The shielding function of task rules in the context of task switching

There is increasing evidence that task rules help shield the response against distractor interference. Here, the authors investigate the cognitive mechanisms underlying this assumed shielding function of task rules and how it is adjusted to changing task demands. In two experiments, participants switched between a noun categorization and an adjective categorization task. Target words were superimposed on distractor pictures. These pictures were always irrelevant and depicted either objects also used as target words in the noun task (noun distractors) or objects that were not part of the noun target-set but could be categorized according to the noun task (noun-related distractors). Results show that (a) on task repetitions shielding prevents interference from any distractors associated with a competing task; this is indicated by the lack of interference on adjective task repetitions; and (b) shielding is reduced on task switches. In the noun task, this reduction resulted in attenuated interference by noun-related distractors. In the adjective task, spatial distractors did not interfere despite the reduction. This result suggests that shielding is supported by a processing advantage for task-related information and not by distractor suppression.     

Improving executive function using transcranial infrared laser stimulation

Transcranial infrared laser stimulation is a new non‐invasive form of low‐level light therapy that may have a wide range of neuropsychological applications. It entails using low‐power and high‐energy‐density infrared light from lasers to increase metabolic energy. Preclinical work showed that this intervention can increase cortical metabolic energy, thereby improving frontal cortex‐based memory function in rats. Barrett and Gonzalez‐Lima (2013, Neuroscience, 230, 13) discovered that transcranial laser stimulation can enhance sustained attention and short‐term memory in humans. We extend this line of work to executive function. Specifically, we ask whether transcranial laser stimulation enhances performance in the Wisconsin Card Sorting Task that is considered the gold standard of executive function and is compromised in normal ageing and a number of neuropsychological disorders. We used a laser of a specific wavelength (1,064 nm) that photostimulates cytochrome oxidase – the enzyme catalysing oxygen consumption for metabolic energy production. Increased cytochrome oxidase activity is considered the primary mechanism of action of this intervention. Participants who received laser treatment made fewer errors and showed improved set‐shifting ability relative to placebo controls. These results suggest that transcranial laser stimulation improves executive function and may have exciting potential for treating or preventing deficits resulting from neuropsychological disorders or normal ageing.     

执行功能与精神分裂症

执行功能障碍是精神分裂症最重要的认知功能障碍,与精神分裂症其它方面的障碍有着密不可分的关系。文章在相关的认知神经心理学和临床研究的基础上,分别综述了精神分裂症执行功能障碍的特点、研究方法、相关脑机制,执行功能与注意、记忆等一般认知功能间的关系,执行功能与精神症状间的联系及其在诊断、康复、判断预后方面的作用等。对精神分裂症执行功能障碍的认识有助于更深入地理解其病因机制,并有利于临床评价与防治     

Iowa Gambling Task performance and executive function predict low-income urban preadolescents’ risky behaviors

This study examines preadolescents’ reports of risk-taking as predicted by two different, but related inhibitory control systems involving sensitivity to reward and loss on the one hand, and higher order processing in the context of cognitive conflict, known as executive functioning (EF), on the other. Importantly, this study examines these processes with a sample of inner-city, low-income preadolescents and as such examines the ways in which these processes may be related to risky behaviors as a function of children’s levels of both concurrent and chronic exposure to household poverty. As part of a larger longitudinal study, 382 children (ages 9–11) provided a self-report of risky behaviors and participated in the Iowa Gambling Task, assessing bias for infrequent loss (preference for infrequent, high magnitude versus frequent, low magnitude loss) and the Hearts and Flowers task assessing executive functioning. Results demonstrated that a higher bias for infrequent loss was associated with higher risky behaviors for children who demonstrated lower EF. Furthermore, bias for infrequent loss was most strongly associated with higher risk-taking for children facing highest levels of poverty. Implications for early identification and prevention of risk-taking in inner-city preadolescents are discussed.     

不同时间的睡眠剥夺对执行功能的影响

睡眠剥夺在日常生活工作中广泛存在,执行功能指需要很多认知过程参与,以使操作优化的机制.目前有关睡眠剥夺对认知功能的影响关注于对执行功能的影响,但是尚没有不同时间睡眠剥夺后执行功能情况的研究,并且研究缺乏系统.本研究应用卡片分类测验、词汇流畅性测验究了32名青年男性在不同睡眠剥夺条件下(睡眠剥夺21h、睡眠剥夺45h、睡眠剥夺69h、正常对照组)的执行功能情况.结果表明:睡眠剥夺后执行功能下降,同剥夺时间有一定关系,45h后下降显著.     

儿童执行功能与情绪调节

大脑执行功能是一种调节、控制、综合、分析个体心理过程和外显行为的认知神经机制。儿童的高级认知活动、社会性行为（同伴交往、攻击性行为）都受到执行功能发展水平的制约。研究者希望通过儿童执行功能的发展,了解整个执行系统的发展成熟过程,揭示执行控制机能的内在机制。同时,有研究者把执行控制这种认知神经机制和儿童的社会性行为包括自我控制、情绪调控等方面的发展结合起来研究,从中发现二者的联系。该文就这方面的核心问题以及研究成果进行了综述。     

Stress,coping, executive function,and brain activation in adolescent offspring of depressed and nondepressed mothers

This study examined the associations among chronic stress, activation in the prefrontal cortex (PFC), executive function, and coping with stress in at-risk and a comparison sample of adolescents. Adolescents (N = 16; age 12–15) of mothers with (n = 8) and without (n = 8) a history of depression completed questionnaires, neurocognitive testing, and functional neuroimaging in response to a working memory task (N-back). Children of depressed mothers demonstrated less activation in the anterior PFC (APFC) and both greater and less activation than controls in distinct areas within the dorsal anterior cingulate cortex (dACC) in response to the N-back task. Across both groups, activation of the dorsolateral PFC (DLPFC; Brodmann area [BA9]) and APFC (BA10) was positively correlated with greater exposure to stress and negatively correlated with secondary control coping. Similarly, activation of the dACC (BA32) was negatively correlated with secondary control coping. Regression analyses revealed that DLPFC, dACC, and APFC activation were significant predictors of adolescents’ reports of their use of secondary control coping and accounted for the effects of stress exposure on adolescents’ coping. This study provides evidence that chronic stress may impact coping through its effects on the brain regions responsible for executive functions foundational to adaptive coping skills.     

前额叶在老年阶段的可塑性及相关机制

大量研究表明, 前额叶的结构和功能更容易受年老化影响; 然而, 近年来的研究发现, 前额叶的结构和功能在老年阶段具有一定的可塑性。对老年人进行认知训练, 能够延缓前额叶皮层厚度的萎缩, 提高白质完整性, 改善神经网络的功能连接和分化, 并可能通过调节多巴胺系统的活动改变前额叶皮质和皮质下结构的功能激活模式。有氧锻炼能够改善心脑血管功能, 保护和促进神经元的存活和生长, 引起前额叶灰质、白质体积的增加及功能激活的变化。认知训练与有氧锻炼等相结合的整合性训练不仅引起前额叶及相关认知功能的改变, 而且具有更好的生态学效度, 使老年人日常认知能力和生活质量得到提高。未来研究应采用多种技术手段, 从多个层面理解老年阶段前额叶的可塑性及相关机制; 加强对与前额叶关系密切的多种认知功能可塑性神经机制的研究; 并重视与整合性训练有关的前额叶可塑性。     

Task-switching abilities in children with autism spectrum disorder

Task-switching performance is often used as a measure of executive control functions. Various task-switching studies in children with autism spectrum disorder (ASD) found, in contrast to expectations, no impairments in cognitive flexibility. Here, we studied whether the role of memory for arbitrary task rules can explain these findings, and how studying rule memory can help to generally better understand executive control. We designed a novel task-switching paradigm to separate cognitive flexibility from demand on memory for arbitrary rules, and we compared 19 children with ASD (9 to 16 years old) with an age- and IQ-matched control group. Children with ASD had increased difficulty with task switching only when memorizing arbitrary rules was required. When no arbitrary rules needed to be memorized, they performed accurately and quickly. Nevertheless, they showed less distraction from task-irrelevant stimulus features, suggesting that they represented tasks differently from the children in the comparison group. We conclude that children with ASD have a weaker capacity of forming rule representations, which only leads to performance impairment when they need to memorize arbitrary rules. Further, executive control impairments in ASD seem more complex than hitherto hypothesized due to mutual interactions between memory demand and task representations.     

Why is it so hard to do my work? The challenge of attention residue when switching between work tasks

In many jobs, employees must manage multiple projects or tasks at the same time. A typical workday often entails switching between several work activities, including projects, tasks, and meetings. This paper explores how such work design affects individual performance by focusing on the challenge of switching attention from one task to another. As revealed by two experiments, people need to stop thinking about one task in order to fully transition their attention and perform well on another. Yet, results indicate it is difficult for people to transition their attention away from an unfinished task and their subsequent task performance suffers. Being able to finish one task before switching to another is, however, not enough to enable effective task transitions. Time pressure while finishing a prior task is needed to disengage from the first task and thus move to the next task and it contributes to higher performance on the next task.     

The hierarchy of task decision and response selection: A task-switching event related potentials study

According to “hierarchical” multi-step theories, response selection is preceded by a decision regarding which task rule should be executed. Other theories assume a “flat” single-step architecture in which task information and stimulus information are simultaneously considered. Using task switching, the authors independently manipulated two kinds of conflict: task conflict (with information that potentially triggers the relevant or the competing task rule/identity) and response conflict (with information that potentially triggers the relevant or the competing response code/motor response). Event related potentials indicated that the task conflict effect began before the response conflict effect and carried on in parallel with it. These results are more in line with the hierarchical view.     

You can't always get what you want: The influence of unexpected task constraint on voluntary task switching

The current study assessed the effect that unexpected task constraint, following self-generated task choice, has on task switching performance. Participants performed a modified double-registration voluntary task switching procedure in which participants specified the task they wanted to perform, were presented with a cue that, on the majority of trials, confirmed the choice, and then performed the cued task. On a small portion of trials, participants were cued to perform a task that did not match their choice. Trials on which cues unexpectedly failed to match the chosen task were associated with costs. These costs were particularly large when participants chose to switch tasks but had to unexpectedly repeat the previous task. The results suggest that when participants choose to switch tasks, they prepare for that switch in anticipation of the stimulus, and the preparation is durable such that it cannot be readily undone.     

基于人机互动的任务中断管理研究述评

科技的发展增加了人机互动中任务中断现象的发生,任务中断管理（Task Interruption Management, TIM）成为工作取得成功日益重要的部分。任务中断管理研究主要采用中断消极影响减少和中断价值评估两种范式,基于记忆的理论、多重资源管理理论和中断管理模型为任务中断管理提供了理论基础,在此基础上研究者发展出基于用户和基于环境的中断管理方法。未来研究需从关注中断的积极影响、内部中断、人的因素尤其是情感性和社会性因素入手加强任务中断管理研究。     

Parent-Child Engagement in Decision Making and the Development of Adolescent Affective Decision Capacity and Binge Drinking

The goal of this study was to investigate how parents’ engagement of their child in everyday decision-making influenced their adolescent’s development on two neuropsychological functions, namely, affective decision-making and working memory, and its effect on adolescent binge-drinking behavior.We conducted a longitudinal study of 192 Chinese adolescents. In 10th grade, the adolescents were tested for their affective decision-making ability using the Iowa Gambling Task (IGT) and working memory capacity using the Self-ordered Pointing Test (SOPT). Questionnaires were used to assess perceived parent-child engagement in decision-making, academic performance and drinking behavior. At one-year follow-up, the same neuropsychological tasks and questionnaires were repeated.Results indicate that working memory and academic performance were uninfluenced by parent-child engagement in decision-making. However, compared to adolescents whose parents made solitary decisions for them, adolescents engaged in everyday decision-making showed significant improvement on affective decision capacity and significantly less binge-drinking one year later.These findings suggest that parental engagement of children in everyday decision-making might foster the development of neurocognitive functioning relative to affective decision-making and reduce adolescent substance use behaviors.     

负荷水平和作业信息输入输出形式对视觉追踪操作心理负荷评估敏感性的影响

就负荷水平和信息输入形式,输出形式对视觉追踪作业心理负荷评估指标敏感性的影响进行了实验,获得以下主要结果：（１）主任务绩效具有较好的评估敏感性;（２）作业信息输入形式、输出形式对评估指标敏感性有显著影响。     

Developmental changes in the relations between inhibitory control and externalizing problems during early childhood

Deficits in executive function, and in particular, reduced capacity to inhibit a dominant action, are a risk factor for externalizing problems (EP). Inhibitory control (IC) develops in the later preschool and early childhood periods, such that IC might not regulate EP in toddlers and younger preschoolers. Aggression was observed during peer play for 66 girls and 49 boys, from 2.75 to 6.00 years (M=4.14, S.D.=0.78). Mothers reported on children's IC and EP concurrently and 12 months later, and concurrent teacher reports of EP were also collected. Factor analysis supported aggregation of mother and teacher‐reported EP and observed physical aggression into one measure of externalizing difficulties. Mothers reported lower IC for children with more externalizing difficulties, and the inverse relation between IC and externalizing difficulties strengthened over the toddler, preschool and kindergarten periods. Similar relations between IC and EP were observed 12 months later, and increases in IC also predicted reductions in EP over 1 year. These data demonstrate that the preschool years are a dynamic period of developmental change in the relations between IC and EP. Copyright © 2010 John Wiley & Sons, Ltd.     

负荷水平和作业信息输入输出形式对视觉追踪操作心理负荷评估敏感性的影响

就负荷水平和信息输入形式、输出形式对视觉追踪作业心理负荷评估指标敏感性的影响进行了实验．获得以下主要结果：①主任务绩效具有较好的评估敏感性;②作业信息输入形式、输出形式对评估指标敏感性有显著影响．     

Math Weaknesses in Survivors of Acute Lymphoblastic Leukemia Compared to Healthy Children

Difficulties in math are the most frequently reported area of academic deficit in survivors of acute lymphoblastic leukemia (ALL) and the most frequent academic complaint among parents of ALL survivors. However, previous studies that included measures of math skills have been limited by the use of only a single measure of math skills, most often a measure of written calculations, without any assessment of math reasoning or math application skills. Further, the nature of these math difficulties has not been adequately investigated. The purpose of this study was to examine the performance of ALL survivors using multiple measures of math skills. Performance was compared to a group of healthy controls matched for age and sex as well as to normative levels. Other measures of neuropsychological function were also administered, and the relationships between these measures and the math measures were explored. Converging evidence for math difficulties in ALL survivors compared to healthy controls and normative levels was found. While ALL survivors generally performed within the average range on measures of math skills, math performance was mostly related to memory function and dominant-hand psychomotor speed. By contrast, math performance of healthy children was mostly related to basic reading skills and visual-motor integration. These findings shed light on the nature of math difficulties in ALL survivors and have implications for intervention.     

早期高级认知发展与前额叶功能发育的fNIRS研究

儿童早期阶段是各项认知能力和脑发育的关键阶段。近红外光谱成像技术(fNIRS)凭借其非侵害性、便捷操作以及对头动容忍度高等特点,在早期阶段儿童认知发展与脑发育的研究中得到越来越多的应用。从早期高级认知发展与前额叶功能的单侧优势变化、对应前额叶脑区逐渐专门化、发展关键期与前额叶功能的可塑性,以及前额叶功能异常与早期发展障碍的关系等四个方面对基于fNIRS技术开展的早期认知发展与脑发育的研究进展进行了梳理和分析。指出未来研究应探究儿童早期认知能力发展和脑发育的轨迹及关键期,探讨有发展性障碍家族风险儿童的早期大脑发育特点,为早期教育和发展障碍的早期预警提供依据。