Temporal buffering and visual capacity: The time course of object formation underlies capacity limits in visual cognition

Capacity limits are a hallmark of visual cognition. The upper boundary of our ability to individuate and remember objects is well known but—despite its central role in visual information processing—not well understood. Here, we investigated the role of temporal limits in the perceptual processes of forming “object files.” Specifically, we examined the two fundamental mechanisms of object file formation—individuation and identification—by selectively interfering with visual processing by using forward and backward masking with variable stimulus onset asynchronies. While target detection was almost unaffected by these two types of masking, they showed distinct effects on the two different stages of object formation. Forward “integration” masking selectively impaired object individuation, whereas backward “interruption” masking only affected identification and the consolidation of information into visual working memory. We therefore conclude that the inherent temporal dynamics of visual information processing are an essential component in creating the capacity limits in object individuation and visual working memory.     

Feature binding in visual short term memory: A General Recognition Theory analysis

Creating and maintaining accurate bindings of elementary features (e.g., color and shape) in visual short-term memory (VSTM) is fundamental for veridical perception. How are low-level features bound in memory? The present work harnessed a multivariate model of perception – the General Recognition Theory (GRT) – to unravel the internal representations underlying feature binding in VSTM. On each trial, preview and target colored shapes were presented in succession, appearing in either repeated or altered spatial locations. Participants gave two same/different responses: one with respect to color and one with respect to shape. Converging GRT analyses on the accuracy confusion matrices provided substantial evidence for binding in the form of violations of perceptual independence at the level of the individual stimulus, such that positive correlations were obtained when both features repeated or alternated together, while negative correlations were obtained when one feature repeated and the other alternated. This “cloverleaf” GRT pattern of binding was similar whether the spatial location of the preview and target repeated or altered. The current results are consistent with: (a) the discrete memory “slots” model of VSTM, and (b) the notion that spatial location is not necessary for the formation of “object files.” The GRT approach presented here offers a viable quantitative model for testing various questions regarding feature binding in VSTM.     

Forming a stable spatial representation

The visual system sometimes fails, partially or completely, to encode and/or retrieve spatial relations among parts of an object. For example, targets can easily be confused with their mirror images, especially when they must be retained in memory. In the current experiments we ask whether our representations of spatial relations can be amended by information from different cognitive domains. Specifically, we ask whether failure to form a stable representation of spatial relations among parts can be overcome by the use of linguistic information. Four year-olds saw squares split by color and matched them after delay. In Experiment 1, children saw the target and were told either “Look, this is a blicket” (Label Condition) or “Look!” (NoLabel Condition). Then, three choices appeared: the target (e.g. vertical split with red left, green right), its mirror image, and another square that had a different internal split (e.g. horizontal). Overall, children performed better than chance. However, their errors were almost exclusively mirror image confusions, suggesting that children failed to bind color and location (e.g. red left, green right). There was no difference between the NoLabel and Label conditions, suggesting the whole-object novel label did not help children form a stable representation of the spatial relation among the parts. Experiment 2 tested whether color–location binding can be improved by providing language that might bind these features. Children were shown a target and were told, e.g. “The red is on the left.” Performance was reliably better than in Experiment 1, suggesting language did help children bind color and location. Experiments 3 and 4 explored whether the same performance improvement could be accomplished by increasing non-linguistic attention to the target (i.e. flashing the red part, Experiment 3) or by using neutral relational language (e.g. “The red is touching the green”). Neither experiment showed enhanced performance, suggesting that language can augment visual–spatial representations only if it conveys very specific information (e.g. direction). Generally, the results suggest that specific linguistic information can help form a stable representation of spatial relationship and that this effect is not attributable to general attentional effects.     

编码任务对来源记忆的影响:一项事件相关电位研究

本研究采用ERPs技术,探讨编码任务对来源记忆的影响及其神经机制。在学习阶段,被试进行两种编码操作：匹配判断任务和大小判断任务;在测验阶段,让被试进行来源判断任务。行为结果发现：在编码阶段,匹配判断任务比大小判断任务需要更长的时间;在测验阶段,匹配判断任务在“项目旧/背景旧”和“部分旧”条件的正确率显著高于大小判断任务,匹配判断任务在“项目旧/背景旧”条件的反应时显著短于大小判断任务。测验阶段ERPs结果发现：两种编码任务的新旧效应在200~700ms均有较广泛的头皮分布,而在700~1100ms呈前额皮层最大化分布;匹配判断任务的新旧效应比大小判断任务更大,表现在600~700ms的FPz电极以及700~800ms的Pz、P4电极。由此可见,在来源记忆中,编码任务影响来源记忆,主要表现在后部顶区位置;晚期前额皮层新旧效应不受任务难度因素的影响。     

Does category labeling lead to forgetting?

What effect does labeling an object as a member of a familiar category have on memory for that object? Recent studies suggest that recognition memory can be negatively impacted by categorizing objects during encoding. This paper examines the “representational shift hypothesis” which argues that categorizing an object impairs recognition memory by altering the trace of the encoded memory to be more similar to the category prototype. Previous evidence for this idea comes from experiments in which a basic-level category labeling task was compared to a non-category labeling incidental encoding task, usually a preference judgment (e.g., “Do you like this item?”). In two experiments, we examine alternative tasks that attempt to control for processing demands and the degree to which category information is explicitly recruited at the time of study. Contrary to the predictions of the representational shift hypothesis, we find no evidence that memory is selectively impaired by category labeling. Overall, the pattern of results across both studies appears consistent with well-established variables known to influence memory such as encoding specificity and distinctiveness effects.     

The interaction between surface color and color knowledge: behavioral and electrophysiological evidence

In this study, we used event-related potentials (ERPs) to evaluate the contribution of surface color and color knowledge information in object identification. We constructed two color-object verification tasks - a surface and a knowledge verification task - using high color diagnostic objects; both typical and atypical color versions of the same object were presented. Continuous electroencephalogram was recorded from 26 subjects. A cluster randomization procedure was used to explore the differences between typical and atypical color objects in each task. In the color knowledge task, we found two significant clusters that were consistent with the N350 and late positive complex (LPC) effects. Atypical color objects elicited more negative ERPs compared to typical color objects. The color effect found in the N350 time window suggests that surface color is an important cue that facilitates the selection of a stored object representation from long-term memory. Moreover, the observed LPC effect suggests that surface color activates associated semantic knowledge about the object, including color knowledge representations. We did not find any significant differences between typical and atypical color objects in the surface color verification task, which indicates that there is little contribution of color knowledge to resolve the surface color verification. Our main results suggest that surface color is an important visual cue that triggers color knowledge, thereby facilitating object identification.     

Color Vision in Alzheimer’s Patients: Can We Improve Object Recognition With Color Cues?

Sixty-three frail, elderly patients seen in a university-based outpatient geriatric assessment clinic were divided into three dementia diagnosis categories (Alzheimer’s disease, “other” dementias, cognitively intact) to investigate the use of color cues as memory aids. Recognition time was measured for three cues: (1) same color/different form; (2) same form/different color; and (3) different color/different form. Log transformed response times were longer for form cues (same color/different form) compared to color cues (different color/same form, p =.001; different color/different form, p <.001). No differences in log transformed response time were noted among dementia categories for each test condition. Color cues make a significant difference in short-term memory recall ability compared to form cues. Vivid color-coding the environment of a frail, elderly population may enhance short-term memory and improve functional ability. This may prove to be especially useful in long-term care settings, which provide services to a variety of people with differing cognitive abilities.     

Remembering “what” brings along “where” in visual working memory

Does a behavioral and anatomical division exist between spatial and object working memory? In this article, we explore this question by testing human participants in simple visual working memory tasks. We compared a condition in which there was no location change with conditions in which absolute location change and absolute plus relative location change were manipulated. The results showed that object memory was influenced by memory for relative but not for absolute location information. Furthermore, we demonstrated that relative space can be specified by a salient surrounding box or by distractor objects with no touching surfaces. Verbal memory was not influenced by any type of spatial information. Taken together, these results indicate that memory for “where” influences memory for “what.” We propose that there is an asymmetry in memory according to which object memory always contains location information.     

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     

Real-time color-frame animation for visual psychophysics on the Macintosh computer

Psychophysical experiments involving moving stimuli require the rapid presentation of animated sequences of images. Although the Macintosh computer is widely used as a color graphics computer in research laboratories, its animation capabilities are generally ignored because of the speed limitations of drawing to the screen. New off-screen color graphics structures help to avoid the speed limitations so that real-time color or gray-scale visual motion stimuli may be generated. Precomputed animation frames are stored in off-screen memory and then rapidly transferred to the screen sequentially. The off-screen graphics structures may also be saved to disk in “Picture” form as “resources” for later retrieval and playback, allowing the experimenter to build in advance a collection of moving stimuli to use in future experiments. Code examples in the C programming language are provided, and the relative strengths and weaknesses of Macin-tosh color-frame animation for psychophysical experimentation are discussed.     

Enhanced perceptual priming for neutral stimuli in a traumatic context: A pathway to intrusive memories?

Clinical observations suggest that re-experiencing symptoms are triggered by stimuli that are perceptually similar to those present shortly before the trauma or its worst moments. Two experiments investigated the possible role of perceptual priming in this phenomenon. Volunteers (N = 28, N = 62) watched a series of “traumatic” and neutral picture stories, and completed blurred object identification (priming) and recognition memory tasks. Neutral objects that immediately preceded the “traumatic” stories were more strongly primed, but not better recognised, than objects from neutral stories. Enhanced priming predicted subsequent re-experiencing symptoms. The results support the role of perceptual priming in re-experiencing.     

Behavioral evidence for task-dependent “what” versus “where” processing within and across modalities

Task-dependent information processing for the purpose of recognition or spatial perception is considered a principle common to all the main sensory modalities. Using a dual-task interference paradigm, we investigated the behavioral effects of independent information processing for shape identification and localization of object features within and across vision and touch. In Experiment 1, we established that color and texture processing (i.e., a “what” task) interfered with both visual and haptic shape-matching tasks and that mirror image and rotation matching (i.e., a “where” task) interfered with a feature-location-matching task in both modalities. In contrast, interference was reduced when a “where” interference task was embedded in a “what” primary task and vice versa. In Experiment 2, we replicated this finding within each modality, using the same interference and primary tasks throughout. In Experiment 3, the interference tasks were always conducted in a modality other than the primary task modality. Here, we found that resources for identification and spatial localization are independent of modality. Our findings further suggest that multisensory resources for shape recognition also involve resources for spatial localization. These results extend recent neuropsychological and neuroimaging findings and have important implications for our understanding of high-level information processing across the human sensory systems.     

Influence of object size on baseline identification, priming, and explicit memory

We investigated the influence of size on identification, priming, and explicit memory for color photos of common objects. Participants studied objects displayed in small, medium, and large sizes and memory was assessed with both implicit identification and explicit recognition tests. Overall, large objects were easier to identify than small objects and study-to-test changes in object size impeded performance on explicit but not implicit memory tests. In contrast to previous findings with line-drawings of objects but consistent with predictions from the distance-as-filtering hypothesis, we found that study-test size manipulations had large effects on old/new recognition memory test for objects displayed in large size at test but not for objects displayed small or medium at test. Our findings add to the growing body of literature showing that the findings obtained using line-drawings of objects do not necessarily generalize to color photos of common objects. We discuss implications of our findings for theories of object perception, memory, and eyewitness identification accuracy for objects.     

The schema provokes a disparity of false recollection between actions and objects in an everyday scene

We explored the effect of the schema on recognition memories and subjective experiences for actions and objects in an everyday scene. At first, participants watched slides of a man cooking in a kitchen. The man performed schema‐consistent actions, and schema‐consistent objects were left. After watching the slides, participants completed a recognition test, a remember/know test, and a Perception/Thought/Emotion/Context questionnaire. We confirmed three main results. First, participants made more false recognitions for schema‐consistent distracters than for schema‐inconsistent distracters with more “remember” judgments accompanied by perceptual, thought, and contextual details, and with more “know” judgments. Second, participants made more false recognitions for schema‐consistent object distracters than for schema‐consistent action distracters. Third, participants more frequently recognized schema‐consistent action targets than schema‐consistent object targets with more “remember” judgments. Both action memory and object memory were reconstructed under the schema, provoking false recognitions for schema‐consistent distracters. However, the memories of schema‐consistent action targets were so recollective that they could prevent false recognitions for schema‐consistent action distracters.     

Object color affects identification and repetition priming

We investigated the influence of color on the identification of both non-studied and studied objects. Participants studied black and white and color photos of common objects and memory was assessed with an identification test. Consistent with our meta-analysis of prior research, we found that objects were easier to identify from color than from black and white photos. We also found substantial priming in all conditions, and study-to-test changes in an object's color reduced the magnitude of priming. Color-specific priming effects were large for color-complex objects, but minimal for color-simple objects. The pattern and magnitude of priming effects was not influenced either by the extent to which an object always appears in the same color (i.e., whether a color is symptomatic of an object) or by the object's origin (natural versus fabricated). We discuss the implications of our findings for theoretical accounts of object perception and repetition priming.     

物体颜色对情景记忆的影响

本研究采用ERP技术和学习-再认范式考察视觉输入的颜色和记忆中的物体颜色知识一致性对情景记忆编码和提取的影响。结果显示, 在对物体图片进行编码时颜色不一致图片诱发更大N400, 而提取阶段则对颜色一致图片有更多熟悉性加工(实验1); 物体名称能够更快激活典型颜色知识, 对颜色一致名称有更多细节回想(LPC更正) (实验2)。实验结果表明, 颜色一致促进知觉水平的记忆编码, 而阻碍语义水平编码。同时, 颜色一致促进物体图片提取(知觉水平)中的熟悉性和回想过程; 而对物体名称提取(概念水平)的促进作用仅表现在回想上。此外, 颜色与物体名称有着密切联系, 同样影响物体的语义表征, 支持激活-扩散模型理论。本研究从知觉和概念水平上为揭示物体颜色在联结记忆中的作用提供了证据。     

Higher body mass index is associated with episodic memory deficits in young adults

Obesity has become an international health crisis. There is accumulating evidence that excess bodyweight is associated with changes to the structure and function of the brain and with a number of cognitive deficits. In particular, research suggests that obesity is associated with hippocampal and frontal lobe dysfunction, which would be predicted to impact memory. However, evidence for such memory impairment is currently limited. We hypothesised that higher body mass index (BMI) would be associated with reduced performance on a test of episodic memory that assesses not only content, but also context and feature integration. A total of 50 participants aged 18–35 years, with BMIs ranging from 18 to 51, were tested on a novel what–where–when style episodic memory test: the “Treasure-Hunt Task”. This test requires recollection of object, location, and temporal order information within the same paradigm, as well as testing the ability to integrate these features into a single event recollection. Higher BMI was associated with significantly lower performance on the what–where–when (WWW) memory task and all individual elements: object identification, location memory, and temporal order memory. After controlling for age, sex, and years in education, the effect of BMI on the individual what, where, and when tasks remained, while the WWW dropped below significance. This finding of episodic memory deficits in obesity is of concern given the emerging evidence for a role for episodic cognition in appetite regulation.     

Holding in Mind Conflicting Information: Pretending,Working Memory,and Executive Control

Preschoolers' recall of the true and pretend identities of an object in pretense was examined along with a battery of executive functioning and working memory tasks. We expected that children would retain separate identities, as well as a link between them, after observing episodes of pretense, and that memory for pretense would be related to executive functioning and working memory. Children (aged 37–59 months) recalled the true identity of an object better than its pretend identity. Children's recall of at least one identity was correlated with executive functioning and “dual” working memory tasks, independent of age and verbal ability. Memory for both identities was only correlated with executive functioning. The findings are generally supportive of the claim that children form separate representations of the true and pretend identities of objects. The results extend findings of well-established relations between false belief tasks and executive functioning and working memory.     

The Symbolic Object

Abstract

The term “symbolic object” is introduced as a way to understand the moments between analyst and patient where “something” new and dynamic emerges within the dyadic relationship. The symbolic object is the bridge between the idealized, all-good object and symbolization proper. The intrapsychic atmosphere between self and object representations is in a relatively non-conflicted state during this process. By reformulating the Nirvana principle and the principle of constancy as ways in which the organism economically strives for the most organized and homoeostatic state possible, the infant or adult can be seen to be searching for the position of lowest unpleasure possible. This is the optimum balance between the libidinal and aggressive forces in the self and object representational field. These moments of “truce” between often highly conflicted phantasies usher in a more refined use of projective identification as a form of intrapsychic/interpersonal communication. This is a particular atmosphere from which both parties, within the projective/introjective, back-and-forth dyadic world, can begin to co-create and rediscover assorted amalgams of self and object functioning. This newly awakened psychic entity is the symbolic object. This outgrowth of something fresh to the dyadic orbit is a mutative moment that propels the relationship into a different direction. Within the pairing of minds, a novel and mutual understanding is produced. Both parties share this new symbolic object and each is shaped by it.     

连续报告任务中无效后线索对后线索效益的影响

本文采用连续报告任务,从非线索指示项目的角度入手,探讨无效后线索的存在是否会影响后线索效应的产生,以此进一步了解“后线索效益”的产生机制。结果表明,无论采用空间后注意线索,还是非空间的颜色后注意线索,都产生了“后线索效益”,即后线索确实提高了被试视觉工作记忆的表现。无效后线索的存在不会影响“后线索效益”的产生,该效益的理论解释符合优先提取说,即被试会利用后注意线索优先提取线索指示项目,产生更快和更准确的反应。