Surveying a blank field with the attentional spotlight

Spatial localization is a unique aspect of selective attention that precedes and facilitates other aspects of sensory processing. A common model of spatial attention is an attentional spotlight that enlarges to fit attentional demands. It is unclear if this attentional spotlight expands to survey a blank field or to scan the spatial environment with a smaller attentional spotlight. Two tachistoscopic experiments with young adults investigated how attention is surveyed in a blank field. Exp. 1 consisted of single letters at two concentric regions and under different conditions of attentional demand. Reaction times were proportionally slower for stimuli occurring in a combination of the two regions located at different distances from the fixation point than for stimuli occurring in each region alone. This finding is not consistent with attentional spread to encompass the entire attentional field. The addition of more stimulus locations within each single region yielded significantly slower reaction times. Together these findings suggest that a small attentional spotlight serially monitors different regions of the visual field when there are anticipated locations to be attended.     

Attentional prioritisation of threatening information: Examining the role of the size of the attentional window

In line with most models of emotion, research has shown that threatening information receives attentional priority over neutral information. Recently, it has been suggested that the degree to which participants divide their attention across the visual field (the attentional window) may modulate the extent to which salient objects are attentionally prioritised. In the current study, participants were required to identify a target inside one of a variable number of coloured circles. One colour (Conditioned Stimulus, CS +) was fear-conditioned using an electrocutaneous stimulus at tolerance level. This search task was combined with a go/no-go task that required participants to either divide attention across the visual field to create a broad attentional window (global group), or focus their attention on the fixation point to create a narrow attentional window (local group). The results showed that only in the global group was the CS + colour prioritised over the neutral colours, indicating that a broader attentional window leads to enhanced attentional prioritisation of threat. Implications for research on attentional bias to threat are discussed.     

Impaired shifting of attention in Balint's syndrome

We assessed the efficiency of attentional shifts across the horizontal and vertical axes of the visual field in a patient with Balint's syndrome caused by bilateral parieto-occipital infarctions. This was performed using an adaptation of Posner's peripheral cueing paradigm. In contrast to normal controls and patients with unilateral parietal lesions previously reported, this patient did not benefit from cues directing attention to the left or right visual field. She appeared to benefit only when the cues directed attention to the upper visual field. This suggests a defect in shifting attention that may occur following bilateral parietal lesions. We discuss the implications of these findings for the role of the parietal lobes in attentional processes and for our understanding of the behavioral abnormalities observed in Balint's syndrome.     

On the benefits of transient attention across the visual field

There are well-known differences in resolution and performance across the visual field with performance generally better for the lower than the upper visual hemifield. Here we attempted to assess how transient attention summoned by a peripheral precue affects performance across the visual field. Four different attentional precueing tasks were used, varying in difficulty and attentional load. When a single discrimination target was presented (experiments 1 and 2), precues that summon transient attention had very little, if any, effect upon performance. However, when the target was presented among distractors (experiments 3 and 4), the precue had a substantial effect upon discrimination performance. The results showed that asymmetries in visual resolution between the upper and lower hemifields become more pronounced with increasing eccentricity. Furthermore, when the observers performed a precued acuity task with distractors, involving the judgment of the relative position of a small disk within a larger one, there was an asymmetry in the transient attentional effect on discrimination performance; the benefits of transient attention were larger in the upper than in the lower hemifield. Areas in the visual field where visual performance is generally worse thus appear to receive the largest attentional boost when needed. Possible ecological explanations for this are discussed.     

The Contribution of Attention to the Right Visual Field Advantage for Word Recognition

Perceptual asymmetries have been explained by structural, attentional bias and attentional advantage models. Structural models focus on asymmetries in the physical access information has to the hemispheres, whereas attentional models focus on asymmetries in the operation of attentional processes. A series of experiments was conducted to assess the contribution of attentional mechanisms to the right visual field (RVF) advantage found for word recognition. Valid, invalid and neutral peripheral cues were presented at a variety of stimulus onset asynchronies to manipulate spatial attention. Results indicated a significant RVF advantage and cueing effect. The effect of the cue was stronger for the left visual field than the RVF. This interaction supports the attentional advantage model which suggests that the left hemisphere requires less attention to process words. The attentional asymmetry is interpreted in terms of the different word processing styles used by the left and right hemispheres. These results have ramifications for the methodology used in divided visual field research and the interpretation of this research.     

Effect of negative emotion on visual attention: Automatic capture by fear‐related stimuli1

Abstract: In this study, we examined the effect of threatening pictures (e.g., snakes and spiders) on control of spatial attention using a probe detection task. In addition to attentional capture by the threatening stimuli (Unpredictable task), the effects of affective valence of the pictures on the voluntary control of attention were explored (Predictable task). Results showed that reaction time (RT) was facilitated to the probe that appeared at the location of threatening stimuli when it occurred in the right visual field (but not in the left visual field), indicating that attention was captured automatically, at least in this visual field. However, when participants were able to predict the probe location, the attentional gains increased similarly for all the conditions (composed of visual field by picture type combinations) relative to those of Unpredictable task, with no indication of deferred deployment of attention to threatening stimuli. The results of this study suggested that the emotional valence, particularly negative valence, affected the automatic control of attention. This effect differed between the two visual fields in which emotional stimuli occurred.     

Electrophysiological and behavioral evidence reveals the effects of trait anxiety on contingent attentional capture

Few studies have investigated the effects of anxiety on contingent attentional capture. The present study examined contingent attentional capture in trait anxiety by applying a rapid serial visual presentation (RSVP) paradigm during electroencephalographic recording. Overall, the behavioral and electrophysiological results showed a larger capture effect when a distractor was the same color as the target compared to when the distractor was not of the target color. Moreover, high-anxiety individuals showed a larger N2pc in the target colored distractor condition and nontarget colored distractor condition compared to the distractor-absent condition. In addition, the reaction time was slower when distractors were presented in the left visual field compared to when they were in the right visual field. This pattern was not seen in low-anxiety individuals. The findings may indicate that high-anxiety individuals allocate attention to the target less efficiently and have reduced suppression of distractors compared to low-anxiety individuals who could suppress attention to the distractors more efficiently. Future work could valuably investigate the consequences of such differences in terms of benefits and disruption associated with attentional capture differences in a range of anxious populations in different risk monitoring situations.     

The role of attention in binding visual features in working memory: Evidence from cognitive ageing

Two experiments were conducted to assess the costs of attentional load during a feature (colour–shape) binding task in younger and older adults. Experiment 1 showed that a demanding backwards counting task, which draws upon central executive/general attentional resources, reduced binding to a greater extent than individual feature memory, but the effect was no greater in older than in younger adults. Experiment 2 showed that presenting memory items sequentially rather than simultaneously, such that items are required to be maintained while new representations are created, selectively affects binding performance in both age groups. Although this experiment exhibited an age-related binding deficit overall, both age groups were affected by the attention manipulation to an equal extent. While a role for attentional processes in colour–shape binding was apparent across both experiments, manipulations of attention exerted equal effects in both age groups. We therefore conclude that age-related binding deficits neither emerge nor are exacerbated under conditions of high attentional load. Implications for theories of visual working memory and cognitive ageing are discussed.     

视觉搜索中基于工作记忆内容的注意捕获与抑制

注意是对有关信息的选择及对无关信息的抑制, 工作记忆是对有关信息的保持以及对无关信息的抑制, 两者在一定程度上都体现了选择性地指向与当前任务有关的刺激并同时抑制无关刺激。在系统地回顾已有研究的基础上结合新近的ERP研究, 从视觉搜索中基于工作记忆内容的注意捕获与注意抑制两个角度综述了视觉工作记忆与视觉选择性注意的相关研究。研究者们主要从两方面对该领域的问题进行了探讨：(1)视觉工作记忆内容对视觉选择性注意的导向作用; (2)视觉工作记忆内容对视觉选择性注意产生导向作用的条件。文章对以往的研究进行了总结, 指出了无论保持在视觉工作记忆的内容是捕获注意还是受到抑制, 都存在着自上而下和自下而上两种加工机制。     

Visual attention in adolescents: Facilitating effects of sport expertise and acute physical exercise

ObjectivesThis study investigated visual attention of adolescent orienteers and physically active adolescents non-practising orienteering both at rest and under acute sub-maximal exercise. It was verified whether the practice of orienteering facilitates the development of visual attentional abilities and whether orienteers, who are used to simultaneously handle physiological and cognitive-attentional loads, may better profit than non-orienteers from the beneficial effects of sub-maximal physical load on processing speed.MethodsBoth the focusing of attention at foveal and parafoveal locations and the orienting of attention at peripheral locations were investigated. In two discriminative reaction time (RT) experiments, a cue of varying size was presented centrally or peripherally and followed by a compound stimulus with local and global target features. The stimulus-onset asynchrony (SOA) varied between a short and a long interval.ResultsIn both experiments, adolescent orienteers and non-practisers showed different patterns of attentional effects. Adolescent orienteers were more similar to young adults in the attentional performance, being better able than non-practisers to perform complex attentional operations involving the intentional zooming of attention in the central visual field and the orienting of the attentional focus in the peripheral visual field. Also, both orienteers and non-orienteers speeded up their performance during exercise, but this facilitation effect was more pronounced for orienteers, who are probably skilled in directing the available resources to task demands.ConclusionsOur results suggest that cognitive expertise represents a key factor in sports that accelerates the development of visual attention and enhances the facilitating effects of physical exercise on attentional performance.     

On the examination couch: the relationship between the egocentric perspective and the attentional focus

Determined by anatomical characteristics, the binocular visual field has an elliptical shape. Whereas the focus of attention – that area of the visual field in which objects can be consciously perceived – is significantly smaller, its shape is not necessarily dependent on the same factors. Indeed, it is yet unknown if the maximum extents of the attentional focus’ meridians are dimensionally stable or adapt to the egocentric perspective. In this study, we intended to measure the expansion up to which peripheral stimuli can still be perceived while participants were sitting and lying on the left and on the right body side. Results demonstrate that contrary to the visual field the maximum extents along the attentional focus’ meridians remain stable across different head positions with a greater horizontal than vertical alignment. This indicates that the expansion ratios of the meridians of the attentional focus are not dependent on the egocentric perspective. Rather, they appear stable in space and gravity-based. Findings are discussed in terms of our visual environment and current as well as alternative interpretations are weighed against each other.     

Effect of object onset on the distribution of visual attention.

There now exists considerable evidence to suggest that the appearance of a new object in the visual field captures visual attention. One of the consequences of this attentional capture is that the object initiates a redistribution of attentional resources across visual space. This is classically observed in the precuing paradigm in which the onset of an abrupt cue influences the processing of a subsequently presented target. The present research describes a new phenomenon that occurs as a result of a new object appearing in the visual field. A stimulus presented in a region of space adjacent to a corner of an onsetting object receives an enhancement of processing relative to a stimulus presented adjacent to one of the object's straight edges. With the use of 2 converging methods, evidence is presented that suggests that the effect is a higher order attentional phenomenon whereby greater resources become directed to the corners of objects.     

Sustained attention, attentional selectivity, and attentional capacity across the lifespan

Changes in sustained attention, attentional selectivity, and attentional capacity were examined in a sample of 113 participants between the ages of 12 and 75. To measure sustained attention, we employed the sustained-attention-to-response task (Robertson, Manly, Andrade, Baddeley, & Yiend, Neuropsychologia 35:747?C58, 1997), a short continuous-performance test designed to capture fluctuations in sustained attention. To measure attentional selectivity and capacity, we employed a paradigm based on the theory of visual attention (Bundesen, Psychological Review 97:523?C547, 1990), which enabled the estimation of parameters related to attentional selection, perceptual threshold, visual short-term memory capacity, and processing capacity. We found evidence of age-related decline in each of the measured variables, but the declines varied markedly in terms of magnitude and lifespan trajectory. Variables relating to attentional capacity showed declines of very large effect sizes, while variables relating to attentional selectivity and sustained attention showed declines of medium to large effect sizes, suggesting that attentional control is relatively preserved in older adults. The variables relating to sustained attention followed a U-shaped, curvilinear trend, and the variables relating to attentional selectivity and capacity showed linear decline from early adulthood, providing further support for the differentiation of attentional functions.     

Investigating the role of exogenous cueing on selection history formation

An abundance of recent empirical data suggest that repeatedly allocating visual attention to task-relevant and/or reward-predicting features in the visual world engenders an attentional bias for these frequently attended stimuli, even when they become task irrelevant and no longer predict reward. In short, attentional selection in the past hinders voluntary control of attention in the present. But do such enduring attentional biases rely on a history of voluntary, goal-directed attentional selection, or can they be generated through involuntary, effortless attentional allocation? An abrupt visual onset triggers such a reflexive allocation of covert spatial attention to its location in the visual field, automatically modulating numerous aspects of visual perception. In this Registered Report, we asked whether a selection history that has been reflexively and involuntarily derived (i.e., through abrupt-onset cueing) also interferes with goal-directed attentional control, even in the complete absence of exogenous cues. To build spatially distinct histories of exogenous selection, we presented abrupt-onset cues twice as often at one of two task locations, and as expected, these cues reflexively modulated visual processing: task accuracy increased, and response times (RTs) decreased, when the cue appeared near the target’s location, relative to that of the distractor. Upon removal of these cues, however, we found no evidence that exogenous selection history modulated task performance: task accuracy and RTs at the previously most-cued and previously least-cued sides were statistically indistinguishable. Thus, unlike voluntarily directed attention, involuntary attentional allocation may not be sufficient to engender historically contingent selection biases.

     

On the Relation Between Visual Spatial Attention and Visual Field Asymmetries

In the typical visual laterality experiment, words and letters are more rapidly and accurately identified in the right visual field than in the left. However, while such studies usually control fixation, the deployment of visual attention is rarely restricted. The present studies investigated the influence of visual attention on the visual field asymmetries normally observed in single-letter identification and lexical decision tasks. Attention was controlled using a peripheral cue that provided advance knowledge of the location of the forthcoming stimulus. The time period between the onset of the cue and the onset of the stimulus (Stimulus Onset Asynchrony—SOA) was varied, such that the time available for attention to focus upon the location was controlled. At short SO As a right visual field advantage for identifying single letters and for making lexical decisions was apparent. However, at longer SOAs letters and words presented in the two visual fields were identified equally well. It is concluded that visual field advantages arise from an interaction of attentional and structural factors and that the attentional component in visual field asymmetries must be controlled in order to approximate more closely a true assessment of the relative functional capabilities of the right and left cerebral hemispheres.     

Splitting attention across the two visual fields in visual short-term memory

Humans have the ability to attentionally select the most relevant visual information from their extrapersonal world and to retain it in a temporary buffer, known as visual short-term memory (VSTM). Research suggests that at least two non-contiguous items can be selected simultaneously when they are distributed across the two visual hemifields. In two experiments, we show that attention can also be split between the left and right sides of internal representations held in VSTM. Participants were asked to remember several colors, while cues presented during the delay instructed them to orient their attention to a subset of memorized colors. Experiment 1 revealed that orienting attention to one or two colors strengthened equally participants' memory for those colors, but only when they were from separate hemifields. Experiment 2 showed that in the absence of attentional cues the distribution of the items in the visual field per se had no effect on memory. These findings strongly suggest the existence of independent attentional resources in the two hemifields for selecting and/or consolidating information in VSTM.     

注意捕获与自上而下的加工过程

注意捕获对揭示两种控制过程——自下而上的加工与自上而下的加工之间的关系有着重要的研究意义。在当前对注意捕获的研究中,主要存在两大类的实验范式：线索化范式与视觉搜索范式;涉及以下几个方面：刺激驱动的注意捕获与自上而下控制的关系;注意捕获是否涉及注意的空间转移;刺激的显著性对注意捕获的影响;实验范式对注意捕获的影响。总的来说,没有任何一种视觉刺激能绝对的独立于自上而下的控制之外来捕获注意,因此也可以这样认为,注意捕获被默认为是一种自动化的过程,但这个自动化的过程可以被内源性的调节所抑制或者易化。     

Matching cue size and task properties in exogenous attention

Exogenous attention is an involuntary, reflexive orienting response that results in enhanced processing at the attended location. The standard view is that this enhancement generalizes across visual properties of a stimulus. We test whether the size of an exogenous cue sets the attentional field and whether this leads to different effects on stimuli with different visual properties. In a dual task with a random-dot kinematogram (RDK) in each quadrant of the screen, participants discriminated the direction of moving dots in one RDK and localized one red dot. Precues were uninformative and consisted of either a large or a small luminance-change frame. The motion discrimination task showed attentional effects following both large and small exogenous cues. The red dot probe localization task showed attentional effects following a small cue, but not a large cue. Two additional experiments showed that the different effects on localization were not due to reduced spatial uncertainty or suppression of RDK dots in the surround. These results indicate that the effects of exogenous attention depend on the size of the cue and the properties of the task, suggesting the involvement of receptive fields with different sizes in different tasks. These attentional effects are likely to be driven by bottom-up mechanisms in early visual areas.     

Cueing attention by relative motion in the periphery of the visual field

Sudden changes of visual stimulation attract attention. The observer's body motion generates retinal-flow field patterns containing information about his/her own speed and trajectory and relative motion of other objects. We investigated the effectiveness of relative motion as an attentional cue and compared it with conventional cueing by appearance of a frame in the far periphery of the visual field. In a group of ten subjects, contrast thresholds for the perception of static Gabor grating orientation [four alternative non-forced-choice (4ANFC)] task were determined at 20 degrees, 30 degrees, 40 degrees, and 60 degrees eccentricity. Subsequently, near-threshold discrimination performance of Gabor pattern orientation without versus with a ring-shaped cue was measured at the same positions. The same Gabor patterns were then presented embedded in a random-dot flow field, and uncued discrimination performance was compared with performance after presentation of a relative-motion cue (RMC), ie a small random-dot field with motion in the opposite direction of the flow field. Both the conventional ring cue and the RMC induced significantly increased discrimination performance at all test locations. With the parameters chosen for this study, the RMC was slightly less effective than the conventional cue, but its effects were somewhat more pronounced in the far periphery of the visual field. Thus, relative motion is a powerful cue to attract attention to peripheral visual objects and improves performance as effectively as a conventional ring cue. The findings have practical relevance for everyday life, in particular for tasks like driving and navigation.     

Attention is biased to near surfaces

It is thought that attention is allocated to figural items over adjacent ground stimuli. It is unclear which attribute of figures drives any previously observed attentional effects (e.g., nearness or shapedness). Moreover, it is unclear whether previous attentional effects are automatic or strategy driven. In the present series of experiments, we tested whether attention is allocated to the nearer of two surfaces under condition where near/far was not confounded with shaped/shapelessness. Using a temporal order judgment paradigm, in the first experiment, we showed that attention is allocated to the nearer of two surfaces. Furthermore, by using the stimuli themselves as the temporal order probe in Experiment 2, we found that this effect is independent of previous attentional allocation across the visual field. A third experiment ruled out the possibility that lateral inhibition by the pretarget backdrop was responsible for attentional bias toward near surfaces. Overall, our results converge to show that near surfaces attract attention.