知觉负载影响注意选择和冲突解决的系列效应

研究考察了无关侧抑制项引起的侧抑制效应如何受到当前试次知觉负载和先前试次知觉负载与目标?侧抑制项关系的交互影响。被试在视觉搜索集中搜索目标朝向刺激(水平或竖直朝向)并作辨别反应, 非目标项在低负载条件下彼此朝向一致, 在高负载条件下彼此朝向不一致。在搜索集的左侧或右侧存在一个与当前目标一致或不一致的无关侧抑制项(flanker)。结果发现, 整体上, 在当前试次低负载条件下会产生较大的干扰效应, 而在当前试次高负载下无干扰效应。此外, 先前试次(trial n-1)为高负载条件时, 当前试次(trial n)出现了典型的知觉负载效应, 即低负载条件干扰效应较大, 高负载条件无干扰效应。但是, 先前试次为低负载条件时, 当前试次的干扰效应大小受到先前试次冲突解决状态的影响。先前试次为低负载条件且目标?无关侧抑制项不一致时, 下一试次低负载条件的侧抑制效应显著减小, 与高负载条件没有差异; 反之, 先前试次为低负载且目标?侧抑制项一致条件时, 下一试次低负载条件的侧抑制效应显著增大。先前试次为低负载条件时, 完成了知觉加工的侧抑制项或者引发了冲突效应(不一致条件), 或者促进了对目标的反应(一致条件), 造成不同的注意选择和冲突解决状态, 显著影响了下一试次的行为表现。这说明, 注意选择与冲突控制过程是动态变化的, 除了受到当前试次知觉负载的影响, 也受到先前试次注意选择和冲突解决状态的调节。     

客体信息在视觉工作记忆编码和维持阶段的不同注意选择模式

视觉工作记忆不同加工阶段(编码、维持)对多特征客体信息的注意选择模式是否相同目前仍存在争议。本研究采用变化觉察范式,引入前注意线索和后注意线索,分别探测在视觉工作记忆编码和维持两个阶段中的注意选择模式。3个实验结果显示,在前注意线索试次中,被试对任务相关特征变化的觉察显著受到任务无关特征变化的干扰,表现为任务无关特征变化条件相比于不变条件的反应更慢,报告标准更低;且该干扰效应并不受记忆负荷的影响。而在后注意线索试次中,仅在低记忆负荷条件下(实验1a/1b)存在干扰效应,当记忆负荷增大后(实验2/3)干扰效应消失。结果表明,在视觉工作记忆编码阶段,客体中任务相关与无关特征均被编码进视觉工作记忆并相互竞争注意资源;而在维持阶段,任务无关特征仅在低记忆负荷条件下得到加工。结果揭示,在编码阶段的注意选择模式是基于客体的;而维持阶段的注意选择模式是基于特征的,且受到记忆负荷的调控。     

自上而下任务定势影响基于关系的注意捕获

采用空间线索化范式,考察在有无任务定势的强化下对涉及关系信息的注意捕获的影响。实验一在线索呈现和目标呈现中分别设置线索颜色关系和靶刺激颜色关系,要求被试在二者关系一致与否两种情况下对目标呈现中颜色奇异的靶刺激进行辨别。实验二在原有的颜色关系的基础上,要求被试忽略目标呈现中某一颜色关系条件下的靶刺激,限定只对另一颜色关系下的目标呈现进行任务反应。实验一结果显示无论颜色关系一致与否,颜色奇异项都优先捕获注意,注意捕获以自动化的形式呈现。实验二结果表明注意会选择性的指向与线索呈现中颜色关系相同的靶刺激而非单纯地捕获奇异颜色项。注意捕获可以基于"关系"模式而非具体的特征。总的来说,基于关系信息的注意捕获只有在建立很强的自上而下注意控制定势的条件下才能产生。     

注意捕获效应受知觉负载及目标与干扰项距离的共同影响

研究考察了无关干扰项引发的注意捕获效应如何受到任务知觉负载以及目标与干扰项距离的共同影响。被试在视觉搜索集中搜索目标并做辨别反应。通过控制搜索集的大小来控制任务知觉负载, 同时在搜索集中存在一个用颜色标定的无关干扰项(奇异项), 该奇异项与当前的搜索目标存在一致、中性或不一致的关系, 该奇异项的位置与当前目标相邻或相距较远。结果发现, 被试在低负载条件下出现显著的干扰效应(不一致条件的反应时减中性条件的反应时), 而在高负载条件下干扰效应减小。此外, 在高负载条件下, 当目标与干扰项相距较近时没有出现干扰效应, 而当目标与干扰项相距较远时存在显著的干扰效应。干扰效应受到任务知觉负载和目标与无关干扰项距离的共同影响。这些结果说明, 与任务无关的刺激是否捕获注意取决于当前任务总体上是否存在可用的剩余注意资源, 也受到其周围临近区域的局部注意资源是否充足的影响。     

多目标视觉追踪中物体属性加工的眼动研究*

采用多目标视觉追踪任务(MOT),探讨物体颜色特征对视觉追踪的影响,同时记录被试的眼动情况,探讨追踪过程中颜色特征对眼动模式的影响。结果发现,视觉追踪机制能够对物体的颜色特征进行加工,但加工程度受制于目标物与分心物之间的特征竞争关系。在物体颜色特征条件下,视觉系统采用知觉组织加工策略,以被追踪目标构成的多边形中心为注意中心。在对物体颜色特征的加工中,内源性注意与外源性注意相互影响。     

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。     

特征的呈现方式对类别学习中规则和相似性知识获得的影响

采用原型变异任务,通过操纵规则和相似性特征的呈现通道,探讨特征的呈现方式对类别学习中规则和相似性知识获得的影响。结果发现,在听觉-视觉条件下习得规则的人数显著多于习得相似性的人数,而在视觉-听觉和视觉-视觉条件下则不存在显著差异;并且,三种条件下习得规则的正确率都高于习得相似性的正确率。这说明特征的呈现方式影响对规则和相似性特征的习得,在听觉通道呈现规则时被试更倾向基于规则分类。     

语义的自动加工和选择性注意对Stroop效应的影响

本实验用正常人和聋哑人作被试进行比较,试图探讨语义的自动加工和选择性注意对Stroop效应的影响。将“红”“绿”“黄”“蓝”四个汉字中的每一个都用这四种颜色中的三种写成,然后按着事先排列好的顺序,分组呈现,并且在两种条件下分别要求被试延迟不同的时间进行反应,一种是刺激呈现前就告诉被试对“字”或“色”反应;另一种是刺激呈现后间隔不同的时间再向被试提出对“字”或“色”反应。实验结果发现,聋哑人和正常人在色—字干扰任务作业上没有明显的差异,说明语义的自动加工是一个普遍现象;而选择性注意能在很大的程度上改善被试的作业成绩,但颜色命名仍比字词反应困难;Stroop效应在延迟反应条件下发生变化,这种变化说明Stroop效应与记忆过程有联系。     

动态非注意盲中的分心物加工机制：是否存在抑制

系统考察在控制目标与非目标颜色特征属性的条件下, 动态非注意盲中视觉系统是否存在对分心物的抑制机制。实验一为基线实验, 将目标与非目标设置为相同的白色圆形, 考察被试对不同颜色特征(白色或者黑色)新异刺激的觉察情况; 实验二和实验三通过改变目标与非目标的颜色特征, 进一步探讨视觉系统对分心物(包括非目标和新异刺激)的抑制机制。结果发现, 视觉系统对干扰目标追踪(并计数)任务的分心物均产生抑制作用, 并且不同颜色特征的分心物受到的抑制作用不同, 与目标颜色特征相同的分心物受到的抑制作用较大, 相应新异刺激的觉察率低; 与目标颜色特征区分明显的分心物受到的抑制作用较小, 相应新异刺激的觉察率较高。     

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。     

Response-mediated spatial priming despite perfectly valid target location cues and intervening response events

Attentional effects are often inferred from keypress reaction time (RT) studies when two sequentially presented stimuli, appearing at the same location, generate costs or benefits. The universality of these attentional attributions is challenged by data from perceptual discrimination tasks, which reveal that location repetition benefits and costs depend on whether a prior response repeats or switches, respectively. According to dual-stage accounts, these post-attentional effects may be abolished by making responses in between two target stimuli or by increasing target location certainty, leaving only attentional effects. Here, we test these accounts by requiring responses to stimuli in between targets and by increasing target location certainty with 100% valid location cues. Contrary to expectations, there was no discernible effect of cueing on any repetition effects, although the intervening response diminished stimulus-response repetition effects while subtly reducing location-response repetition effects. Despite this, there was little unambiguous evidence of attentional effects independent of responding. Taken together, the results further highlight the robustness of location-response repetition effects in perceptual discrimination tasks, which challenge whether there are enduring attentional effects in this paradigm.     

Regularity of unit length boosts statistical learning in verbal and nonverbal artificial languages

Humans have remarkable statistical learning abilities for verbal speech-like materials and for nonverbal music-like materials. Statistical learning has been shown with artificial languages (AL) that consist of the concatenation of nonsense word-like units into a continuous stream. These ALs contain no cues to unit boundaries other than the transitional probabilities between events, which are high within a unit and low between units. Most AL studies have used units of regular lengths. In the present study, the ALs were based on the same statistical structures but differed in unit length regularity (i.e., whether they were made out of units of regular vs. irregular lengths) and in materials (i.e., syllables vs. musical timbres), to allow us to investigate the influence of unit length regularity on domain-general statistical learning. In addition to better performance for verbal than for nonverbal materials, the findings revealed an effect of unit length regularity, with better performance for languages with regular- (vs. irregular-) length units. This unit length regularity effect suggests the influence of dynamic attentional processes (as proposed by the dynamic attending theory; Large & Jones (Psychological Review 106: 119–159, 1999)) on domain-general statistical learning.     

Spatial attention based on 2D location and relative depth order modulates visual working memory in a 3D environment

The attentional effect on visual working memory (VWM) has been a heated research topic in the past two decades. Studies show that VWM performance for an attended memory item can be improved by cueing its two-dimensional (2D) spatial location during retention. However, few studies have investigated the effect of attentional selection on VWM in a three-dimensional setting, and it remains unknown whether depth information can produce beneficial attentional effects on 2D visual representations similar to 2D spatial information. Here we conducted four experiments, displaying memory items at various stereoscopic depth planes, and examined the retro-cue effects of four types of cues – a cue would either indicate the 2D or depth location of a memory item, and either in the form of physical (directly pointing to a location) or symbolic (numerically mapping onto a location) cues. We found that retro-cue benefits were only observed for cues directly pointing to a 2D location, whereas a null effect was observed for cues directly pointing to a depth location. However, there was a retro-cue effect when cueing the relative depth order, though the effect was weaker than that for cueing the 2D location. The selective effect on VWM based on 2D spatial attention is different from depth-based attention, and the divergence suggests that an object representation is primarily bound with its 2D spatial location, weakly bound with its depth order but not with its metric depth location. This indicates that attentional selection based on memory for depth, particularly metric depth, is ineffective.     

Statistical regularities modulate attentional capture independent of search strategy

An earlier study using the additional singleton task showed that statistical regularities regarding the distractor location can cause an attentional bias that affects the amount of attentional capture by distractors and the efficiency of selection of targets. The distractor singleton was systematically present more often in one location than in all other locations. The present study investigated whether this bias also occurs when observers adopt a feature search mode, i.e., when they search for a specific feature (circle) between elements with different shapes, while ignoring a colored distractor singleton. It is assumed that in feature search, observers can ignore distractors in a top-down way and as such one expects that statistical regularities about the distractor location should not play a role. Contrary to this prediction, we found that even in feature search, both attentional capture by the distractors and the efficiency of selecting the target were impacted by these statistical regularities. Moreover, statistical regularities regarding the feature value of the distractor (its color) had no effect on the amount of capture or the efficiency of selection. We claim that statistical regularities cause passive lingering biases of attention such that on the priority map, the location containing a high probability distractor competes less for attention than locations that are less likely to contain distractors.     

Coordination of voluntary and stimulus-driven attentional control in human cortex

Visual attention may be voluntarily directed to particular locations or features (voluntary control), or it may be captured by salient stimuli, such as the abrupt appearance of a new perceptual object (stimulus-driven control). Most often, however, the deployment of attention is the result of a dynamic interplay between voluntary attentional control settings (e.g., based on prior knowledge about a target's location or color) and the degree to which stimuli in the visual scene match these voluntary control settings. Consequently, nontarget items in the scene that share a defining feature with the target of visual search can capture attention, a phenomenon termed contingent attentional capture. We used functional magnetic resonance imaging to show that attentional capture by target-colored distractors is accompanied by increased cortical activity in corresponding regions of retinotopically organized visual cortex. Concurrent activation in the temporoparietal junction and ventral frontal cortex suggests that these regions coordinate voluntary and stimulus-driven attentional control settings to determine which stimuli effectively compete for attention.     

Enhancement of the Simon effect by response precuing.

When stimuli are presented to the left or right of fixation, and stimulus location is irrelevant, responses are faster if the stimulus location coincides with the location of the assigned response. This phenomenon is called the Simon effect. The present study examined the influence on the Simon effect of attentional precues that signaled the likely stimulus location and intentional precues that signaled the likely response. Experiment 1 was a close procedural replication of an experiment by Verfaellie, Bowers, and Heilman (1988); consistent with their findings, the Simon effect was enhanced by the intentional precue and unaffected by the attentional precue. Experiments 2 and 3 demonstrated the importance of the intentional precue with simpler procedures that involved only intentional and attentional precues, respectively. Finally, the intentional precuing enhancement of the Simon effect was obtained when two stimuli were assigned to each response, regardless of whether the hands were uncrossed (experiment 4) or crossed (experiment 5). Overall, the results indicate that response precuing enhances the Simon effect and favor response-selection accounts over those that attribute the effect to stimulus identification.     

Probing attentional modulation of contextual cueing

The repetition of spatial layout implicitly facilitates visual search (contextual cueing effect; Chun & Jiang, 1998). Although a substantial number of studies have explored the mechanism underlying the contextual cueing effect, the manner in which contextual information guides spatial attention to a target location during a visual search remains unclear. We investigated the nature of attentional modulation by contextual cueing, using a hybrid paradigm of a visual search task and a probe dot detection task. In the case of a repeated spatial layout, detection of a probe dot was facilitated at a search target location and was inhibited at distractor locations relative to nonrepeated spatial layouts. Furthermore, these facilitatory and inhibitory effects possessed different learning properties across epochs (Experiment 1) and different time courses within a trial (Experiment 2). These results suggest that contextual cueing modulates attentional processing via both facilitation to the location of “to-be-attended” stimuli and inhibition to the locations of “to-be-ignored” stimuli.     

特征和位置信息在价值驱动注意捕获中的作用

本研究采用训练−测试范式考察颜色和位置信息在价值驱动注意捕获中的作用。实验1考察是否存在基于具体位置的价值驱动的注意捕获效应。在训练阶段, 被试对8个位置中两个位置出现的红色目标反应伴随着高奖励反馈, 而对另外两个位置出现的红色目标反应伴随着低奖励反馈, 其它4个位置为中性位置, 没有目标出现。在测试阶段, 一半试次中红色刺激作为分心物出现。结果发现, 只有当分心刺激出现在高奖励位置和两个高奖励位置之间的中性位置时才能够捕获注意; 实验2考察颜色和位置信息在价值驱动注意捕获中的交互作用。在训练阶段, 将颜色特征和位置信息联合起来进行学习。在测试阶段, 和高、低奖励相联结的颜色刺激各在1/3试次中作为分心物出现。结果发现, 只有当高奖励颜色出现在高奖励位置或出现在高奖励位置之间的中性位置时才能够捕获注意。研究结果表明：(1)位置联结的价值驱动的注意捕获效应能够泛化到特定邻近位置上; (2)个体在训练阶段将颜色和位置的联合特征与奖励建立联结, 训练阶段建立的联结不能泛化到部分特征上。价值驱动注意捕获效应的泛化具有选择性。     

注意偏向训练对广泛性焦虑障碍负性情绪注意偏向的影响

采用改良的点探测任务,探讨了注意偏向训练能否改变GAD患者的负性情绪注意偏向并缓解其焦虑状态,及注意偏向训练的作用机制。结果发现,与控制组相比,训练组被试的负性注意偏向分数显著降低,具体表现为训练后训练组的负性注意解除能力显著高于控制组,两组被试的负性注意警觉在前后测均未有显著变化;注意偏向训练引起了GAD患者积极情绪的变化,缓解了状态焦虑。这证明了注意偏向训练对改变GAD患者负性情绪注意偏向及缓解其焦虑状态的有效性,并揭示这种改变主要是通过提升其对负性刺激的注意解除能力来实现的。     

Modulation of auditory spatial attention by visual emotional cues: differential effects of attentional engagement and disengagement for pleasant and unpleasant cues

Previous research has demonstrated that threatening, compared to neutral pictures, can bias attention towards non-emotional auditory targets. Here we investigated which subcomponents of attention contributed to the influence of emotional visual stimuli on auditory spatial attention. Participants indicated the location of an auditory target, after brief (250 ms) presentation of a spatially non-predictive peripheral visual cue. Responses to targets were faster at the location of the preceding visual cue, compared to at the opposite location (cue validity effect). The cue validity effect was larger for targets following pleasant and unpleasant cues compared to neutral cues, for right-sided targets. For unpleasant cues, the crossmodal cue validity effect was driven by delayed attentional disengagement, and for pleasant cues, it was driven by enhanced engagement. We conclude that both pleasant and unpleasant visual cues influence the distribution of attention across modalities and that the associated attentional mechanisms depend on the valence of the visual cue.