Improving visual short-term memory by sequencing the stimulus array

When multiple objects are presented briefly and simultaneously in a visual array, visual short-term memory (VSTM) can maintain only a limited number of these items. The present research report reveals that splitting the to-be-remembered items into two sequential arrays significantly increases VSTM performance relative to the simultaneous presentation of the same items. A memory benefit also emerges when the full object array is flashed twice (repeated) rather than being presented continuously for the same duration. Moreover, the sequential and repetition benefits are specifically pronounced for individuals with low performance for simultaneously presented items. Our results suggest that the conventional, simultaneous presentation mode may underestimate VSTM performance due to attentional limitations and/or competition between stimulus representations. In contrast, temporal segregation of the stimulus input may help participants maximize their performance and utilize their full VSTM capacity.     

Integrating information from two pictorial animations: Complexity and cognitive prerequisites influence performance

Dividing visual attention between spatially distinct sources of information could either be beneficial (if there is too much information for a single visualization) or detrimental (if interrelated information has to be mentally re‐integrated) for learning. We present a new display technology allowing for the presentation of two distinct animations by avoiding split foci of visual attention: learners are able to switch between animations by moving their head. We examined how 84 naïve learners integrated information in three presentation modes: the ‘vexing‐image’ mode displaying two animations, participants being able to switch between them without shifting the visual focus, a classical ‘split‐screen’ and an ‘overlaid’ condition. Results showed that reduced complexity led to higher performance. Further, we showed that participants with high mental rotation abilities were best in the ‘split‐screen’ mode, whereas participants with low mental rotation abilities benefited most from the ‘vexing‐image’. Theoretical and instructional consequences of these findings are discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

Selective working memory disables inhibition of visual features

Recent research suggests that information held in working memory can facilitate subsequent attentional processing. Here, we explore the negative corollary of this conception: Under which circumstances does information in working memory disrupt subsequent processing? Seventy participants performed visual discriminations in a dual-task paradigm. They were asked to judge colors or shapes in an online attention task under three different working-memory conditions: Same, Switch, or Unknown. In the Same condition, participants selectively maintained one visual feature in working memory, from the same dimension as in the online attention task. In the Switch condition, participants selectively maintained one visual feature in working memory, but had to focus on another visual dimension in the online attention task. In the Unknown condition, participants could not predict which visual feature would be relevant for the working-memory task. We found that irrelevant features in the online attention task were particularly difficult to ignore in the Switch condition, that is, when the irrelevant features belong to a visual dimension that is simultaneously prioritized in selective working memory. The findings are consistent with accounts in terms of neural overlap between working-memory and attention circuits, and suggest that mechanisms of selection, rather than resource limitations, critically determine the extent of visual interference.     

Splitting focal attention.

The study was based on the inverse relationship between the effect of attention on reaction time (RT) and the size of the area over which focal attention is allocated. Independent occurrence of this in 2 locations in the opposite hemifields would be evidence of attention splitting. In Experiment 1, in which the 2 locations were denoted by empty boxes, there was an inverse relationship between size of the stimulated box and RT. Experiment 2 replicated the finding with different stimulation conditions. In Experiment 3, no relationship was found between RT and length of a cuing line. In Experiment 4, in which attention was manipulated by central cues, there was an effect of box size on valid and neutral trials but not invalid trials. Observers could split focal attention and manipulate simultaneously 2 independent attentional foci on objects located in the opposite hemifields.     

Managing split‐attention and redundancy in multimedia instruction

Two experiments investigated alternatives to split‐attention instructional designs. It was assumed that because a learner has a limited working memory capacity, any increase in cognitive resources required to process split‐attention materials decreases resources available for learning. Using computer‐based instructional material consisting of diagrams and text, Experiment 1 attempted to ameliorate split‐attention effects by increasing effective working memory size by presenting the text in auditory form. Auditory presentation of text proved superior to visual‐only presentation but not when the text was presented in both auditory and visual forms. In that case, the visual form was redundant and imposed a cognitive load that interfered with learning. Experiment 2 ameliorated split‐attention effects by using colour coding to reduce cognitive load inducing search for diagrammatic referents in the text. Mental load rating scales provided evidence in both experiments that alternatives to split‐attention instructional designs were effective due to reductions in cognitive load. Copyright © 1999 John Wiley & Sons, Ltd.     

Time course of visual attention across perceptual levels and objects

Theories of shifts of visual attention based on attentional blink or dwell time do not directly address shifts of attention across different levels (global or local) involving multiple objects. Two experiments were conducted employing the attentional dwell time paradigm to investigate the shifts of visual attention between objects selected at same or different levels. Participants were instructed to identify two successive compound stimuli at a pre-specified level (global or local) presented at two different locations with variable SOA. The initial pair of locations in which the stimulus was presented was fixed in Experiment 1 but not in Experiment 2. Experiment 1 results showed very little impairment for second target identification when both the targets were at the global level. Attentional shift was better with both targets at the same level compared to different levels. Experiment 2 results showed that local followed by global target identification is difficult at short SOAs compared to other conditions. The results indicate that scope of attention affects the time course of visual attention. Global processing could be performed with very little capacity limitation simultaneously with distributed attention. The default mode of attention might be distributed and attention becomes focused for target identification. Different mechanisms may underlie shifts in focused attention between different locations and changes in attentional set required by changes in perceptual levels.     

不同编码对听写困难儿童字形记忆的促进效应

听写困难是一种发生率较高的儿童学习障碍现象。实验考察笔画语音编码和动作编码对听写困难儿童字形记忆水平的影响。结果发现, 笔画语音编码对听写困难儿童的字形记忆成绩没有明显影响, 但却明显促进了正常儿童的字形记忆成绩; 与之相对, 动作编码对正常儿童的字形记忆成绩没有明显影响, 但却明显促进了听写困难儿童的字形记忆成绩。上述现象, 既可能源于编码加工阶段, 也可能源于字形表征的提取阶段。     

Identifying a “default” visual search mode with operant conditioning

The presence of a singleton in a task-irrelevant domain can impair visual search. This impairment, known as the attentional capture depends on the set of participants. When narrowly searching for a specific feature (the feature search mode), only matching stimuli capture attention. When searching broadly (the singleton detection mode), any oddball captures attention. The present study examined which strategy represents the “default” mode using an operant conditioning approach in which participants were trained, in the absence of explicit instructions, to search for a target in an ambiguous context in which one of two modes was available. The results revealed that participants behaviorally adopted the singleton detection as the default mode but reported using the feature search mode. Conscious strategies did not eliminate capture. These results challenge the view that a conscious set always modulates capture, suggesting that the visual system tends to rely on stimulus salience to deploy attention.     

媒体多任务经验对不同注意模式下内隐记忆的影响

本研究采用经典背景线索范式,在分布式注意（限制眼动）和集中式注意（自由观看）两种模式下考察不同媒体多任务经验者的内隐记忆表现。实验1要求被试在学习阶段自由观看场景并搜索目标,在测试阶段限制眼动并使用外周视野搜索目标。实验2将学习、测试阶段的注意模式反转。结果发现,高媒体多任务经验者在两种注意模式下均表现出背景线索效应;低媒体多任务经验者仅在集中式注意模式下表现出背景线索效应。结果表明,高媒体多任务经验者在分布式注意模式下存在一定的内隐记忆优势。     

A processing advantage associated with analytic perceptual tendencies: European Americans outperform Asians on multiple object tracking

Analytic visual processing and holistic visual processing have been conceptualized in terms of attention to focal objects vs. the background. We expand the study of perceptual biases associated with these attentional patterns using the multiple object tracking task, which measures people's ability to track multiple moving target objects amidst otherwise identical distractors. We test two competing hypotheses: (1) Asians' more frequent eye saccades will enable them to quickly cycle through the multiple target objects before the objects move too far away, giving them another perceptual advantage; and (2) European Americans' tendency to focus attention on the focal objects while inhibiting attention to less important objects might facilitate tracking of multiple moving objects. We find that European Americans significantly outperform Asians on multiple object tracking. The research expands the conceptualization of analytic processing and holistic processing to include selective attention as a key component, a facet that has not been previously identified.     

The brain circuitry of attention

From an operational perspective, attention is a matter of organizing multiple brain centres to act in concert on the task at hand. Taking focal visual attention as an example, recent anatomical findings suggest that the pulvinar might act as a remote hub for coordinating spatial activity within multiple cortical visual maps. The pulvinar can, in turn, be influenced by signals originating in the frontal and parietal eye fields, using common visuomotor neural circuitry, with the superior colliculus acting as an important link. By identifying a complex, real neural architecture ('RNA') model for attention, it is possible to integrate several different modes of operation - such as parallel or serial, bottom-up or top-down, preattentive or attentive - that characterize conflicting cognitive models of attention in visual search paradigms.     

The generality of outside-in processing routines in the analysis of form

In a previous study, Earhard and Walker (1985) showed that outer details of forms were more accurately reported than inner details. Although they suggested that this pattern might reflect a routinely applied outside-in processing strategy, their ability to generalize was limited by a reliance on small, single forms which occupied a fixed position in the visual field. To provide a more adequate assessment of generality of outside-in processing, a series of five experiments examined the discriminability of inner- and outer-line detail under a wide variety of conditions. Support for a general outside-in processing routine was obtained. More accurate reporting of outer detail was evident with large as well as small forms, with long and short exposure durations, and with trial-by-trial variations in the size and orientation of forms. Outer lines were also reported more accurately when a number of forms were presented simultaneously for inspection and under circumstances where error rates were low and reaction time procedures were employed. Evidence was presented to support the view that the more accurate discrimination of outer detail reflected the deployment of an attentional strategy.     

Investment behavior and the negative side of emotion

Can dysfunction in neural systems subserving emotion lead, under certain circumstances, to more advantageous decisions? To answer this question, we investigated how normal participants, patients with stable focal lesions in brain regions related to emotion (target patients), and patients with stable focal lesions in brain regions unrelated to emotion (control patients) made 20 rounds of investment decisions. Target patients made more advantageous decisions and ultimately earned more money from their investments than the normal participants and control patients. When normal participants and control patients either won or lost money on an investment round, they adopted a conservative strategy and became more reluctant to invest on the subsequent round; these results suggest that they were more affected than target patients by the outcomes of decisions made in the previous rounds.     

Measuring the spatial distribution of the metaattentional spotlight

Studies in cognitive psychology have shown that the deployment of visual attention operates under spatial limitations, rendering its assignment to multiple locations difficult or costly. This study explored whether this conventional understanding applies to human metaattention as well. I measured the spatial distribution of metaattention during viewing of natural scenes and found that participants believed they could attend to multiple locations simultaneously. Study 2 tested whether this tendency could be modified by information about the tendency to overestimation. After participants were informed of this tendency toward overestimation with both verbal instruction and demonstrations of attentional blindness and blindness to these phenomena, the selectivity of metaattention increased. Study 3 demonstrated that participants overestimated their attentional abilities by comparing the metaattentional drawings and the actual behavioral performances of the same participants. These results were consistent with recent findings of metaattentional overestimation in change detection and suggested human insensitivity in monitoring attentional limitations.     

Does media multitasking always hurt? A positive correlation between multitasking and multisensory integration

Heavy media multitaskers have been found to perform poorly in certain cognitive tasks involving task switching, selective attention, and working memory. An account for this is that with a breadth-biased style of cognitive control, multitaskers tend to pay attention to various information available in the environment, without sufficient focus on the information most relevant to the task at hand. This cognitive style, however, may not cause a general deficit in all kinds of tasks. We tested the hypothesis that heavy media multitaskers would perform better in a multisensory integration task than would others, due to their extensive experience in integrating information from different modalities. Sixty-three participants filled out a questionnaire about their media usage and completed a visual search task with and without synchronous tones (pip-and-pop paradigm). It was found that a higher degree of media multitasking was correlated with better multisensory integration. The fact that heavy media multitaskers are not deficient in all kinds of cognitive tasks suggests that media multitasking does not always hurt.     

Monitoring eye movements to investigate the picture superiority effect in spatial memory

Spatial memory is usually better for iconic than for verbal material. Our aim was to assess whether such effect is related to the way iconic and verbal targets are viewed when people have to memorize their locations. Eye movements were recorded while participants memorized the locations of images or words. Images received fewer, but longer, gazes than words. Longer gazes on images might reflect greater attention devoted to images due to their higher sensorial distinctiveness and/or generation with images of an additional phonological code beyond the visual code immediately available. We found that words were scanned mainly from left to right while a more heterogeneous scanning strategy characterized encoding of images. This suggests that iconic configurations tend to be maintained as global integrated representations in which all the item/location pairs are simultaneously present whilst verbal configurations are maintained through more sequential processes.     

视觉注意离散性的实验范式

注意离散性是注意间歇性地采集外界信息的特性。文章综述了视觉注意离散性的4种实验范式:(1)车轮错觉范式,刺激强度大、实验条件少、被试任务量小,较早地证实了视觉注意的离散性;(2)视觉探测范式,同时观察了被试的行为表现与电生理信号,确定了视觉注意离散性与神经振荡的关联;(3)线索靶子范式和视觉搜索范式,通过系统地变化SOA大幅提高了行为数据的时间分辨率,直观地探测到注意离散性调制的行为振荡。     

Multisensory numerosity judgments for visual and tactile stimuli

To date, numerosity judgments have been studied only under conditions of unimodal stimulus presentation. It is therefore unclear whether the same limitations on correctly reporting the number of unimodal visual or tactile stimuli presented in a display might be expected under conditions in which participants have to count stimuli presented simultaneously in two or more different sensory modalities. In Experiment 1, we investigated numerosity judgments using both unimodal and bimodal displays consisting of one to six vibrotactile stimuli (presented over the body surface) and one to six visual stimuli (seen on the body via mirror reflection). Participants had to count the number of stimuli regardless of their modality of presentation. Bimodal numerosity judgments were significantly less accurate than predicted on the basis of an independent modality-specific resources account, thus showing that numerosity judgments might rely on a unitary amodal system instead. The results of a second experiment demonstrated that divided attention costs could not account for the poor performance in the bimodal conditions of Experiment 1. We discuss these results in relation to current theories of cross-modal integration and to the cognitive resources and/or common higher order spatial representations possibly accessed by both visual and tactile stimuli.     

跨通道语义启动对视觉注意的影响

采用生活中的真实客体,考察了跨通道语义相关性对视觉注意的影响以及跨通道促进的时程。结合启动范式和点探测范式,实验1发现在听觉启动600ms后,被试对高相关视觉刺激的反应比对低相关刺激的反应更快,而在视觉启动下没有发现启动效应。实验2发现在启动刺激呈现900ms后跨通道启动效应消失。研究证明了基于先前经验的视、听语义相关能够促进视觉的选择性注意。     

Top-down selective visual attention: A neurodynamical approach

We propose a system of interconnected modules consisting of populations of neurons for modelling the underlying mechanisms involved in selective visual attention. We demonstrate that it is plausible to build a neural system for visual search, which works across the visual field in parallel, but, due to the intrinsic dynamics of the system, resembles apparent modes of visual attention, namely the serial focal and the parallel spread over the space mode. Thus, neither explicit serial focal search nor saliency maps need to be assumed. A focal attentional spotlight is not included in the system but rather focal attention emerges due to the convergence of the dynamic behaviour of the neural networks. The dynamics of the system can be interpreted as a mechanism for routing information from the sensory input.