Spatial Cuing Experiments Research Articles

Unseeing the white bear: Negative search criteria guide visual attention through top-down suppression.

In three spatial cueing experiments, we investigated whether a negative search criterion (i.e., a task-relevant feature that negatively defines the target) can guide visual attention in a top-down manner. Our participants searched for a target defined by a negative feature (e.g., red if the target was a nonred horizontal bar). Before the target, a peripheral singleton cue was shown at the target position (valid condition) or a nontarget position (invalid condition). We found slower reaction times in valid than invalid trials only with singleton cues matching the negative feature. Importantly, we ruled out that participants searched for target-associated features instead of suppressing the negative feature (Experiment 1). Furthermore, we demonstrated that suppression of cues with a negative feature was stronger than mere ignorance of singleton cues with a task-irrelevant feature. Finally, cue-target intervals of 60 ms and 150 ms elicited the same suppression effects for cues matching the negative feature. These findings suggest that the usage of a negative search criterion elicited feature-selective proactive suppression (Experiments 2 and 3). Thus, our results provide first evidence of top-down attentional suppression dependent on current task goals as a strategy operating in parallel to the goal-directed search for target-defining features (Experiment 2). (PsycInfo Database Record (c) 2022 APA, all rights reserved).

No identification of abrupt onsets that capture attention: evidence against a unified model of spatial attention.

Many studies have reported that spatial attention can be involuntarily captured by salient stimuli such as abrupt onsets. These involuntary shifts are often assumed to have the same effects on feature extraction as voluntary shifts: there are two different ways of moving the same attentional mechanism. According to this unified model of spatial attention, all shifts of attention should enhance the identification of attended objects. We directly tested this assumption using compatibility effects in a series of spatial cueing experiments. Participants searched a display and indicated whether the target number was greater or less than five. The salient precues were also numbers, allowing measurement of compatibility effects between the precue and the target. Precues that reliably predicted the target location produced compatibility effects (e.g., the precue "1" facilitated responding to the target "one"), indicating enhanced identification of the precue. Compatibility effects were also found for precues that were nonpredictive but had the target-finding feature (i.e., contingent capture). Critically, however, four separate experiments failed to find compatibility effects for salient abrupt onsets that were neither predictive nor task-relevant. This is surprising given that these same precues produced enormous cue validity effects (up to 186ms), suggesting salience-based attention capture. Our findings argue against the unified model: salience-based attention capture recruits different attentional mechanisms than contingent capture or voluntary shifts in attention.

Contingent Attentional Engagement: Stimulus- and Goal-Driven Capture Have Qualitatively Different Consequences

We examined whether shifting attention to a location necessarily entails extracting the features at that location, a process referred to as attentional engagement. In three spatial-cuing experiments (N = 60), we found that an onset cue captured attention both when it shared the target’s color and when it did not. Yet the effects of the match between the response associated with the cued object’s identity and the response associated with the target (compatibility effects), which are diagnostic of attentional engagement, were observed only with relevant-color onset cues. These findings demonstrate that stimulus- and goal-driven capture have qualitatively different consequences: Before attention is reoriented to the target, it is engaged to the location of the critical distractor following goal-driven capture but not stimulus-driven capture. The reported dissociation between attentional shifts and attentional engagement suggests that attention is best described as a camera: One can align its zoom lens without pressing the shutter button.

Contingent capture is weakened in search for multiple features from different dimensions.

Can observers maintain more than 1 attentional set and search for 2 features in parallel? Previous studies that relied on attentional capture by irrelevant distractors to answer this question focused on features from the same dimension and specifically, on color. They showed that 2 separate color templates can guide attention selectively and simultaneously. Here, the authors investigated attentional guidance by 2 features from different dimensions. In three spatial-cueing experiments, they compared contingent capture during single-set versus dual-set search. The results showed that attention was guided less efficiently by 2 features than by just 1. This impairment varied considerably across target-feature dimensions (color, size, shape and orientation). Confronted with previous studies, our findings suggest avenues for future research to determine whether impaired attentional guidance by multiple templates occurs only in cross-dimensional disjunctive search or also in within-dimension search. The present findings also showed that although performance improved when the target feature repeated on successive trials, a relevant-feature cue did not capture attention to a larger extent when its feature matched that of the previous target. These findings suggest that selection history cannot account for contingent capture and affects processes subsequent to target selection. (PsycINFO Database Record

The problem of latent attentional capture: Easy visual search conceals capture by task-irrelevant abrupt onsets.

Researchers are sharply divided regarding whether irrelevant abrupt onsets capture spatial attention. Numerous studies report that they do and a roughly equal number report that they do not. This puzzle has inspired numerous attempts at reconciliation, none gaining general acceptance. The authors propose that abrupt onsets routinely capture attention, but the size of observed capture effects depends critically on how long attention dwells on distractor items which, in turn, depends critically on search difficulty. In a series of spatial cuing experiments, the authors show that irrelevant abrupt onsets produce robust capture effects when visual search is difficult, but not when search is easy. Critically, this effect occurs even when search difficulty varies randomly across trials, preventing any strategic adjustments of the attentional set that could modulate probability of capture by the onset cue. The authors argue that easy visual search provides an insensitive test for stimulus-driven capture by abrupt onsets: even though onsets truly capture attention, the effects of capture can be latent. This observation helps to explain previous failures to find capture by onsets, nearly all of which used an easy visual search. (PsycINFO Database Record

An effective attentional set for a specific colour does not prevent capture by infrequently presented motion distractors.

An organism's survival depends on the ability to rapidly orient attention to unanticipated events in the world. Yet, the conditions needed to elicit such involuntary capture remain in doubt. Especially puzzling are spatial cueing experiments, which have consistently shown that involuntary shifts of attention to highly salient distractors are not determined by stimulus properties, but instead are contingent on attentional control settings induced by task demands. Do we always need to be set for an event to be captured by it, or is there a class of events that draw attention involuntarily even when unconnected to task goals? Recent results suggest that a task-irrelevant event will capture attention on first presentation, suggesting that salient stimuli that violate contextual expectations might automatically capture attention. Here, we investigated the role of contextual expectation by examining whether an irrelevant motion cue that was presented only rarely (∼3-6% of trials) would capture attention when observers had an active set for a specific target colour. The motion cue had no effect when presented frequently, but when rare produced a pattern of interference consistent with attentional capture. The critical dependence on the frequency with which the irrelevant motion singleton was presented is consistent with early theories of involuntary orienting to novel stimuli. We suggest that attention will be captured by salient stimuli that violate expectations, whereas top-down goals appear to modulate capture by stimuli that broadly conform to contextual expectations.

Onsets do not override top-down goals, but they are responded to more quickly

Do onsets automatically capture attention? Spatial-cuing experiments often reveal no capture by onset cues in searches for color targets. However, recent experiments have shown faster responses to an uncued color target presented as an abrupt onset than as a change to an existing item, which has been argued to reflect capture by the onset. In the present experiment, we tested whether this onset advantage reflects the capture of attention or processing independent of shifts of attention. In a modified spatial-cuing paradigm, noninformative color precues were paired with color targets presented as abrupt onsets or as no-onset characters. Critically, the number of other onset items in the target display was manipulated, which has previously been shown to disrupt attention allocation to any particular item. It was reasoned that if the onset advantage for uncued color targets reflects attentional capture, then the appearance of additional onsets should eliminate this advantage. The results showed that even with multiple onsets on the target display, the onset advantage remained additive with cue validity. The additive effects are inconsistent with automatic capture by onsets, suggesting instead that the onset advantage arises from an independent source.

Exogenous visual orienting by reward.

Classic spatial cueing experiments have demonstrated that salient cues have the ability to summon attention as evidenced by performance benefits when the cue validly indicates the target location and costs when the cue is invalid. Here we show that nonsalient cues that are associated with reward also have the ability to capture attention. We demonstrate performance costs and benefits in attentional orienting towards a nonsalient cue that acquired value through reward learning. The present study provides direct evidence that stimuli associated with reward have the ability to exogenously capture spatial attention independent of task-set, goals and salience.

Attentional Capture Does Not Depend on Feature Similarity, but on Target-Nontarget Relations

What factors determine which stimuli of a scene will be visually selected and become available for conscious perception? The currently prevalent view is that attention operates on specific feature values, so attention will be drawn to stimuli that have features similar to those of the sought-after target. Here, we show that, instead, attentional capture depends on whether a distractor’s feature relationships match the target-nontarget relations (e.g., redder). In three spatial-cuing experiments, we found that (a) a cue with the target color (e.g., orange) can fail to capture attention when the cue–cue-context relations do not match the target-nontarget relations (e.g., redder target vs. yellower cue), whereas (b) a cue with the nontarget color can capture attention when its relations match the target-nontarget relations (e.g., both are redder). These results support a relational account in which attention is biased toward feature relationships instead of particular feature values, and show that attentional capture by an irrelevant distractor does not depend on feature similarity, but rather depends on whether the distractor matches or mismatches the target’s relative attributes (e.g., relative color).

Attentional Capture by Salient Distractors during Visual Search Is Determined by Temporal Task Demands

The question whether attentional capture by salient but task-irrelevant visual stimuli is triggered in a bottom-up fashion or depends on top-down task settings is still unresolved. Strong support for bottom-up capture was obtained in the additional singleton task, in which search arrays were visible until response onset. Equally strong evidence for top-down control of attentional capture was obtained in spatial cueing experiments in which display durations were very brief. To demonstrate the critical role of temporal task demands on salience-driven attentional capture, we measured ERP indicators of capture by task-irrelevant color singletons in search arrays that could also contain a shape target. In Experiment 1, all displays were visible until response onset. In Experiment 2, display duration was limited to 200 msec. With long display durations, color singleton distractors elicited an N2pc component that was followed by a late Pd component, suggesting that they triggered attentional capture, which was later replaced by location-specific inhibition. When search arrays were visible for only 200 msec, the distractor-elicited N2pc was eliminated and was replaced by a Pd component in the same time range, indicative of rapid suppression of capture. Results show that attentional capture by salient distractors can be inhibited for short-duration search displays, in which it would interfere with target processing. They demonstrate that salience-driven capture is not a purely bottom-up phenomenon but is subject to top-down control.

Going rogue in the spatial cuing paradigm: High spatial validity is insufficient to elicit voluntary shifts of attention.

Voluntary shifts of attention are often motivated in experimental contexts by using well-known symbols that accurately predict the direction of targets. The authors report 3 experiments, which showed that the presentation of predictive spatial information does not provide sufficient incentive to elicit voluntary shifts of attention. For instance, when allowed to spontaneously choose between using a 100%-valid spatial word cue versus searching without the aid of the cue, observers consistently searched for a unique target without the aid of the cue. Another experiment showed that observers' choice to use spatial word cues could be biased by providing dedicated time to process the cue before the target display appeared (i.e., nonzero, cue-target SOAs). Although this dedicated processing time has routinely been included in spatial cuing experiments, its incentive-inducing role has never been acknowledged. Implications for theories of both voluntary and involuntary control are discussed.

Attention reverses the effect of prediction in silencing sensory signals

Predictive coding models of perception suggest that predicted sensory signals are attenuated (silencing of prediction error). These models, though influential, are challenged by the fact that prediction sometimes enhances, rather than reduces task-relevant sensory signals, as in the case of spatial cueing experiments. One possible explanation is that in these experiments, prediction (i.e. whether a stimulus is likely to be presented) is confounded with attention (i.e. whether a stimulus requires a behavioural response), which is known to boost rather than reduce sensory signal. However, recent theoretical work on predictive coding inspires an alternative hypothesis, and suggests that attention and prediction may operate synergistically to improve the precision of perceptual inference. This model posits that attention leads to heightened weighting of sensory evidence, thereby reversing the sensory silencing by prediction. We factorially manipulated attention and prediction in an fMRI study to test the validity of this model. Our results support a predictive coding model wherein attention reverses the sensory attenuation of predicted signals. This may explain the seemingly contradictory findings in the literature regarding the effects of prediction on neural responses.

The role of relational information in contingent capture.

On the contingent capture account, top-down attentional control settings restrict involuntary attentional capture to items that match the features of the search target. Attention capture is involuntary, but contingent on goals and intentions. The observation that only target-similar items can capture attention has usually been taken to show that the content of the attentional control settings consists of specific feature values. In contrast, the present study demonstrates that the top-down target template can include information about the relationship between the target and nontarget features (e.g., redder, darker, larger). Several spatial cuing experiments show that a singleton cue that is less similar to the target but that shares the same relational property that distinguishes targets from nontargets can capture attention to the same extent as cues that are similar to the target. Moreover, less similar cues can even capture attention more than cues that are identical to the target when they are relationally better than identical cues. The implications for current theories of attentional capture and attentional guidance are discussed.

Response-selection Conflict Contributes to Inhibition of Return

Here we examined the relationship between inhibition of return (IOR) and response-selection conflict. In two go/no-go and spatial-cueing experiments, we measured the amplitude of the fronto-central N2 event-related potential component to estimate the degree of response-selection conflict for validly cued and invalidly cued targets. When the probability of a go target was high (Experiment 1), both the amplitude of the N2 elicited on no-go trials and the number of false alarm errors were greater on invalid-cue than on valid-cue trials. When the probability of a go target was low (Experiment 2), neither of these effects was observed and the magnitude of the IOR effect was greatly reduced. These results show that a relative response bias toward responding on invalid-cue trials contributes to the IOR reaction time effect when the required response is prepotent.

Lateralized ERP components related to spatial orienting: Discriminating the direction of attention from processing sensory aspects of the cue

Two spatial cueing experiments were conducted to examine the functional significance of lateralized ERP components after cue-onset and to discriminate components related to sensory cue aspects and components related to the direction of attention. In Experiment 1, a simple detection task was presented. In Experiment 2, attentional selection was augmented. Two unimodal visual cueing tasks were presented using nonlateralized line cues and lateralized arrow cues. Lateralized cue effects and modulation after stimulus onset were stronger in Experiment 2. An early posterior component was related to the physical shape of arrows. A posterior negativity (EDAN) may be related to the encoding of direction from arrow cues. An anterior negativity (ADAN) and a posterior positivity (LDAP) were related to the direction of attention. The ADAN was delayed when it was more difficult to derive cue meaning. Finally, the data suggested an overlap of the LDAP and the EDAN.

Number magnitude orients attention, but not against one’s will

Recent evidence has shown that uninformative numbers can trigger attention shifts congruent with the spatial representation of number magnitude (Fischer, Castel, Dodd, & Pratt, 2003). In the present study, three spatial-cuing experiments whose aim was to qualify the automaticity of this number-mediated orienting are described. Experiment 1 replicated the phenomenon, showing that uninformative numbers can evoke orienting in a simple detection task. In Experiment 2, target location was random, but the participants were encouraged to shift attention to the left in response to large numbers and to the right in response to small numbers. No evidence for strong automaticity was observed, since the participants' performance was better when left-side targets were preceded by large numbers than when they were preceded by small numbers and vice versa. Experiment 3 corroborated this pattern by comparing gaze- and number-mediated cuing under conditions of real counterpredictiveness.The results indicate that unlike gaze-driven orienting, number-mediated orienting is not obligatory.

Top-down modulation of preattentive processing: Testing the recovery account of contingent capture

One highly controversial issue with respect to preattentive processing concerns the degree to which the preattentive detection of “singletons” elicits an involuntary shift of spatial attention (i.e., attentional capture) that is immune from top-down modulation. According to the “pure-capture” perspective, preattentive processing drives the allocation of spatial attention in a purely bottom-up manner, in order of relative salience. According to the “contingent-capture” perspective, preattentive processing can produce attentional capture, but such capture is contingent on whether the eliciting stimulus carries a feature property consistent with the current attentional set. Pure-capture proponents have recently argued that the evidence for contingencies in attentional capture actually reflects the rapid disengagement and recovery from capture. Two spatial cueing experiments tested the rapid recovery by measuring (1) compatibility effects associated with irrelevant distractors and (2) inhibition of return to irrelevant distractors. These two measures provide converging evidence against the rapid recovery account.

The role of response in spatial attention: direct versus indirect stimulus–response mappings

Recent research has suggested that inhibition of return (IOR) develops more quickly when subjects must respond with an eye movement than when they make a manual response to the target (Perception and Psychophysics 62 (2000) 1512–1524). Four spatial cueing experiments were conducted where subjects had to indicate the location of visual targets. Within each of the oculomotor and manual modalities, responses could be either directed towards the target (saccade or pointing) or had a more complex stimulus–response (S–R) mapping. For both saccadic and manual responses, IOR onset was delayed as the required S–R mapping became more indirect. This finding further emphasizes the role of response-related processes in spatial attention. Possible explanations for this pattern of results are considered, including the notion that activity in prefrontal cortex, needed for execution of such abstract S–R mappings, may influence the time course of reflexive spatial cueing effects.

A dissociation between attention and selection.

It is widely assumed that the allocatian of spatial attention results in the "selection" of attended objects or regions of space. That is, once a stimulus is attended, all its feature dimensions are processed irrespective of their relevance to behavioral goals. This assumption is based in part on experiments showing significant interference for attended stimuli when the response to an irrelevant dimension conflicts with the response to the relevant dimension (e.g., the Stroop effect). Here we show that such interference is not due to attending per se. In two spatial cuing experiments, we found that it was possible to restrict processing of attended stimuli to task-relevant dimensions. This new evidence supports two novel conclusions: (a) Selection involves more than the focusing of attention per se: and (b) task expectations play a key role in detertnining the depth of processing of the elementary feature dimensions of attended stimuli.

Contingent attentional capture or delayed allocation of attention?

Under certain circumstances, external stimuli will elicit an involuntary shift of spatial attention, referred to as attentional capture. According to the contingent involuntary orienting account (Folk, Remington, & Johnston, 1992), capture is conditioned by top-down factors that set attention to respond involuntarily to stimulus properties relevant to one's behavioral goals. Evidence for this comes from spatial cuing studies showing that a spatial cuing effect is observed only when cues have goal-relevant properties. Here, we examine alternative, decision-level explanations of the spatial cuing effect that attribute evidence of capture to postpresentation delays in the voluntary allocation of attention, rather than to on-line involuntary shifts in direct response to the cue. In three spatial cuing experiments, delayed-allocation accounts were tested by examining whether items at the cued location were preferentially processed. The experiments provide evidence that costs and benefits in spatial cuing experiments do reflect the on-line capture of attention. The implications of these results for models of attentional control are discussed.