Movement and working memory: Patterns and positions in space

Five experiments are reported in which subjects were asked to remember short, visually presented sequences of whole body movement patterns, words, and spatial positions. The items were recalled in order in a memory span paradigm. During presentation of the items to be remembered subjects simply watched, or they carried out a concurrent activity involving articulatory suppression, movement to external spatial targets, or body-related movement. When the movement patterns to be remembered were familiar to subjects, movement span was not disrupted by articulatory suppression or movement to spatial targets but was disrupted by body-related movement. This movement suppression task, however, did not interfere with performance on a spatial span task or on verbal span. It is concluded that the memory for patterns of limb movement differs from memory for movement to spatial targets and that accounts of visuo-spatial processes in working memory involve the latter type of movement.     

Attention and spatial selection: electrophysiological evidence for modulation by perceptual load

Behavioral data have suggested that perceptual load can modulate spatial selection by influencing the allocation of attentional resources at perceptual-level processing stages (Lavie & Tsal, 1994). To directly test this hypothesis, event-related potentials (ERPs) were recorded for both low- and high-perceptual-load targets in a probabilistic spatial cuing paradigm. The results from three experiments showed that, as measured by the lateral occipital P1 and N1 ERP components, the magnitude of spatially selective processing in extrastriate visual cortex increased with perceptual load. Furthermore, these effects on spatial selection were found in the P1 at lower levels of perceptual load than in the N1. The ERP data thus provide direct electrophysiological support for proposals that link perceptual load to early spatial selection in visual processing. However, our findings suggest a relatively broader model--where perceptual load is but one of many factors mediating early selection.     

Attention and the crossmodal construction of space

Traditional studies of spatial attention consider only a single sensory modality at a time (e.g. just vision, or just audition). In daily life, however, our spatial attention often has to be coordinated across several modalities. This is a non-trivial problem, given that each modality initially codes space in entirely different ways. In the last five years, there has been a spate of studies on crossmodal attention. These have demonstrated numerous crossmodal links in spatial attention, such that attending to a particular location in one modality tends to produce corresponding shifts of attention in other modalities. The spatial coordinates of these crossmodal links illustrate that the internal representation of external space depends on extensive crossmodal integration. Recent neuroscience studies are discussed that suggest possible brain mechanisms for the crossmodal links in spatial attention.     

Attention and perception: An information-integration perspective

Attentional effects in perceptual processing are analyzed within a framework of a fuzzy logical model of perception. The recognition of a pattern is conceptualized as involving three stages of processing: featural evaluation, integration of features, and pattern classification. The model predicts no loss of resolution when multiple sources of information are integrated to recognize a perceptual event. This model is contrasted with a single-channel model in which only one source of information can be recognized at a time. The task involves a relatively novel situation of speech perception by ear and eye. No attentional decrement is observed when observers process both auditory and visual speech specifying a single speech event. This result contrasts with previous studies showing a loss when attention has to be divided between different events along auditory and visual modalities. The different results are interpreted in terms of the number of events that have to be processed. Processing two different modalities leads to an attentional decrement when the two inputs specify different events whereas no attentional decrement occurs when these inputs are integrated to recognize a single event. A distinction is made between detection that requires only the evaluation of a single source of information and recognition that requires the evaluation and integration of multiple sources of information. The current framework is also used to discuss previous empirical and theoretical work and the issue of early versus late selection.     

Knowledge scale effects in face recognition: An electrophysiological investigation

Although the amount or scale of biographical knowledge held in store about a person may differ widely, little is known about whether and how these differences may affect the retrieval processes triggered by the person’s face. In a learning paradigm, we manipulated the scale of biographical knowledge while controlling for a common set of minimal knowledge and perceptual experience with the faces. A few days after learning, and again after 6 months, knowledge effects were assessed in three tasks, none of which concerned the additional knowledge. Whereas the performance effects of additional knowledge were small, event-related brain potentials recorded during testing showed amplitude modulations in the time range of the N400 component—indicative of knowledge access—but also at a much earlier latency in the P100 component—reflecting early stages of visual analysis. However, no effects were found in the N170 component, which is taken to reflect structural analyses of faces. The present findings replicate knowledge scale effects in object recognition and suggest that enhanced knowledge affects both early visual processes and the later processes associated with semantic processing, even when this knowledge is not task-relevant.     

Attention and anticipation in response to varying levels of uncertain threat: An ERP study

Individual differences in responding to uncertainty have been proposed as a key mechanism of how anxiety disorders develop and are maintained. However, most empirical work has compared responding to uncertain versus certain threat dichotomously. This is a significant limitation because uncertainty in daily life occurs along a continuum of probability, ranging from very low to high chances of negative outcomes. The current study investigated (1) how varying levels of uncertainty impact attention and anticipatory emotion, and (2) how these effects are moderated by individual differences in risk factors for anxiety disorders, particularly intolerance of uncertainty (IU) and worry. Participants (n = 65) completed a card task in which the probability of shock varied across trials. Two event-related potential components were examined: the P2, an index of attention, and the stimulus-preceding negativity (SPN), an index of anticipation. The P2 tracked the level of uncertainty and was smaller for more uncertain outcomes. Participants higher in IU exhibited greater differences in the P2 across levels of uncertainty. The SPN did not track specific levels of uncertainty but was largest for uncertain threat compared with certain threat and safety. Greater worry was associated with blunting of the SPN in anticipation of all outcomes. Thus, attention appears to be sensitive to variations in uncertainty, whereas anticipation seems sensitive to uncertainty globally. The two processes appear to be distinctly related to anxiety risk factors. These results highlight the value of examining multiple aspects of anticipatory responding to varying levels of uncertainty for understanding risk for anxiety disorders.     

Fixation positions after skipping saccades: A single space makes a large difference

During reading, saccadic eye movements are generated to shift words into the center of the visual field for lexical processing. Recently, Krügel and Engbert (Vision Research 50:1532?C1539, 2010) demonstrated that within-word fixation positions are largely shifted to the left after skipped words. However, explanations of the origin of this effect cannot be drawn from normal reading data alone. Here we show that the large effect of skipped words on the distribution of within-word fixation positions is primarily based on rather subtle differences in the low-level visual information acquired before saccades. Using arrangements of ??x?? letter strings, we reproduced the effect of skipped character strings in a highly controlled single-saccade task. Our results demonstrate that the effect of skipped words in reading is the signature of a general visuomotor phenomenon. Moreover, our findings extend beyond the scope of the widely accepted range-error model, which posits that within-word fixation positions in reading depend solely on the distances of target words. We expect that our results will provide critical boundary conditions for the development of visuomotor models of saccade planning during reading.     

Delay discounting as emotional processing: An electrophysiological study

Both theoretical models and functional imaging studies implicate the involvement of emotions within the delay discounting process. However, defining this role has been difficult to establish with neuroimaging techniques given the automaticity of emotional responses. To address this, the current study examined electrophysiological correlates involved in the detection and evaluation of immediate and delayed monetary outcomes. Our results showed that modulation of both early and later ERP components previously associated with affective stimuli processing are sensitive to the signalling of delayed rewards. Together with behavioural reaction times that favoured immediacy, we demonstrated, for the first time, that time delays modify the incentive value of monetary rewards via mechanisms of emotional bias and selective visual attention. Furthermore, our data are consistent with the hypothesis that delayed and thus intangible rewards are perceived less saliently, and rely on emotion as a common currency within decision making. This study provides a new approach to delay discounting and highlights a potential novel route through which delay discounting may be investigated.     

刺激前负波:奖赏期待的电生理指标

刺激前负波(Stimulus-Preceding Negativity,SPN)是从关联性负变化中分离出来的非运动性慢电位,其波幅随着反馈刺激的临近逐渐升高。先前研究侧重于将SPN视为一种认知性成分,而最近的研究支持了SPN是奖赏期待的可靠指标。本文从奖赏的基本属性、结果评价、神经发生源以及特殊人群等角度,对SPN反映奖赏期待这一假说进行了梳理,并提出了未来的研究方向,旨在为研究奖赏期待受损的神经精神类疾病提供可靠的生物学标记。     

基于物体的注意的机制与影响因素

视觉选择性注意的研究是认知心理学领域的热点之一。注意选择的表征不仅可以基于空间, 也可以基于物体。基于物体的注意(object-based attention, OBA)的研究范式主要有双矩形提示范式和侧干扰范式, 有关基于物体的注意的机制的理论有感觉增强理论、注意优先理论和注意转换理论。影响基于物体的注意效应的因素主要有刺激本身的特征(如刺激呈现时间)、其它知觉过程和经验因素等。视觉物体的概念既包括格式塔知觉组织原则定义的物体, 也包括无意识下的物体、变化之后的物体和自上而下的物体。     

Attention to errors and learning: Across-task and across-domain analysis of the postfailure reflectivity measure

The ratio between the mean postfailure and postsuccess latencies on a self-paced task (Postfailure Reflectivity) has been proposed as a measure of attention to errors, affecting learning across domains. This study was devised to test the generality of Postfailure Reflectivity (PFR). In Experiment 1, performance on two nonverbal, inference, and induction/deduction tasks was examined. Reading disabled subjects showed significantly less PFR than normally achieving subjects, and PFR correlated positively with the score in two nonverbal tasks, and across two testing times. In Experiment 2, PFR was significantly correlated with performance on two nonverbal tasks and one arithmetic task, and with measures of deep planning during interviews following the learning of a nonverbal inference task, as well as following motor and cognitive learning tasks. PFR also correlated with intentional learning, as measured on the Implicit Theories Interview. Jointly considered, these findings support the view that attention to errors plays a central role in learning, and that PFR is a good measure of attention to errors. It appears that Postfailure Reflectivity is a metacognitive skill which possesses adaptive, generalized, and trans-domain characteristics.     

Turning Our Attention to Stigma: An Objective Self-Awareness Analysis of Stigma and Its Consequences

Theories of deindividuation predict that the formation of a group serves to decrease the inhibitions of the constituent members and increase the probability of aggression in situations where the group must compete, or interact, with nongroup members. This prediction is tested in a real-world confrontation situation-that of police on patrol. It was hypothesized that the level of violence individual officers encounter in the performance of specific activities will vary according to the nature of the activity and the degree of anxiety associated with that activity, the number of officers present, and the number of civilian bystanders. The data of the study provide support for each of these predictions and demonstrate the extent to which social psychological theory can provide useful insights into day-to-day behaviors.     

Distraction and placebo: two separate routes to pain control

An explosion of recent research has studied whether placebo treatments influence health-related outcomes and their biological markers, but almost no research has examined the psychological processes required for placebo effects to occur. This study tested whether placebo treatment and cognitive distraction reduce pain through shared or independent processes. We tested the joint effects of performance of an executive working memory task and placebo treatment on thermal pain perception. An interactive effect of these two manipulations would constitute evidence for shared mechanisms, whereas additive effects would imply separate mechanisms. Participants (N = 33) reported reduced pain both when they performed the working memory task and when they received the placebo treatment, but the reductions were additive, a result indicating that the executive demands of the working memory task did not interfere with placebo analgesia. Furthermore, placebo analgesia did not impair task performance. Together, these data suggest that placebo analgesia does not depend on active redirection of attention and that expectancy and distraction can be combined to maximize pain relief.     

The generality of the levels of processing hypothesis: An application to memory for chess positions

The generality of the levels of processing approach to memory was tested by using chess positions rather than words as stimuli. Experiment 1 compared recall following semantic orienting instructions (find the best move and determine which side has the advantage), formal orienting instructions (determine the number of pieces on light squares and the number of pieces on dark squares), and intentional learning instructions using 19 novice chess players as subjects. Formal orienting instructions produced poorer recall than did either semantic orienting or intentional learning instructions, which yielded similar levels of retention. These results were replicated in Experiment 2 with 16 tournament chess players. Chess rating correlated with recall .82 under semantic orienting instructions but only —.15 under formal orienting instructions. It was concluded that the levels of processing framework has applicability outside the area of verbal learning.     

Visual Attention to Pictorial Food Stimuli in Individuals With Night Eating Syndrome: An Eye-Tracking Study

Night eating syndrome (NES) is characterized by excessive evening and/or nocturnal eating episodes. Studies indicate an attentional bias towards food in other eating disorders. For NES, however, evidence of attentional food processing is lacking. Attention towards food and non-food stimuli was compared using eye-tracking in 19 participants with NES and 19 matched controls without eating disorders during a free exploration paradigm and a visual search task. In the free exploration paradigm, groups did not differ in initial fixation position or gaze duration. However, a significant orienting bias to food compared to non-food was found within the NES group, but not in controls. A significant attentional maintenance bias to non-food compared to food was found in both groups. Detection times did not differ between groups in the search task. Only in NES, attention to and faster detection of non-food stimuli were related to higher BMI and more evening eating episodes. The results might indicate an attentional approach-avoidance pattern towards food in NES. However, further studies should clarify the implications of attentional mechanisms for the etiology and maintenance of NES.     

Attention Network Performance and Psychopathic Symptoms in Early Adolescence: An ERP Study

Reaction time (RT) and event-related potential (ERP) measures were used to examine the relationships between psychopathic symptoms and three major attention networks (alerting, orienting, and executive attention) among a community sample of youth. Antisocial Process Screening Device (APSD; Frick and Hare 2001) total and subscale scores were negatively correlated with ERP measures of attentional alerting, indicating that youth with psychopathic symptoms had difficulty using warning cues to prepare for upcoming targets. APSD total scores were not related to performance on measures of orienting or executive attention, although weaker executive attention was found among youth with higher scores on the Impulsivity subscale. These findings support attention-based models of psychopathy and provide evidence of specific deficits in attentional alerting among youth with psychopathic traits. Deficiencies in attentional alerting may be related to noradrenergic functioning and may have cascading effects on higher order cognitive and affective processing.