线索靶子关联和搜索策略对注意捕获的作用——来自意义线索的证据

采用线索化范式,操作性地建立线索和靶子间的关联,通过比较不同搜索策略任务下不同线索靶子关联条件间的捕获量考察关联水平及搜索策略对注意捕获的作用,并分析抽象的意义概念对空间注意分配的调节作用。结果发现(1)意义线索的注意捕获符合关联性的注意定向假说,只有符合当前注意控制定势的线索才具有捕获注意的能力;(2)知觉关联在调节无意注意定向上具有主导性,调节能力强,能将其他因素效应掩盖;语义关联单独作用时对无意注意定向有调节作用,但调节程度小,效应易被掩盖;(3)搜索策略虽然能够大大提高反应速度,但只有基于特征独子的搜索模式对无意注意定向有调节作用,且调节能力有限。研究再次认证了空间无意注意转移中注意控制定势的作用,同时指出抽象的概念加工能够根据当前的环境有效指导后续的选择和行为。     

语义关联的注意捕获——来自线索化范式的证据

采用线索化范式, 操作性地建立线索和靶子的语义关联, 考察语义关联对注意捕获的影响。实验1采用特征线索意义靶子的形式, 建立某一特定语义水平的注意控制定势, 发现线索靶子语义一致时线索捕获注意, 线索靶子语义不一致时同样的线索失去捕获注意的能力。实验2随机呈现线索颜色和靶子汉字, 建立两种语义概念的注意控制定势, 发现所有的线索都出现了捕获效应, 而不论其在某一具体试次中是否与靶子意义一致。实验3交换了线索与靶子的属性及概念, 采用意义线索特征靶子的形式, 结果与实验1一致。这些结果表明, (1)语义关联的注意捕获符合关联性的无意注意定向假说, 刺激的捕获能力受当前的注意控制定势调节; (2)由语义概念激活的知觉表征在调节空间注意分配上与其自身相比形式相同, 但程度有所下降; (3)知觉特征水平的注意控制定势能够激活与其相应的语义概念, 使其吸引注意并调节空间注意分配; (4)知觉表征和语义概念的激活可能是双向的, 激活后在指导注意转移上表现出相同的特性。     

掩蔽线索引发的注意定向——易化和抑制

采用空间线索化范式,考察了阈下线索引发的外源性注意定向.实验一调控线索和掩蔽呈现时间设置最佳阈下参数;实验二和实验三分别采用检测和辨别任务,考察了多SOA下阈下线索引发的外源性空间注意定向.结果发现,无论在检测任务还是辨别任务中,阈下线索均可引发抑制效应,且完成辨别任务时得到了注意定向的双阶段效应——易化和抑制.这表明,在不需要意识参与下阈下线索可以引导注意,产生易化效应与抑制效应,后者的机制可能与返回抑制相同.     

三维空间中不同视野深度位置上的返回抑制

通过虚拟现实构建虚拟三维场景,将二维平面视觉空间返回抑制范式应用到三维空间,通过两个实验操纵了目标深度、线索有效性以及视野位置三个变量,考察注意在三维空间不同视野深度位置上进行定向/重定向产生的返回抑制效应。结果发现,(1)二次线索化位于固定的中央视野时,不论目标出现在近处空间还是出现在远处空间,外周视野条件下的返回抑制大于中央视野条件下的返回抑制;(2)二次线索化位于非固定的中央视野时,近处空间和远处空间的返回抑制存在分离,表现为当目标出现在远处空间时,外周视野条件下的返回抑制效应减小。研究表明,三维空间中外周视野深度位置上的返回抑制与中央视野深度位置上的返回抑制存在差异。     

目光注视线索对客体注意的影响及作用机制

目光注视在人类社交以及捕获和维持注意方面发挥重要作用。但是, 目光注视如何与客体交互以引导注意分配至今尚不明确。因此, 本研究采用双框线索范式, 以具有两种注视方向(直视或回避)的面孔或实物作为客体, 通过操纵线索到目标间的SOA来考察目光注视对客体注意的影响及作用机制。实验1发现, 目光注视对客体效应的影响只出现在300 ms SOA时; 进一步分析发现, 客体效应的差异来自于直视条件下被试对无效相同客体位置上的目标比回避条件下反应更快。这表明与回避目光相比, 直视更能捕获我们的注意, 从而产生更大的客体效应。实验2将面孔对比度反转, 排除了低水平物理特征对实验1结果的影响。实验3使用两种注视方向的眼睛叠加杯子作为客体, 以探究目光注视效应是否能扩展到其他客体中, 结果与实验1相同。本研究结果表明, 目光注视能够与客体交互共同引导注意分配, 直视更能捕获注意, 但受SOA的影响, 上述结果支持了感觉增强理论。     

线索靶子关联和搜索策略对注意捕获的作用

采用线索化范式, 通过实验任务设计线索与靶子不同的关联并鼓励被试采用不同的搜索策略, 探讨线索与靶子间的知觉关联、语义关联及特征独子检测模式、特征搜索模式对注意捕获的作用。通过线索无效条件和线索有效条件反应时之差判断每一条件下的捕获量, 并综合各条件的反应情况做出结论如下：(1)线索与靶子的知觉关联调控注意捕获, 其效应不受语义关联和搜索策略影响; (2)线索与靶子的语义关联只在排除知觉关联后调控注意捕获; (3)控制知觉关联和语义关联后, 特征搜索模式不影响注意捕获, 而特征独子检测模式对注意捕获有影响。这表明语义知识和知觉经验根据当前任务要求共同作用指导个体的视觉加工, 表现了人类加工系统的灵活性和可调节性。     

三维空间中视觉空间返回抑制对Simon效应的影响

通过虚拟现实技术构建虚拟三维场景,采用视觉空间返回抑制范式与Simon任务的变式相结合,操纵了目标深度、线索有效性以及空间一致性三个变量,考察三维空间深度位置上视觉空间返回抑制如何影响任务无关的反应表征(Simon效应)。结果发现,(1)三维空间深度位置上存在基于空间的返回抑制效应,且空间返回抑制效应会削减Simon效应;(2)目标出现在远处空间时,线索化条件下的Simon效应显著大于非线索化条件下的Simon效应;(3)目标出现在近处空间时,线索化条件与非线索化条件下的Simon效应之间无显著差异。研究表明,空间返回抑制并不是"深度盲",且目标的空间位置会对空间返回抑制与Simon效应的交互关系产生影响。     

自上而下的注意控制定势在注意捕获中的作用

采用经典前线索范式的变式, 通过100%有效的提示考察了自上而下的注意控制定势在注意捕获中的作用。实验1要求被试在整个实验中只搜索一个固定颜色的目标, 但是通过在每个试次前对目标进行提示加强注意控制定势的强度。实验2通过在每个试次中变化要搜索的目标颜色使被试必须建立两个更强的注意控制定势。实验结果一致表明和目标颜色相匹配的线索捕获了注意, 而和目标颜色无关的线索被抑制; 实验2的捕获效应和抑制效应都显著大于实验1; 对无关冲突线索和无关中性线索的注意抑制效应没有差异, 抑制效应显著小于捕获效应。研究表明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, 支持注意转移假说; 对匹配线索的捕获和对无关线索的抑制运用了同一加工系统, 抑制作为捕获的附加产品出现, 两者都可以作为注意捕获的指标。     

三维动静态场景下返回抑制的扩散

使用虚拟现实技术探讨三维动静态空间下返回抑制是否敏感于深度线索及返回抑制效应是否存在空间扩散。采用线索−靶子范式,分别设置三维静态和动态场景。结果发现：三维静态场景,不同深度及不同侧位置均发生返回抑制且产生效应大小有差异;三维动态场景,不同线索条件反应时无显著差异。结果表明,三维静态场景下,返回抑制敏感于深度线索,其效应在空间中存在扩散;客体运动破坏了返回抑制的产生及其效应的空间扩散。     

自上而下的目标调节奖赏联结干扰子的注意定向和脱离

近年来传统的注意控制理论已经无法解释部分注意控制现象,有研究者提出将奖赏联结/价值驱动的注意捕获作为一种新的注意引导源。奖赏联结的注意捕获是否会受到自上而下的目标定势的调节已成为该领域一个重要的理论问题。研究采用空间线索范式的变式,探讨了奖赏联结干扰子与目标的相关性对奖赏联结注意捕获中的定向和脱离的调节作用。研究结果发现:当学习阶段习得的奖赏联结干扰子在测验阶段与目标相关时(实验1),有奖干扰子相对于无奖干扰子具有优先的注意定向和延迟脱离;而学习阶段习得的奖赏联结干扰子在测验阶段与目标无关时(实验2),有奖干扰子和无奖干扰子在注意定向和脱离方面均无显著差异。由此可见,奖赏联结的注意捕获并不是完全自动化的,自上而下的目标定势能够调节其注意定向和脱离的成分,支持奖赏联结的注意捕获与自上而下的目标定势交互引导视觉注意的观点。     

Exogenous and endogenous spatial attention effects on visuospatial working memory

In this study, we investigate how exogenous and endogenous orienting of spatial attention affect visuospatial working memory (VSWM). Specifically, we focused on two attentional effects and their consequences on storage in VSWM, when exogenous (Experiment 1) or endogenous (Experiment 2) orienting cues were used. The first effect, known as the meridian effect, is given by a decrement in behavioural performance when spatial cues and targets are presented in locations separated by vertical and/or horizontal meridians. The second effect, known as the distance effect, is given by a decrement in the orienting effects as a function of the spatial distance between cues and targets. Our results revealed a dissociation between exogenous and endogenous orienting mechanisms in terms of both meridian and distance effects. We found that meridian crossing affects performance only when endogenous cues were used. Specifically, VSWM performance with endogenous cueing depended more on the number of meridian crossings than on distance between cue and target. By contrast, a U-shaped distance dependency was observed using exogenous cues. Our findings therefore suggest that exogenous and endogenous orienting mechanisms lead to different forms of attentional bias for storage in VSWM.     

Capturing spatial attention with multisensory cues

We assessed the influence of multisensory interactions on the exogenous orienting of spatial attention by comparing the ability of auditory, tactile, and audiotactile exogenous cues to capture visuospatial attention under conditions of no perceptual load versus high perceptual load. In Experiment 1, participants discriminated the elevation of visual targets preceded by either unimodal or bimodal cues under conditions of either a high perceptual load (involving the monitoring of a rapidly presented central stream of visual letters for occasionally presented target digits) or no perceptual load (when the central stream was replaced by a fixation point). All of the cues captured spatial attention in the no-load condition, whereas only the bimodal cues captured visuospatial attention in the highload condition. In Experiment 2, we ruled out the possibility that the presentation of any changing stimulus at fixation (i.e., a passively monitored stream of letters) would eliminate exogenous orienting, which instead appears to be a consequence of high perceptual load conditions (Experiment 1). These results demonstrate that multisensory cues capture spatial attention more effectively than unimodal cues under conditions of concurrent perceptual load.     

Peripheral cuing by abrupt-onset cues: the influence of color in S-R corresponding conditions

Research on visuospatial attention indicates that a peripheral abrupt-onset cue at target position (valid condition) facilitates processing of the target, whereas a cue at another position interferes. This validity effect seems to be contingent on a similarity of the cue's color to the set of target colors (cf. J. Exp. Psychol.: Human Percep. Perform. 18 (1992) 1030). In Experiments 1-3, we confirm this contingency with cues that have the potential to activate responses. Thus, attentional capture and response capture are apparently governed by the same principle. In Experiment 2, it is demonstrated that color priming is not responsible for the contingency. In Experiment 3, it is shown that a more efficient reallocation of attention after color-dissimilar cues than after color-similar cues might contribute to the contingency.     

Inhibition of return and attentional control settings

In the present study, we used a spatial cuing paradigm in conjunction with a choice identification task to investigate whether exogenous attentional orienting and inhibition of return are affected by attentional control settings. As in previous studies (e.g., Folk, Remington, & Johnston, 1992), onset- and color-defined targets were crossed with uninformative onset- and color-defined cues. As expected, when the cue-target stimulus onset asynchrony (SOA) was short (i.e., 100 msec), the results showed that exogenous attentional orienting was contingent on attentional set; attentional capture occurred in response to a particular cue only when the feature that defined the cue also defined the target (Folk et al., 1992). More importantly, when the cue-target SOA was long (i.e., 1,000 msec), the results showed that the occurrence of inhibition of return was also contingent on attentional set, at least partially so; inhibition of return occurred in response to onset cues only when they preceded onset targets. In contrast, inhibition of return never occurred in response to color cues (at a variety of long SOAs). The associations and dissociations that were observed between exogenous attentional orienting and inhibition of return are discussed in terms of posterior and anterior attention networks in the brain (Posner & Petersen, 1990).     

Spatial Stroop and spatial orienting: the role of onset versus offset cues

The present study investigated whether offset cues have the same attentional consequences in the spatial Stroop effect as onset cues. Experiments 1 and 2 compared the attentional effects of onset–offset cues versus offset cues on the spatial Stroop effect, whereas Experiment 3 compared the attentional effects of onset versus offset cues. Across these experiments, independent of cue type (onset–offset or onset vs. offset) and even at long stimulus-onset asynchrony, attentional cueing did not revert into inhibition of return and was modulated by spatial Stroop with greater cueing effects for incongruent arrow’s direction and position. In addition, onset–offset or onset and offset cues produced comparable cueing effects in the location-direction congruent condition, and onset–offset or onset cues produced greater facilitation than offset cues in the incongruent condition. From a different perspective, peripheral cueing modulated the spatial Stroop effect in the same direction for onset–offset or onset and offset cues, although the reduction in spatial Stroop at cued locations was smaller with offset than with onset–offset or onset cues.     

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.     

Problems inhibiting attentional capture by irrelevant stimuli in patients with frontotemporal dementia

We studied the role of the frontal lobes in orienting spatial attention and inhibiting attentional capture by goal-irrelevant stimuli, using a spatial cueing method in patients with frontotemporal dementia (FTD). Two blocks of trials were presented, one with non-predictive cues and the other with counter-predictive cues. FTD patients showed a global orienting deficit, with a greater difference between invalid and valid trials than age-matched controls. However, they were able to use the (counter-) predictiveness of the cue to reduce the invalid/valid difference when targets occurred most often in the location opposite the cue. Thus, endogenous control of attention in our FTD patients was sufficient to reorient attention on the basis of the probability of events, but not to resist the capture of attention by goal-irrelevant stimuli. These results confirm the role of frontal lobes in the inhibition of attentional capture.     

Memory-based attentional capture by colour and shape contents in visual working memory

Current theories assume that there is substantial overlap between visual working memory (VWM) and visual attention functioning, such that active representations in VWM automatically act as an attentional set, resulting in attentional biases towards objects that match the mnemonic content. Most evidence for this comes from visual search tasks in which a distractor similar to the memory interferes with the detection of a simultaneous target. Here we provide additional evidence using one of the most popular paradigms in the literature for demonstrating an active attentional set: The contingent spatial orienting paradigm of Folk and colleagues. This paradigm allows memory-based attentional biases to be more directly attributed to spatial orienting. Experiment 1 demonstrated a memory-contingent spatial attention effect for colour but not for shape contents of VWM. Experiment 2 tested the hypothesis that the placeholders used for spatial cueing interfered with the shape processing, and showed that memory-based attentional capture for shape returned when placeholders were removed. The results of the present study are consistent with earlier findings from distractor interference paradigms, and provide additional evidence that biases in spatial orienting contribute to memory-based influences on attention.     

Orienting of attention with eye and arrow cues and the effect of overtraining

In contrast to the classical distinction between a controlled orienting of attention induced by central cues and an automatic capture induced by peripheral cues, recent studies suggest that central cues, such as eyes and arrows, may trigger a reflexive-like attentional shift. Yet, it is not clear if the attention shifts induced by these two cues are similar or if they differ in some important aspect. To answer this question, in Experiment 1 we directly compared eye and arrow cues in a counter-predictive paradigm while in Experiment 2 we compared the above cues with a different symbolic cue. Finally, in Experiment 3 we tested the role of over-learned associations in cueing effects. The results provide evidence that eyes and arrows induce identical behavioural effects. Moreover, they show that over-learned associations between spatially neutral symbols and the cued location play an important role in yielding early attentional effects.     

Eye gaze is not unique: automatic orienting in response to uninformative arrows

Recent studies (Driver et al., 1999; Friesen & Kingstone, 1998; Langton & Bruce, 1999) have argued that the perception of eye gaze may be unique, as compared with other symbolic cues (e.g., arrows), in being able to automatically trigger attentional orienting. In Experiment 1, 17 participants took part in a visuospatial orienting task to investigate whether arrow cues might also trigger automatic orienting. Two arrow cues were presented for 75 msec to the left and right of a fixation asterisk. After an interval of either 25 or 225 msec, the letter O or X appeared. After both time intervals, mean response times were reliably faster when the arrows pointed toward, rather than away from, the location of the target letter. This occurred despite the fact that the participants were informed that the arrows did not predict where the target would appear. In Experiment 2, the same pattern of data was recorded when several adjustments had been made in an attempt to rule out alternative explanations for the cuing effects. Overall, the findings suggest that the eye gaze is not unique in automatically triggering orienting.