眼睛注视线索提示效应: 内源性注意还是外源性注意?

采用改进的Posner视-空间线索提示范式, 对眼睛注视线索提示效应(eyes gaze cueing effect)的加工机制进行了探讨。实验一考察注视提示线索对空间Stroop效应的影响; 实验二考察注视提示线索对特征抽取和特征整合的影响。实验结果显示: 注视线索提示有效时的空间Stroop效应显著大于提示无效的情景; 在单一特征搜索与特征联合搜索任务中, 注视线索提示效应无差别。这说明, 注视线索通过在头脑里形成空间方位表征诱导注意转移; 注视线索通过影响特征抽取、而非特征整合阶段, 对客体加工产生易化。本研究支持注视线索提示效应属于内源性注意的观点。     

Does gaze direction really trigger a reflexive shift of spatial attention?

Previous studies have found that the gaze direction of a centrally presented face facilitates response time (RT) to a lone peripheral target. The widely accepted interpretation of this finding is that gaze direction triggers a cortically mediated reflexive shift of spatial attention. In the present study we tested an alternative explanation, that a target appearing abruptly on its own in the visual field triggers a subcortically mediated reflexive shift of spatial attention, which is modulated by compatibility with gaze direction. Using central gaze cues, we compared RT to a single peripheral onset target with RT to a peripheral onset target accompanied by an equivalent distractor at the mirror opposite location. In both cases the facilitation effect was the same, demonstrating conclusively that the observed orienting is attributable to the reflexive effects of the gaze cue.     

Attention‐shift vs. response‐priming explanations for the spatial cueing effect in cross‐modal tasks

The task‐irrelevant spatial location of a cue stimulus affects the processing of a subsequent target. This “Posner effect” has been explained by an exogenous attention shift to the spatial location of the cue, improving perceptual processing of the target. We studied whether the left/right location of task‐irrelevant and uninformative tones produces cueing effects on the processing of visual targets. Tones were presented randomly from left or right. In the first condition, the subsequent visual target, requiring response either with the left or right hand, was presented peripherally to left or right. In the second condition, the target was a centrally presented left/right‐pointing arrow, indicating the response hand. In the third condition, the tone and the central arrow were presented simultaneously. Data were recorded on compatible (the tone location and the response hand were the same) and incompatible trials. Reaction times were longer on incompatible than on compatible trials. The results of the second and third conditions are difficult to explain with the attention‐shift model emphasizing improved perceptual processing in the cued location, as the central target did not require any location‐based processing. Consequently, as an alternative explanation they suggest response priming in the hand corresponding to the spatial location of the tone. Simultaneous lateralized readiness potential (LRP) recordings were consistent with the behavioral data, the tone cues eliciting on incompatible trials a fast preparation for the incorrect response and on compatible trials preparation for the correct response.     

Attentional shift by eye gaze requires joint attention: Eye gaze cues are unique to shift attention1

Researchers have demonstrated that attentional shift triggered by gaze direction is reflexive. However, here we show that attentional shift by gaze direction was not always reflexive, but could be modulated by another's perspective. In Experiment 1, a schematic face's line of sight to a peripheral target was obstructed by a vertical barrier located between the face and the target under two conditions. However, the line of sight of the face was clear under another two conditions, in which the barrier was located behind the line of sight by utilizing a depth cue. The gaze cue shifted attention only when the line of sight was not blocked (i.e. joint attention was attained). The arrow cue did not shift attention regardless of the obstruction conditions in Experiment 2. These results suggest that attentional shift by gaze cues, but not arrow cues, involve a higher social cognitive process such as interpretation of the gaze.     

Investigating hemispheric lateralization of reflexive attention to gaze and arrow cues

Recent studies have demonstrated that central cues, such as eyes and arrows, reflexively trigger attentional shifts. However, it is not clear whether the attentional mechanisms induced by these two cues are similar or rather differ in some important way. We investigated hemispheric lateralization of the orienting effects induced by the two cue types in a group of 48 healthy participants comparing arrows and eye gaze as central non-predictive cues in a discrimination task, in which a target stimulus was briefly presented in one of two peripheral positions (left or right of fixation). As predicted by neuropsychological data, reflexive orienting to gaze cues was only observed when the target was presented in the left visual field, whereas reflexive orienting to arrow cues occurred for targets presented in both left and right visual fields.     

Contrast polarity of eyes modulates gaze‐cueing effect1

Two experiments using a modified Posner‐type visual cueing paradigm tested the prediction that detecting the darker region of the eyes of another's gaze triggers a reflexive orienting of the observer in the direction of the gaze. A target was presented in the left or right visual‐field following a gaze‐cue with positive or negative‐image polarity (Experiment 1). In Experiment 2, the polarity of the eyes was manipulated independently of the negative polarity of the face (eye‐positive or eye‐negative‐image polarity conditions). The results showed that the response to the target presented at the side the eyes gazed toward was faster than for the target presented at the other side in the positive polarity condition (Experiment 1), whereas, in the negative polarity condition, the gaze‐cuing effect was not found. In Experiment 2, in the eye‐negative condition, a reversed gaze‐cueing effect appeared, whereas in the eye‐positive polarity condition, a typical gaze‐cueing effect was obtained. These findings suggested that the reflexive orienting of the observer shifts toward the position indicated by the darker region of the other's eyes.     

Training attention: Interactions between central cues and reflexive attention

Three experiments are reported in which we investigate whether the recently reported interactions between central cues (e.g., arrows) and reflexive attention are attributable to the overlearned spatial properties of certain central cues. In all three experiments, a nonpredictive cue with arbitrary spatial properties (a colour patch) is presented prior to a detection target in the left or right visual field. Reaction times to detect targets are compared before and after a training session in which participants are trained to associate each colour patch with left and right space, either via a target detection task in which colour predicts target location 100% of the time (Experiments 1 and 3), or via a left/right motor movement as a function of colour (Experiments 2 and 3). In the first two experiments, a small but highly significant training effect is observed. Participants are approximately 10 ms faster to detect targets at congruent locations relative to incongruent locations after training relative to before training, despite the fact that cue colour was nonpredictive during the test sessions. In Experiment 3, the length of the training session is increased and the magnitude of the training effect also increases as a result. Implications for the interaction between central cues and reflexive attention, as well as premotor theory of attention, are discussed.     

The owl and the pussycat: Gaze cues and visuospatial orienting

Recent research has shown that nonpredictive gaze cues trigger reflexive shifts in attention toward the looked-at location. But just how generalizable is this spatial cuing effect? In particular, are people especially tuned to gaze cues provided by conspecifics, or can comparable shifts in visual attention be triggered by other cue providers and directional cues? To investigate these issues, we used a standard cuing paradigm to compare the attentional orienting produced by different cue providers (i.e., animate vs. inanimate) and directional cues (i.e., eyes vs. arrows). The results of three experiments revealed that attentional orienting was insensitive to both the identity of the cue provider and the nature of the triggering cue. However, compared with arrows, gaze cues prompted a general enhancement in the efficiency of processing operations. We consider the implications of these findings for accounts of reflexive visual orienting.     

Is chimpanzee (Pan troglodytes) spatial attention reflexively triggered by gaze cue?

Humans show a reflexive shift in spatial attention triggered by gaze cues. Chimpanzees (Pan troglodytes) have an excellent ability to follow another's gaze, but they exhibit a limited capacity to engage in triadic interactions based on joint attention, suggesting the possibility of contributions of the different mechanisms underlying joint attention between humans and chimpanzees. The present study thus examined how the chimpanzee's visual spatial attention is triggered by gaze cues. Two chimpanzees showed no clear signs of attention shift triggered by various kinds of nonfacial and facial stimuli with averted gaze under the letter-discrimination tasks but showed significant cueing effects when the head-turning cue was presented in a quasi-dynamic manner. These cueing effects were, however, affected by the predictability of the gaze cue: Highly predictive gaze cues caused stronger cueing effects than less predictive cues. Thus, these results suggest that the shift in spatial attention caused by gaze cues does occur in chimpanzees, but, in contrast to humans, vulnerability against the cue predictability suggests that the voluntary mechanism contributes more dominantly than the reflexive mechanism to this attention shift.     

双通道分配性注意对视听觉返回抑制的影响

本研究基于线索-靶子范式, 操纵目标刺激类型(视觉、听觉、视听觉)与线索有效性(有效线索、中性条件、无效线索)两个自变量, 通过3个实验来考察双通道分配性注意对视听觉返回抑制(inhibition of return, IOR)的影响。实验1 (听觉刺激呈现在左/右侧)结果发现, 在双通道分配性注意条件下, 视觉目标产生显著IOR效应, 而视听觉目标没有产生IOR效应; 实验2 (听觉刺激呈现在左/右侧)与实验3 (听觉刺激呈现在中央)结果发现, 在视觉通道选择性注意条件下, 视觉与视听觉目标均产生显著IOR效应但二者无显著差异。结果表明：双通道分配性注意减弱视听觉IOR效应。     

Gaze and arrow distractors influence saccade trajectories similarly

Perceiving someone's averted eye-gaze is thought to result in an automatic shift of attention and in the preparation of an oculomotor response in the direction of perceived gaze. Although gaze cues have been regarded as being special in this respect, recent studies have found evidence for automatic attention shifts with nonsocial stimuli, such as arrow cues. Here, we directly compared the effects of social and nonsocial cues on eye movement preparation by examining the modulation of saccade trajectories made in the presence of eye-gaze, arrows, or peripheral distractors. At a short stimulus onset asynchrony (SOA) between the distractor and the target, saccades deviated towards the direction of centrally presented arrow distractors, but away from the peripheral distractors. No significant trajectory deviations were found for gaze distractors. At the longer SOA, saccades deviated away from the direction of the distractor for all three distractor types, but deviations were smaller for the centrally presented gaze and arrow distractors. These effects were independent of whether line-drawings or photos of faces were used and could not be explained by differences in the spatial properties of the peripheral distractor. The results suggest that all three types of distractors (gaze, arrow, peripheral) can induce the automatic programming of an eye movement. Moreover, the findings suggest that gaze and arrow distractors affect oculomotor preparation similarly, whereas peripheral distractors, which are classically regarded as eliciting an automatic shift of attention and an oculomotor response, induce a stronger and faster acting influence on response preparation and the corresponding inhibition of that response.     

线索类型对阈下注视线索效应的影响

实验结合连续闪烁抑制范式和线索化范式, 通过操纵直视面孔和斜视面孔的呈现方式, 考察了动静线索类型对注视线索效应的影响。结果表明：两种线索在阈上条件都能产生注视线索效应, 且动态线索诱发的效应更大; 无意识条件下有且仅有动态注视线索能诱发注视线索效应。这说明眼睛运动是产生阈下注视线索效应的必要条件; 眼睛运动会增强阈上注视线索效应, 静态注视线索效应依赖于意识。研究结果支持了社会知觉与心理理论交互模型。     

Interaction between endogenous and exogenous orienting in crossmodal attention

Using a cue-target paradigm, we investigated the interaction between endogenous and exogenous orienting in cross-modal attention. A peripheral (exogenous) cue was presented after a central (endogenous) cue with a variable time interval. The endogenous and exogenous cues were presented in one sensory modality (auditory in Experiment 1 and visual in Experiment 2) whereas the target was presented in another modality. Both experiments showed a significant endogenous cuing effect (longer reaction times in the invalid condition than in the valid condition). However, exogenous cuing produced a facilitatory effect in both experiments in response to the target when endogenous cuing was valid, but it elicited a facilitatory effect in Experiment 1 and an inhibitory effect in Experiment 2 when endogenous cuing was invalid. These findings indicate that endogenous and exogenous cuing can co-operate in orienting attention to the crossmodal target. Moreover, the interaction between endogenous and exogenous orienting of attention is modulated by the modality between the cue and the target.     

The role of crossmodal competition and dimensional overlap in crossmodal attention switching

Crossmodal selective attention was investigated in a cued task switching paradigm using bimodal visual and auditory stimulation. A cue indicated the imperative modality. Three levels of spatial S–R associations were established following perceptual (location), structural (numerical), and conceptual (verbal) set-level compatibility. In Experiment 1, participants switched attention between the auditory and visual modality either with a spatial-location or spatial-numerical stimulus set. In the spatial-location set, participants performed a localization judgment on left vs. right presented stimuli, whereas the spatial-numerical set required a magnitude judgment about a visually or auditorily presented number word. Single-modality blocks with unimodal stimuli were included as a control condition. In Experiment 2, the spatial-numerical stimulus set was replaced by a spatial-verbal stimulus set using direction words (e.g., “left”). RT data showed modality switch costs, which were asymmetric across modalities in the spatial-numerical and spatial-verbal stimulus set (i.e., larger for auditory than for visual stimuli), and congruency effects, which were asymmetric primarily in the spatial-location stimulus set (i.e., larger for auditory than for visual stimuli). This pattern of effects suggests task-dependent visual dominance.     

Deployment of spatial attention to words in central and peripheral vision

Four perceptual identification experiments examined the influence of spatial cues on the recognition of words presented in central vision (with fixation on either the first or last letter of the target word) and in peripheral vision (displaced left or right of a central fixation point). Stimulus location had a strong effect on word identification accuracy in both central and peripheral vision, showing a strong right visual field superiority that did not depend on eccentricity. Valid spatial cues improved word identification for peripherally presented targets but were largely ineffective for centrally presented targets. Effects of spatial cuing interacted with visual field effects in Experiment 1, with valid cues reducing the right visual field superiority for peripherally located targets, but this interaction was shown to depend on the type of neutral cue. These results provide further support for the role of attentional factors in visual field asymmetries obtained with targets in peripheral vision but not with centrally presented targets.     

注视方向和面部表情对注意朝向的影响

摘 要 本文以三种表情面孔为材料,运用事件相关电位（ERP）方法探讨表情线索在注意朝向中与注视转移发生的交互及两者如何共同影响观察者的反应。结果发现：（1）线索效应在三种表情面孔的两种SOA中都出现了;（2）SOA较长时,注视线索效应量间的显著差异出现在中性和恐惧面孔、高兴和恐惧面孔间;（3）面部表情的效应出现在了表情线索诱发的P1成分上;（4）目标诱发的P1和N1说明了注视线索效应的存在及与表情间的交互。结论：表情线索先对观察者的朝向反应产生影响,随后是注视线索及其与表情线索发生的交互。     

Why does the gaze of others direct visual attention?

Viewing another person directing his or her gaze can produce automatic shifts of covert visual attention in the same direction. This holds true even when the task‐relevant target is much more likely to occur at the uncued location. These findings, along with other evidence, have been taken to suggest that gaze represents a “special” stimulus—the foundation of a social cognition system that can make inferences about the mental states of other people. However, gaze‐driven cueing effects could simply be due to spatial compatibility between cue and target. We compared the attentional effects of gaze shifts to a face with the tongue extended laterally to the left or right. When tongue direction was a nonpredictive cue, we found cueing effects from tongues that were indistinguishable from those produced by gaze. However, in contrast to previous findings with gaze, tongue cues did not overcome a validity manipulation in which targets were four times more likely to appear at the uncued location. We conclude that simple attentional cueing effects from gaze may be better explained by spatial compatibility, and that more complex, unique features of cueing from gaze may be better indices into perceptual systems specialized for social cognition.     

The eyes have it! Reflexive orienting is triggered by nonpredictive gaze

Normal subjects were presented with a simple line drawing of a face looking left, right, or straight ahead. A target letter F or T then appeared to the left or the right of the face. All subjects participated in target detection, localization, and identification response conditions. Although subjects were told that the line drawing’s gaze direction (the cue) did not predict where the target would occur, response time in all three conditions was reliably faster when gaze was toward versus away from the target. This study provides evidence for covert, reflexive orienting to peripheral locations in response to uninformative gaze shifts presented at fixation. The implications for theories of social attention and visual orienting are discussed, and the brain mechanisms that may underlie this phenomenon are considered.     

Spatial attentional distribution is modulated by head direction during eccentric gaze

Visual perception during eccentric gaze can be facilitated when a visual stimulus appears in front of the head direction. This study investigated the relative effects of gaze location and head direction on visual perception in central and peripheral vision. Participants identified the orientation of a T-shaped figure presented in the centre of a monitor and simultaneously localised a dot appearing in the periphery, while head direction relative to gaze location was to the left, right or centre. Effects of head direction were found only when the dot appeared far from the gaze fixation point, such that dot detection was superior when it appeared to the left (right) of fixation in the left (right) head direction. Experimental results indicated this was not due to a small shift of gaze location. Thus this study suggests that head direction influences visual perception particularly in peripheral vision where visual acuity decreases.     

内外源性空间注意对多感觉整合的影响

本文采用内-外源性空间线索靶子范式, 操控内源性线索有效性(有效线索、无效线索)、外源性线索有效性(有效线索、无效线索)、目标刺激类型(视觉刺激、听觉刺激、视听觉刺激)三个自变量。通过两个不同任务难度的实验(实验1: 简单定位任务; 实验2: 复杂辨别任务)来考察内外源性空间注意对多感觉整合的影响。两个实验结果均发现外源性空间注意显著减弱了多感觉整合效应, 内源性空间注意没有显著增强多感觉整合效应; 实验2中还发现了内源性空间注意会对外源性空间注意减弱多感觉整合效应产生影响。结果表明, 与内源性空间注意不同, 外源性空间注意对多感觉整合的影响不易受任务难度的调控; 当任务较难时内源性空间注意会影响外源性空间注意减弱多感觉整合效应的过程。由此推测, 内外源性空间注意对多感觉整合的调节并非彼此独立、而是相互影响的。