Irrelevant Singleton Research Articles

Electrophysiological and behavioral evidence for the attention capture and suppression failure of irrelevant singleton in test anxiety

Attention bias (ABs) and inhibition deficits play crucial roles in the development, maintenance, and recurrence of test anxiety. However, whether test-anxious individuals will show ABs and inhibition deficits of general task-irrelevant stimuli in a complex visual display is unclear. Thus, we used the additional singleton task (AST) and recorded event-related potentials (ERPs) indices of attentional selection (the N2 posterior contralateral, N2pc), suppression (distractor positivity, PD), and maintenance of working memory (the sustained posterior contralateral negativity, SPCN) to explore this issue. Twenty-eight participants in the high test-anxious (HTA) group and twenty-eight participants in the low test-anxious (LTA) group attended the experiment and were required to search for a target and synchronously ignore a singleton distractor on some trials. Consequently, HTA and LTA individuals had poorer accuracies and longer response times in the distractor-present condition than in the distractor-absent condition. The HTA group got larger interferences from singleton distractors than the LTA group. Electrophysiological results revealed a distractor N2pc and SPCN in the HTA group. Moreover, target N2pc and SPCN in the HTA group were larger when the singleton distractor and target were on the same side than on the opposite side. These results indicated that HTA individuals were captured attention by singleton distractors and failed to expel them from working memory. Accordingly, the present findings extended previous work by providing direct evidence that test anxiety could increase the effects of stimulus-driven attention systems and impair the function of goal-directed attention systems.

Statistical distractor learning modulates perceptual sensitivity.

The present study used perceptual sensitivity (d′) to determine the spatial distribution of attention in displays in which participants have learned to suppress a location that is most likely to contain a distractor. Participants had to indicate whether a horizontal or a vertical line, which was shown only briefly before it was masked, was present within a target shape. Critically, the target shape could be accompanied by a singleton distractor color, which when present appeared with a high probability at one display location. The results show that perceptual sensitivity was reduced for locations likely to contain a distractor, as d′ was lower for this location than for all other locations in the display. We also found that the presence of an irrelevant color singleton reduced the gain for input at the target location, particularly when the irrelevant singleton was close to the target singleton. We conclude that, through the repeated encounter with a distractor at a particular location, the weights within the attentional priority map are changed such that the perceptual sensitivity for objects presented at that location is reduced relative to all other locations. This reduction of perceptual sensitivity signifies that this location competes less for attention than all other locations.

Working memory content guides attention

Previous studies showed that working memory (WM) content can guide attention; however, whether working memory capacity (WMC) and state anxiety could affect this remains unclear. This study aimed to examine the effect of WMC and state anxiety on attention guided by WM content. Participants with high and low WMC were assigned to either a neutral or an anxiety condition. They were asked to perform a modified change detection task with irrelevant singletons while their event-related potentials were recorded. N2pc and Pd were observed in the low-WMC and anxiety group, and Pd was observed in both the high-WMC and anxiety and the high-WMC and control groups, whereas neither N2pc nor Pd was found in the low-WMC and control group. These findings suggest that attention is guided or suppressed by WM content, depending on the WMC and anxiety level of the individual. This study provides a new perspective on WM content-guided attention.

Multivariate analysis of EEG activity indexes contingent attentional capture

An extensive body of work has shown that attentional capture is contingent on the goals of the observer: Capture is strongly reduced or even eliminated when an irrelevant singleton stimulus does not match the target-defining properties (Folk et al., 1992). There has been a long-standing debate on whether attentional capture can be explained by goal-driven and/or stimulus-driven accounts. Here, we shed further light on this matter by using EEG activity (raw EEG and alpha power) to provide a time-resolved index of attentional orienting towards salient stimuli that either matched or did not match target-defining properties. A search display containing the target stimulus was preceded by a spatially uninformative singleton cue that either matched the color of the upcoming target (contingent cues), or that appeared in an irrelevant color (non-contingent cues). Multivariate analysis of raw EEG and alpha power revealed preferential tuning to the location of both contingent and non-contingent cues, with a stronger bias towards contingent than non-contingent cues. The time course of these effects, however, depended on the neural signal. Raw EEG data revealed attentional orienting towards the contingent cue early on in the trial (>156 ms), while alpha power revealed sustained spatial selection in the cued locations at a later moment in the trial (>250 ms). Moreover, while raw EEG showed stronger capture by contingent cues during this early time window, an advantage for contingent cues arose during a later time window in alpha band activity. Thus, our findings suggest that raw EEG activity and alpha-band power tap into distinct neural processes that index separate aspects of covert spatial attention.

Attentional priming does not enable observers to ignore salient distractors

ABSTRACTIt is commonly assumed that we find targets faster if we know what they look like. Such top-down guidance plays an important role in theories of visual attention. A recent provocative proposal is that effects attributed to top-down guidance instead reflect attentional priming. Theeuwes and van der Burg [(2011). On the limits of top-down control of visual selection. Attention, Perception, and Psychophysics. 73(7), 2092–2103. doi:10.3758/s13414-011-0176-9] found that observers could not use top-down set to ignore irrelevant singletons but when priming was maximal such distractors could be successfully ignored, suggesting that feature-based top-down selection is impossible but that this can be overcome when a target feature is constant on consecutive trials. Using a variant of their task, we found that participants were unable to ignore a known colour singleton, but also that repetition priming did not help participants ignore the salient distractor. Our results stand in direct contrast to the results of Theeuwes and van der Burg and cast doubt upon the claim that priming effects can explain top-down effects in visual search. Notably the priming effects we do see are mostly episodic rather than featural which means that they cannot serve as a feature-based selection mechanism.

Pure colour novelty captures the gaze

ABSTRACTWhile it is common wisdom that a salient visual event draws attention, experimental research provided mixed support for this hypothesis. The present experiment seeks evidence that a singleton draws attention to the degree that its feature is novel or unexpected. Two visual search experiments were conducted where an irrelevant colour singleton is presented on each pre-critical trial to familiarize participants with the presence of the singleton. In the critical trial of Experiment 1, the singleton was presented in a novel colour without prior announcement. The singleton was gazed at significantly earlier and longer in the critical trial, as compared to pre-critical trials. This result is consistent with predictions from the expectancy discrepancy hypothesis that colour novelty is sufficient to capture attention. Experiment 2 tested the alternative explanation that a surprising event mainly leads to a breakdown of the previously acquired attentional set, which in turn causes a reorientation towards perceptual salience. An unannounced change of the background colour in the critical trial while the singleton colour remained unchanged did not induce an attentional capture by the singleton like in Experiment 1. This result further confirms that surprising events capture attention in a spatial manner.

Suppression of overt attentional capture by salient-but-irrelevant color singletons.

For more than 2 decades, researchers have debated the nature of cognitive control in the guidance of visual attention. Stimulus-driven theories claim that salient stimuli automatically capture attention, whereas goal-driven theories propose that an individual's attentional control settings determine whether salient stimuli capture attention. In the current study, we tested a hybrid account called the signal suppression hypothesis, which claims that all stimuli automatically generate a salience signal but that this signal can be actively suppressed by top-down attentional mechanisms. Previous behavioral and electrophysiological research has shown that participants can suppress covert shifts of attention to salient-but-irrelevant color singletons. In this study, we used eye-tracking methods to determine whether participants can also suppress overt shifts of attention to irrelevant singletons. We found that under conditions that promote active suppression of the irrelevant singletons, overt attention was less likely to be directed toward the salient distractors than toward nonsalient distractors. This result provides direct evidence that people can suppress salient-but-irrelevant singletons below baseline levels.

Attentional Control Theory in Childhood: Enhanced Attentional Capture by Non-Emotional and Emotional Distractors in Anxiety and Depression.

Attentional control theory (ACT) proposes that anxiety is associated with executive functioning deficits. The theory has been widely investigated in adults. The current study tested whether symptoms of childhood anxiety and depression were associated with experimentally measured attentional control in the context of non-emotional and emotional stimuli. Sixty-one children (mean age = 9.23 years, range = 8.39–10.41) reported their trait anxiety and depression symptoms and completed three visual search tasks. The tasks used a variant of an irrelevant singleton paradigm and measured attentional capture by task-irrelevant non-emotional (color) and emotional (facial expressions) distractors. Significant attentional capture by both non-emotional and emotional distractors was observed, and was significantly correlated with trait anxiety and symptoms of depression. The strength of relationship between attentional capture and the symptoms did not differ significantly for non-emotional and emotional distractors. The results suggest that symptoms of childhood anxiety and depression are associated with poorer attentional control both in the presence of emotional and non-emotional stimuli, supporting ACT in younger populations. This attentional deficit in the context of non-emotional information might be as central to childhood internalizing symptoms as attentional biases often observed on tasks investigating processing of emotional stimuli.

Direct Evidence for Active Suppression of Salient-but-Irrelevant Sensory Inputs

Researchers have long debated whether attentional capture is purely stimulus driven or purely goal driven. In the current study, we tested a hybrid account, called the signal-suppression hypothesis, which posits that stimuli automatically produce a bottom-up salience signal, but that this signal can be suppressed via top-down control processes. To test this account, we used a new capture-probe paradigm in which participants searched for a target shape while ignoring an irrelevant color singleton. On occasional probe trials, letters were briefly presented inside the search shapes, and participants attempted to report these letters. Under conditions that promoted capture by the irrelevant singleton, accuracy was greater for the letter inside the singleton distractor than for letters inside nonsingleton distractors. However, when the conditions were changed to avoid capture by the singleton, accuracy for the letter inside the irrelevant singleton was reduced below the level observed for letters inside nonsingleton distractors, an indication of active suppression of processing at the singleton location.

Capture by colour: evidence for dimension-specific singleton capture.

Previous work on attentional capture has shown the attentional system to be quite flexible in the stimulus properties it can be set to respond to. Several different attentional "modes" have been identified. Feature search mode allows attention to be set for specific features of a target (e.g., red). Singleton detection mode sets attention to respond to any discrepant item ("singleton") in the display. Relational search sets attention for the relative properties of the target in relation to the distractors (e.g., redder, larger). Recently, a new attentional mode was proposed that sets attention to respond to any singleton within a particular feature dimension (e.g., colour; Folk & Anderson, 2010). We tested this proposal against the predictions of previously established attentional modes. In a spatial cueing paradigm, participants searched for a colour target that was randomly either red or green. The nature of the attentional control setting was probed by presenting an irrelevant singleton cue prior to the target display and assessing whether it attracted attention. In all experiments, the cues were red, green, blue, or a white stimulus rapidly rotated (motion cue). The results of three experiments support the existence of a "colour singleton set," finding that all colour cues captured attention strongly, while motion cues captured attention only weakly or not at all. Notably, we also found that capture by motion cues in search for colour targets was moderated by their frequency; rare motion cues captured attention (weakly), while frequent motion cues did not.

Barking up the wrong tree in attentional bias modification? Comparing the sensitivity of four tasks to attentional biases

Background and objectivesAttentional bias modification (ABM) is a potentially exciting new development in the treatment of anxiety disorders. However, reported therapeutic benefits have not always been replicated. To gauge the sensitivity of tasks used in ABM treatment and assessment, we used a counterbalanced within-subject design to measure their discriminant sensitivity to neutral and threatening facial expressions, comparing them with other well-known tasks that measure visual attention. MethodsWe compared two tasks often used in the assessment and treatment of attention bias (the dot-probe and the spatial cueing paradigms) with two well-known visual attention tasks (the irrelevant singleton and attentional blink paradigms), measuring their sensitivity to processing differences between threatening and neutral expressions for non-clinical observers. ResultsThe dot-probe, spatial cueing and irrelevant singleton paradigms showed little or no sensitivity to processing differences between facial expressions while the attentional blink task proved very sensitive to such differences. Furthermore, the attentional blink task provided an intriguing picture of the temporal dynamics of attentional biases that the other paradigms cannot do. LimitationsThese results need to be replicated with larger samples, including a comparison of a group of individuals diagnosed with social anxiety disorder and normal controls. ConclusionsOur results indicate that the sensitivity of putative attentional bias measures should be assessed experimentally for more powerful assessment and treatment of such biases. If the attentional blink task is indeed particularly sensitive to attentional biases, as our findings indicate, it is not unreasonable to expect that interventions based on this task may be more effective than those based on the tasks that are currently used.

Attention capture while switching search strategies: Evidence for a breakdown in top-down attentional control

Whereas capture experiments typically repeat a single task many times, real world cognition is characterized by frequent switching. Lien, Ruthruff, and Johnston (2010) reported that the attentional control system can rapidly and fully switch between different search settings (e.g., red to green), with no carryover and no intertrial priming. The present study examined whether this impressive flexibility is possible even when the switch is not between different features along the same dimension, but between mutually incompatible search modes. On each trial, participants were prompted to find and identify the letter that was in a specific colour (feature search mode) or was uniquely coloured (singleton search mode). Within each block, search mode was either pure or mixed; the mixed blocks contained a fixed AABB search sequence (singleton-singleton-feature-feature) in Experiment 1 and a random sequence in Experiment 2. The target display was preceded by a noninformative cue display containing a nontarget colour singleton. In pure feature search blocks, these irrelevant singleton cues were generally unable to capture attention, replicating previous findings of “contingent capture”. In mixed blocks, however, irrelevant colour singletons captured attention on feature search trials. This breakdown indicates a limitation in the sharpness of attentional control following mode switches, which might be common in the real world.

Ear-catching? Real-world distractibility scores predict susceptibility to auditory attentional capture

Although many of the everyday distractions that we encounter are auditory, most research on distractor processing to date has focused on the visual domain. A common measure of everyday distractibility is the Cognitive Failures Questionnaire (CFQ; Broadbent, Cooper, FitzGerald, & Parkes British Journal of Clinical Psychology 21: 1-16, 1982), which has previously been successfully linked with performance on controlled visual-attention tasks (e.g., Forster & Lavie Psychological Science 18: 377-381, 2007; Kanai, Dong, Bahrami, & Rees Journal of Neuroscience 31: 6620-6626, 2011; Tipper & Baylis Personality and Individual Differences 8: 667-675, 1987), such that high scorers tend to display greater distractor interference than do low scorers. We examined whether the same relationship would hold in hearing. Participants performed an auditory attentional-capture task, by responding to a target sound while ignoring an irrelevant singleton distractor (presented on half of the trials). We found that CFQ score successfully predicted distractor interference, since participants who reported being more distractible in everyday life produced more errors in the presence of the irrelevant singleton than did low scorers on the CFQ. This finding is the first to demonstrate a relationship between auditory distractor interference and everyday distractibility, and it confirms that performance on this type of laboratory-based attentional-capture task can successfully be related to behavior outside the laboratory.

The same-location cost is unrelated to attentional settings: an object-updating account.

What mechanisms allow us to ignore salient yet irrelevant visual information has been a matter of intense debate. According to the contingent-capture hypothesis, such information is filtered out, whereas according to the salience-based account, it captures attention automatically. Several recent studies have reported a same-location cost that appears to fit neither of these accounts. These showed that responses may actually be slower when the target appears at the location just occupied by an irrelevant singleton distractor. Here, we investigated the mechanisms underlying this same-location cost. Our findings show that the same-location cost is unrelated to automatic attentional capture or strategic setting of attentional priorities, and therefore invalidate the feature-based inhibition and fast attentional disengagement accounts of this effect. In addition, we show that the cost is wiped out when the cue and target are not perceived as parts of the same object. We interpret these findings as indicating that the same-location cost has been previously misinterpreted by both bottom-up and top-down theories of attentional capture. We propose that it is better understood as a consequence of object updating, namely, as the cost of updating the information stored about an object when this object changes across time.

Saccadic Inhibition of Return After Attention Shifts to Relevant and Irrelevant Color Singletons

Saccadic Inhibition of Return After Attention Shifts to Relevant and Irrelevant Color Singletons

Dissociating compatibility effects and distractor costs in the additional singleton paradigm

The interpretation of identity compatibility effects associated with irrelevant items outside the nominal focus of attention has fueled much of the debate over early versus late selection and perceptual load theory. However, compatibility effects have also played a role in the debate over the extent to which the involuntary allocation of spatial attention (i.e., attentional capture) is completely stimulus-driven or whether it is contingent on top-down control settings. For example, in the context of the additional singleton paradigm, irrelevant color singletons have been found to produce not only an overall cost in search performance but also significant compatibility effects. This combination of search costs and compatibility effects has been taken as evidence that spatial attention is indeed allocated in a bottom-up fashion to the salient but irrelevant singletons. However, it is possible that compatibility effects in the additional singleton paradigm reflect parallel processing of identity associated with low perceptual load rather than an involuntary shift of spatial attention. In the present experiments, manipulations of load were incorporated into the traditional additional singleton paradigm. Under low-load conditions, both search costs and compatibility effects were obtained, replicating previous studies. Under high-load conditions, search costs were still present, but compatibility effects were eliminated. This dissociation suggests that the costs associated with irrelevant singletons may reflect filtering processes rather than the allocation of spatial attention.

What we remember affects how we see: Spatial working memory steers saccade programming

Relationships between visual attention, saccade programming, and visual working memory have been hypothesized for over a decade. Awh, Jonides, and Reuter-Lorenz (Journal of Experimental Psychology: Human Perception and Performance 24(3):780-90, 1998) and Awh et al. (Psychological Science 10(5):433-437, 1999) proposed that rehearsing a location in memory also leads to enhanced attentional processing at that location. In regard to eye movements, Belopolsky and Theeuwes (Attention, Perception & Psychophysics 71(3):620-631, 2009) found that holding a location in working memory affects saccade programming, albeit negatively. In three experiments, we attempted to replicate the findings of Belopolsky and Theeuwes (Attention, Perception & Psychophysics 71(3):620-631, 2009) and determine whether the spatial memory effect can occur in other saccade-cuing paradigms, including endogenous central arrow cues and exogenous irrelevant singletons. In the first experiment, our results were the opposite of those in Belopolsky and Theeuwes (Attention, Perception & Psychophysics 71(3):620-631, 2009), in that we found facilitation (shorter saccade latencies) instead of inhibition when the saccade target matched the region in spatial working memory. In Experiment 2, we sought to determine whether the spatial working memory effect would generalize to other endogenous cuing tasks, such as a central arrow that pointed to one of six possible peripheral locations. As in Experiment 1, we found that saccade programming was facilitated when the cued location coincided with the saccade target. In Experiment 3, we explored how spatial memory interacts with other types of cues, such as a peripheral color singleton target or irrelevant onset. In both cases, the eyes were more likely to go to either singleton when it coincided with the location held in spatial working memory. On the basis of these results, we conclude that spatial working memory and saccade programming are likely to share common overlapping circuitry.

Experience-dependent attentional tuning of distractor rejection

Irrelevant salient distractors often capture attention, but given a sufficiently specific search template, these salient items no longer capture attention. In the present experiments, we investigated whether specific target templates are sufficient to resist capture, or whether experience with the salient distractors is also necessary. To test this hypothesis, observers completed four blocks of trials, each with a different-colored irrelevant singleton present on half of the trials. Color singletons captured attention early within a block, but after sufficient experience with the irrelevant singletons, those singletons no longer captured attention in the second halves of the blocks. This result suggests that to resist capture, a specific target template must be accompanied by experience-dependent attentional tuning to distractor properties.

When do luminance changes capture attention?

In two experiments, we examined the ability of task-irrelevant changes in luminance to capture attention in an irrelevant singleton search. By using uniform increment and decrement arrays, we were able to create changes of the same absolute magnitude, but resulting in a singleton with either higher or lower contrast magnitude, relative to other elements in the search array. A condition where a singleton changed contrast polarity without a concomitant change in the overall contrast magnitude was also included. It was found that only luminance changes resulting in a singleton having increased contrast (or saliency) were effective in capturing attention. In addition, no attentional capture was observed when the irrelevant singleton was characterized by the equivalent amount of static luminance differences, suggesting a unique attentional prioritization of luminance changes that increase singleton saliency.

On the limits of top-down control of visual selection

In the present study, observers viewed displays in which two equally salient color singletons were simultaneously present. Before each trial, observers received a word cue (e.g., the word red, or green) or a symbolic cue (a circle colored red or green) telling them which color singleton to select on the upcoming trial. Even though many theories of visual search predict that observers should be able to selectively attend the target color singleton, the results of the present study show that observers could not select the target singleton without interference from the irrelevant color singleton. The results indicate that the irrelevant color singleton captured attention. Only when the color of the target singleton remained the same from one trial to the next was selection perfect—an effect that is thought to be the result of passive automatic intertrial priming. The results of the present study demonstrate the limits of top-down attentional control.