基于中央执行功能的儿童工作记忆可塑性机制

近期的研究发现儿童的工作记忆能力具有一定的可塑性。研究者采用双盲对照实验设计, 通过改编的工作记忆广度、N-back、活动记忆和GO-NOGO等任务对15岁以下的正常儿童和特殊儿童(多动症、智力低下等)的工作记忆能力进行训练, 训练的周期一般为15~30天不等, 每天训练时长约15~25分钟。研究结果发现, 工作记忆训练不仅可以提高儿童的工作记忆能力, 而且还可以迁移至其它高级认知功能(流体智力、数学能力等), 甚至可以改善多动症儿童的临床症状。研究者还发现这种训练效应可以保持3~6个月。通过工作记忆中央执行功能的训练, 是否可以促进儿童认知功能的发展？儿童认知功能的可塑性表现为短暂的提高还是促进认知发展？中央执行功能的训练如何影响儿童认知加工过程的发展？这些问题的回答对于近一步探索认知活动和认知神经的可塑性具有一定的理论意义。可以为工作记忆缺陷儿童的临床干预和治疗提供有效的工具, 具有实践意义。     

泛自闭症障碍执行功能的神经心理学和神经成像研究

文章主要回顾了泛自闭症障碍在四个方面的执行功能缺陷-维持注意、注意定向、反应抑制、和设置转换/认知灵活性.总括了泛自闭症障碍在这些特定的执行功能方面的神经心理学和神经成像研究,并提出了以后研究的建议.     

任务转换训练和执行功能可塑性

任务转换训练是提高个体执行功能的方法之一。学者们采用不同的任务范式进行任务转换训练。研究结果发现, 任务转换训练可以降低个体的转换代价、提高其他认知任务的绩效。训练效果可以维持一定的时间。但是, 也有研究未发现明显的迁移效果和维持效果。年龄、其他执行成分的参与度、认知灵活性和策略可能会影响训练效果。任务转换训练可能通过提高个体解决任务设置冲突的能力、提高与任务转换相关的额-顶脑网络的参与程度以及建立自下而上的自动控制来提高个体的转换能力。未来研究应当对现有研究方法和程序进行标准化, 从执行功能整体与分离的结构特征角度看待任务转换训练, 寻找更为灵活的训练手段, 如tDCS技术。     

视觉特征提取加工中的认知可塑性

本研究采用“加因素法”研究范式,通过两个实验分别检测20名飞行员和lO名老年被试及其相应控制组在视觉特征提取任务上的认知加工水平,旨在探讨视觉特征提取这一高水平视觉表象加工上的认知可塑性水平。研究结果表明,视觉特征提取加工既表现出了随外界系统训练而发生功能增强的练习效应,也表现出了随年老化过程而发生相应功能显著改变的年龄效应。研究提示,由于受大脑神经细胞活动特性改变的影响,视觉特征提取加工更多地表现出了可塑性或易变性相对较高的认知特性。结合相关的工作基础,研究结果还进一步证实高水平视觉认知加工所表现出的练习效应和年龄效应在大脑神经网络上的分布是不平衡的。本研究不仅对于揭示高水平视觉表象加工的认知特性具有重要的理论意义,而且在实践中对于建立飞行员、宇航员等特殊职业人员的选拔模型以及揭示飞行空间定向障碍的认知机制也具有重要的应用价值。     

儿童执行功能与算术认知策略的关系

对35名小学2年级儿童的四种执行功能与有无工作记忆负荷两种情况下算术认知策略表现之间的关系进行了探讨.结果表明,双任务协调功能与工作记忆负荷增加时放弃策略的使用次数具有显著负相关;策略转换功能越强的儿童.算术认知策略的使用越灵活;抑制功能强的儿童在提取策略的相关表现上更好;记忆更新功能与工作记忆负荷增加时策略执行的正确率具有显著正相关.这说明,执行功能与儿童算术认知策略之间存在着特定的联系.     

执行功能与儿童数学认知

儿童数学认知能力的发展与儿童执行功能之间有着密切的联系.这种联系不仅仅表现在认知加工机制方面,如工作记忆、抑制控制等,还涉及到深层的认知神经机制,如前额叶皮质等.此外,儿童数学认知和执行功能在研究范式上也存在着一些共同的模式,例如冲突抑制任务和规则转换任务等.     

国外最新研究动态：执行功能与认知控制

Kern J G, Cohen J D, MacDonaldⅢ A W, Cho R Y, Stenger V A, Carter C S. Anterior cingulated conflict monitoring and adjustments in control. Science, 2004, 303(13): 1023 ~1026 该研究对前扣带回(ACC)在冲突监控中的作用进行考察。许多研究假定,前扣带回负责监控冲突的产生,进而引发更强的认知控制的需要,促使其它脑区(如背外侧前额叶和顶叶)进行神经和行为活动上的调节。然而,对ACC的活动能否预测随后的控制一直存在争论。该文采用STROOP颜色命名任务,控制了重复效应,结果发现,与冲突相关的ACC活动在很大程度上…     

身体活动对老年认知功能的影响

如何促进老年人的认知功能, 延缓认知老化, 是老年心理学的关键课题之一。大量研究表明不同的身体活动类型、活动强度、活动量以及生命早期的身体活动可能对老年人认知功能的各个方面有积极的影响, 包括执行功能、注意力、认知速度、记忆力等。此外, 选择性提高假说、心血管功能假说以及认知-锻炼模型用来解释这一影响机制。这些发现对维护老年人认知功能, 提高老年人的生命质量, 有效延缓衰老有着重要的意义。     

执行控制：一个具有广阔理论前途

面对千变万化的世界,我们需要实施计划行为、形成推理、解决问题、同时完成多项任务、适应新的环境和遵守社会规范。而要做到这些,我们必须随时监控外部世界和内心活动,排除或抑制无关信息的干扰,选择必要的信息输入,并从长时记忆中提取有关信息,对这些     

执行功能中认知灵活性发展的研究进展

近十多年以来,执行功能已成为研究的热点和前沿。认知灵活性是执行功能的主要成分,它对个体能力发展和对环境适应的方面起着重要作用。该文从认知灵活性的本质、发展、研究方法及其与教育的关系进行探讨。     

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。     

社会隔离对老年人认知功能的影响：有调节的链式中介效应

基于5162名老年被试,探究社会隔离对老年人认知功能的影响、孤独感和抑郁的中介作用以及认知储备的调节作用。研究发现：（1）社会隔离显著负向预测认知功能,朋友隔离的预测作用较家庭隔离突出;（2）抑郁在其间发挥独立中介作用,孤独感和抑郁在其间发挥链式中介作用;（3）认知储备显著调节社会隔离、孤独感和抑郁对认知功能的影响,低认知储备是孤独感独立中介作用成立的条件,且低认知储备下抑郁的独立中介作用以及孤独感和抑郁的链式中介作用更强。研究结论对于老年人认知功能的保护工作具有积极意义。     

运动习惯与社区老年人认知功能的关系

为评估社区老年人运动习惯与认知功能的关系,在北京市通过分层、方便取样的方法选取60岁以上的老年人732名,采用自编调查表收集一般人口学资料及运动习惯情况（包括有无运动习惯,运动频率,运动持续时间）,使用简明精神状态评估量表（MMSE）和北京版蒙特利尔认知评估量表（MoCA-BJ）评估认知功能。结果发现：（1）运动组整体认知功能及视空间定向能力得分均高于无运动组;（2）有无运动习惯可正向预测整体认知功能及视空间定向能力得分;（3）运动持续10年及以上组整体认知功能得分高于运动持续10年以下组。结果表明：相对于无运动习惯的社区老年人,有运动习惯的社区老年人的整体认知功能及视空间定向能力更好;运动持续年数较长,对社区老年人的认知功能起到促进作用。     

Enhancing the Cognitive Vitality of Older Adults

Aging is associated with decline in a multitude of cognitive processes and brain functions. However, a growing body of literature suggests that age-related decline in cognition can sometimes be reduced through experience, cognitive training, and other interventions such as fitness training. Research on cognitive training and expertise has suggested that age-related cognitive sparing is often quite narrow, being observed only on tasks and skills similar to those on which individuals have been trained. Furthermore, training and expertise benefits are often realized only after extensive practice with specific training strategies. Like cognitive training, fitness training has narrow effects on cognitive processes, but in the case of fitness training, the most substantial effects are observed for executive-control processes.     

Behavioural and ERP Effects of Cognitive and Combined Cognitive and Physical Training on Working Memory and Executive Function in Healthy Older Adults

Cognitive and physical training have been shown to be effective in improving older adults’ cognition. However, it is not yet clear whether combined cognitive and physical training offers an advantage compared to cognitive training alone. Twenty-two older adults performed cognitive or combined cognitive and physical training in order to compare their effects on working memory event-related potentials (ERPs) and on working memory and executive function performance. Before and after eight weeks of training, performance in Plus Minus, Flanker, Updated Span, and Complex Span tasks was measured, and ERPs were registered during performance of an n-back task (0-back, 2-back, and 3-back). Post-training behavioural improvement was observed in Updated Span, Complex Span, and n-back tasks. During the n-back task, the N2/P3 complex was modulated by training, with a decrease in N2 amplitude and an increase in P3 amplitude in the posttraining session compared to the pretraining session. These changes in ERP components suggest that both types of training potentially reduce the need for attentional control to perform the tasks correctly and increase working memory capacity. Thus, based on our data, no conclusion can be reached on the direct advantage of combined training, either at behavioural or at neural level. However, the present study might suggest an indirect advantage of such a combined training, because the cognitive benefit was found to be highly similar in both types of training. Using combined cognitive and physical training may produce a potential improvement in general fitness and an increased appeal of training.     

Absence of Ankle Stiffening While Standing in Focus and Cognitive Task Conditions in Older Adults

Abstract

Research suggests that an external focus or cognitive task may improve postural control. Removing attention from movement production may promote automaticity, or the tasks may promote ankle stiffening. To investigate these two theories, twenty older adults stood while performing baseline standing, internal focus, external focus, and two cognitive tasks. Changes in postural control occurred in external focus and cognitive task conditions compared to baseline and internal focus, while no change occurred in cocontraction indices. This suggests that an external focus and cognitive task can improve postural control in older adults. Since no change occurred in cocontraction indices across conditions, this suggests that stiffening cannot explain these changes. Instead, changes could be due to automaticity of sway.     

Presentation of Depression and Response to Group Cognitive Therapy with Older Patients

Concerned with response prediction, this research examines the relationships between pre-treatment components of depressive symptomatology and outcome of short-term group cognitive therapy for depression with older adults. Aspects of depressive symptomatology under examination were initial intensity of self-reported depressive symptomatology, profile of melancholic depression, perceived health status, perceived social support, and intensity of negative view of self. Findings indicate that perceived social support is not related to outcome but that a more intense depressive symptomatology, a more negative health evaluation, and a more negative view of self are variables associated with a less favorable outcome. Despite showing a sizable decrease in depressive symptoms over the course of intervention, severely depressed subjects still presented residual depressive symptoms at the conclusion of intervention. There was a tendency for subjects with a melancholic profile to show a poorer response to this intervention.     

Cognitive Behavior Therapy for Older Adults: Practical Guidelines for Adapting Therapy Structure

Cognitive behavioral therapy (CBT) has been shown to be an effective approach for a wide range of problems affecting older adults. While a variety of empirical and clinical papers have examined modifications to the content and delivery of CBT to enhance its efficacy with older adults, changes to the structure of therapy with this population have not been as widely discussed. Issues around optimizing the structure of CBT with older adults are presented, along with suggestions for realizing these changes within a clinical context.