The effect of prevalence on distractor speeded search termination.

Visual search can be disrupted by irrelevant salient stimuli. Recently, Moher (Psychological Science, 31(1), 31-42, 2020) found salient distractors to speed search when a target was absent and increase error rates when the target was present. That is, distractors lowered search-quitting thresholds. Nonetheless, the salient distractors Moher used were present on 50% of all trials. Since distractor prevalence has been found to influence search processes more broadly, here, we aimed to test the effect of distractor prevalence on this distractor-quitting threshold effect (QTE). To do so, we conducted two experiments. Experiment 1 compared the performance of individuals in a search task where the target was present on 50% of trials across two distractor-prevalence conditions (25% vs. 75% prevalence). Experiment 2 followed the same procedure, except with a wider probability margin (10% vs. 90% prevalence). In Experiment 1, distractor prevalence did not modulate the QTE. Critically, in Experiment 2, the QTE was modulated. For high-prevalence distractors (90%), a QTE was observed. However, as low-prevalence distractors (10%) did not speed search, no QTE was observed. One potential reason no QTE was observed was because low-prevalence distractors have significantly greater attentional capture, which washed out speeded termination effects.

The specificity of feature-based attentional guidance is equivalent under single- and dual-target search.

Individuals actively maintain attentional templates to prioritize target-matching inputs. While previous works have established that multiple templates can be held simultaneously, current understanding is limited with respect to the representational quality of such templates. We thus investigated: (a) whether the maintenance of two templates is limited to broad, coarse-grained representations, and if not, (b) whether there is nonetheless a decline in the achievable level of specificity when multiple attentional templates are held simultaneously. Using a spatial cueing procedure, we probed the breadth of attentional templates while participants maintained either one (Experiment 1) or two target colors (Experiment 2) under conditions of low- or high-similarity search and found specific template maintenance during high-similarity search for both single- and dual-target conditions. We then directly compared template specificity during single- and dual-target maintenance in Experiment 3, probing at the point of differentiation between target and nontarget feature values observed during single-target search. Here we found no difference in the selectivity of cue validity effects between single- and dual-target search, suggesting equivalent template specificity regardless of whether one or two features are relevant to search. Lastly, in Experiment 4, we established that such template specificity is dependent on access to visual working memory. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Delayed onsets are not necessary for generating distractor quitting thresholds effects in visual search.

Salient distractors lower quitting thresholds in visual search. That is, when searching for the presence of a target among filler items, a large heterogeneously coloured distractor presented at a delayed onset produces quick target-absent judgements and increased target-present errors. The aim of the current study was to explore if the timing of the salient distractor modulates this Quitting Threshold Effect (QTE). In Experiment 1, participants completed a target detection search task in the presence or absence of a salient singleton distractor that either appeared simultaneously with other search items or appeared at a delayed onset (i.e., 100 ms or 250 ms after other array items appeared). In Experiment 2, a similar method was used, except that the salient singleton distractor appeared simultaneously, 100 ms before, or 100 ms after the other array items. Across both experiments, we observed robust distractor QTEs. Regardless of their onset, salient distractors decreased target-absent search speeds and increased target-present error rates. In all, the present findings suggest that delayed onsets are not required for lowered quitting thresholds in visual search.

The interaction of internal and external attention.

The internal/external framework of attention characterizes attention focused to perceptual stimuli and internal representations as highly similar processes. While much research on external attention examines how attention may be broadened or narrowed (attentional zoom lens), it is unclear if internal attention functions in a similar way. In the present study, we manipulate both internal and external attentions to be either broad or narrow. Participants first encoded either a broad or narrow working memory array containing three differently colored items. This array was maintained as they performed an Eriksen flanker task that was either distributed broadly or narrowly, followed by a memory test for a random memory item. We found that regardless of whether the flanker fell inside or outside of the internal breadth of attention, flanker congruency effects did not change. The exception to this was when internal breadth was manipulated with retrocuing, which resulted in greater congruency effects when flankers aligned with the span of internal breadth rather than falling outside of it. Overall, this study shows that internal breadth information is unlikely to alter processing of external distractors until some of the information is cued internally after encoding, suggesting limitations in the internal/external attention framework.

Top-down then automatic: Instructions can continue to influence visual search when no longer actively implemented.

The present study investigated the automaticity of top-down instructions in visual search when the instruction was no longer actively implemented. To do so, we exploited the Priming of Pop-out (PoP) effect, a selection history phenomenon that reflects faster responses when the target and distractor colors are repeated than switched across trials of singleton search. We then had participants perform a color singleton search task where they implemented the instruction of imagining the opposite color of the previous target, which put the target colors underlying PoP and the imagery instruction in opposition. To assess automaticity, on some trials participants were instructed to stop implementing the imagery instruction. When the imagery instruction was implemented, responses were faster when the target and distractor colors switched (i.e., imagery congruent) than repeated (i.e., imagery incongruent) across search displays - a pattern of results opposite to the PoP effect. When participants were to not implement this instruction, the PoP effect was absent, indicating the imagery instruction had a lingering influence on visual search. This remained true even when participants reported successfully not implementing the instruction, and only when the imagery abandonment instruction was supplanted by a different top-down task was the lingering influence removed such that the PoP effect returned. Overall, the present study demonstrates that top-down instructions can continue to influence visual search despite the will of the observer.

The item-specific proportion congruency effect transfers to non-category members based on broad visual similarity.

The item-specific proportion congruency (ISPC) effect-that Stroop effects are reduced for items that are more likely to be incongruent than congruent-indicates that humans have the remarkable capacity to resolve conflict when it is associated with statistical regularities in the environment. It has been demonstrated that an ISPC signal induced by mostly congruent and mostly incongruent inducer items transfers to a set of distinct but visually similar transfer items that are equally likely to be congruent and incongruent; however, it is unclear what the ISPC signal is associated with to allow its transfer. To investigate this issue, an animal Stroop task was used to evaluate whether the ISPC signal would transfer to animal pictures that were different but visually similar same-category members (e.g., retrievers to retrievers, Experiment 1), visually dissimilar same-category members with broadly similar features (e.g., retrievers to bulldogs, Experiment 2), and visually dissimilar different-category members with broadly similar features (e.g., retrievers to house cats, Experiment 3). It was revealed that an ISPC effect was observed for the transfer items of each experiment, suggesting that these conflict signals can be linked based on broad feature similarity.

Eliminating the Low-Prevalence Effect in Visual Search With a Remarkably Simple Strategy.

The low-prevalence effect in visual search occurs when rare targets are missed at a disproportionately high rate. This effect has enormous significance for health and public safety and has proven resistant to intervention. In three experiments (Ns = 41, 40, and 44 adults), we documented a dramatic reduction of the effect using a simple cognitive strategy requiring no training. Instead of asking participants to search for the presence or absence of a target, as is typically done in visual search tasks, we asked participants to engage in "similarity search"-to identify the display element most similar to a target on every trial, regardless of whether a target was present. When participants received normal search instructions, we observed strong low-prevalence effects. When participants used similarity search, we failed to detect the low-prevalence effect under identical visual conditions across three experiments.

Typicality modulates the visual awareness of objects.

In the present study, we assessed whether typicality can influence the visual awareness of objects. Participants tracked moving images of objects and counted how often members of one category bounced off the edges of the display. On the last trial, an unexpected object moved across the display. In our first two experiments, this object could belong to the same category as the tracked or untracked objects. While participants were more likely to notice atypical members of the untracked category, this pattern of results reversed when participants tracked atypical objects. In our last two experiments, the unexpected object could belong to the same category as the tracked objects or a new category of objects. In this case, participants were more likely to notice typical members of both the tracked category and the new category. Together, these findings suggest that typicality can modulate the visual awareness of objects.

How is location defined? Implications for learning and transfer of location-specific control.

Much research has explored location-specific proportion compatibility (LSPC) effects (i.e., how the appearance of a stimulus in certain locations can reactively trigger different attentional control settings) to elucidate mechanisms underlying reactive control. Recently, however, failures to reproduce key evidence showing transfer of LSPC effects (originally reported in Crump & Milliken, 2009) have called into question whether control per se supports these effects. Notably, Crump and Milliken (2009), and all studies attempting to reproduce their findings, presented stimuli in two locations, one above and one below fixation. Inspired by research on differences between horizontal and vertical meridians, we examined the consequences of defining location in this way compared with alternatives. Experiments 1 and 2 demonstrated that LSPC effects are robust when location is defined as left versus right and larger than when location is defined as upper versus lower, and additionally demonstrated LSPC effects for two locations within the same coarse spatial category (e.g., left vs. farther left). In Experiment 3, we aimed to reproduce Crump and Milliken's key findings using left and right locations for the first time. Critically, we found transfer of the LSPC effect to diagnostic items across two designs and the first evidence for a robust experiment wide LSPC effect for inducer items. Our findings support theories positing that LSPC effects reflect location-specific attentional control and more generally suggest that choosing a definition of location is not a minor methodological decision but critically impacts learning and transfer of location-specific attentional control. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Can arrows change the subjective perception of space? Exploring symbolic attention repulsion.

The attention repulsion effect (ARE) refers to distortions in the perception of space for areas near the focus of attention. For instance, when attending to the right-hand side of the visual field, objects in central vision may appear as though they are shifted to the left. The phenomenon is likely caused by changes in visual cell functioning. To date, research on the ARE has almost exclusively used exogenous manipulations of attention. In contrast, research exploring endogenous attention repulsion has been mixed, and no research has explored the effects of nonpredictive arrow cues on this phenomenon. This gap in the literature is unexpected, as symbolic attention appears to be a unique form of attentional orienting compared with endogenous and exogenous attention. Therefore, this study explored the effects of symbolic orienting on spatial repulsion and compared it with an exogenously generated ARE. Across four experiments, both exogenous and symbolic orienting resulted in AREs; however, the magnitude of the symbolic ARE was smaller than the exogenous ARE. This difference in magnitude persisted, even after testing both phenomena using stimulus timing parameters known to produce optimal effects in traditional attentional cueing paradigms. Therefore, compared with symbolic attention, it appears that exogenous manipulations may tightly constrict attention resources on the cued location, in turn, potentially influencing the functioning of visual cells for enhanced perceptual processing.

Is the attentional SNARC effect truly attentional? Using temporal order judgements to differentiate attention from response.

The spatial-numerical association of response codes (SNARC) effect reflects the phenomenon that low digits are responded to faster with the left hand and high digits with the right. Recently, a particular variant of the SNARC effect known as the attentional SNARC (which reflects that attention can be shifted in a similar manner) has had notable replicability issues. However, a potentially useful method for measuring it was revealed by Casarotti et al. using a temporal order judgement (TOJ) task. Accordingly, the present study evaluated whether Casarotti et al.'s results were reproducible by presenting a low (1) or high (9) digit prior to a TOJ task where participants had to indicate which of two peripherally presented targets appeared first (Experiment 1) or second (Experiment 2). In Experiment 1, it was revealed that the findings of Casarotti et al.'s were indeed observable upon replication. In Experiment 2, when attention and response dimensions were put in opposition, the SNARC effect corresponded to the side of response rather than attention. Taken together, the present study confirms the robustness of the attentional SNARC in TOJ tasks, but that it is not likely due to shifts in attention.

Salience matters: Distractors may, or may not, speed target-absent searches.

Attention is often captured by irrelevant but salient changes in the environment, and usually results in slowed search speeds and increased errors during a typical visual search task. Nonetheless, a recent study conducted by Moher (2020, Psychological Science, 31[1], 31-42) found that the effect of a highly salient distractor on visual search depended on whether or not a target was also present in the display. While the distractor slowed search and increased errors for target-present trials, it speeded search for target-absent trials. Here, we aimed to replicate this finding and explore a potential boundary condition to the effect by manipulating the overall salience of the distractor. We did this by changing the size of the distractor to make it more or less salient. In Experiment, participants conducted a target-present and target-absent visual search task in the presence of a large, delayed-onset color distractor similar to that used in Moher's Study. In Experiment 2, a distractor that was much smaller than that used in the original Moher study was utilized. Critically, when a large distractor was used, the original findings of Moher were largely replicated; large salient distractors speeded target-absent visual search and increased errors for target-present visual search. However, when a smaller distractor was used, the results differed. For target-absent trials, search speeds were slower when the distractor was present compared with when it was absent. Thus, it appears that a highly salient distractor might be needed to trigger a shift in visual search strategy, and subsequently, lower quitting thresholds.

The item-specific proportion congruency effect can be contaminated by short-term repetition priming.

The item-specific proportion congruency (ISPC) effect reflects the phenomenon that Stroop congruency effects are larger for Stroop items that are more likely to be congruent (MC) than incongruent (MI). While the ISPC effect is purported to reflect long-term memory associations, the proportion manipulation entails that stimulus repetitions vary as a function of the MC and MI conditions, suggesting that a short-term repetition priming process may also contribute. In the present study, we investigated whether the ISPC effect reflected contributions from separate long-term associative learning and short-term repetition priming processes. To do so, the magnitude of the ISPC effect was compared when stimulus repetitions were present and absent. While the ISPC effect was robust, it was revealed that removing stimulus repetitions significantly attenuated the effect. Overall, the present study indicates the ISPC effect can reflect contributions from both short-term repetition and long-term memory processes.

Comparing imagery and perception: Using eye movements to dissociate mechanisms in search.

It has been demonstrated that color imagery can have a profound impact when generated prior to search, while at the same time, perceptual cues have a somewhat limited influence. Given this discrepancy, the present study evaluated the processes impacted by imagery and perception using a singleton search task where participants had to find an oddball colored target among homogenously colored distractors. Prior to each trial, a perceptual color was displayed or imagery was generated that could match the target, distractors, or neither item in the search array. It was revealed that color imagery led to both a larger benefit when it matched the target and a larger cost when it matched the distractors relative to perceptual cues. By parsing response times into pre-search, search, and response phases based on eye movements, it was revealed that, while imagery and perceptual cues both influenced the search phase, imagery had a significantly greater influence than perceptual cues. Further, imagery influenced pre-search and response phases as well. Overall, the present findings reveal that the influence of imagery is profound as it affects multiple processes in the vision-perception pipeline, while perception only appeared to impact search.

Tuning the ensemble: Incidental skewing of the perceptual average through memory-driven selection.

The process by which multiple items within an object grouping are rapidly summarized along a given visual dimension into a single mean value (i.e., perceptual averaging) has increasingly been shown to interact dynamically with visual working memory (VWM). Commonly, this interaction is studied with respect to the influence of perceptual averaging over VWM, but it is also the case that VWM can support perceptual averaging. Here, we argue that, in the presence of memory-matching elements, VWM exerts an obligatory influence over perceptual averaging even when it is detrimental to do so. Over four experiments, we tested our hypothesis by having individuals perform a mean orientation estimation task while concurrently maintaining a colored object in VWM. We anticipated that mean orientation reports would be attracted to the local mean of memory-matching items if such items are prioritized in perceptual average judgments. This was indeed the case as we observed a persistent bias in mean orientation judgments toward the subset mean of items matching the VWM item color, despite color being entirely irrelevant to the mean orientation task. Our results thus highlight a goal-invariant influence of VWM over perceptual averaging, which we attribute to amplification through memory-driven selection. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Typicality modulates attentional capture by object categories.

What we pay attention to in the visual environment is often driven by what we know about the world. For example, a number of studies have found that observers can adopt attentional sets for a particular semantic category. However, some objects are more typical members of a category than others. While previous evidence suggests that an object's typicality can influence the guidance of attention in visual search, it is unclear whether typicality can also influence the capture of attention. To test whether this is the case, participants were given a category of objects at the beginning of each trial. Then, a rapid serial visual presentation (RSVP) stream was presented at fixation, and participants had to indicate whether an object of the given category was present or absent from the stream. Importantly, a single flanker image also appeared above or below the central stream just before the target. This flanker could belong either to the same category as the target or a different category, and could be a typical or atypical exemplar of that category. Participants were less accurate at detecting the target when the flanker belonged to the same category as the target. Moreover, participants were even less accurate when the flanker was a typical exemplar of this category. Similar findings were observed when targets consisted of typical and atypical exemplars. Together, these findings indicate that the extent of attentional capture toward a distractor depends on whether the distractor matches the category and typicality of one's attentional set.

Context isn't everything: Search performance is influenced by the nature of the task but not the background.

AbstractIt has been demonstrated in the literature that cues in the environment that are predictive of how a task ought to be performed can influence performance. In an extension of this general notion, Cosman and Vecera (Journal of Experimental Psychology: Human Perception and Performance, 39(3), 836-848, 2013) reported that simply performing singleton and feature search tasks when irrelevant scenes were displayed in the background automatically modulated the search strategies adopted by participants when these scenes were reinstated at a later time. While intriguing, this result was also somewhat surprising given that an adaptive system (like the human brain) should disregard irrelevant information so task competencies generalize across environments. To investigate this issue further, we replicated the experimental procedures of Cosman and Vecera, while varying whether the test phase was either a singleton search (Experiments 1 and 3) or a feature search (Experiment 2) task. While it was observed that the nature of the search task varied whether a color singleton distractor influenced performance, there was no evidence that background scenes modulated the search strategies adopted by participants, contrasting the results of Cosman and Vecera. Overall, the findings here support the conclusion that the visual system prioritizes task-relevant information while disregarding irrelevant background information.

Shifting attention does not influence numerical processing.

Many theories of numerical cognition assume that numbers and space share a common representation at the response level. For example, observers are faster to respond to small numbers with their left hand and large numbers with their right hand (the SNARC effect). There is also evidence that viewing numbers can produce spatial shifts of attention, suggesting that attention may play a role in the spatial representation of numbers. In the present study, we assessed whether shifts of attention can influence numerical processing. Participants viewed a leftward or rightward peripheral cue followed by a centrally presented number, then judged whether the number was odd or even. Participants responded faster and made fewer errors when the number magnitude and response side were compatible, revealing a response-based SNARC effect. Participants also responded faster when the cue direction and response side were compatible, revealing a Simon effect. However, participants did not respond faster when the cue direction and number magnitude were compatible. Similar findings were observed when the association between numbers and space was relatively explicit. Moreover, although we failed to observe a response-based SNARC effect when number magnitude was directly relevant to observers' task, we observed a large Simon effect. Together, these findings suggest that although numbers and space share a common representation at the response level, attention does not play a substantial role in the spatial representation of numbers.

Directed avoidance and its effect on visual working memory.

Attentional control processes help to prioritize the storage of information in visual working memory (VWM) by gating what enters the system and influencing how precisely this information is stored. However, the extent to which such prioritization occurs deliberately, opposed to incidentally, is poorly understood. In large part, this is because investigations of this matter have almost exclusively relied on comparisons of memory for exogenously cued items versus uncued items. To understand whether prioritization occurs independent of intention, though, it is essential to examine instances in which attended items are entirely task-irrelevant. Thus, in the current study we used a directed avoidance paradigm to examine VWM performance following the selection of an item known to be task-irrelevant. In Experiment 1, we confirmed that cueing the color of a non-target item paradoxically increases attention to the cued item when the target color is unknown, resulting in longer search times (in line with previous findings). In Experiments 2 and 3, we applied the same cueing procedure to a delayed-estimation task of VWM, but now found a non-target cueing benefit in which the recall of task-relevant items was improved by directed avoidance. We further found that this effect is not solely due to the reprioritization of cognitive resources during maintenance (Exp. 4), but involves additional control processes that 1) reallocate resources to relevant items at encoding, and 2) selectively stabilize such items during the transition from encoding to maintenance (Exp. 5). As such, we suggest that while attentionally selected items may initially be prioritized independent of importance, more controlled mechanisms reallocate resources on the basis of relevance when sufficient time is provided before the sensory information is removed or displaced.