Understanding vulnerability for depression from a cognitive neuroscience perspective: A reappraisal of attentional factors and a new conceptual framework

We propose a framework to understand increases in vulnerability for depression after recurrent episodes that links attention processes and schema activation to negative mood states, by integrating cognitive and neurobiological findings. Depression is characterized by a mood-congruent attentional bias at later stages of information processing. The basic idea of our framework is that decreased activity in prefrontal areas, mediated by the serotonin metabolism which the HPA axis controls, is associated with an impaired attenuation of subcortical regions, resulting in prolonged activation of the amygdala in response to stressors in the environment. Reduced prefrontal control in interaction with depressogenic schemas leads to impaired ability to exert attentional inhibitory control over negative elaborative processes such as rumination, leading in turn to sustained negative affect. These elaborative processes are triggered by the activation of negative schemas after confrontation with stressors. In our framework, attentional impairments are postulated as a crucial process in explaining the increasing vulnerability after depressive episodes, linking cognitive and biological vulnerability factors. We review the empirical data on the biological factors associated with the attentional impairments and detail how they are associated with rumination and mood regulation. The aim of our framework is to stimulate translational research.     

Attentional disengagement in adults with Williams syndrome

Williams syndrome (WS) is a neurodevelopmental disorder characterized by a distinctive behavioral and cognitive profile, including widespread problems with attention. However, the specific nature of their attentional difficulties, such as inappropriate attentional allocation and/or poor attentional disengagement abilities, has yet to be elucidated. Furthermore, it is unknown if there is an underlying difficulty with the temporal dynamics of attention in WS or if their attentional difficulties are task-dependent, because previous studies have examined attention in established areas of deficit and atypicality (specifically, visuospatial and face processing). In this study, we examined attentional processing in 14 adults with WS (20–59 years) and 17 typically developing controls (19–39 years) using an attentional blink (AB) paradigm. The AB is the decreased ability to detect a second target when it is presented in close proximity to an initial target. Overall, adults with WS had an AB that was prolonged in duration, but no different in magnitude, compared with typically developing control participants. AB performance was not explained by IQ, working memory, or processing speed in either group. Thus, results suggest that the attention problems in WS are primarily due to general attentional disengagement difficulties rather than inappropriate attentional allocation.     

Electrophysiological evidence for cognitive control during conflict processing in visual spatial attention

Event-related potentials were measured to investigate the role of visual spatial attention mechanisms in conflict processing. We suggested that a more difficult target selection leads to stronger attentional top-down control, thereby reducing the effects of arising conflicts. This hypothesis was tested by varying the selection difficulty in a location negative priming (NP) paradigm. The difficult task resulted in prolonged responses as compared to the easy task. A behavioral NP effect was only evident in the easy task. Psychophysiologically the easy task was associated with reduced parietal N1, enhanced frontocentral N2 and N2pc components and a prolonged P3 latency for the conflict as compared to the control condition. The N2pc effect was also obvious in the difficult task. Additionally frontocentral N2 amplitudes increased and latencies of N2pc and P3 were delayed compared to the easy task. The differences at frontocentral and parietal electrodes are consistent with previous studies ascribing activity in the prefrontal and parietal cortex as the source of top-down attentional control. Thus, we propose that stronger cognitive control is involved in the difficult task, resulting in a reduced behavioral NP conflict.     

A single bout of meditation biases cognitive control but not attentional focusing: Evidence from the global–local task

Recent studies show that a single bout of meditation can impact information processing. We were interested to see whether this impact extends to attentional focusing and the top-down control over irrelevant information. Healthy adults underwent brief single bouts of either focused attention meditation (FAM), which is assumed to increase top-down control, or open monitoring meditation (OMM), which is assumed to weaken top-down control, before performing a global–local task. While the size of the global-precedence effect (reflecting attentional focusing) was unaffected by type of meditation, the congruency effect (indicating the failure to suppress task-irrelevant information) was considerably larger after OMM than after FAM. Our findings suggest that engaging in particular kinds of meditation creates particular cognitive-control states that bias the individual processing style toward either goal-persistence or cognitive flexibility.     

注意过程中的行为振荡现象

行为振荡是个体心理加工过程的周期性动态变化在行为上的表现。通过高时间分辨率的行为采样方法, 行为振荡研究为探索视觉注意的时间动态结构提供了一个新的视角。各种不同的注意任务中都发现存在行为振荡现象。大量行为振荡证据表明, 注意过程存在两种主要的节律成分：反映注意抑制的α节律(8~13 Hz)和反映注意转移的θ节律(4~8 Hz)。这些结果有助于揭示注意的时间动态结构, 也为序列搜索理论和平行搜索理论之间的争论提供了新的分析思路。行为振荡的节律特征会受到一些潜在因素(如任务难度、线索有效性)的影响。行为振荡和神经振荡在某些任务中表现出相同的节律成分, 提示两者涉及了相似的心理过程。后续研究应进一步关注各种不同的注意控制过程以及多模态交互任务, 深入探索其行为振荡特点, 以更好地揭示注意的动态加工过程。     

Transient spatial attention and the perceived duration of brief visual events

This study was designed to explore the effects of transient attention—the stimulus-driven component of spatial attention—on the perceived duration of a brief visual event. Observers had to compare the duration of two disks presented successively within a single trial. The disks’ location and duration varied independently. One of these disks, the “attended disk”, was preceded by an attentional cue indicating the disk's location, attracting transient attention in advanced to the disk location. This attentional cue was either a typical onset cue (Experiments 1, 2, and 4) or a singleton cue (Experiment 3) that minimized the differences between the cues. The other disk, the “neutral disk”, was cued with a neutral cue that did not convey information regarding the disk location. We found that the attraction of transient attention to the location of the attended disk prolonged its perceived duration, but only when compared to brief nonattend stimuli.     

Dissociations in visual attention deficits among persons with mild cognitive impairment

Impairments in visual attention and visual information processing have been identified as part of the neuropsychological features of Alzheimer's disease (AD), even in its earliest stages. There is increasing recognition that these deficits may be selective rather than global, with some attentional subtypes being more vulnerable than others. The few studies that have investigated attentional deficits in mild cognitive impairment (MCI), a putatively prodromal phase of AD, have not satisfactorily addressed the possible selectivity in attentional deficits in MCI. This study examined potential dissociations in visual attention deficits in MCI using a measure that assesses simple, divided, and selective attention. The results indicated a hierarchy of attentional impairments, with divided attention being the most affected and simple attention the least. Among participants with MCI, 53% showed evidence of impairment in divided attention compared to 19% of controls (OR = 4.81, p < .001). Poorer visual attention was also associated with poorer overall cognitive status. The implications of these findings for early identification of MCI, prevention of functional decline in MCI, and delay/reversal of cognitive degradation in MCI are discussed.     

Altering attentional control settings causes persistent biases of visual attention

Attentional control settings have an important role in guiding visual behaviour. Previous work within cognitive psychology has found that the deployment of general attentional control settings can be modulated by training. However, research has not yet established whether long-term modifications of one particular type of attentional control setting can be induced. To address this, we investigated persistent alterations to feature search mode, also known as an attentional bias, towards an arbitrary stimulus in healthy participants. Subjects were biased towards the colour green by an information sheet. Attentional bias was assessed using a change detection task. After an interval of either 1 or 2 weeks, participants were then retested on the same change detection task, tested on a different change detection task where colour was irrelevant, or were biased towards an alternative colour. One experiment included trials in which the distractor stimuli (but never the target stimuli) were green. The key finding was that green stimuli in the second task attracted attention, despite this impairing task performance. Furthermore, inducing a second attentional bias did not override the initial bias toward green objects. The attentional bias also persisted for at least two weeks. It is argued that this persistent attentional bias is mediated by a chronic change to participants’ attentional control settings, which is aided by long-term representations involving contextual cueing. We speculate that similar changes to attentional control settings and continuous cueing may relate to attentional biases observed in psychopathologies. Targeting these biases may be a productive approach to treatment.     

EPS Mid-Career Award 2004: brain mechanisms of attention

There are many varieties of "attention", to some extent separate yet working together to produce coherent perception, thought, and behaviour. Using data from human behaviour, functional neuroimaging, and single-cell recording in the behaving monkey, I consider different levels of attention and their basis in physiological mechanisms of biased competition. Beginning with visual attention, I suggest that processing is competitive in many brain systems that code visual input. Competition is biased towards stimuli that match task requirements and is integrated between systems coding different object properties. The result is flexible, object-based attentional selection. In the second part of the paper, I describe recent experiments on attentional competition within and between sensory modalities. Though competition is often modality specific, more global levels of interference are also easy to demonstrate. In the third part of the paper, I move to frontoparietal cortex and to a pattern of similar brain regions recruited by many different cognitive demands. This multiple-demand (MD) pattern, I suggest, reflects neurons with highly flexible response properties, adapting to represent the information and events of many different tasks. Biased competition in MD regions may play a central role in broad attentional capacity limits and attentional focusing. More generally, I suggest that biased competition is characteristic of many different cognitive domains and brain systems. Coherent "attention" develops as different systems converge to work on related cognitive content.     

不安全依恋者注意偏向的形成机制及神经基础

不安全依恋者的注意偏向是指依恋焦虑和回避个体对依恋信息产生或趋近或回避的注意偏好, 这一注意偏好使得个体形成了处理与依恋对象关系的特殊认知机制：依恋回避个体偏好采用防御性机制, 倾向于回避对依恋信息的注意; 依恋焦虑个体偏好采用夸大性机制, 倾向于夸大威胁性信息, 因而会积极寻求与依恋对象的亲近。不安全依恋者注意偏向的差异主要体现在情绪信息、痛觉感受和工作记忆三个方面; 加工阶段特征主要涉及P1、N1波等代表的注意自动加工和LPP波代表的注意控制加工; 脑网络上主要包括两个子网络, 即负责情绪评估的边缘系统和负责情绪调节的以前额叶为代表的神经网络。未来研究中更应该关注刺激物的生态效度, 检验依恋系统是否激活, 不安全依恋者注意偏向的自动加工和控制加工阶段的关系, 不安全依恋者注意偏向产生的分子遗传机制以及注意偏向的跨文化研究。     

Dissociations in Visual Attention Deficits among Persons with Mild Cognitive Impairment

ABSTRACT

Impairments in visual attention and visual information processing have been identified as part of the neuropsychological features of Alzheimer's disease (AD), even in its earliest stages. There is increasing recognition that these deficits may be selective rather than global, with some attentional subtypes being more vulnerable than others. The few studies that have investigated attentional deficits in mild cognitive impairment (MCI), a putatively prodromal phase of AD, have not satisfactorily addressed the possible selectivity in attentional deficits in MCI. This study examined potential dissociations in visual attention deficits in MCI using a measure that assesses simple, divided, and selective attention. The results indicated a hierarchy of attentional impairments, with divided attention being the most affected and simple attention the least. Among participants with MCI, 53% showed evidence of impairment in divided attention compared to 19% of controls (OR = 4.81, p < .001). Poorer visual attention was also associated with poorer overall cognitive status. The implications of these findings for early identification of MCI, prevention of functional decline in MCI, and delay/reversal of cognitive degradation in MCI are discussed.     

Effects of stress and anxiety on the processing of threat stimuli

Two experiments extended the work of MacLeod and Mathews (1988) and examined whether a cognitive bias for threat information is a function of state or trait anxiety. Color-naming and attention deployment tasks were used to assess the effects of a stress manipulation procedure on attentional responses in high and low trait anxious subjects. Subjects under high stress selectively allocated processing resources toward threat stimuli, irrespective of their trait anxiety level. There was no consistent evidence of a cognitive bias associated with trait anxiety, and the effect of the stress manipulation did not appear to be mediated by state anxiety. It was suggested that trait factors do not modify attentional biases associated with acute stress, but may influence such biases when stress is prolonged.     

Brief mindfulness meditation intervention improves attentional control of athletes in virtual reality shooting competition: Evidence from fNIRS and eye tracking

Attentional control is a crucial cognitive ability for sports performance. The current research aimed to investigate whether a brief (20-min) pre-competition mindfulness meditation (MM) intervention enhances athletes' attentional control during competitions and alters the activity of brain regions related to attentional control. We created a virtual reality shooting competition to compare the eye-gaze indicators and functional near-infrared spectroscopy (fNIRS) parameters of 78 university athletes after 20 min of MM or 20 min of mind wandering (MW). Participants’ average fixation durations (AFDs) on task-relevant information (targets) were significantly longer in the MM group. In contrast, both average fixation counts (AFCs) and AFDs on task-irrelevant information (the ranking screen) were significantly lower in the MM group than in the MW group. Additionally, the MM group exhibited significantly stronger activation of the left and right dorsolateral prefrontal cortex (dlPFC) as well as higher levels of oxygenated haemoglobin [HbO] and greater functional connectivity (FC) of the right dlPFC, which was considered evidence of recruitment for attentional control. Moreover, the MM group achieved significantly better shooting performance than the MW group. Overall, the findings suggest that one session 20-min MM practice pre-competition facilitates focus during competition and improves athletic performance. We recommend the application of brief mindfulness practice in sports, especially in closed-skill sports that require high attention participation (e.g., shooting, archery, darts, golf, gymnastics, skating etc.).     

Sources of individual differences in working memory: Contributions of strategy to capacity

Some research on attentional control in working memory has emphasized theoretical capacity differences. However, strategic behavior, which has been relatively unexplored, can also influence attentional control and its relationship to cognitive performance. In two experiments, we examined the relationship between attentional control (measured with operation span) and interference in a part-list cuing paradigm. Paradoxically, the results indicated that superior attentional control was related to increased interference. This relationship reflected the participants’ use of more complex encoding strategies, rather than superior interference control at retrieval, and was eliminated following brief encoding strategy training. The results suggest that complex span measures sometimes predict individual differences in task strategies related to interference control and that these strategies may be amenable to training. The implications for working memory research and the roles of strategies in basic memory and attention paradigms are briefly discussed.     

Coordination of voluntary and stimulus-driven attentional control in human cortex

Visual attention may be voluntarily directed to particular locations or features (voluntary control), or it may be captured by salient stimuli, such as the abrupt appearance of a new perceptual object (stimulus-driven control). Most often, however, the deployment of attention is the result of a dynamic interplay between voluntary attentional control settings (e.g., based on prior knowledge about a target's location or color) and the degree to which stimuli in the visual scene match these voluntary control settings. Consequently, nontarget items in the scene that share a defining feature with the target of visual search can capture attention, a phenomenon termed contingent attentional capture. We used functional magnetic resonance imaging to show that attentional capture by target-colored distractors is accompanied by increased cortical activity in corresponding regions of retinotopically organized visual cortex. Concurrent activation in the temporoparietal junction and ventral frontal cortex suggests that these regions coordinate voluntary and stimulus-driven attentional control settings to determine which stimuli effectively compete for attention.     

Mind over matter: reappraising arousal improves cardiovascular and cognitive responses to stress

Researchers have theorized that changing the way we think about our bodily responses can improve our physiological and cognitive reactions to stressful events. However, the underlying processes through which mental states improve downstream outcomes are not well understood. To this end, we examined whether reappraising stress-induced arousal could improve cardiovascular outcomes and decrease attentional bias for emotionally negative information. Participants were randomly assigned to either a reappraisal condition in which they were instructed to think about their physiological arousal during a stressful task as functional and adaptive, or to 1 of 2 control conditions: attention reorientation and no instructions. Relative to controls, participants instructed to reappraise their arousal exhibited more adaptive cardiovascular stress responses-increased cardiac efficiency and lower vascular resistance-and decreased attentional bias. Thus, reappraising arousal shows physiological and cognitive benefits. Implications for health and potential clinical applications are discussed.     

对威胁刺激的注意偏向：注意定向加速还是注意解除困难？

对威胁刺激的注意偏向普遍存在。注意定向加速和注意解除困难在不同阶段对注意偏向产生影响。威胁刺激属性、呈现时间以及被试特征是重要的调节因素。以杏仁核为核心的杏仁核?前扣带回网络可能是注意定向加速的神经基础, 而以眶额叶为中心的前额叶皮层可能是注意解除的神经基础。未来还需要就注意定向加速与注意解除困难的关系、注意偏向的调节机制以及其神经基础做更深入的研究。     

手机成瘾与抑郁：社交焦虑和负性情绪信息注意偏向的多重中介作用

为考察手机成瘾与抑郁的关系, 研究同时整合情绪和认知两方面因素, 探讨了社交焦虑和负性情绪信息注意偏向在手机成瘾和抑郁之间的多重中介作用。研究1共有545名大学生完成了大学生手机成瘾倾向量表、贝克抑郁量表和社会交往焦虑量表。研究2选取51名大学生采用问卷法和2(配对面孔表情的情绪类型: 负性、中性) × 2(探测点位置: 与负性情绪面孔表情同侧、与负性情绪面孔表情异侧)的被试内实验设计。结果表明: (1)手机成瘾、社交焦虑和抑郁两两间存在显著正相关, 且社交焦虑在手机成瘾和抑郁之间起完全中介作用; (2)社交焦虑和负性情绪信息注意偏向在手机成瘾与抑郁的关系中起链式中介作用, 而负性情绪信息注意偏向在手机成瘾与抑郁间的单独中介效应不显著。具体而言, 手机成瘾通过两条路径影响抑郁: 一是社交焦虑的单独中介作用; 二是社交焦虑→负性情绪信息注意偏向的链式中介作用。     

Working memory retention systems: a state of activated long-term memory

High temporal resolution event-related brain potential and electroencephalographic coherence studies of the neural substrate of short-term storage in working memory indicate that the sustained coactivation of both prefrontal cortex and the posterior cortical systems that participate in the initial perception and comprehension of the retained information are involved in its storage. These studies further show that short-term storage mechanisms involve an increase in neural synchrony between prefrontal cortex and posterior cortex and the enhanced activation of long-term memory representations of material held in short-term memory. This activation begins during the encoding/comprehension phase and evidently is prolonged into the retention phase by attentional drive from prefrontal cortex control systems. A parsimonious interpretation of these findings is that the long-term memory systems associated with the posterior cortical processors provide the necessary representational basis for working memory, with the property of short-term memory decay being primarily due to the posterior system. In this view, there is no reason to posit specialized neural systems whose functions are limited to those of short-term storage buffers. Prefrontal cortex provides the attentional pointer system for maintaining activation in the appropriate posterior processing systems. Short-term memory capacity and phenomena such as displacement of information in short-term memory are determined by limitations on the number of pointers that can be sustained by the prefrontal control systems.     

老年人情绪注意积极效应的发生机制

20世纪, 许多心理学家从“厄运与苦难”视角研究人晚年遭遇的身体、认知和情绪衰老, 但是近年的理论与实证研究从“老化悖论”——老年人情绪加工的积极效应——视角挑战这一“定论”。积极效应指老年人认知加工过程中比年轻人更偏好正性而非负性材料的现象。第二代社会情绪选择理论包括积极效应理论、认知控制假说和强弱整合模型3个关于认知和情绪功能年龄差异的理论模型, 特别强调了认知控制在老年人积极情绪加工中的潜在作用, 而自动化加工与控制性加工的区分则取决于注意资源配置。因此, 认知控制在老年人对积极情绪的注意加工中起重要作用。此外, 注意偏向的时间进程也是影响老年人情绪注意中积极效应的关键因素。最后, 综合以往研究构建出认知控制对老年人积极效应发生作用的注意阶段模型。未来研究可从中国老年人情绪注意加工模式、不同认知控制子成分的作用机制、提高研究生态学效度和注意的治疗品质几个方面继续探索。