内源性注意与外源性注意的跨通道比较

该研究利用空间线索技术的实验模式,考察跨视觉和听觉通道的内源性选择注意与外源性选择性注意的相互关系。实验结果表明：(1)听觉中央线索在较长的SOA(至少500毫秒)条件下,可以引导内源性空间选择性注意;同时外周线索突现也能自动化地吸引部分注意资源。(2)听觉和视觉选择注意是分离的加工通道,但二者之间存在相互联系。     

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。     

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。     

内源性注意与外源性注意对数字加工的不同影响

分别采用内源性注意和外源性注意实验范式,材料为小数（1－4）和大数（6－9）的中文与阿拉伯数字,任务为判断数字是否大于5,考察在注意与非注意条件下不同大小数字加工的距离效应和符号效应。结果发现：⑴在内源性线索和外源性线索的注意条件下,大小数都出现了距离效应;但在非注意条件下,内源性线索时的大小数都出现了距离效应,而外源性线索时只有小数出现了距离效应,大数的距离效应明显减弱或消失。⑵在内源性线索和外源性线索的注意条件下,大小数都没有出现符号效应;但在非注意条件下,大数没有出现符号效应,而小数出现了符号效应（阿拉伯数字的绩效比中文数字差）,并且内源性线索时的符号效应强度小于外源性线索。     

内源性注意和外源性注意对中小学生SNARC效应的影响

采用内源性注意和外源性注意实验范式,以判断数字奇偶为任务,材料为1～9的阿拉伯数字,考察内源性和外源性线索不同注意条件下中小学生的数字加工SNARC效应。结果发现:(1)内源性线索和外源性线索条件下,中小学生在数字加工任务中所表现出来的SNARC效应随着年龄增长逐渐增大;(2)内源性线索和外源性线索注意条件下,各年级学生均表现出显著的SNARC效应;(3)内源性线索非注意条件下,中学生能够表现出显著的SNARC效应,但小学生的SNARC效应不明显;外源性线索非注意条件下,高中生能够表现出显著的SNARC效应,但小学生和初中生的SNARC效应不明显,说明外源性注意对中小学生数字加工SNARC效应的影响比内源性注意大,且对SNARC效应的影响主要表现在较大的数字8和9上。     

不同注意条件下的空间－数字反应编码联合效应

考察在无线索、内源性线索与外源性线索时不同符号数字在注意与非注意条件下的空间－数字的反应编码联合效应（Spatial Numerical Association of Response Codes,简称SNARC效应）。采用1到9的中文与阿拉伯数字为材料,以判断数字奇偶为任务。实验结果表明：⑴无线索时注意条件下阿拉伯和中文数字都出现了SNARC效应,而非注意条件下则都没有出现,并且受影响的主要是较大的数字（8、9）;⑵外源性线索和内源性线索时,我们得到一个逐渐递减的SNARC效应,受影响的也主要是较大的数字（8、9）。在内源性线索的注意条件阿拉伯和中文数都有SNARC效应,而在非注意条件只有阿拉伯数有SNARC效应;在外源性线索的注意条件只有阿拉伯数有SNARC效应,而在非注意条件阿拉伯和中文都没有SNARC效应,说明外源性注意的影响比内源性注意更大,中文数字所受的影响比阿拉伯数字更大。     

外源性视觉选择性注意的时空特征

使用与目标出现位置无关的外周空现刺激作为线索,研究在不同刺激呈现间隔（ＳＯＡ）下它对不同偏心 视觉目标的辨别反应时的影响,以考察外源性觉选择性注意的加工特生,并下三种注意空间分布模型对选择性注意时空特征的不同预测,结果表明：１．外周突现刺激能够不随意地吸引注意,符合自动加工特性;２．注意转移以注意中心连续移动的方式进行,支持探照灯模型,不支持透镜模型和静态的空间梯度模型,并在注意移动速率进行了估计     

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。     

内源性注意和外源性注意条件下SOA变化对数字距离效应的影响

采用内源性注意和外源性注意实验范式,材料为小数(1～4)和大数(6～9)的阿拉伯数字,以判断数字是否大于5为任务,考察内源性和外源性线索不同注意条件下SOA对数字距离效应的影响。结果发现:(1)内源性线索条件下,随着SOAs增加,大小数的距离效应逐渐增大,当SOA为900ms时,大小数的距离效应最明显;(2)外源性线索条件下,当SOA为300ms时,大小数的距离效应最显著,随着SOAs增加,大小数的距离效应逐渐减小。     

视觉选择性注意对注意缺损多动障碍儿童数字距离效应的影响

采用Posner的内源性和外源性线索实验范式,材料为1~9的阿拉伯数字(不包括5),以判断目标数字是否大于5为任务,考察视觉选择性注意中的内源性注意和外源性注意对注意缺陷型多动障碍儿童(ADHD)数字加工距离效应的影响。结果发现:(1)内源性和外源性注意条件下,正常儿童在数字判断加工任务中的反应时短于ADHD儿童;(2)内源性有效线索提示条件下,ADHD儿童和正常儿童均表现出显著的数字距离效应;而无效线索提示条件下,ADHD儿童的大小数字距离效应均不明显,正常儿童仍然表现出显著的数字距离效应;(3)外源性有效线索提示条件下,ADHD儿童的小数字距离效应显著,但大数字距离效应不明显,正常儿童则表现出显著的大小数字距离效应;而无效线索提示条件下,只有正常儿童表现出显著的数字距离效应,ADHD儿童的数字距离效应不显著。     

Tradeoffs between attentional effects of spatial cues and abrupt onsets

We determined the relative effectiveness and tradeoffs among central, peripheral, and abrupt onset cues in directing attention to a potential target character. Central cues were arrows located at the fixation point, whereas peripheral cues were arrows occurring about 3° away from fixation, near the location of a potential target. These were contrasted with the abrupt onset of an ambiguous part of a character, which later was filled in to reveal a target or a distractor item. Each trial included an arrow cue and an abrupt onset cue, and both expected cue validities and cue-character SOAs were varied factorially. The results showed that, in general, abrupt onsets captured attention more effectively than either central or peripheral arrow cues. However, tradeoffs among separate cue effects indicated that the power of abrupt onsets to capture attention automatically could be overridden by a high-validity spatial cue presented in advance of the onset character. Tradeoffs between the effects of central and abrupt onset cues were additive, indicating that endogenous and exogenous cues have their main effects at different levels in the visual attention system. Peripheral cues and abrupt onsets showed mainly interactive effects, however, consistent with the idea that both types of cues have exogenous components that affect a common pool of attentional resources.     

Attentional capture within and between objects

The present study addressed the question whether attentional capture by abrupt onsets is affected by object-like properties of the stimulus field. Observers searched for a target circle at one of four ends of two solid rectangles. In the focused attention condition the location of the upcoming target was cued by means of a central arrowhead, whereas in the divided attention condition, the target location was not cued. Irrelevant abrupt onsets could appear either within the attended or within the non-attended object. The results showed that in the focused attention condition, onsets ceased to capture attention irrespective of whether the onset appeared within an attended object or within a non-attended object.     

Perceptual load modulates attentional capture by abrupt onsets

The abrupt appearance of a new object captures attention, even when the object is task irrelevant. These findings suggest that abrupt onsets capture attention in a stimulus-driven manner and are not susceptible to top-down influences on attentional control. However, previous studies examining the ability of abrupt onsets to capture attention have used search displays that lacked significant complexity. Because attention is a limited capacity mechanism, it is possible that increasing the complexity, or perceptual load, of the search arrays may modulate capture by abrupt onsets. We used a flanker task to examine the effect of perceptual load on attentional capture by abruptly appearing objects. Subjects searched for a target letter through low-load (set size=1) and high-load (set size=6) displays. On each trial, irrelevant flankers also appeared, one as an onset and the other as an offset. Onset flankers affected search in low-load but not high-load displays. This modulation of attentional capture was not caused by generalized slowing when subjects searched through high-load displays; search for a single perceptually degraded target slowed response times but did not affect attentional capture. These findings demonstrate that attentional capture by an abrupt onset is attenuated when people search through high-load scenes.     

Abrupt onsets capture attention independent of top-down control settings

Previous research using a spatial cuing paradigm in which a distractor cue preceded the target has shown that new objects presented with abrupt onsets only capture attention when observers are set to look for them (e.g., Folk, Remington, & Johnston, 1992). In the present study, we used the same spatial cuing paradigm as Folk et al. (1992) to demonstrate that even when observers have an attentional set for a color singleton or a specific color feature, an irrelevant new object presented with an abrupt onset interfered with search. We also show that the identity of the abrupt-onset distractor affects responses to the target, indicating that at some point spatial attention was allocated to the abrupt onset. We conclude that abrupt onsets ornew objects override a top-down set for color. Abrupt onsets or new objects appear to capture attention independently of top-down control settings.     

Abrupt visual onsets and selective attention: voluntary versus automatic allocation

The hypothesis that abrupt visual onsets capture attention automatically, as suggested by Yantis and Jonides (1984) was tested in four experiments. A centrally located cue directed attention to one of several stimulus positions in preparation for the identification of a target letter embedded in an array of distractor letters. In all experiments, one stimulus (either the target or one of the distractors) had an abrupt onset; the remaining letters did not. The effectiveness of the cue was manipulated (varying either its duration or its predictive validity) to test whether abrupt onsets capture attention even when subjects are in a highly focused attentional state. Results showed that onsets do not necessarily capture attention in violation of an observer's intentions. A mechanism for partially automatic attentional capture by abrupt onset is proposed, and the diagnosticity of the intentionality criterion for automaticity is discussed.     

The time course of attentional capture under dual-task conditions

Several recent studies have shown that attentional capture is not an automatic process. For example, abrupt peripheral onsets do not affect the processing of targets presented subsequently at that location when participants have to concurrently perform a perceptually demanding task elsewhere. This result leaves open the question of whether peripheral onsets lose their effectiveness in capturing attention or whether, instead, the performance of a perceptually demanding task entails a faster disengagement of attention from the cued location. Here, we measured exogenous spatial attentional-orienting effects either while participants performed a concurrent perceptually demanding central-monitoring task (a rapid serial visual presentation of letters for a to-be-detected digit target; Experiments 1 and 2) or in isolation (the baseline condition in Experiment 2). The results showed that peripheral onsets captured participants' attention at both the 80- and 190-ms stimulus onset asynchronies (SOAs) in the baseline condition. Crucially, however, during concurrent central monitoring, peripheral onsets were effective in capturing attention only at an 80-ms SOA, while the orienting effect disappeared as soon as a changing letter drew participants' attention back to the central stream (at an SOA of 190 ms). These findings demonstrate that task-irrelevant abrupt onsets cannot be entirely overridden by top-down attentional control, although attentional capture effects are dramatically reduced by an ongoing perceptually demanding task.     

Automatic and voluntary control of attention in young and older adults

Young and older adults searched for a target character in a 3-item display. On each trial, both a symbolic cue (arrow at fixation) and a spatial cue (abrupt onset of one item) could indicate the target's position. Participants were told to use the central arrow cue on all trials because it had 75% validity. The onset cue also had 75% validity for half the participants and 25% validity for the other half. Both age groups showed about the same cost and benefit effects for the central arrow cues, but the abrupt onsets had much larger cuing effects for older adults. Young adults were able to suppress at least partially an automatic attentional response to an abrupt onset item when the arrow cue preceded the onset and had a higher validity than the onset cue. Older adults appeared to be less able to inhibit their responses to abrupt onsets and to disengage their attention from invalid onset cues than were the young adults.     

Relative Effectiveness of Central, Peripheral, and Abrupt-onset Cues in Visual Attention

The relative effectiveness of central arrow, peripheral arrow, and abrupt-onset cues was assessed in a character recognition task. On each trial, either a central or a peripheral arrow cue was presented 0, 100, or 200 msec before the appearance of a three-digit display. Two of the digits were “uncamouflaged” from previous figure-eight masks, whereas the third digit appeared abruptly in a previously empty space. Four different groups of subjects were run in factorial combinations of high or low expected validities for arrow and onset cues. In Experiment 1, arrow cues were located centrally, near the fixation point. Abrupt onsets showed larger cost-plus benefits than central arrows, except when subjects expected the central cues to have higher validity than the onsets. In Experiment 2, arrow cues were located peripherally, near the display digits, and abrupt onsets were again more effective in capturing attention except when peripheral cues had higher validity and led the onsets by 100 msec or more. In both experiments, the relative effectiveness of abrupt onsets decreased with arrow SOA. The results were consistent with a model in which automatic and voluntary processes interact in their control of attentional resources.     

Mechanisms of attentional priority

When a single abrupt onset occurs in a multielement visual display, it captures attention, possibly by generating an attentional interrupt that designates onsets as being of high priority. In 3 experiments, the mechanisms subserving attentional priority setting were investigated. Subjects searched for a prespecified target letter among multiple distractor letters, half of which had abrupt onsets and half of which did not. The target, when present, was equally often an onset element and a no-onset element. Several models for attentional priority, differing in how many onset elements have priority over no-onset elements, were assessed. The data support a model in which approximately 4 onset stimuli are processed before any no-onset stimuli are processed. Two attentional priority mechanisms are proposed: (a) queuing of a limited number of high-priority elements and (b) temporally modulated decay of attentional priority tags.     

Attentional capture by abrupt onsets and feature singletons produces inhibitory surrounds

Two experiments found that form discriminations to a target item were inhibited when the target appeared adjacent to an attentionally salient item. Experiment 1 manipulated the attentional salience of an irrelevant color singleton through the attentional set adopted by the subjects. Color singletons captured attention when the target was itself a feature singleton, but not when the target was defined as a conjunction of features. Attentional capture was accompanied by an inhibitory region (i.e., slowed target reaction times), which dissipated with distance from the color singleton. In Experiment 2, the attentional salience of abrupt onsets and color singletons was compared. Irrelevant abrupt onsets captured attention, whereas irrelevant color singletons failed to capture attention. Again, an inhibitory region surrounded the attentionally salient abrupt onsets, but not the color singletons. The results are discussed in the context of current models of visual spatial attention and suggest a distinction between attentional preparation and attentional selection.