Episodic representation of diagnostic and nondiagnostic object colour

In three experiments, we investigated transsaccadic object file representations. In each experiment, participants moved their eyes from a central fixation cross to a saccade target located between two peripheral objects. During the saccade, this preview display was replaced with a target display containing a single object to be named. On trials in which the target identity matched one of the preview objects, its colour either matched or did not match the previewed object colour. The results indicated that colour changes disrupt perceptual continuity, but only for the class of objects for which colour is diagnostic of object identity. When the colour is not integral to identifying an object (for example, when the object is a letter or an object without a characteristic colour), object continuity is preserved regardless of changes to the object's colour. These results suggest that object features that are important for defining the object are incorporated into its episodic representation. Furthermore, the results are consistent with previous work showing that the quality of a feature's representation determines its importance in preserving continuity.     

物体表征强度对基于动态物体的注意的影响

基于物体的注意已得到许多静态物体实验的证实, 然而, 对注意分配如何受动态物体影响的研究较少, 存在提示物体假设和动态更新假设两种观点。提示物体假设认为基于物体的注意由最初的物体决定, 而动态更新假设则认为由变化之后的物体决定。动态物体的注意研究还发现了即时物体效应, 即注意基于新物体进行。对于物体变化时注意究竟基于旧物体还是新物体, 新旧物体的相对物体表征强度在其中起决定作用; 当提示物体表征较强时表现为提示物体(即旧物体)决定注意分配, 而当即时物体表征较强时表现为即时物体(即新物体)决定注意分配。相对物体表征强度的概念对理解物体动态变化情况下基于物体的注意的分配以及解决相关理论之冲突可能有重要作用。     

Parts, cavities, and object representation in infancy

Part representation is not only critical to object perception but also plays a key role in a number of basic visual cognition functions, such as figure-ground segregation, allocation of attention, and memory for shapes. Yet, virtually nothing is known about the development of part representation. If parts are fundamental components of object shape representation early in life, then the infant visual system should give priority to parts over other aspects of objects. We tested this hypothesis by examining whether part shapes are more salient than cavity shapes to infants. Five-month-olds were habituated to a stimulus that contained a part and a cavity. In a subsequent novelty preference test, 5-month-olds exhibited a preference for the cavity shape, indicating that part shapes were more salient than cavity shapes during habituation. The differential processing of part versus cavity contours in infancy is consistent with theory and empirical findings in the literature on adult figure-ground perception and indicates that basic aspects of part-based object processing are evident early in life.     

The role of color diagnosticity in object recognition and representation

The role of color diagnosticity in object recognition and representation was assessed in three Experiments. In Experiment 1a, participants named pictured objects that were strongly associated with a particular color (e.g., pumpkin and orange). Stimuli were presented in a congruent color, incongruent color, or grayscale. Results indicated that congruent color facilitated naming time, incongruent color impeded naming time, and naming times for grayscale items were situated between the congruent and incongruent conditions. Experiment 1b replicated Experiment 1a using a verification task. Experiment 2 employed a picture rebus paradigm in which participants read sentences one word at a time that included pictures of color diagnostic objects (i.e., pictures were substituted for critical nouns). Results indicated that the “reading” times of these pictures mirrored the pattern found in Experiment 1. In Experiment 3, an attempt was made to override color diagnosticity using linguistic context (e.g., a pumpkin was described as painted green). Linguistic context did not override color diagnosticity. Collectively, the results demonstrate that color information is regularly utilized in object recognition and representation for highly color diagnostic items.     

Past experience influences object representation in working memory

The nature of object representation in working memory is vital to establishing the capacity of working memory, which in turn shapes the limits of visual cognition and awareness. Although current theories discuss whether representations in working memory are feature-based or object-based, no theory has considered the role of past experience. However, work with humans and non-human primates suggests that once participants learn which features are important for category membership, these diagnostic features become more salient than non-diagnostic features in long-term memory and object recognition. Critically, the brain areas involved in this diagnosticity effect are also recruited during working memory tasks. We report two experiments testing whether a diagnosticity effect exists in working memory; and whether it is present when visual information is encoded into working memory, or if it is the result of maintenance within working memory. Results showed a diagnosticity effect which was present at encoding. Maintenance did not influence the nature of object representation in working memory. These findings show that the meaning we glean from our past experience has a profound influence on the nature of object representation in working memory.     

Priorities for representation: Task settings and object interaction both influence object memory

Following an active task, the memory representations for used and unused objects are different. However, it is not clear whether these differences arise due to prioritizing objects that are task-relevant, objects that are physically interacted with, or a combination of the two factors. The present study allowed us to tease apart the relative importance of task-relevance and physical manipulation on object memory. A paradigm was designed in which objects were either necessary to complete a task (target), moved out of the way (obstructing, but interacted with), or simply present in the environment (background). Participants’ eye movements were recorded with a portable tracker during the task, and they received a memory test on the objects after the task was completed. Results showed that manipulating an object is sufficient to change how information is extracted and retained from fixations, compared to background objects. Task-relevance provides an additional influence: information is accumulated and retained differently for manipulated target objects than manipulated obstructing objects. These findings demonstrate that object memory is influenced both by whether we physically interact with an object, and the relevance of that object to our behavioral goals.     

可操作物体识别过程中的两种操作动作表征

已有大量研究表明, 视觉背侧通路中的背侧−背侧通路和腹侧−背侧通路分别表征与物体相关的抓握和使用动作, 形成结构性和功能性操作动作表征。这两种操作动作表征在神经基础、激活条件、时间进程, 以及与长时记忆的联系方面都存在差异, 并且共同参与到可操作物体的识别过程中。关于结构性和功能性操作动作表征的研究不仅证明了操作动作信息对于可操作物体识别的重要性, 而且对于深入研究物体如何在大脑中表征具有重要意义。     

Oscillatory gamma activity in humans and its role in object representation

We experience objects as whole, complete entities irrespective of whether they are perceived by our sensory systems or are recalled from memory. However, it is also known that many of the properties of objects are encoded and processed in different areas of the brain. How then, do coherent representations emerge? One theory suggests that rhythmic synchronization of neural discharges in the gamma band (around 40 Hz) may provide the necessary spatial and temporal links that bind together the processing in different brain areas to build a coherent percept. In this article we propose that this mechanism could also be used more generally for the construction of object representations that are driven by sensory input or internal, top-down processes. The review will focus on the literature on gamma oscillatory activities in humans and will describe the different types of gamma responses and how to analyze them. Converging evidence that suggests that one particular type of gamma activity (induced gamma activity) is observed during the construction of an object representation will be discussed.     

Saccade latency reveals episodic representation of object color

While previous studies suggest that identity, but not color, plays a role in episodic object representation, such studies have typically used tasks in which only identity is relevant, raising the possibility that the results reflect task demands, rather than the general principles that underlie object representation. In the present study, participants viewed a preview display containing one (Experiments 1 and 2) or two (Experiment 3) letters, then viewed a target display containing a single letter, in either the same or a different location. Participants executed an immediate saccade to fixate the target; saccade latency served as the dependent variable. In all experiments, saccade latencies were longer to fixate a target appearing in its previewed location, consistent with a bias to attend to new objects rather than to objects for which episodic representations are being maintained in visual working memory. The results of Experiment 3 further demonstrate, however, that changing target color eliminates these latency differences. The results suggest that color and identity are part of episodic representation even when not task relevant and that examining biases in saccade execution may be a useful approach to studying episodic representation.     

Object-based attention: strength of object representation and attentional guidance

Two or more features belonging to a single object are identified more quickly and more accurately than are features belonging to different objects--a finding attributed to sensory enhancement of all features belonging to an attended or selected object. However, several recent studies have suggested that this "single-object advantage" may be a product of probabilistic and configural strategic prioritizations rather than of object-based perceptual enhancement per se, challenging the underlying mechanism that is thought to give rise to object-based attention. In the present article, we further explore constraints on the mechanisms of object-based selection by examining the contribution of the strength of object representations to the single-object advantage. We manipulated factors such as exposure duration (i.e., preview time) and salience of configuration (i.e., objects). Varying preview time changes the magnitude of the object-based effect, so that if there is ample time to establish an object representation (i.e., preview time of 1,000 msec), then both probability and configuration (i.e., objects) guide attentional selection. If, however, insufficient time is provided to establish a robust object-based representation, then only probabilities guide attentional selection. Interestingly, at a short preview time of 200 msec, when the two objects were sufficiently different from each other (i.e., different colors), both configuration and probability guided attention selection. These results suggest that object-based effects can be explained both in terms of strength of object representations (established at longer exposure durations and by pictorial cues) and probabilistic contingencies in the visual environment.     

Image representation,scaling and cognitive model of object perception

Neuropsychological investigations of visual imagery and representations have led to a deeper understanding of the spatial perception, representation and memory. But how each individual perceives object’s geometrical properties and how they differ from person to person, both under event-related memory and normal recollecting memory in the presence or in the absence of direct sensory stimulation is still unclear. Spatial knowledge is diverse, complex, and multi-modal, as are the situations in which it is used. All seem to agree that a cognitive map is a mental representation of an external environment. The image scaling is important in understanding the psychological dysfunctions of patients suffering from spatial cognition problems. The scaling becomes self-evident in art forms, when people are asked to draw image of objects they see actively or from their short or long term memory. In this paper we develop a comprehensive model of this scaling factor and its implications in spatial image representation and memory. We also extend its notion in understanding the perception of objects whose representations are normally not possible (like the perception of universal scales, infinities and parallel lines) but are well comprehended by the human brains. Here we give a scaling factor which is variable depending on the situations for a person based on his visual memory and drawing capabilities. And then extend it to analyse his cognitive strengths, disorders and any imperfections. This model also helps in formalizing the architectural cognitive maps needed to change the scaling factor, depending on the types of visual works one performs.     

Changes in self- and object representation as revealed by reflection response

This article considers the three Rorschach tests obtained over an 8-year period for one female patient who struggled around her image of herself and others. Her struggle is revealed in the vicissitudes of the reflection responses over the three testings. A formulation is advanced regarding the meaning and significance of the reflection response as an indication of an emerging self-experience.     

Conceptual structures, representation of objects and object relations]

This article provides an overview of psychological studies of object concepts, highlighting the more recent re-conceptualizations, and the latest developments in research in this field. These developments have tended to focus on the notion of context, as well as on the notion of causal relations between features. Our theoretical analysis of this field is backed up by experimental illustrations. We complete with an examination of "category-specific impairments" studies, in the light of the evolution of concept theories.     

On-line story representation in boys with attention deficit hyperactivity disorder

Children with attention deficit hyperactivity disorder (ADHD) face an increased risk of poor achievement in school. Thus, knowledge of the cognitive processing abilities of children with ADHD is critical to understanding and improving their academic performance. Although many studies have focused on the specific nature of the attention deficit experienced by children with ADHD, few have examined higher order cognitive processing such as comprehension of stories. The present study examined the processes of encoding story information, building a story representation, and modifying a story representation in boys with ADHD and nonreferred boys. Boys were asked to narrate a story from a picture book twice. Boys with ADHD showed deficits in representing goals and goal plans in their narrations, as compared to nonreferred boys. Boys with ADHD also committed more errors than nonreferred boys, but did correct certain types of errors on their second telling. Implications are discussed in terms of future research needed to identify the cognitive deficits that account for these narrative deficits.