state. The typical IOR effect was observed with neutral and happy face targets, which disappeared with angry face targets. Similar results were observed for all anxiety groups and in both experiments. The results indicate that IOR is overridden when the target is a biologically relevant angry face, as highly relevant targets should suffer less from habituation to attentional capture regardless of anxiety. We suggest that these data show that attentional capture is less likely to habituate for threatening information, so that no cost is measured in detecting new threatening information appearing at recently cued locations.     

Individual differences in susceptibility to inattentional blindness

Inattentional blindness refers to the finding that people do not always see what appears in their gaze. Though inattentional blindness affects large percentages of people, it is unclear if there are individual differences in susceptibility. The present study addressed whether individual differences in attentional control, as reflected by variability in working memory capacity, modulate susceptibility to inattentional blindness. Participants watched a classic inattentional blindness video (Simons & Chabris, 1999) and were instructed to count passes among basketball players, wherein 58% noticed the unexpected: a person wearing a gorilla suit. When participants were accurate with their pass counts, individuals with higher working memory capacity were more likely to report seeing the gorilla (67%) than those with lesser working memory capacity (36%). These results suggest that variability in attentional control is a potential mechanism underlying the apparent modulation of inattentional blindness across individuals.     

When facts go down the rabbit hole: contrasting features and objecthood as indexes to memory

People will often look to empty, uninformative locations in the world when trying to recall spoken information. This spatial indexing behaviour occurs when the information had previously been associated with those locations. It remains unclear, however, whether this behaviour is an example of a simple association across perceptual and cognitive systems, or whether location information plays a role in memory retrieval. In the current study, we investigate whether higher-level cognitive processes, such as object-based attention, are involved in spatial indexing. Participants saw creatures burrowing around the screen, appearing from underground to tell them facts. They saw the same creature in two locations, or two identical creatures in two locations, depending on spatiotemporal cues conveyed by a burrowing animation. While answering questions, we found that participants relied on these spatiotemporal cues, fixating the previous locations of the creature associated with the relevant fact, rather than the location of an identical creature. We interpret these findings in terms of an object-based attentional mechanism that is common to semantic memory and scene perception, and allows 'external memory' to be exploited in a dynamic environment.     

Changing scenes: memory for naturalistic events following change blindness

Research on scene perception indicates that viewers often fail to detect large changes to scene regions when these changes occur during a visual disruption such as a saccade or a movie cut. In two experiments, we examined whether this relative inability to detect changes would produce systematic biases in event memory. In Experiment 1, participants decided whether two successively presented images were the same or different, followed by a memory task, in which they recalled the content of the viewed scene. In Experiment 2, participants viewed a short video, in which an actor carried out a series of daily activities, and central scenes' attributes were changed during a movie cut. A high degree of change blindness was observed in both experiments, and these effects were related to scene complexity (Experiment 1) and level of retrieval support (Experiment 2). Most important, participants reported the changed, rather than the initial, event attributes following a failure in change detection. These findings suggest that attentional limitations during encoding contribute to biases in episodic memory.     

Development of a repeated measures affective change blindness task

Flicker-induced change blindness paradigms have been used to explore attentional biases for a range of concern-related cues. However, previous studies have had limitations related to concerns about carryover effects in repeated measures designs, as well as problems with response modalities. The present article develops a repeated measures paradigm utilising nonverbal responses and explores the implications of these design modifications for the reliability and validity of the paradigm. Affective stimuli were presented to participants, and the results suggest that the modified paradigm is a useful tool for assessing attentional bias. A number of recommendations for the future use of this methodology are made.     

Configural representations in spatial working memory

Two studies investigate the nature of representations in spatial working memory, directly addressing the question of whether people represent the configuration information above and beyond independent positional information when representing multiple sequentially presented locations. In Experiment 1, participants performed a location memory task in which they recalled the location of objects that were presented sequentially on a screen. Comparison of participants' data with simulated data modelled to represent independent positional representation of spatial locations revealed that participants represented the configural properties of shorter sequences (3 and 4 locations) but not of longer ones (5 and 7 locations). Experiment 2 employed a sequential recognition task in which participants were asked to judge whether two consequently presented spatial sequences were identical. These experiments confirmed sensitivity to configural properties of spatial sequences.     

But consider the alternative: The influence of positive affect on overconfidence

Three studies find evidence that positive affect reduces comparative overconfidence (overplacement). This occurs because positive affect attenuates focalism via decreasing people's tendency to overweight information regarding themselves in the light of information concerning others. Specifically, Study 1 provides evidence that positive affect leads to more realistic estimates of comparative ability and that other-focus partially mediates this effect. Then, Study 2 provides causal evidence that positive affect independently influences other-focus and that other-focus, in turn, influences overplacement. Additionally, Study 2 uses an indirect measure of focalism to better capture this attentional process. Finally, Study 3 explores the influence of negative affect on overplacement. In addition, each study finds that positive affect does not influence overconfidence regarding participant's raw performances (overestimation) as this type of overconfidence is not dependent on self-other comparisons.     

女大学生中共情对自我中心和利他行为关系的调节作用

目的：考察在女大学生中特质与状态共情对个体自我中心特质与利他行为之间的关系。方法：研究一采用问卷调查考察特质共情对自我中心特质与利他行为倾向的调节作用; 研究二采用行为实验 (自我中心特质高或低的女大学生) 来考察启动的状态共情对真实利他行为的影响。结果：共情特质/状态会与自我中心特质交互作用来影响个体的利他行为/倾向。结论：高共情状态/特质的被试其自我中心会降低利他行为/倾向, 而低共情状态或特质的被试无此倾向。     

Spatial attention is necessary for object-based attention: Evidence from temporal-order judgments

Attentional selection is a dynamic process that relies on multiple types of representations. That object representations contribute to attentional selection has been known for decades; however, most evidence for this contribution has been gleaned from studies that have relied on various forms of spatial cueing (some endogenous and some exogenous). It has thus remained unclear whether object-based attentional selection is a direct result of spatial cuing, or whether it still emerges without any spatial marker. Here we used a novel method—the temporal-order judgment (TOJ)—to examine whether object-based guidance emerges in the absence of spatial cuing. Participants were presented with two rectangles oriented either horizontally or vertically. Following a 150-ms preview time, two target stimuli were presented on the same or on different objects, and participants were asked to report which of the two stimuli had appeared first. The targets consisted of stimuli that formed a percept of a “hole” or a “hill.” First, we demonstrated that the “hill” target was indeed processed faster, as evidenced by a positive perceived simultaneity (PSS) measure. We then demonstrated that if two targets appeared with equal probabilities on the same and on different objects, the PSS values, although positive, were not modulated by the objects. In a subsequent set of experiments, we showed that objects can modulate attentional allocation—however, only when they are biased by a spatial (endogenous) cue. In other words, in the absence of a spatial cue or bias, object representations do not guide attentional selection. In addition to providing new constraints for theories of object-based attentional guidance, these experiments introduce a novel paradigm for measuring object-based attentional effects.     

Measuring the interrelations among multiple paradigms of visual attention: an individual differences approach

A large part of the empirical research in the field of visual attention has focused on various concrete paradigms. However, as yet, there has been no clear demonstration of whether or not these paradigms are indeed measuring the same underlying construct. We collected a very large data set (nearly 1.3 million trials) to address this question. We tested 257 participants on nine paradigms: conjunction search, configuration search, counting, tracking, feature access, spatial pattern, response selection, visual short-term memory, and change blindness. A fairly general attention factor was identified. Some of the participants were also tested on eight other paradigms. This general attention factor was found to be correlated with intelligence, visual marking, task switching, mental rotation, and Stroop task. On the other hand, a few paradigms that are very important in the attention literature (attentional capture, consonance-driven orienting, and inhibition of return) were found to be dissociated from this general attention factor.     

Immunity to attentional capture at ignored locations

Certain stimuli have the power to rapidly and involuntarily capture spatial attention against our will. The present study investigated whether such stimuli capture spatial attention even when they appear in ignored regions of visual space. In other words, which force is more powerful: attentional capture or spatial filtering? Participants performed a spatial cuing task, searching for a letter target defined by color (e.g., green) and then reporting that letter’s identity. Two of the four search locations were always irrelevant. Unlike many previous experiments, participants were forced to ignore these locations because they always contained a target-colored distractor letter. Experiment 1 assessed capture by a salient-but-irrelevant abrupt onset cue appearing 150 ms before the search display. One might expect onset cues to capture attention even at ignored locations given that the main function of capture, presumably, is to rapidly alert observers to unexpected yet potentially important stimuli. However, they did not. Experiment 2 replicated this result with a different neutral baseline condition. Experiment 3 replicated the absence of capture effects at ignored locations with an even more potent stimulus: a relevant cue possessing the target color. We propose that people are effectively immune to attentional capture by objects in ignored locations – spatial filtering dominates attentional capture.     

Manipulations of distractor frequency do not mitigate emotion-induced blindness

Emotional distractors can impair perception of subsequently presented targets, a phenomenon called emotion-induced blindness. Do emotional distractors lose their power to disrupt perception when appearing with increased frequency, perhaps due to desensitisation or enhanced recruitment of proactive control? Non-emotional tasks, such as the Stroop, have revealed that high frequency distractors or conflict lead to reduced interference, and distractor frequency appears to modulate attentional capture by emotional distractors in spatial attention tasks. But emotion-induced blindness is thought to reflect perceptual competition between targets and emotional distractors, and it is unclear whether high frequency emotional stimuli cause less disruption at this relatively early stage of processing. In four experiments, participants searched streams of images for a rotated target image. A negative or neutral distractor appeared before the target, and their relative frequency was manipulated. Across all experiments, the frequency of emotional distractors did not modulate emotion-induced blindness even when participants were explicitly informed that they would appear often or seldom. Thus, increased distractor frequency does not appear to mitigate the priority allotted to emotional distractors during perceptual competition.