工作记忆中的注意焦点转换

在工作记忆中的选择性注意及注意焦点机制的基础上,从3个方面回顾了对工作记忆中注意焦点转换的研究：（1）工作记忆中的注意焦点转换的概念及其基本研究方法;（2）影响注意焦点转换代价的因素,包括提取、复述、加工、更新和记忆集大小等;（3）注意焦点转换与工作记忆各功能成分之间的关系,包括注意焦点转换与工作记忆执行功能的关系,注意焦点转换反映的存储、加工和执行功能之间的相互关系,注意焦点转换与工作记忆中资源分配的关系。最后,该文展望了未来的研究方向     

作业中断对任务绩效的影响及心理疲劳的调节作用

作业中断会对中断后行为绩效产生影响,探讨不同疲劳状态下中断对作业绩效影响的认知机制将有助于完善和发展中断的认知理论。本研究采用事件相关电位(ERP),通过在不同心理疲劳状态下执行数学题任务中断、暂停中断和不中断的空间2-back任务,结合行为数据和ERPs结果,分析作业中断对任务绩效的影响以及心理疲劳在其中的调节作用。实验结果发现,中断后诱发的P200和P300振幅显著提高,作业中断使得主任务的注意力资源下降,任务中断的无关信息干扰了主任务工作记忆,而疲劳状态则进一步加剧了中断对注意资源、工作记忆及行为绩效的负面效应。本研究在揭示作业中断认知过程及疲劳对其影响机理的同时,也支持了中断的目标记忆模型。     

工作记忆中的积极效应：情绪效价与任务相关性的影响

积极效应指相比于年轻人, 老年人更倾向于优先加工积极情绪刺激而非消极情绪刺激。近年来工作记忆的研究发现积极效应会受到情绪效价与任务相关性的影响：情绪效价作为任务相关属性的研究支持工作记忆中存在积极效应, 具体表现为老年人对积极情绪刺激记忆的增强, 以及对消极情绪刺激记忆的减弱; 情绪效价作为工作记忆任务无关属性的研究相对较少, 且未发现一致的积极效应, 提示情绪效价及任务相关性均为影响工作记忆积极效应的关键因素。脑成像的研究初步表明, 工作记忆中情绪加工上的年龄效应与背侧执行系统和腹侧情绪系统的随龄功能变化有关。社会情绪选择理论与双竞争模型对工作记忆中的积极效应具备较大的解释力, 而动态整合理论尚缺乏实证研究支持。未来研究可进一步探究老年人工作记忆不同阶段情绪加工的特点, 澄清不同情绪材料内在编码过程上的差异对积极效应发生机制的潜在影响, 探讨情绪效价及任务相关性影响工作记忆积极效应的关键神经环路, 并揭示情绪工作记忆训练提升老年人认知功能与情绪体验的内在机制及其潜在应用价值。     

工作记忆在监控作业情境意识保持中的作用

本研究通过模拟复杂人机系统的监控作业,考察了长时工作记忆与短时工作记忆在情境意识保持中的作用。研究采用模拟的飞行相撞判断任务,通过考察中断任务对情境意识的影响,分析情境意识在记忆中的存储地点,以及保持时间是否会突破1分钟的限制。本研究选择了心理旋转和算式判断两种中断任务。实验结果表明,在问题回答之前的中断阶段,无论施加心理旋转任务,还是施加算式判断任务,无论中断任务的加工负荷与记忆负荷有多高,熟练被试的情境意识始终保持于较高的水平,并没有因受到中断任务的干扰而出现下降。新手被试的情境意识受到心理旋转任务和算式判断任务的显著影响,而且两种任务的执行速度越快、记忆负荷越大,情绪意识水平就越低。本研究结果说明熟练被试可以利用长时工作记忆存储情境意识,新手被试主要利用短时工作记忆存储情境意识。     

执行意向影响事件性前瞻记忆的加工机制

本研究旨在探究不同执行意向编码形式对前瞻记忆加工机制的影响是否存在差异。结果显示在低认知负荷下,混合编码效果最好,仅执行意向编码次之,标准编码效果最差,而在高认知负荷下三种编码效果无差异。眼动指标显示在低认知负荷下混合编码的注视点数量最多,总注视时间最长;在混合编码条件下进行中任务和前瞻记忆任务的总注视时间均长于仅执行意向编码和标准编码。结果说明,执行意向编码容易受认知负荷的影响;在低认知负荷下混合编码的被试对任务刺激进行更多的监控和加工,而仅执行意向编码促进前瞻记忆任务的自动化加工。     

视觉工作记忆负载类型对注意选择的影响

通过操纵Flanker任务相对于视觉工作记忆任务的呈现位置, 探讨在视觉工作记忆编码和保持阶段, 精度负载和容量负载对注意选择的影响。行为结果发现, Flanker任务呈现位置和视觉工作记忆负载类型影响注意选择; ERP结果发现, 在保持阶段, 当搜索目标和干扰项不一致时, 负载类型影响N2成分。研究表明, 在编码阶段, 视觉工作记忆负载主要通过占用更多知觉资源降低干扰效应, 支持知觉负载理论; 而在保持阶段, 当Flanker任务位于记忆项内部时, 两类负载在工作记忆表征过程中不同的神经活动导致投入到注意选择的认知控制资源不同, 可能是两类负载影响保持阶段注意选择的机制。     

负荷越大，转换更难-来自数字大小交替比较的证据

工作记忆与认知灵活性是执行功能的两个核心成分,但两者之间的关系并不清晰。本研究在一个数字大小交替比较任务中操纵工作记忆负荷,考察转换代价在不同记忆负荷下的差异。结果显示与非转换条件相比,转换条件下的反应时更长,正确率更低。另外,高记忆负荷下的转换代价显著高于低记忆负荷下的转换代价。这些结果表明工作记忆负荷越大,转换越难,代价越大。     

论执行功能及其发展研究

执行功能(executive function,EF)是一个还没有明确定义的概念,但又是一个重要的概念,通常是指个体对思想和行动进行有意识控制的心理过程。目前的主要观点包括神经心理学观点、抑制控制理论、高级认知能力理论(包括工作记忆理论、抑制及工作记忆理论)和认知复杂性和控制理论。主要的研究任务类型包括卡片分类任务、延迟反应任务、基于Stroop任务的冲突反应模式任务、心理理论任务、问题解决任务、“热”执行功能任务等。未来的研究应着重弄清执行功能的本质,结合认知神经科学阐明其与脑神经结构和功能的关系,并从区分“冷”执行功能和“热”执行功能的角度,探讨以情感激活为特点的“热认知”在执行功能中的作用。     

负荷越大，转换越难——来自数字大小交替比较的证据

工作记忆与认知灵活性是执行功能的两个核心成分,但两者之间的关系并不清晰。本研究在一个数字大小交替比较任务中操纵工作记忆负荷,考察转换代价在不同记忆负荷下的差异。结果显示与非转换条件相比,转换条件下的反应时更长,正确率更低。另外,高记忆负荷下的转换代价显著高于低记忆负荷下的转换代价。这些结果表明工作记忆负荷越大,转换越难,代价越大。     

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.     

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。     

Improving the effectiveness of an interruption lag by inducing a memory-based strategy

The memory for goals model (Altmann & Trafton, 2002) posits the importance of a short delay (the ‘interruption lag’) before an interrupting task to encode suspended goals for retrieval post-interruption. Two experiments used the theory of soft constraints (Gray, Simms, Fu & Schoelles, 2006) to investigate whether the efficacy of an interruption lag could be improved by increasing goal-state access cost to induce a more memory-based encoding strategy. Both experiments used a copying task with three access cost conditions (Low, Medium, and High) and a 5-s interruption lag with a no lag control condition. Experiment 1 found that the participants in the High access cost condition resumed more interrupted trials and executed more actions correctly from memory when coupled with an interruption lag. Experiment 2 used a prospective memory test post-interruption and an eyetracker recorded gaze activity during the interruption lag. The participants in the High access cost condition with an interruption lag were best at encoding target information during the interruption lag, evidenced by higher scores on the prospective memory measure and more gaze activity on the goal-state during the interruption lag. Theoretical and practical issues regarding the use of goal-state access cost and an interruption lag are discussed.     

Developmental change in working memory strategies: from passive maintenance to active refreshing

Change in strategies is often mentioned as a source of memory development. However, though performance in working memory tasks steadily improves during childhood, theories differ in linking this development to strategy changes. Whereas some theories, such as the time-based resource-sharing model, invoke the age-related increase in use and efficiency of a strategy of active maintenance of memory traces, other theories, such as the task-switching model, do not mention strategy change. According to these models, either the cognitive load of the task or the duration of maintenance would account for recall performance. In the present study, we varied orthogonally these 2 factors. The results revealed that a different and unique factor affected recall performance at different ages: the duration of maintenance at age 6 and the cognitive load at age 7. As described by the task-switching model, younger children would not implement any maintenance activities while performing a concurrent task, their memory traces suffering from a time-based decay. This suggests that an increasing capacity of cognitive monitoring allows children to shift from this passive maintenance of memory traces to the active refreshing thereof at around the age of 7, reunifying the 2 current accounts of working memory development as 2 developmental stages.     

How do we handle interruptions? Investigating the processes underlying the resumption of interrupted tasks

Although many researchers have studied interruptions and how detrimental they can be for performance, only a small number of studies have successfully identified the cognitive processes involved in the resumption of the primary task after an interruption. We carried out two experiments in which the complexity and the timing of interruption were manipulated. The participants also completed a set of cognitive tests assessing cognitive functions, such as working memory, inhibition or shifting, etc. Results showed that decreasing the complexity and introducing the interruption later in the task reduced the time needed to resume the primary task [i.e. resumption lag (RL)]. Moreover, the complexity effect was related to inhibition, shifting, selective attention and automation, while timing was related to working memory and divided attention. This study provides clues to help us better understand the processes involved when we interrupt our activities and indicates the need to look more deeply at the processes underlying resumption after interruptions.     

人类工作记忆的事件相关电位研究

20世纪90年代以来,采用ERP技术对人类工作记忆脑机制的研究已取得大量的成果。主要探讨了特定类型的工作记忆（词语、空间、客体工作记忆）是否存在与其贮存、复述以及中央执行功能相关的特异性ERP成分,并从它们的时间进程及头皮分布来考察工作记忆的心理过程和神经机制。研究结果对于Baddeley的认知结构模型提供了有益的修正和补充。     

Working memory and executive function: The influence of content and load on the control of attention

In a series of three experiments, increasing working memory (WM) load was demonstrated to reduce the executive control of attention, measured via task-switching and inhibitory control paradigms. Uniquely, our paradigms allowed comparison of the ability to exert executive control when the stimulus was either part of the currently rehearsed memory set or an unrelated distractor item. The results demonstrated a content-specific effect-insofar as switching attention away from, or exerting inhibitory control over, items currently held in WM was especially difficult-compounded by increasing WM load. This finding supports the attentional control theory that active maintenance of competing task goals is critical to executive function and WM capacity; however, it also suggests that the increased salience provided to the contents of WM through active rehearsal exerts a content-specific influence on attentional control. These findings are discussed in relation to cue-induced ruminations, where active rehearsal of evocative information (e.g., negative thoughts in depression or drug-related thoughts in addiction) in WM typically results from environmental cuing. The present study has demonstrated that when information currently maintained in WM is reencountered, it is harder to exert executive control over it. The difficulty with suppressing the processing of these stimuli presumably reinforces the maintenance of these items in WM, due to the greater level of attention they are afforded, and may help to explain how the cue-induced craving/rumination cycle is perpetuated.     

Goal-directed access to mental objects in working memory: The role of task-specific feature retrieval

In the present study, we examined the hypothesis of task-specific access to mental objects from verbal working memory. It is currently assumed that a mental object is brought into the focus of attention in working memory by a process of object selection, which provides this object for any upcoming mental operation (Oberauer, 2002). We argue that this view must be extended, since the selection of information for processing is always guided by current intentions and task goals. In our experiments, it was required that two kinds of comparison tasks be executed on digits selected from a set of three digits held in working memory. The tasks differed in regard to the object features the comparison was based on. Access to a new mental object (object switch) took consistently longer on the semantic comparison task than on the recognition task. This difference is not attributable to object selection difficulty and cannot be fully accounted for by task difficulty or differences in rehearsal processes. The results support our assumptions that (1) mental objects are selected for a given specific task and, so, are accessed with their specific task-relevant object features; (2) verbal mental objects outside the focus of attention are usually not maintained at a full feature level but are refreshed phonologically by subvocal rehearsal; and (3) if more than phonological information is required, access to mental objects involves feature retrieval processes in addition to object selection.     

An analysis of memory-based theories of automaticity

Memory-based theories of automaticity predict that performance in a memory search task which is automatic will not require a representation of the memory set in working memory. The information contained in working memory was manipulated by inserting an interference task between the presentation of a memory set and a probe stimulus in a memory search task. The interference task prevented rehearsal, necessitating the retrieval of the memory set from long-term memory in variably mapped (VM) conditions. Performance in consistently mapped (CM) conditions provided strong support for memory-based theories of automaticity. With CM practice, both the effects of memory load and the effect of the interference task were eliminated. Furthermore, there was a temporal coupling in the reduction of these two effects with consistent practice. Monte Carlo simulations of memory-based automaticity predict such a temporal coupling. Automaticity is viewed as a continuum reflecting the relative contribution of the direct memory access of past solutions from long-term memory on performance.     

The effects of environmental support and secondary tasks on visuospatial working memory

In the present experiments, we examined the effects of environmental support on participants’ ability to rehearse locations and the role of such support in the effects of secondary tasks on memory span. In Experiment 1, the duration of interitem intervals and the presence of environmental support for visuospatial rehearsal (i.e., the array of possible memory locations) during the interitem intervals were both manipulated across four tasks. When support was provided, memory spans increased as the interitem interval durations increased, consistent with the hypothesis that environmental support facilitates rehearsal. In contrast, when environmental support was not provided, spans decreased as the duration of the interitem intervals increased, consistent with the hypothesis that visuospatial memory representations decay when rehearsal is impeded. In Experiment 2, the ratio of interitem interval duration to intertrial interval duration was kept the same on all four tasks, in order to hold temporal distinctiveness constant, yet forgetting was still observed in the absence of environmental support, consistent with the decay hypothesis. In Experiment 3, the effects of impeding rehearsal were compared to the effects of verbal and visuospatial secondary processing tasks. Forgetting of locations was greater when presentation of to-be-remembered locations alternated with the performance of a secondary task than when rehearsal was impeded by the absence of environmental support. The greatest forgetting occurred when a secondary task required the processing visuospatial information, suggesting that in addition to decay, both domain-specific and domain-general effects contribute to forgetting on visuospatial working memory tasks.