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.     

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.     

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).     

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.     

Selective attention modulates implicit learning

The effect of selective attention on implicit learning was tested in four experiments using the "contextual cueing" paradigm (Chun & Jiang, 1998, 1999). Observers performed visual search through items presented in an attended colour (e.g., red) and an ignored colour (e.g., green). When the spatial configuration of items in the attended colour was invariant and was consistently paired with a target location, visual search was facilitated, showing contextual cueing (Experiments 1, 3, and 4). In contrast, repeating and pairing the configuration of the ignored items with the target location resulted in no contextual cueing (Experiments 2 and 4). We conclude that implicit learning is robust only when relevant, predictive information is selectively attended.     

Probabilities in implicit learning

The visual system possesses a remarkable ability in learning regularities from the environment. In the case of contextual cuing, predictive visual contexts such as spatial configurations are implicitly learned, retained, and used to facilitate visual search-all without one's subjective awareness and conscious effort. Here we investigated whether implicit learning and its facilitatory effects are sensitive to the statistical property of such implicit knowledge. In other words, are highly probable events learned better than less probable ones even when such learning is implicit? We systematically varied the frequencies of context repetition to alter the degrees of learning. Our results showed that search efficiency increased consistently as contextual probabilities increased. Thus, the visual contexts, along with their probability of occurrences, were both picked up by the visual system. Furthermore, even when the total number of exposures was held constant between each probability, the highest probability still enjoyed a greater cuing effect, suggesting that the temporal aspect of implicit learning is also an important factor to consider in addition to the effect of mere frequency. Together, these findings suggest that implicit learning, although bypassing observers' conscious encoding and retrieval effort, behaves much like explicit learning in the sense that its facilitatory effect also varies as a function of its associative strengths.     

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.     

Attentional guidance of the eyes by contextual information and abrupt onsets.

Contextual cuing is a memory-based phenomenon in which previously encountered global pattern information in a display can automatically guide attention to the location of a target (Chun & Jiang, 1998), leading to rapid and accurate responses. What is not clear is how contextual cuing works. By monitoring eye movements, we investigated the roles that recognition and guidance play in contextual cuing. Recognition does not appear to occur on every trial and sometimes does not have its effects until later in the search process. When recognition does occur, attention is guided straight to the target rather than in the general direction. In Experiment 2, we investigated the interaction between memory-driven search (contextual cuing) and stimulus-driven attentional capture by abrupt onsets. Contextual cuing was able to override capture by abrupt onsets. In contrast, onsets had almost no effect on the degree of contextual cuing. These data are discussed in terms of the role of top-down and bottom-up factors in the guidance of attention in visual search.     

Categorical implicit learning in real-world scenes: evidence from contextual cueing

The present study examined the extent to which learning mechanisms are deployed on semantic-categorical regularities during a visual searching within real-world scenes. The contextual cueing paradigm was used with photographs of indoor scenes in which the semantic category did or did not predict the target position on the screen. No evidence of a facilitation effect was observed in the predictive condition compared to the nonpredictive condition when participants were merely instructed to search for a target T or L (Experiment 1). However, a rapid contextual cueing effect occurred when each display containing the search target was preceded by a preview of the scene on which participants had to make a decision regarding the scene's category (Experiment 2). A follow-up explicit memory task indicated that this benefit resulted from implicit learning. Similar implicit contextual cueing effects were also obtained when the scene to categorize was different from the subsequent search scene (Experiment 3) and when a mere preview of the search scene preceded the visual searching (Experiment 4). These results suggested that if enhancing the processing of the scene was required with the present material, such implicit semantic learning can nevertheless take place when the category is task irrelevant.     

Local contextual cuing in visual search

Previous research has indicated that covariations between the global layout of search displays and target locations result in contextual cuing: the global context guides attention to probable target locations. The present experiments extend these findings by showing that local redundancies also facilitate visual search. Participants searched for randomly located targets in invariant homogenous displays, i.e., the global context provided information neither about the location nor about the identity of the target. The only redundancy referred to spatial relations between the targets and certain distractors: Two of the distractors were frequently presented next to the targets. In four of five experiments, targets with frequent flankers were detected faster than targets with rare flankers. The data suggest that this local contextual cuing does not depend on awareness of the redundant local topography but needs the redundantly related stimuli to be attended to.     

Age,skill, and contextual cuing in target detection

This study examined the extent to which structural regularities inherent in visual arrays help to guide target detection and reduce age-related differences in skilled visual search performance. The target-detection performance of medical laboratory technologists in 2 age groups (M = 24.3 years and M = 49.0 years) and age-matched novices was assessed using images of bacterial morphology taken from Gram's stain photomicrographs as targets and search arrays. For skilled observers, response times were longer for middle-aged adults than for young adults except when external location cues were available, or when contextual cues inherent in the array were available to guide target detection. These results demonstrate that contextual information aids the skilled search of middle-aged experts, and suggest that contextual cuing is 1 means by which middle-aged adults can circumvent the effects of normally age-deficient processes on performance in a skilled domain.     

物体拓扑性质对背景线索效应的影响及其加工机制

背景线索效应是指在视觉搜索中由于场景的重复曝光而产生的行为便利。而以往研究关注于刺激的欧式性质所代表的属性信息对背景线索效应的影响, 然而在视知觉加工过程中扮演重要角色的拓扑性质对背景线索效应的影响仍缺乏相关实证研究。因此, 研究采用视觉搜索任务, 通过操控不同场景中刺激的拓扑性质或欧式性质的变化, 考察拓扑性质与欧式性质两种属性信息对背景线索效应的调制。结果发现：(1)拓扑性质和欧式性质与目标之间的联结关系均可促进行为反应, 获得背景线索效应; (2)视觉学习机制对拓扑性质的重复性更加敏感, 并且拓扑性质与目标之间联结关系的稳定性相对于欧式性质与目标之间的联结关系稳定性对于背景线索效应的获得具有更为重要的意义。     

Attentional prioritization to contextually new objects

Using a hybrid paradigm of a contextual cuing task and a probe detection task, we tested whether or not contextually new objects can be prioritized in visual search. After several hundred visual search practice trials with repeated and nonrepeated layouts, an additional distractor that was contextually new was presented in the repeated layouts. The results showed that detection of probe dots appearing at the location of a search target was faster in the repeated than in the nonrepeated layouts. More importantly, detection of probe dots at the new object locations was as fast as that of probe dots at the target locations in repeated layouts, suggesting that the attentional system implicitly prioritizes the processing of a location where a change in contextual information has occurred.     

Contextual cueing in 3D layouts defined by binocular disparity

Under incidental learning conditions, a spatial layout can be acquired implicitly and facilitates visual search (the contextual cueing effect; Chun & Jiang, 1998). We investigated two aspects of this effect: Whether spatial layouts of a 3D display are encoded automatically or require selective processing (Experiment 1), and whether the learned layouts are limited to 2D configurations or can encompass three dimensions (Experiment 2). In Experiment 1, participants searched for a target presented only in a specific depth plane. Contextual cueing effect was obtained only when the location of the items in the attended plane was invariant and consistently paired with a target location. In contrast, repeating and pairing the layout of the ignored items with the target location did not produce a contextual cueing effect. In Experiment 2, we found that reaction times for the repeated condition increased significantly when the disparity of the repeated distractors was reversed in the last block of trials. These results indicate that contextual cueing in 3D displays occurs when the layout is relevant and selectively attended, and that 3D layouts can be preserved as an implicit visual spatial context.     

Top‐down contextual knowledge guides visual attention in infancy

The visual context in which an object or face resides can provide useful top‐down information for guiding attention orienting, object recognition, and visual search. Although infants have demonstrated sensitivity to covariation in spatial arrays, it is presently unclear whether they can use rapidly acquired contextual knowledge to guide attention during visual search. In this eye‐tracking experiment, 6‐ and 10‐month‐old infants searched for a target face hidden among colorful distracter shapes. Targets appeared in Old or New visual contexts, depending on whether the visual search arrays (defined by the spatial configuration, shape and color of component items in the search display) were repeated or newly generated throughout the experiment. Targets in Old contexts appeared in the same location within the same configuration, such that context covaried with target location. Both 6‐ and 10‐month‐olds successfully distinguished between Old and New contexts, exhibiting faster search times, fewer looks at distracters, and more anticipation of targets when contexts repeated. This initial demonstration of contextual cueing effects in infants indicates that they can use top‐down information to facilitate orienting during memory‐guided visual search.     

Intertrial temporal contextual cuing: association across successive visual search trials guides spatial attention

Contextual cuing refers to the facilitation of performance in visual search due to the repetition of the same displays. Whereas previous studies have focused on contextual cuing within single-search trials, this study tested whether 1 trial facilitates visual search of the next trial. Participants searched for a T among Ls. In the training phase, the spatial layout on trial N=1 was predictive of the target location on trial N. In the testing phase, the predictive value was removed. Results revealed an intertrial temporal contextual cuing effect: Search speed became progressively shorter in the training phase, but it significantly lengthened during testing. The authors conclude that the visual system is capable of retaining spatial contextual memory established earlier to facilitate perception.     

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。     

Region segmentation and contextual cuing

Contextual information provides an important source for behavioral orienting. For instance, in the contextualcuing paradigm, repetitions of the spatial layout of elements in a search display can guide attention to the target location. The present study explored how this contextual-cuing effect is influenced by the grouping of search elements. In Experiment 1, four nontarget items could be arranged collinearly to form an imaginary square. The presence of such a square eliminated the contextual-cuing effect, despite the fact that the square’s location still had a predictive value for the target location. Three follow-up experiments demonstrated that other types of grouping abolished contextual cuing in a similar way and that the mere presence of a task-irrelevant singleton had only a diminishing effect (by half ) on contextual cuing. These findings suggest that a segmented, salient region can interfere with contextual cuing, reducing its predictive impact on search.