自上而下的目标调节奖赏联结干扰子的注意定向和脱离

近年来传统的注意控制理论已经无法解释部分注意控制现象,有研究者提出将奖赏联结/价值驱动的注意捕获作为一种新的注意引导源。奖赏联结的注意捕获是否会受到自上而下的目标定势的调节已成为该领域一个重要的理论问题。研究采用空间线索范式的变式,探讨了奖赏联结干扰子与目标的相关性对奖赏联结注意捕获中的定向和脱离的调节作用。研究结果发现:当学习阶段习得的奖赏联结干扰子在测验阶段与目标相关时(实验1),有奖干扰子相对于无奖干扰子具有优先的注意定向和延迟脱离;而学习阶段习得的奖赏联结干扰子在测验阶段与目标无关时(实验2),有奖干扰子和无奖干扰子在注意定向和脱离方面均无显著差异。由此可见,奖赏联结的注意捕获并不是完全自动化的,自上而下的目标定势能够调节其注意定向和脱离的成分,支持奖赏联结的注意捕获与自上而下的目标定势交互引导视觉注意的观点。     

注意定向方式对立体视觉加工的影响

研究采用边缘位置提示与中央符号提示,探讨了外源性与内源性注意定向对立体视觉加工的影响.结果发现:(1)短SOA下,非预测性边缘位置线索对2D和3D空间中的视觉辨认任务均产生了启动效应.3D空间中线索提示诱发了注意的自动定向,注意在深度面间的转移需要耗费一定时间.(2)长SOA下,2D平面上非预测性边缘位置线索导致了返回抑制,3D空间中的返回抑制波及至不同的深度面上.(3)不同SOA下,3D空间中预测性中央符号线索对视觉辨认任务均产生了启动效应,其效应量不随SOA延长而变化.     

发展性阅读障碍的视觉空间注意加工能力

鉴于阅读起始于基础视觉加工阶段, 越来越多的研究者开始关注阅读障碍者的视觉空间注意加工能力。视觉空间注意是指个体对视觉刺激的空间位置的注意, 可通过线索提示、视觉搜索和视觉注意广度等视觉任务来考察。大量国内外研究发现, 发展性阅读障碍者在视觉空间注意任务下表现出行为和神经活动方面的异常。其中的神经机制问题不仅反映在与视觉空间注意有关的顶叶区域激活异常, 还存在于脑区间功能连接异常(如顶叶区域与字形加工区的功能连接)。未来研究还需利用横断和追踪研究探讨阅读障碍与视觉空间注意能力发展关系的内在机制, 以及探究语言特性对阅读障碍者视觉空间注意缺陷的可能调节作用。     

早期ERP效应与视觉注意空间等级的脑调节机制

通过事件相关电位(ERP)记录研究注意的空间等级的脑内时程动态变化。视觉搜索任务的目标受不同大小提示范围的启动。提示范围增大时,识别目标的反应时延长,P1波幅增大而N1波幅减小,该效应在短间隔条件下尤为明显。P1增大反映了促进目标识别时,适当注意范围的空间等级变化需要额外的运算资源。而N1波幅减小则可能扩散了空间注意倾斜。研究结果提供了以下电生理学证据：注意空间等级的改变调节了早期视皮层的神经活动,并激活了视觉搜索中至少2个时间重叠的ERP成分。     

空间工作记忆负载对真实场景情境提示效应的影响

重复的画面布局能够促进观察者对目标项的搜索 (情境提示效应)。本研究采用双任务范式,分别在视觉搜索任务的学习阶段 (实验2a) 和测验阶段 (实验2b) 加入空间工作记忆任务, 并与单任务基线 (实验1)进行比较, 考察空间工作记忆负载对真实场景搜索中情境线索学习和情境提示效应表达的影响。结果发现: 空间负载会增大学习阶段的情境提示效应量, 同时削弱测验阶段的情境提示效应量, 而不影响情境线索的外显提取。由此可见, 真实场景中情境线索的学习和提示效应的表达均会受到有限的工作记忆资源的影响, 但情境线索提取的外显性不变。     

背景线索对室内场景中目标搜索的注意引导

以室内3D场景图为实验材料,采用眼动追踪技术,探讨背景线索对真实场景视觉搜索过程中的注意引导。结果发现：在室内场景目标搜索过程中存在背景线索效应,该效应基于对背景-目标共变关系的外显记忆;背景线索对搜索的启动和确认阶段无影响,对扫描阶段的注视行为有促进作用,有助于更有效地选择注视区域,将注视更直接地导向目标所在位置。     

眼睛注视是独特的吗?——来自发展的证据

采用改编的Posner视空间线索化任务,考查6~9岁儿童对眼睛注视、手指指向、箭头指向和代向汉字4种中央线索的注意定向。结果发现,6岁儿童已经能对眼睛注视线索进行注意定向,并随着年龄增长而改善。7岁组和8岁组儿童注意定向的成绩显著改善,7岁可能是儿童对中央线索注意定向发展的特定阶段。而对手指指向和箭头的注意定向,只有8岁和9岁儿童表现出来。对代向汉字线索的注意定向,8岁时开始出现,9岁时表现出显著的提高。结果提示,眼睛注视线索可能是一种独特的视觉线索,有别于其他中央线索引发的注意定向的发展。     

孤独症谱系障碍者视觉定向与视觉搜索的特点及神经机制

定向网络是注意网络的重要组成部分, 主要包括视觉定向与视觉搜索两大任务。对于这两大注意任务, 正常个体在神经机制上存在较大的重叠, 然而, 孤独症个体却表现出截然相反的行为证据。研究者从非社会信息的注意视角发现, 一般而言, 在视觉定向上, 孤独症个体注意转移不存在缺陷, 而注意脱离存在困难, 但该结论仍有争议; 在视觉搜索上, 孤独症个体存在视觉搜索优势, 但该优势发生的阶段及原因仍需进一步探究。未来研究应进一步考察孤独症个体在视觉定向任务中左右视野的不对称性、视觉搜索优势的内在机制及两大注意任务之间的相互关系。     

三维空间中外源性注意启动效应的ERP研究

采用行为测量与ERP分析相结合的范式,以视差分离方式和线索提示有效性为自变量,考察三维空间中外源性注意定向的启动效应及其脑电机制.结果发现:短SOA下,无论是3D还是2D,非预测性边缘位置线索对后续辨认任务均发生了启动效应;3D空间中,边缘位置线索提示诱发了注意的自动定向,注意从一个深度面转移到另一深度面需要耗费一定时间;3D空间中,经典注意提示效应在ERP上表现为有效提示下P1、N1、N2等早成分的增强,跨深度空间启动效应主要应由N1的增强效应加以解释.     

工作记忆表征的激活与抑制状态对注意引导效应的影响

本研究采用双任务范式, 通过定向遗忘任务操纵工作记忆表征状态, 分别在目标无关和目标相关条件下考察工作记忆激活与抑制状态对视觉搜索早期注意引导效应的影响。实验1与实验2发现当工作记忆表征只可能与视觉搜索分心物匹配时(目标无关条件), 处于激活状态的工作记忆表征会引导视觉注意偏向到与之匹配的分心物, 表现出注意引导效应, 而处于抑制状态的工作记忆表征则没有观察到注意引导效应。实验3与实验4发现, 当工作记忆表征有可能与视觉搜索目标匹配时(目标相关条件), 处于激活状态的工作记忆表征能捕获注意, 而处于抑制状态的工作记忆表征只有与视觉搜索目标匹配时, 才表现出对该搜索目标反应的延迟。这些研究的结果表明(1)处于激活状态的工作记忆表征能有效地引导注意偏向到与之匹配的搜索目标或分心物, 并且这种注意引导效应并未受到抑制动机的影响而被消除或反转; (2)处于抑制状态的工作记忆表征能将抑制状态传递到视觉搜索阶段, 并延迟对与之匹配的搜索目标的反应。     

场景在价值驱动注意捕获中的作用

本研究采用训练-测试范式考察场景信息在价值驱动注意捕获中的作用。实验1训练阶段将唯一性的场景信息与奖励建立联结,测试阶段发现只有当分心刺激出现在高奖励场景中才能捕获注意;实验2训练阶段将场景和颜色信息联合但分别独立预测奖励,结果发现高奖励颜色出现在任何场景中都能捕获注意。研究结果表明:(1)场景-价值联结能够引发注意捕获效应;(2)与场景相比,颜色特征在价值驱动的注意捕获中具有优势效应。     

Nonspatial attentional capture by previously rewarded scene semantics

Recent research has shown that reward influences visual perception and cognition in a way that is distinct from the well-documented goal-directed mechanisms. In the current study we explored how task-irrelevant stimulus-reward associations affect processing of stimuli when attention is constrained and reward no longer delivered. During a training phase, participants performed a choice game, exposing them to different reward schedules for different semantic categories of natural scene pictures. In a separate test session in which no additional reward was provided, the differentially rewarded scene categories were used as task-irrelevant non-targets in a rapid serial visual presentation (RSVP) task. Participants performed a detection task on a previously non-rewarded target category. Results show that participants' sensitivity index (d′) for target detection decreased as a function of whether the reward was coupled to the distractor category during training. The semantic category of natural scenes associated with high reward caused more interference in target detection than the semantic category associated with a low reward. The same was found when new, unseen distractor pictures of the same semantic categories were used. The present findings suggest that reward can be selectively associated with high level scene semantics. We argue that learned stimulus-reward associations persistently bias perceptual processing independently of spatial shifts in attention and the immediate prospect of reward.     

How does reward compete with goal-directed and stimulus-driven shifts of attention?

In order to behave adaptively, attention can be directed in space either voluntarily (i.e. endogenously) according to strategic goals, or involuntarily (i.e. exogenously) through reflexive capture by salient or novel events. The emotional or motivational values of stimuli can also influence attentional orienting. However, little is known about how reward-related effects compete or interact with endogenous and exogenous attention mechanisms. Here we designed a visual search paradigm in which goal-driven and stimulus-driven shifts of attention were manipulated by classic spatial cueing procedures, while an irrelevant, but previously rewarded stimulus also appeared as a distractor and hence competed with both types of spatial attention during search. Our results demonstrated that stimuli previously associated with a high monetary reward received higher attentional priority in the subsequent visual search task, even though these stimuli and reward were no longer task-relevant, mitigating the attentional orienting induced by both endogenous and exogenous cues.     

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。     

Value-driven attentional capture is modulated by spatial context

When stimuli are associated with reward outcome, their visual features acquire high attentional priority such that stimuli possessing those features involuntarily capture attention. Whether a particular feature is predictive of reward, however, will vary with a number of contextual factors. One such factor is spatial location: for example, red berries are likely to be found in low-lying bushes, whereas yellow bananas are likely to be found on treetops. In the present study, I explore whether the attentional priority afforded to reward-associated features is modulated by such location-based contingencies. The results demonstrate that when a stimulus feature is associated with a reward outcome in one spatial location but not another, attentional capture by that feature is selective to when it appears in the rewarded location. This finding provides insight into how reward learning effectively modulates attention in an environment with complex stimulus–reward contingencies, thereby supporting efficient foraging.     

低自尊个体对拒绝性信息的注意偏向

自尊是个体对自我的情感性评价, 影响着个体对周围环境的应对方式。低自尊个体由于容易知觉到外部的拒绝性信息, 也更倾向于将别人的行为知觉为拒绝, 因而存在对拒绝性信息的注意偏向。本文首先综述了低自尊个体的认知与行为特点, 其次简单介绍了低自尊个体注意偏向的常用研究范式(Stroop范式、点探测任务、空间线索任务、惊吓探测范式、注意监测任务、注意转移任务), 随后列举了解释低自尊个体注意偏向的理论(社会计量理论、关系图式理论、注意成分说、注意控制说), 最后总结了低自尊个体注意偏向的脑机制研究。未来的研究应更多关注自尊结构的复杂性, 注意偏向的信息加工阶段性及其脑机制, 注意训练的作用机制及低自尊个体注意偏向的本土研究等问题。     

Fortune and reversals of fortune in visual search: Reward contingencies for pop-out targets affect search efficiency and target repetition effects

Rewards have long been known to modulate overt behavior. But their possible impact on attentional and perceptual processes is less well documented. Here, we study whether the (changeable) reward level associated with two different pop-out targets might affect visual search and trial-to-trial target repetition effects (see Maljkovic & Nakayama, 1994). Observers searched for a target diamond shape with a singleton color among distractor diamond shapes of another color (e.g., green among red or vice versa) and then judged whether the target had a notch at its top or bottom. Correct judgments led to reward, with symbolic feedback indicating this immediately; actual rewards accumulated for receipt at study end. One particular target color led to a higher (10:1) reward for 75% of its correct judgments, whereas the other singleton target color (counterbalanced over participants) yielded the higher reward on only 25% of the trials. We measured search performance in terms of inverse efficiency (response time/proportion correct). The reward schedules not only led to better performance overall for the more rewarding target color, but also increased trial-to-trial priming for successively repeated targets in that color. The actual level of reward received on the preceding trial affected this, as did (orthogonally) the likely level. When reward schedules were reversed within blocks, without explicit instruction, corresponding reversal of the impact on search performance emerged within around 6 trials, asymptoting at around 15 trials, apparently without the observers’ explicit knowledge of the contingency. These results establish that pop-out search and target repetition effects can be influenced by target reward levels, with search performance and repetition effects dynamically tracking changes in reward contingency.     

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.     

奖赏预期调节局部注意干扰效应

局部注意干扰效应(Localized attentional interference, LAI)是指在视觉搜索任务中同时搜索在空间上分离的两个目标时, 或者目标周围存在一个无关奇异项时, 这两个关键刺激相距较近时产生的干扰现象。本实验采用视觉搜索范式, 探讨了奖赏预期对局部注意干扰效应的影响。实验1采用双目标搜索任务, 要求被试判断搜索画面中两个奇异项刺激的形状是否相同。结果显示奖赏条件和无奖赏条件都表现出显著的距离主效应, 随着目标间距离增大, 被试的正确率提高, 反应时下降。同时, 在远距离时, 奖赏条件下的正确率高于无奖赏条件, 而在近距离时, 奖赏条件下的正确率反而低于无奖赏条件, 即, 奖赏条件下局部注意干扰效应反而增大。高动机状态增强了两个目标的表征, 反而不利于解决局部注意干扰效应。实验2采用单目标搜索任务, 要求被试判断特定目标的方位并忽略另一无关奇异项刺激。与实验1不同的是, 实验2仅在无奖赏条件下观察到显著的距离主效应, 即被试行为表现在远距离时更好; 而在奖赏条件下, 被试在近距离和远距离的表现一样好, 即没有局部注意干扰效应。这说明在奖赏预期条件, 个体可以有效抑制分心物刺激的干扰, 将注意集中于目标刺激的加工, 从而对局部注意干扰效应产生调节。整个研究表明, 奖赏整体上能够提高对任务相关刺激的表征, 并抑制任务无关刺激, 虽然这并不总是能够提高任务表现。     

Valuable orientations capture attention

Visual attention has long been known to be drawn to stimuli that are physically salient or congruent with task-specific goals. Several recent studies have shown that attention is also captured by stimuli that are neither salient nor task relevant, but that are rendered in a colour that has previously been associated with reward. We investigated whether another feature dimension—orientation—can be associated with reward via learning and thereby elicit value-driven attentional capture. In a training phase, participants received a monetary reward for identifying the colour of Gabor patches exhibiting one of two target orientations. A subsequent test phase in which no reward was delivered required participants to search for Gabor patches exhibiting one of two spatial frequencies (orientation was now irrelevant to the task). Previously rewarded orientations robustly captured attention. We conclude that reward learning can imbue features other than colour—in this case, specific orientations—with persistent value.