真实场景视觉搜索中的背景线索效应特点与机制

背景线索效应揭示了个体在视觉搜索过程中对刺激之间具有的稳定空间关系（刺激间不变的相对空间位置）的学习能够提高搜索效率。本文基于经典背景线索效应在内隐习得空间布局的机制下结合真实场景视觉搜索的相关理论，对真实场景背景线索效应的实验范式、学习性质与内容进行归纳梳理，将真实场景视觉搜索中影响背景线索效应的视觉信息分为低水平物理特征及高水平语义信息两个维度进行论述。虽然当前研究涉及真实场景背景线索效应在不同场景维度信息的加工机制，但对于发挥作用的场景信息类别以及作用阶段还较少涉及，未来研究仍需进一步的探讨。     

基于双眼视差探讨深度知觉信息对背景线索效应的影响

背景线索效应是由重复场景导致搜索效率提高的现象。以往研究发现三维场景下能获得背景线索效应,但对三维场景下深度知觉线索信息如何影响空间场景提供有效线索引导注意仍缺乏实证研究。本研究以矩阵刺激为材料,通过设置不同的刺激项目水平数探讨深度知觉线索对背景线索效应的影响模式。结果发现:(1)在场景布局由较少项目构成时,深度知觉线索提供目标与刺激项目的有效联结,获得背景线索效应;(2)当刺激项目水平达到一定程度时,深度知觉线索增加了背景线索任务的搜索难度,干扰了重复场景中的背景信息对注意的指导性加工,背景线索效应消失。研究结果为三维场景下深度信息对空间场景中注意引导加工的影响提供了证据。     

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。     

背景线索和认知风格对真实场景中目标搜索影响的眼动研究

采用眼动记录方法,研究背景线索和认知风格对真实场景中目标搜索三阶段的影响。实验以真实的室内场景图片为材料,通过重复呈现整体背景一致或局部背景一致的场景,考察不同场认知风格被试在整体背景线索和局部背景线索条件下在目标搜索各阶段的眼动特征。结果表明,整体背景线索和局部背景线索对目标搜索的启动和确认阶段没有影响,对扫描阶段有促进作用,且整体背景线索效应大于局部背景线索效应,主要体现在能更有效地选择注视区域,在单次注视中获得更多的信息,更迅速地拒绝当前注视区域和计划下一次眼跳;认知风格不影响个体在真实场景目标搜索过程中对背景线索的利用。     

视觉搜索中风味引发对关联颜色的注意偏向

人们常将特定的颜色与风味联系起来形成色味联结, 而且颜色线索会影响风味感知, 这体现了视觉信息对味觉信息加工的跨通道影响。本研究通过两个行为实验, 考察了味觉信息是否也会影响视觉搜索。实验任务要求被试品尝饮品后对形状靶子进行视觉搜索, 并且操纵了味觉刺激的提示性以及靶子颜色与风味之间的关联性。实验1的结果表明, 当风味线索提示的靶子颜色是与风味关联的颜色时可以加快视觉搜索。但如果与该风味关联的颜色出现在干扰项上, 风味线索则无法促进视觉搜索。其后, 我们在实验2中排除了语义启动的混淆, 也发现了与实验1一致的结果。本研究的结果表明, 风味线索会引发对关联颜色的注意偏向, 证实了味觉刺激对视觉注意的跨通道影响, 为色味交互提供了新的实验证据, 揭示了跨通道影响可能的发生机制。     

奖赏性线索启动和调控视觉搜索额顶网络的神经机制

近期关于奖赏性信息与视觉搜索任务的交互作用研究体现在两个层面, 其一是施加外部奖赏能够影响被试的视觉搜索反应时和正确率, 其二是搜索目标本身具有奖赏特性也能够影响行为反应。但是, 奖赏性信息对负责视觉搜索的额顶注意网络的动态启动和调控作用仍不清楚。本研究结合Posner空间预提示范式和视觉搜索范式, 采用快速事件相关功能磁共振成像技术, 分别操纵线索提示阶段的线索奖赏属性(奖赏性vs.非奖赏性)和线索空间注意属性(有效提示目标位置vs.无效提示目标位置), 并操纵目标搜索阶段的目标属性(奖赏性vs.非奖赏性), 探讨以下两个核心问题：(1)在线索提示阶段, 奖赏性线索产生的自上而下注意准备信号的神经基础, 以及该神经基础与传统的空间注意准备信号的异同; (2)在目标搜索阶段, 奖赏性线索对负责视觉搜索的额顶注意网络产生的启动和调控作用, 重点考察对正确的奖赏性信息的定向过程和对错误的奖赏性信息的重新定向过程。     

在真实场景中记忆对学龄儿童注意的导向

采用背景线索范式,探讨在真实场景中记忆对学龄儿童的注意导向。结果发现：（1）搜索任务中,学龄儿童在重复场景中的目标搜索随着学习阶段的增加而得到促进,获得显著的背景线索效应,但在新异场景中却没有出现。（2）回忆任务中,学龄儿童对重复场景及其共变目标位置的记忆好于对新异场景的,且显著地高于随机水平。结果表明,在真实场景中,对背景及目标-背景共变关系的记忆引导着学龄儿童的注意分布,且该引导随着经验的增加而变得更有效;该记忆具有外显性。     

非注意状态下拓扑性质优先加工的电生理学证据

采用ERP技术并运用跨通路延迟反应范式来探讨拓扑性质知觉理论在非注意状态下是否成立,发现存在视觉MMN且视觉系统在非注意状态下对拓扑性质的加工比颜色加工更早,表明与局部属性(颜色)相比,拓扑性质在无意识中优先得到加工,拓扑性质知觉理论在非注意状态下是成立的。     

幼儿地图定向任务中几何线索的运用及发展

几何线索对儿童理解地图与现实空间之间的对应关系具重要意义。目前研究以几何地图为材料,通过定向任务,考察儿童对不同几何线索(拓扑关系、欧式几何特征、度量结构)的利用与发展,揭示了儿童对地图与现实空间之间对应关系的认知过程。研究发现,3岁儿童已初步发展出使用欧氏几何特征和度量结构表征空间位置的能力;但不同欧式几何特征(相对距离、角度、方向)被儿童掌握的时间存在明显差别;关于拓扑关系的研究较少,尚未掌握儿童利用该线索的发展规律。提高生态效度是未来研究需解决的主要问题。     

拓扑几何在知觉组织与空间概念形成中的运用

陈霖的拓扑知觉理论运用几何性质解释知觉组织,并强调拓扑性质的优先性——拓扑知觉是其他几何知觉的基础,拓扑知觉先于其他几何知觉发生。皮亚杰的拓扑首位理论认为儿童的空间概念发展顺序为先发展拓扑几何概念,之后再发展射影与欧式几何概念。两大理论都运用拓扑性质来解释心理现象,其研究对象、研究方法存在很大不同,但它们在理论结构上具有高度一致性,对几何学在心理学上的运用有非常重要的启示意义。     

Awareness in contextual cuing with extended and concurrent explicit tests

The term contextual cuing refers to improved visual search performance with repeated exposure to a configuration of objects. Participants use predictive cues-derived from learned associations between target locations and the spatial arrangement of the surrounding distractors in a configuration--to efficiently guide search behavior. Researchers have claimed that contextual cuing can occur implicitly. The present experiments examined two explicit measures--generation and recognition. In Experiment 1, we found that contextual cuing information was consciously retrievable when the number of trials used in a generation test was increased, and the results also suggested that the shorter tests that were used previously were not statistically powerful enough to detect a true awareness effect. In Experiment 2, concurrent implicit and explicit (generation and recognition) tests were employed. At a group level, learning did not precede awareness. Although contextual cuing was evident in participants who were selected post hoc as having no explicit awareness, and for specific configurations that did not support awareness, we argue that awareness may nevertheless be a necessary concomitant of contextual cuing. These results demonstrate that contextual cuing knowledge is accessible to awareness.     

Selective learning of spatial configuration and object identity in visual search

To conduct an efficient visual search, visual attention must be guided to a target appropriately. Previous studies have suggested that attention can be quickly guided to a target when the spatial configurations of search objects or the object identities have been repeated. This phenomenon is termed contextual cuing. In this study, we investigated the effect of learning spatial configurations, object identities, and a combination of both configurations and identities on visual search. The results indicated that participants could learn the contexts of spatial configurations, but not of object identities, even when both configurations and identities were completely correlated (Experiment 1). On the other hand, when only object identities were repeated, an effect of identity learning could be observed (Experiment 2). Furthermore, an additive effect of configuration learning and identity learning was observed when, in some trials, each context was the relevant cue for predicting the target (Experiment 3). Participants could learn only the context that was associated with target location (Experiment 4). These findings indicate that when multiple contexts are redundant, contextual learning occurs selectively, depending on the predictability of the target location.     

Use of spatial context is restricted by relative position in implicit learning

For inefficient search, target detection is faster for repeated than for regenerated layouts. This effect, calledcontextual cuing, was assumed to arise from implicit learning of local spatial relationships between targets and distractors. However, a more global influence from distractors far from the target has not been tested. In this study, the search field was divided into upper and lower halves containing a repeated and a regenerated configuration set, respectively. The positions of the two sets were or were not exchanged, meaning that their relative as well as their absolute positions were the same or different (Experiment 1). In Experiment 2, the repeated set appeared alone in either the same or the other half of the screen (same or different absolute position). The contextual cuing effect remained when only absolute position was changed, but not when both absolute and relative positions were changed. These results suggest that contextual cuing depends on relative positional information.     

Contextual cuing based on spatial arrangement of color

Previous studies have demonstrated that, in visual search, repetition of a target's "context" significantly improves search performance (contextual cuing; Chun & Jiang, 1998). Context in those studies was defined as either spatial configuration or featural combination. In the present work, we demonstrate that repeating the spatial arrangement of object colors (conjunction of spatial configuration and featural combination) also leads to contextual cuing (Experiment 1). Experiments 2 and 3 rule out the possibility that the contextual cuing we find in Experiment 1 is caused only by the spatial configuration of color patches. Experiment 4 rules out the possibility that it is caused only by featural combination. Experiments 5 and 6 demonstrate that color-arrangement-based contextual cuing is an unconscious process. Experiments 7 and 8 demonstrate that contextual cuing seems to be more effective onchromatic (hue) variation than on achromatic (luminance) variation. In sum, our results demonstrate that contextual cuing is not merely associated learning in separate domains; it is a more integrated process than has perhaps been appreciated.     

Implicit,long-term spatial contextual memory

Learning and memory of novel spatial configurations aids behaviors such as visual search through an implicit process called contextual cuing (M. M. Chun & Y. Jiang, 1998). The present study provides rigorous tests of the implicit nature ofcontextual cuing. Experiment 1 used a recognition test that closely matched the learning task, confirming that memory traces of predictive spatial context were not accessible to conscious retrieval. Experiment 2 gave explicit instructions to encode visual context during learning, but learning was not improved and conscious memory remained undetectable. Experiment 3 illustrates that memory traces for spatial context may persist for at least 1 week, suggesting along-term component of contextual cuing. These experiments indicate that the learning and memory of spatial context in the contextual cuing task are indeed implicit. The results have implications for understanding the neural substrate of spatial contextual learning, which may depend on an intact medial temporal lobe system that includes the hippocampus (Mi. M. Chun & E. A. Phelps, 1999).     

What is learned in spatial contextual cuing— configuration or individual locations?

With the use of spatial contextual cuing, we tested whether subjects learned to associate target locations with overall configurations of distractors or with individual locations of distractors. In Experiment 1, subjects were trained on 36 visual search displays that contained 36 sets of distractor locations and 18 target locations. Each target location was paired with two sets of distractor locations on separate trials. After training, the subjects showed perfect transfer to recombined displays, which were created by combining half of one trained distractor set with half of another trained distractor set. This result suggests that individual distractor locations were sufficient to cue the target location. In Experiment 2, the subjects showed good transfer from trained displays to rescaled, displaced, and perceptually regrouped displays, suggesting that the relative locations among items were also learned. Thus, both individual target-distractor associations and configural associations are learned in contextual cuing.     

What is learned in spatial contextual cuing--configuration or individual locations?

With the use of spatial contextual cuing, we tested whether subjects learned to associate target locations with overall configurations of distractors or with individual locations of distractors. In Experiment 1, subjects were trained on 36 visual search displays that contained 36 sets of distractor locations and 18 target locations. Each target location was paired with two sets of distractor locations on separate trials. After training, the subjects showed perfect transfer to recombined displays, which were created by combining half of one trained distractor set with half of another trained distractor set. This result suggests that individual distractor locations were sufficient to cue the target location. In Experiment 2, the subjects showed good transfer from trained displays to rescaled, displaced, and perceptually regrouped displays, suggesting that the relative locations among items were also learned. Thus, both individual target-distractor associations and configural associations are learned in contextual cuing.     

Response time modeling reveals multiple contextual cuing mechanisms

Contextual cuing refers to a response time (RT) benefit that occurs when observers search through displays that have been repeated over the course of an experiment. Although it is generally agreed that contextual cuing arises via an associative learning mechanism, there is uncertainty about the type(s) of process(es) that allow learning to influence RT. We contrast two leading accounts of the contextual cuing effect that differ in terms of the general process that is credited with producing the effect. The first, the expedited search account, attributes the cuing effect to an increase in the speed with which the target is acquired. The second, the decision threshold account, attributes the cuing effect to a reduction in the response threshold used by observers when making a subsequent decision about the target (e.g., judging its orientation). We use the diffusion model to contrast the quantitative predictions of these two accounts at the level of individual observers. Our use of the diffusion model allows us to also explore a novel decision-level locus of the cuing effect based on perceptual learning. This novel account attributes the RT benefit to a perceptual learning process that increases the quality of information used to drive the decision process. Our results reveal both individual differences in the process(es) involved in contextual cuing but also identify several striking regularities across observers. We find strong support for both the decision threshold account as well as the novel perceptual learning account. We find relatively weak support for the expedited search account.     

Does contextual cuing guide the deployment of attention?

Contextual cuing experiments show that when displays are repeated, reaction times to find a target decrease over time even when observers are not aware of the repetition. It has been thought that the context of the display guides attention to the target. The authors tested this hypothesis by comparing the effects of guidance in a standard search task with the effects of contextual cuing. First, in standard search, an improvement in guidance causes search slopes (derived from Reaction Time x Set Size functions) to decrease. In contrast, the authors found that search slopes in contextual cuing did not become more efficient over time (Experiment 1). Second, when guidance was optimal (e.g., in easy feature search), they still found a small but reliable contextual cuing effect (Experiments 2a and 2b), suggesting that other factors, such as response selection, contribute to the effect. Experiment 3 supported this hypothesis by showing that the contextual cuing effect disappeared when the authors added interference to the response selection process. Overall, the data suggest that the relationship between guidance and contextual cuing is weak and that response selection can account for part of the effect.     

Spatial constraints on learning in visual search: modeling contextual cuing

Predictive visual context facilitates visual search, a benefit termed contextual cuing (M. M. Chun & Y. Jiang, 1998). In the original task, search arrays were repeated across blocks such that the spatial configuration (context) of all of the distractors in a display predicted an embedded target location. The authors modeled existing results using a connectionist architecture and then designed new behavioral experiments to test the model's assumptions. The modeling and behavioral results indicate that learning may be restricted to the local context even when the entire configuration is predictive of target location. Local learning constrains how much guidance is produced by contextual cuing. The modeling and new data also demonstrate that local learning requires that the local context maintain its location in the overall global context.