Visual orienting in response to attentional cues: Spatial correspondence is critical,conscious awareness is not

Three experiments examined visual orienting in response to spatial precues. In Experiments 1 and 2, attentional effects of central letters were stimulus driven: Orienting was dependent on the spatial layout of the cue display. When there were no correspondences between spatial features of the cue display and target location, attentional effects were absent, despite a conscious intention to orient in response to the symbolic information carried by the cue letters. In Experiment 3 clear orienting effects were observed when target location corresponded with spatial features of the cue display, but the magnitude of these effects was unaffected by whether participants were aware or unaware of the cue–target relationship. These findings are consistent with the view that (1) spatial correspondences between cues and targets are a critical factor driving visual orienting in cueing paradigms, and (2) attentional effects of spatial precues are largely independent of participants’ conscious awareness of the cue–target relationship.     

内源性空间线索有效性对视听觉整合的影响

采用内源性线索-靶子范式, 操纵线索类型(有效线索、无效线索)和靶刺激通道类型(视觉刺激、听觉刺激、视听觉刺激)两个自变量, 通过两个实验, 分别设置50%和80%两种内源性空间线索有效性来考察不同空间线索有效性条件下内源性空间注意对视听觉整合的影响。结果发现, 当线索有效性为50%时(实验1), 有效线索位置和无效线索位置的视听觉整合效应没有显著差异; 当线索有效性为80%时(实验2), 有效线索位置的视听觉整合效应显著大于无效线索位置的视听觉整合效应。结果表明, 线索有效性不同时, 内源性空间注意对视听觉整合产生了不同的影响, 高线索有效性条件下内源性空间注意能够促进视听觉整合效应。     

Inhibition of return for the length of a line?

Inhibition of return is most often measured using an exogenous spatial cuing method. The experiments presented here follow up on a small number of studies that have examined whether a similar effect occurs for nonspatial stimulus attributes. In Experiments 1 and 2, the task was to identify a target line as either short or long. In this context, targets on valid trials were of the same length as that of a preceding cue, whereas targets on invalid trials were of a different length than that of a preceding cue. The results were similar to those in spatial orienting studies in that responses were slower for valid than for invalid targets only at stimulus onset asynchronies (SOAs) longer than 300 msec. In Experiment 3, the stimuli were the same but the task was to detect the onset of the target line. This task change resulted in slower responses for valid than for invalid targets at all SOAs. A similar result was observed in Experiment 4, in which validity was defined by color rather than line length, and the task was to identify the target color. The discussion centers on an opponent process approach to interpreting cuing effects, and consequent difficulties in distinguishing spatial and nonspatial cuing effects based on their time course.     

The influence of a salience distinction between bilateral cues on the latency of target‐detection saccades

The spatial cueing paradigm, with saccades to targets as the method of response, was used to investigate the influence of two simultaneously presented cues on the orienting of visual attention. Participants were presented with bilateral cues, one of which was perceptually salient (high luminance) relative to the other. They participated in one of three conditions: in the ‘bright side likely’ condition targets usually (p = .8) appeared near the more salient cue; in the ‘dim side likely’ condition targets usually (p = .8) appeared near the less salient cue; and in the ‘neutral’ condition the arrangement of the cues was uninformative with respect to target location. Brief SOAs (0, 50, 100 and 150 ms) were employed. Rapid reflexive orienting to the more salient stimulus was observed in the neutral condition: saccadic latencies were faster when the target appeared near the bright cue, and this was found even across the two shortest SOAs. However, this reflexive orienting was suppressed in both the bright side likely and dim side likely conditions: the advantage observed at the bright cue's location across the two shortest SOAs in the neutral condition was significantly attenuated in the two contingent conditions. Results point to rapid expectancy‐based interference in the reflexive process of attention capture.     

Attention precuing and Simon effects: A test of the attention-coding account of the Simon effect

Simon effects refer to the finding that choice-response latencies to a nonspatial aspect of a stimulus vary depending on the spatial correspondence between the stimulus position and the position of the correct response alternative. Recently, researchers have proposed an attention-coding account of Simon effects whereby the (irrelevant) stimulus spatial code involved in the generation of the effect is formed in the process of attentional orienting to the stimulus. This account predicts that if attentional orienting is unnecessary at stimulus onset, as when the stimulus appears at an attended location, Simon effects will not be observed. This prediction was tested by measurement of Simon effects in an attention-precuing task in which the stimulus was presented at attended and unattended locations. Significant Simon effects were observed independently of the focus of attention. This result was obtained over a large range of precue-target SOAs, and did not depend on whether central or peripheral precues were used to direct attention or on whether the relevant target dimension was color or form. Significant Simon effects were not observed when the precue-target SOA was 50 ms, irrespective of the other precue and task conditions. The data do not support the prediction of the attention-coding account and thus question the generality of the account in its current form. It is suggested that spatial and temporal uncertainties are important factors that influence the pattern of results, and that these factors must be incorporated into attention-coding models of the Simon effect.     

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

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

Hand-hemispace spatial compatibility,precueing, and stimulus-onset asynchrony

Summary The role of attention and the resolution of coding conflicts in hand-hemispace spatial-compatibility effects was examined in a precueing experiment in which visual and vibrotactile precues, with various stimulus-onset asynchronies (SOAs), were presented in blocked and random order. It was expected that precues at the shorter SOAs would fail to facilitate the shifting of attention, as they occur too close to the imperative stimulus to be informative. The task would therefore approximate one of choice reaction time (RT), resulting in a hand-hemispace spatial-compatibility effect. Conversely, the longer SOAs would provide the subject with sufficient time in which to shift attention fully, and would therefore result in a task more like that of simple reaction time (SRT). It was expected that the hand-hemispace spatial-compatibility effect would then be absent. As was expected, this effect was present at the shorter SOAs, and absent at the longer SOAs. In Experiments 2 and 3, provision of a visual precue further facilitated attentional deployment, as did blocking the presentation of various SOAs in Experiment 3. Vibrotactile and visual precues did not differ in their ability to direct attention, implying that these modalities orient attention and precue location in essentially similar ways. These findings are discussed within the context of the mechanisms thought to underlie the time course of spatial compatibility and the dissipation of a fading trace of interfering spatial codes.     

Scale of attentional focus in visual search.

The effects of the spatial scale of attention on feature and conjunction search were examined in two experiments. Adult participants in three age groups--young, young-old, and old-old--were given precues of varying validity and precision in indicating the location of a target letter subsequently presented in a visual array. Systematic decreases in the size of a valid precue (toward the size of the target) progressively facilitated both feature and conjunction search, with a greater benefit accruing to conjunction search. Age-related slowing in conjunction search was mitigated by precise (small and valid) precues, presumably because they reduced the need for participants in the young-old group to focus and to shift attention. Nevertheless, this benefit was reduced in the old-old group. The effects of valid location precue size varied with cue-target stimulus onset asynchrony (SOA) in a manner that interacted with search difficulty: Effects of cue size developed more rapidly in feature search but more slowly in conjunction search. Finally, when precues were invalid for target location, search was faster with larger sized precues. Thus, in both easy feature search and hard conjunction search, the scale of visuospatial attention modulates the speed of visual search. Furthermore, when the SOA is sufficiently long for cue effects to develop, the ability to dynamically adjust the scale of visuospatial attention appears to decline in advanced age. These results go beyond current models in suggesting that visuospatial attention possesses two dynamic properties--shifting in space and varying in scale--that are deployed independently, depending on task demands.     

Response-specifying cue for action interferes with perception of feature-sharing stimuli

Perceiving a visual stimulus is more difficult when a to-be-executed action is compatible with that stimulus, which is known as blindness to response-compatible stimuli. The present study explored how the factors constituting the action event (i.e., response-specifying cue, response intention, and response feature) affect the occurrence of this blindness effect. The response-specifying cue varied along the horizontal and vertical dimensions, while the response buttons were arranged diagonally. Participants responded based on one dimension randomly determined in a trial-by-trial manner. The response intention varied along a single dimension, whereas the response location and the response-specifying cue varied within both vertical and horizontal dimensions simultaneously. Moreover, the compatibility between the visual stimulus and the response location and the compatibility between that stimulus and the response-specifying cue was separately determined. The blindness effect emerged exclusively based on the feature correspondence between the response-specifying cue of the action task and the visual target of the perceptual task. The size of this stimulus–stimulus (S–S) blindness effect did not differ significantly across conditions, showing no effect of response intention and response location. This finding emphasizes the effect of stimulus factors, rather than response factors, of the action event as a source of the blindness to response-compatible stimuli.     

Scale of attentional focus in visual search

The effects of the spatial scale of attention on feature and conjunction search were examined in two experiments. Adult participants in three age groups—young, young-old, and old-old—were given precues of varying validity and precision in indicating the location of a target letter subsequently presented in a visual array. Systematic decreases in the size of a valid precue (toward the size of the target) progressively facilitated both feature and conjunction search, with a greater benefit accruing to conjunction search. Age-related slowing in conjunction search was mitigated by precise (small and valid) precues, presumably because they reduced the need for participants in the young-old group to focus and to shift attention. Nevertheless, this benefit was reduced in the old-old group. The effects of valid location precue size varied with cue-target stimulus onset asynchrony (SOA) in a manner that interacted with search difficulty: Effects of cue size developed more rapidly in feature search but more slowly in conjunction search. Finally, when precues were invalid for target location, search was faster with larger sized precues. Thus, in both easy feature search and hard conjunction search, the scale of visuospatial attention modulates the speed of visual search. Furthermore, when the SOA is sufficiently long for cue effects to develop, the ability to dynamically adjust the scale of visuospatial attention appears to decline in advanced age. These results go beyond current models in suggesting that visuospatial attention possesses two dynamic properties—shifting in space and varying in scale—that are deployed independently, depending on task demands.     

注意控制定势和线索类型在注意捕获中的作用

采用前线索范式, 通过3个实验考察了注意控制定势和线索类型在注意捕获中的作用。实验1要求被试搜索颜色奇异项目标或突现目标, 涉及较弱的注意控制定势, 结果表明, 突现线索在作为匹配线索和不匹配线索时都能捕获注意, 而颜色奇异项线索只有在作为匹配线索时才能捕获注意。实验2要求被试搜索具体特征的红色或白色目标, 使被试建立较强的特征搜索定势, 结果表明, 颜色奇异项线索和突现线索在作为匹配线索时都能捕获注意, 但是在不匹配条件下, 颜色奇异项线索被抑制了, 而突现线索不能捕获注意; 实验3采取go/no-go范式, 要求被试对红色目标进行反应, 对白色目标进行抑制, 并通过设置不同的线索-目标时间间隔来进一步考察注意捕获的机制, 结果表明, 在600 ms间隔下, no-go突现线索被抑制, 而对于go颜色奇异项线索来说, 随着时间间隔的增加, 注意捕获效应减少。结果与相倚捕获假说和抑制独立捕获假说不符, 支持注意转移假说：自上而下的注意控制定势通过把注意从和目标不匹配的特征位置转移发挥作用; 颜色奇异项线索和突现线索的注意捕获机制相同, 但是突现线索相对于颜色奇异项线索来说, 在与目标不匹配的条件下, 更容易捕获注意, 更难被抑制。     

The spatial distribution of attention following an exogenous cue

Three target-discrimination experiments were conducted to explore the spatial distribution t)f covert visual attention following an exogenous cue. On each trial, a brief peripheral onset was followed by a target stimulus in an otherwise empty visual field at one of eight (Experiment 1) or one of four (Experiments 2 and 3) possible locations centered at the fixation point. The spatial relation between the cue and the target was manipulated. The main results were that (1) performance was better at the cued location than at another nearby location in the same visual quadrant; (2) performance was not affected by the major horizontal and vertical visual meridians; and (3) performance was affected by the spatial distance between the cued and target locations. Together, the results suggest that the spatial distribution of exogenously oriented attention cart be most easily integrated with a simple gradient model.     

Timing of reflexive visuospatial orienting in young, young-old, and old-old adults

This study examined adult age differences in reflexive orienting to two types of uninformative spatial cues: central arrows and peripheral onsets. In two experiments using a Posner cuing task, young adults (ages 18–28 years), young-old adults (60–74 years), and old-old adults (75–92 years) responded to targets that were preceded 100–1,000 ms earlier by a central arrow or a peripheral abrupt onset. In Experiment 1, the cue remained present upon target onset. Facilitation effects at short cue–target stimulus onset asynchronies (SOAs) were prolonged in duration for the two older groups relative to the young adults. At longer cue–target SOAs, inhibition of return (IOR) that was initiated by peripheral onset cues was observed in the performance of young adults but not in that of the two older groups. In Experiment 2, the cue was presented briefly and removed prior to target onset. The change in cue duration minimized age differences (particularly for young-old adults) in facilitation effects and led to IOR for all three age groups. The findings are consistent with the idea that attentional control settings change with age, with higher settings for older adults leading to delayed disengagement from spatial cues.     

Capturing attention is not that simple: Different mechanisms for stimulus-driven and contingent capture

Attentional orienting can be involuntarily directed to task-irrelevant stimuli, but it remains unsolved whether such attentional capture is contingent on top-down settings or could be purely stimulus-driven. We propose that attentional capture depends on the stimulus property because transient and static features are processed differently; thus, they might be modulated differently by top-down controls. To test this hybrid account, we adopted a spatial cuing paradigm in which a noninformative onset or color cue preceded an onset or color target with various stimulus onset asynchronies (SOAs). Results showed that the onset cue captured attention regardless of target type at short—but not long—SOAs. In contrast, the color cue captured attention at short and long SOAs, but only with a color target. The overall pattern of results corroborates our hypothesis, suggesting that different mechanisms are at work for stimulus-driven capture (by onset) and contingent capture (by color). Stimulus-driven capture elicits reflexive involuntary orienting, and contingent capture elicits voluntary feature-based enhancement.     

The time course of attentional deployment in contextual cueing

The time course of attention is a major characteristic on which different types of attention diverge. In addition to explicit goals and salient stimuli, spatial attention is influenced by past experience. In contextual cueing, behaviorally relevant stimuli are more quickly found when they appear in a spatial context that has previously been encountered than when they appear in a new context. In this study, we investigated the time that it takes for contextual cueing to develop following the onset of search layout cues. In three experiments, participants searched for a T target in an array of Ls. Each array was consistently associated with a single target location. In a testing phase, we manipulated the stimulus onset asynchrony (SOA) between the repeated spatial layout and the search display. Contextual cueing was equivalent for a wide range of SOAs between 0 and 1,000 ms. The lack of an increase in contextual cueing with increasing cue durations suggests that as an implicit learning mechanism, contextual cueing cannot be effectively used until search begins.     

Oculomotor readiness and covert orienting: differences between central and peripheral precues.

The costs produced by invalid precues can depend on the spatial relationship between the cued location and the target location. If oculomotor programs mediate attention shifts, then the effect of varying the spatial relation between the cue and target should be the same for covert orienting (indexed by manual responses) and saccadic responses. We found this to be true only for central precues. With central precues, both manual and saccadic costs were greater when cue and target occurred on opposite sides of the vertical meridian than when they occurred on the same side. With peripheral precues, there were no meridian effects in either response condition, but there was a significant dissociation in the pattern of saccadic and manual costs. For manual responses costs were greater when the target was eccentric relative to the cue, whereas for saccades costs were greater when the cue was eccentric to the target. These results provide additional support for the idea that different orienting mechanisms are engaged by central and peripheral precues. They further suggest that the relationship between oculomotor and attentional orienting may depend on the nature of the precue, with the potential for interdependence being greater with central precues.     

Oculomotor readiness and covert orienting: Differences between central and peripheral precues

The costs produced by invalid precues can depend on the spatial relationship between the cued location and the target location. If oculomotor programs mediate attention shifts, then the effect of varying the spatial relation between the cue and target should be the same for covert orienting (indexed by manual responses) and saccadic responses. We found this to be true only for central precues. With central precues, both manual and saccadic costs were greater when cue and target occurred on opposite sides of the vertical meridian than when they occurred on the same side. With peripheral precues, there were no meridian effects in either response condition, but there was a significant dissociation in the pattern of saccadic and manual costs. For manual responses costs were greater when the target was eccentric relative to the cue, whereas for saccades costs were greater when the cue was eccentric to the target. These results provide additional support for the idea that different orienting mechanisms are engaged by central and peripheral precues. They further suggest that the relationship between oculomotor and attentional orienting may depend on the nature of the precue, with the potential for interdependence being greater with central precues.     

Location cuing and response time distributions in visual attention

The allocation of visual attention was investigated in two experiments. In Experiment 1 (n = 24), a peripheral cue was presented, and in Experiment 2 (n = 24), a central cue was used. In both experiments, cue validity was 90%, and the task was four-choice target identification. Response time distributions were collected for valid trials over five cue-target stimulus onset asynchronies (SOAs), and ex-Gaussian parameters were extracted. In both experiments, only the mean of the Gaussian component decreased as a function of cue-target SOA, which implied a strict time axis translation of the distributions. The results were consistent with sequential sampling models featuring a variable delay in the onset of information uptake.     

A glimpse is not a glimpse: Differential processing of flashed scene previews leads to differential target search benefits

The question of whether words can be identified without spatial attention has been a topic of considerable interest over the last five and a half decades, but the literature has yielded mixed conclusions. The present experiments manipulated the proportion of valid trials (the proportion of trials in which a cue appeared in the same location as the upcoming target word) so as to encourage distributed (50% valid cues; Experiments 1 and 3) or focused (100% valid cues; Experiments 2 and 4) spatial attention in a priming-type paradigm. Participants read aloud a target word, and the impact of a simultaneously presented distractor word was assessed. Semantic and orthographic priming effects were present when conditions promoted distributed spatial attention but absent when conditions promoted focused spatial attention. In contrast, Experiment 5 yielded a distractor word effect in the 100% valid cue condition when subjects identified a colour (Stroop task). We take these results to suggest that (1) spatial attention is a necessary preliminary to visual word recognition and (2) examining the role of spatial attention in the context of the Stroop task may have few implications for basic processes in reading because colour processing makes fewer demands on spatial attention than does visual word recognition.     

Effects of spatial and symbolic precues on localization performance

One of the fundamental properties of spatial vision is the ability to localize objects in space. According to a recent proposal, accurate localization performance involves the operation of two systems: the attention system and the eye movement system. Upon stimulus presentation, attention is shifted to the target area: this provides coarse location information. Subsequently, a saccadic eye movement is executed: this provides fine location information. In this study we tested predictions derived from this model concerning the effects of precue information on localization performance. In a series of five experiments we manipulated duration of precue (71, 400, and 1,000 ms) and type of precue (spatial versus symbolic). Results showed that very short duration (i.e., 71 ms) spatial precues improved localization performance whereas very short duration symbolic precues did not. In contrast, the 1,000 ms duration precue condition showed similar amounts of precuing benefit for the spatial and symbolic precues. This pattern of differential precuing effects corroborated the two-process model of localization performance. Received: 24 June 1999 / Accepted: 28 January 2000