Encoding color and shape from different parts of an object in visual short-term memory

Can we find an object-based encoding benefit in visual short-term memory (VSTM) when the features to be remembered are from different parts of an object? Using object parts defined by either figure-ground separation or negative minima of curvature, results from five experiments in which the visual change detection paradigm was used showed that the object-based encoding benefit in VSTM is modulated by how features are assigned to parts of an object: Features are best retained when the color and shape features to be remembered belong to the same part of an object. Although less well retained in comparison, features from different parts of an object are still better remembered than features from spatially separated objects. An object-based feature binding therefore exists even when the color and shape features to be remembered are from different parts of an object.     

Feature bindings endure without attention: Evidence from an explicit recall task

Are integrated objects the unit of capacity of visual working memory, or is continued attention needed to maintain bindings between independently stored features? In a delayed recall task, participants reported the color and shape of a probed item from a memory array. During the delay, attention was manipulated with an exogenous cue. Recall was elevated at validly cued positions, indicating that the cue affected item memory. On invalid trials, participants most frequently recalled either both features (perfect object memory) or neither of the two features (no object memory); the frequency with which only one feature was recalled was significantly lower than predicted by feature independence as determined in a single-feature recall task. These data do not support the view that features are remembered independently when attention is withdrawn. Instead, integrated objects are stored in visual working memory without need for continued attention.     

Priming infants to attend to color and pattern information in an individuation task

Wilcox (Cognition 72 (1999) 125) reported that infants are more sensitive to form than surface features when individuating objects in occlusion events: it is not until 7.5 months that infants spontaneously use pattern information, and 11.5 months that they spontaneously use color information, as the basis for object individuation. The present research assessed the extent to which infants' sensitivity to surface features could be increased under more supportive conditions. More specifically, we examined whether younger infants could be primed to draw on color and pattern features in an individuation task if they were first shown the functional value of attending to color and pattern information (i.e. the color or the pattern of an object predicted the function it would engage in). Five experiments were conducted with infants 4.5 to 9.5 months of age. The main findings were that 9.5- and 7.5-month-olds could be primed to use color information, and 5.5- and 4.5-month-olds could be primed to attend to pattern information, after viewing the function events. The results are discussed in terms of the kinds of experiences that can lead to increased sensitivity to surface features and the mechanisms that support feature priming in young infants.     

客体在视觉工作记忆中的存储机制

采用变化觉察范式,通过两个实验对不同类型视觉信息在工作记忆中的存储机制进行了探讨。实验一中要求记忆的客体由颜色和形状两基本特征构成;实验二中的客体为具有不同颜色及开口朝向的兰道环。通过观察检测项变化方式对记忆绩效的影响,获得以下结论:（1）对颜色和形状两基本特征的存储以整合客体为单位;（2）兰道环的颜色与开口朝向信息难以以整合客体方式存储。笔者推测,视觉工作记忆中存储的整合客体并非如现有理论假设的,是在集中注意参与下创建的,而是由并行加工阶段所获信息构成;客体中所含需集中注意提取的细节特征信息难以与其基本特征信息整合于该客体表征     

Sensory memory of illusory depth in structure-from-motion

When multistable displays (stimuli consistent with two or more equally plausible perceptual interpretations) are presented intermittently, their perceptions are stabilized by sensory memory. Independent memory traces are generated not only for different types of multistable displays (Maier, Wilke, Logothetis, & Leopold, Current Biology 13:1076–1085, 2003), but also for different ambiguous features of binocular rivalry (Pearson & Clifford, Journal of Vision 4:196–202, 2004). In the present study, we examined whether a similar independence of sensory memories is observed in structure-from-motion (SFM), a multistable display with two ambiguous properties. In SFM, a 2-D planar motion creates a vivid impression of a rotating 3-D volume. Both the illusory rotation and illusory depth (i.e., how close parts of an object appear to the observer) of an SFM object are ambiguous. We dissociated the sensory memories of these two ambiguous properties by using an intermittent presentation in combination with a forced-ambiguous-switch paradigm (Pastukhov, Vonau, & Braun, PLoS ONE 7:e37734, 2012). We demonstrated that the illusory depth of SFM generates a sensory memory trace that is independent from that of illusory rotation. Despite this independence, the specificities levels of the sensory memories were identical for illusory depth and illusory rotation. The history effect was weakened by a change in the volumetric property of a shape (whether it was a hollow band or a filled drum volume), but not by changes in color or size. We discuss how these new results constrain models of sensory memory and SFM processing.     

Object-based representations govern both the storage of information in visual short-term memory and the retrieval of information from it

Interest is growing in how information is retained in visual short-term memory (VSTM). We describe an experiment that assesses VSTM within the context of multidimensional signal detection theory. On every trial, participants were presented with a 250-ms display containing four colored shapes. They were then probed 900 ms later with a colored shape and made separate old/new judgments about the color and the shape. In any particular trial, one, both, or neither of the probed features had been presented. Performance differed according to whether both probed features belonged to a single object or to two different objects. When both probed features belonged to the same object, featural retrieval was better than would be predicted by independent feature storage. When both probed features belonged to two different objects, featural retrieval was worse than would be predicted by independent feature storage. We conclude that storage in and retrieval from VSTM operate on the basis of object-based representations.     

Retrospective cues based on object features improve visual working memory performance in older adults

Research with younger adults has shown that retrospective cues can be used to orient top-down attention toward relevant items in working memory. We examined whether older adults could take advantage of these cues to improve memory performance. Younger and older adults were presented with visual arrays of five colored shapes; during maintenance, participants were presented either with an informative cue based on an object feature (here, object shape or color) that would be probed, or with an uninformative, neutral cue. Although older adults were less accurate overall, both age groups benefited from the presentation of an informative, feature-based cue relative to a neutral cue. Surprisingly, we also observed differences in the effectiveness of shape versus color cues and their effects upon post-cue memory load. These results suggest that older adults can use top-down attention to remove irrelevant items from visual working memory, provided that task-relevant features function as cues.     

Evidence against Rank-Dependent Utility Theories: Tests of Cumulative Independence,Interval Independence,Stochastic Dominance,and Transitivity

This study tests between two modern theories of decision making. Rank- and sign-dependent utility (RSDU) models, including cumulative prospect theory (CPT), imply stochastic dominance and two cumulative independence conditions. Configural weight models, with parameters estimated in previous research, predict systematic violations of these properties for certain choices. Experimental data systematically violate all three properties, contrary to RSDU but consistent with configural weight models. This study also tests whether violations of stochastic dominance can be explained by violations of transitivity. Violations of transitivity may be evidence of a dominance detecting mechanism. Although some transitivity violations were observed, most choice triads violated stochastic dominance without violating transitivity. Judged differences between gambles were not consistent with the CPT model. Data were not consistent with the editing principles of cancellation and combination. The main findings are interpreted in terms of coalescing, the principle that equal outcomes can be combined in a gamble by adding their probabilities. RSDU models imply coalescing but configural weight models violate it, allowing configural weighting to explain violations of stochastic dominance and cumulative independence.     

多目标追踪中基于运动信息的分组效应

本研究旨在探讨运动信息对多目标追踪的影响, 具体为考察多目标追踪中是否存在基于运动信息的分组效应, 以及不同类型表面特征(颜色和形状)对这一效应的影响。实验1发现多目标追踪中存在基于运动信息的分组效应, 并且这一分组效应是自动化的。实验2和实验3分别在不同颜色和不同形状组合条件下考察了基于运动信息的分组效应的稳定性, 结果都表明不同表面特征的组合不会干扰基于运动信息的分组效应的形成, 但其效应量都因表面特征的出现而缩减。整体而言, 多目标追踪中存在基于运动信息的自动化分组效应, 并且这一效应是格式塔法则中共同命运律的具体表现, 能稳定存在于不同表面特征组合之间。     

Attentional demands and recall of verbal and color information in action events

Two experiments addressed the influence of secondary task performance at encoding on recall of different features of subject-performed tasks (SPTs) involving objects (e.g., turn the wallet). In Experiment 1, memory for verbs and colors of objects was assessed, with object names serving as cues. In Experiment 2, object and color memory were assessed, with verbs serving as cues. Results from both experiments indicated a greater deterioration of memory performance under divided attention for verbal features than for colors. In addition, intention to remember did not affect performance for any feature in either experiment. The overall pattern of outcome is discussed relative to the view that encoding of verbal features of SPTs is more attention-demanding than encoding of physical task features, such as color.     

The time course of object encoding

Four experiments examined the effects of encoding time on object identification priming and recognition memory. After viewing objects in a priming phase, participants identified objects in a rapid stream of non-object distracters; display times were gradually increased until the objects could be identified (Experiments 1-3). Participants also made old/new recognition judgments about previously viewed objects (Experiment 4). Reliable priming for object identification occurred with 150 ms of encoding and reached a maximum after about 300 ms of encoding time. In contrast, reliable recognition judgments occurred with 75 ms of encoding and continued to improve for encoding times of up to 1200 ms. These results suggest that recognition memory may be based on multiple levels of object representation, from rapidly activated representations of low-level features to semantic knowledge associated with the object. In contrast, priming in this object identification task may be tied specifically to the activation of representations of object shape.     

The benefit of surface uniformity for encoding boundary features in visual working memory

Using a change detection paradigm, the present study examined an object-based encoding benefit in visual working memory (VWM) for two boundary features (two orientations in Experiments 1-2 and two shapes in Experiments 3-4) assigned to a single object. Participants remembered more boundary features when they were conjoined into a single object of uniform color than when they were not bound together into an object. However, such an object-based benefit diminished or disappeared when those features occurred on different parts of an object, as defined by surface discontinuity or by negative minima of curvature. These results suggest that the number of boundary features that can be stored in VWM is influenced by the hierarchical structure of objects: surface uniformity facilitates the integration of two boundary features into a single object representation, but this integration is weakened when the features occur on different parts of an object.     

Internal attention to features in visual short-term memory guides object learning

Attending to objects in the world affects how we perceive and remember them. What are the consequences of attending to an object in mind? In particular, how does reporting the features of a recently seen object guide visual learning? In three experiments, observers were presented with abstract shapes in a particular color, orientation, and location. After viewing each object, observers were cued to report one feature from visual short-term memory (VSTM). In a subsequent test, observers were cued to report features of the same objects from visual long-term memory (VLTM). We tested whether reporting a feature from VSTM: (1) enhances VLTM for just that feature (practice-benefit hypothesis), (2) enhances VLTM for all features (object-based hypothesis), or (3) simultaneously enhances VLTM for that feature and suppresses VLTM for unreported features (feature-competition hypothesis). The results provided support for the feature-competition hypothesis, whereby the representation of an object in VLTM was biased towards features reported from VSTM and away from unreported features (Experiment 1). This bias could not be explained by the amount of sensory exposure or response learning (Experiment 2) and was amplified by the reporting of multiple features (Experiment 3). Taken together, these results suggest that selective internal attention induces competitive dynamics among features during visual learning, flexibly tuning object representations to align with prior mnemonic goals.     

The nonindependence of stimulus properties in human category learning

Typically, models of category learning are verified through behavioral experiments with stimuli consisting of putatively independent dimensions such as shape, size, and color. The assumption of independence is critical in both the design of behavioral experiments and the development of models and theories of learning. Using the standard classification learning paradigm and a common stimulus set, the present work demonstrates that the assumption of independence is unwarranted. Systematic relations span stimulus dimensions and govern learning performance. For example, shape is not independent of size and color, because humans quantify size and color over shape when shape is relevant to the categorization. This quantification is reflected in natural language use (e.g., "blue triangle" as opposed to "triangle and blue"). In this example, color and size are predicates and shape is the argument. Across four experiments, the difficulty of mastering a classification rule can be predicted by the number of predicates that must be unbound in order to free rule-relevant stimulus dimensions.     

Individual differences in the shape bias in preschool children with specific language impairment and typical language development: theoretical and clinical implications

We investigated whether preschool children with specific language impairment (SLI) exhibit the shape bias in word learning: the bias to generalize based on shape rather than size, color, or texture in an object naming context (‘This is a wek; find another wek’) but not in a non‐naming similarity classification context (‘See this? Which one goes with this one?’). Fifty‐four preschool children (16 with SLI, 16 children with typical language [TL] in an equated control group, and 22 additional children with TL included in individual differences analyses but not group comparisons) completed a battery of linguistic and cognitive assessments and two experiments. In Experiment 1, children made generalization choices in object naming and similarity classification contexts on separate days, from options similar to a target object in shape, color, or texture. On average, TL children exhibited the shape bias in an object naming context, but children with SLI did not. In Experiment 2, we tested whether the failure to exhibit the shape bias might be linked to ability to detect systematicities in the visual domain. Experiment 2 supported this hypothesis, in that children with SLI failed to learn simple paired visual associations that were readily learned by children with TL. Analyses of individual differences in the two studies revealed that visual paired‐associate learning predicted degree of shape bias in children with SLI and TL better than any other measure of nonverbal intelligence or standard assessments of language ability. We discuss theoretical and clinical implications.     

问题解决测验中过程数据的特征抽取与能力评估

基于计算机的问题解决测验可以实时记录被试探索环境和解决问题时的详细行动痕迹, 并保存为过程数据。首先介绍了过程数据的分析流程, 然后从问题解决测验入手, 分别对过程数据的特征抽取和能力估计建模两方面的研究进行了梳理和评价。未来研究应注意：提高分析结果的可解释性; 特征提取时纳入更多信息; 实现更复杂问题情景下的能力评估; 注重方法的实用性; 以及融合与借鉴不同领域的分析方法。     

Attention and perceptual implicit memory: effects of selective versus divided attention and number of visual objects

Extant research presents conflicting results on whether manipulations of attention during encoding affect perceptual priming. Two suggested mediating factors are type of manipulation (selective vs divided) and whether attention is manipulated across multiple objects or within a single object. Words printed in different colors (Experiment 1) or flanked by colored blocks (Experiment 2) were presented at encoding. In the full-attention condition, participants always read the word, in the unattended condition they always identified the color, and in the divided-attention conditions, participants attended to both word identity and color. Perceptual priming was assessed with perceptual identification and explicit memory with recognition. Relative to the full-attention condition, attending to color always reduced priming. Dividing attention between word identity and color, however, only disrupted priming when these attributes were presented as multiple objects (Experiment 2) but not when they were dimensions of a common object (Experiment 1). On the explicit test, manipulations of attention always affected recognition accuracy.     

Object-based attentional selection can modulate the Stroop effect

The Stroop (1935) effect is the inability to ignore a color word when the task is to report the ink color of that word (i.e., to say "green" to the word RED in green ink). The present study investigated whether object-based processing contributes to the Stroop effect. According to this view, observers are unable to ignore irrelevant features of an attended object (Kahneman & Henik, 1981). In three experiments, participants had to name the color of one of two superimposed rectangles and to ignore words that appeared in the relevant object, in the irrelevant object, or in the background. The words were congruent, neutral, or incongruent with respect to the correct color response. Words in the irrelevant object and in the background produced significant Stroop effects, consistent with earlier findings. Importantly, however, words in the relevant object produced larger Stroop effects than did the other conditions, suggesting amplified processing of all the features of an attended object. Thus, object-based processing can modulate the Stroop effect.     

图形颜色、形状及质地表征特性的研究

记忆中的图形特征既可以按一定方式被直接储存,也可以按抽象形式存储。虽然目前尚无法确定图形特征（形状、颜色等）分别以何种方式存储,但可以肯定,图形的颜色和形状可以分开表征。那么,图形的其它特征之间是否也是可以分开表征呢？该研究中的两个实验对图形的质地与形状、质地与颜色之间表征关系进行了探讨。实验结果表明,图形的质地可以分别与形状、颜色分开表征,这一结果提示,人们在记忆图形时,可以将图形的不同特征按分离方式进行加工。同时,通过对两实验结果比较发现,图形的形状、颜色和质地的记忆难度之间存在差异,形状最易,颜色最难,质地居中。