工作记忆

已由Xebec进行初步翻译。由和光同尘审校。

Working memory is a cognitive system with a limited capacity that can hold information temporarily. Working memory is important for reasoning and the guidance of decision-making and behavior. Working memory is often used synonymously with short-term memory, but some theorists consider the two forms of memory distinct, assuming that working memory allows for the manipulation of stored information, whereas short-term memory only refers to the short-term storage of information. Working memory is a theoretical concept central to cognitive psychology, neuropsychology, and neuroscience.

Working memory is a cognitive system with a limited capacity that can hold information temporarily. Working memory is important for reasoning and the guidance of decision-making and behavior. Working memory is often used synonymously with short-term memory, but some theorists consider the two forms of memory distinct, assuming that working memory allows for the manipulation of stored information, whereas short-term memory only refers to the short-term storage of information. Working memory is a theoretical concept central to cognitive psychology, neuropsychology, and neuroscience.

工作记忆 Working Memory是一种能临时容纳有限信息的认知系统，对推理、决策倾向和行为倾向有着重要影响。工作记忆常作为短期记忆 short-term Memory的同义词，但一些理论学者认为，工作记忆能够调用存储的信息，而短期记忆仅指短期存储的信息，故二者不同。工作记忆是认知心理学 cognitive psychology 、神经心理学 neuropsychology 和神经科学 neuroscience 的核心概念之一。

历史 History

The term "working memory" was coined by Miller, Galanter, and Pribram, and was used in the 1960s in the context of theories that likened the mind to a computer. In 1968, Atkinson and Shiffrin used the term to describe their "short-term store". What we now call working memory was formerly referred to variously as a "short-term store" or short-term memory, primary memory, immediate memory, operant memory, and provisional memory. Short-term memory is the ability to remember information over a brief period (in the order of seconds). Most theorists today use the concept of working memory to replace or include the older concept of short-term memory, marking a stronger emphasis on the notion of manipulating information rather than mere maintenance.

The term "working memory" was coined by Miller, Galanter, and Pribram, and was used in the 1960s in the context of theories that likened the mind to a computer. In 1968, Atkinson and Shiffrin used the term to describe their "short-term store". What we now call working memory was formerly referred to variously as a "short-term store" or short-term memory, primary memory, immediate memory, operant memory, and provisional memory. Short-term memory is the ability to remember information over a brief period (in the order of seconds). Most theorists today use the concept of working memory to replace or include the older concept of short-term memory, marking a stronger emphasis on the notion of manipulating information rather than mere maintenance.

“工作记忆 Working Memory”这个术语由米勒 Miller、加兰特 Galanter和普里布拉姆 Pribram 提出，在20世纪60年代被应用于把大脑比作计算机的理论研究之中。1968年，阿特金森 Atkinson和谢福林 Shiffrin 用该术语来表述“短期存储”。我们现在所说的工作记忆就是之前所谓的“短期存储”、“短期记忆”、“初级记忆”、“即时记忆”、“操作记忆”或“临时记忆”。短期记忆是在短时间内（以秒为单位）记住信息的能力。如今，大多数理论学者会使用“工作记忆”这一概念取代或包含早期“短期记忆”的概念，这体现出对信息操纵观念的重视。

The earliest mention of experiments on the neural basis of working memory can be traced back to more than 100 years ago, when Hitzig and Ferrier described ablation experiments of the prefrontal cortex (PFC); they concluded that the frontal cortex was important for cognitive rather than sensory processes. In 1935 and 1936, Carlyle Jacobsen and colleagues were the first to show the deleterious effect of prefrontal ablation on delayed response.

The earliest mention of experiments on the neural basis of working memory can be traced back to more than 100 years ago, when Hitzig and Ferrier described ablation experiments of the prefrontal cortex (PFC); they concluded that the frontal cortex was important for cognitive rather than sensory processes. In 1935 and 1936, Carlyle Jacobsen and colleagues were the first to show the deleterious effect of prefrontal ablation on delayed response.

关于工作记忆神经学基础的实验最早可追溯到100多年前希齐格 Hitzig 和费里尔 Ferrier 对前额叶皮质消融实验的研究（PFC）。额叶皮层 frontal cortex对认知程序比对感官程序更重要是当时研究得出的一大结论。在1935年和1936年， 卡莱尔 · 雅各布森 Carlyle Jacobsen及其同事们首次披露了前额叶切除对延时反映的不良影响 。

理论 Theories

Numerous models have been proposed for how working memory functions, both anatomically and cognitively. Of those, the two that have been most influential are summarized below.

Numerous models have been proposed for how working memory functions, both anatomically and cognitively. Of those, the two that have been most influential are summarized below.

基于解剖学和认识学，人们设计出工作记忆运行的神经模型，其中最有影响力的两个模型概括如下：

多组件模型 The multicomponent model

Main article: Baddeley's model of working memory

巴德利 Baddeley和希池 Hitch 的工作记忆模型

[图1：巴德利 Baddeley和希池 Hitch 的工作记忆模型]

In 1974, Baddeley and Hitch introduced the multicomponent model of working memory. The theory proposed a model containing three components: the central executive, the phonological loop, and the visuospatial sketchpad with the central executive functioning as a control center of sorts, directing info between the phonological and visuospatial components. The central executive is responsible for, among other things, directing attention to relevant information, suppressing irrelevant information and inappropriate actions, and coordinating cognitive processes when more than one task is simultaneously performed. A "central executive" is responsible for supervising the integration of information and for coordinating subordinate systems responsible for the short-term maintenance of information. One subordinate system, the phonological loop (PL), stores phonological information (that is, the sound of language) and prevents its decay by continuously refreshing it in a rehearsal loop. It can, for example, maintain a seven-digit telephone number for as long as one repeats the number to oneself again and again. The other subordinate system, the visuospatial sketchpad, stores visual and spatial information. It can be used, for example, for constructing and manipulating visual images and for representing mental maps. The sketchpad can be further broken down into a visual subsystem (dealing with such phenomena as shape, colour, and texture), and a spatial subsystem (dealing with location).

In 1974, Baddeley and Hitch introduced the multicomponent model of working memory. The theory proposed a model containing three components: the central executive, the phonological loop, and the visuospatial sketchpad with the central executive functioning as a control center of sorts, directing info between the phonological and visuospatial components. The central executive is responsible for, among other things, directing attention to relevant information, suppressing irrelevant information and inappropriate actions, and coordinating cognitive processes when more than one task is simultaneously performed. A "central executive" is responsible for supervising the integration of information and for coordinating subordinate systems responsible for the short-term maintenance of information. One subordinate system, the phonological loop (PL), stores phonological information (that is, the sound of language) and prevents its decay by continuously refreshing it in a rehearsal loop. It can, for example, maintain a seven-digit telephone number for as long as one repeats the number to oneself again and again. The other subordinate system, the visuospatial sketchpad, stores visual and spatial information. It can be used, for example, for constructing and manipulating visual images and for representing mental maps. The sketchpad can be further broken down into a visual subsystem (dealing with such phenomena as shape, colour, and texture), and a spatial subsystem (dealing with location).

1974年，Baddeley和Hitch提出了工作记忆多组件模型 Multicomponent Model of Working Memory——该模型由三个组件构成：中央执行器 Central Executive、语音回路（PL） Phonological Loop (PL)、视觉绘板 Visuospatial Sketchpad。其中，中央执行器作为某种控制中心，负责疏通语音回路和视觉绘板之间的信息传递通道，引导相关信息，抑制无关信息及不当行为，保持认知程序在执行多任务时的协调。中央执行器还会监督信息的整合以及协调各个负责短期信息维护的子系统。语音回路（PL）组件用于存储语音信息并通过不断刷新防止其受损，例如，只要不断重复一个7位数的电话号码它就可以被很好地储存。而视觉绘板组件则负责存储视觉和空间信息，例如构建、操控视觉图像及展现精神世界。视觉绘板还可进一步分为视觉子系统visual subsystem（处理形状、颜色和纹理等）和空间子系统spatial subsystem（处理位置）。

In 2000, Baddeley extended the model by adding a fourth component, the episodic buffer, which holds representations that integrate phonological, visual, and spatial information, and possibly information not covered by the subordinate systems (e.g., semantic information, musical information). The episodic buffer is also the link between working memory and long-term memory. The component is episodic because it is assumed to bind information into a unitary episodic representation. The episodic buffer resembles Tulving's concept of episodic memory, but it differs in that the episodic buffer is a temporary store.

In 2000, Baddeley extended the model by adding a fourth component, the episodic buffer, which holds representations that integrate phonological, visual, and spatial information, and possibly information not covered by the subordinate systems (e.g., semantic information, musical information). The episodic buffer is also the link between working memory and long-term memory. The component is episodic because it is assumed to bind information into a unitary episodic representation. The episodic buffer resembles Tulving's concept of episodic memory, but it differs in that the episodic buffer is a temporary store.

2000年，Baddeley 增加了第四个组件情景缓冲区 Episodic Buffer，这进一步扩展了该模型。情景缓冲区可以整合语音、视觉、空间信息，及可能未被子系统涵盖的信息（例如语义、音乐）。它同时是工作记忆和长期记忆之间的枢纽。该组件的基本原理是把信息绑定到单一情节，因此它的运行是情节性的。情景缓冲区与图尔文 Tulving情景记忆 Episodic Memory的概念类似，不同之处在于情景缓冲区是临时存储 。

作为长期记忆一部分的工作记忆 Working memory as part of long-term memory

模板:Annotated imageAnders Ericsson and Walter Kintsch have introduced the notion of "long-term working memory", which they define as a set of "retrieval structures" in long-term memory that enable seamless access to the information relevant for everyday tasks. In this way, parts of long-term memory effectively function as working memory. In a similar vein, Cowan does not regard working memory as a separate system from long-term memory. Representations in working memory are a subset of representations in long-term memory. Working memory is organized into two embedded levels. The first consists of long-term memory representations that are activated. There can be many of these—there is theoretically no limit to the activation of representations in long-term memory. The second level is called the focus of attention. The focus is regarded as having a limited capacity and holds up to four of the activated representations.

Anders Ericsson and Walter Kintsch have introduced the notion of "long-term working memory", which they define as a set of "retrieval structures" in long-term memory that enable seamless access to the information relevant for everyday tasks. In this way, parts of long-term memory effectively function as working memory. In a similar vein, Cowan does not regard working memory as a separate system from long-term memory. Representations in working memory are a subset of representations in long-term memory. Working memory is organized into two embedded levels. The first consists of long-term memory representations that are activated. There can be many of these—there is theoretically no limit to the activation of representations in long-term memory. The second level is called the focus of attention. The focus is regarded as having a limited capacity and holds up to four of the activated representations.

模板:Annotated image安德斯 · 埃里克森 Anders Ericsson 和沃尔特 · 金奇 Walter Kintsch 引入了“长期工作记忆 Long-term Working Memory”这一概念，即一组能让人从长期记忆 Long-term Memory中无缝获取日常所需信息的“检索结构” 。也就是说，一部分长期记忆有效地发挥了工作记忆的作用。同样，考恩 Cowan 并不认为工作记忆完全独立于长期记忆的。工作记忆的表征是长期记忆表征的一个子集。工作记忆被处理成两个嵌入层次。第一层为被激活的长期记忆表征（可能会很多，毕竟理论上长期记忆表征的激活是没有上限的）。第二层叫做注意力焦点focus，焦点被认为是一种有限能力，可容纳四个激活的表征。

Oberauer has extended Cowan's model by adding a third component, a more narrow focus of attention that holds only one chunk at a time. The one-element focus is embedded in the four-element focus and serves to select a single chunk for processing. For example, four digits can be held in mind at the same time in Cowan's "focus of attention". When the individual wishes to perform a process on each of these digits—for example, adding the number two to each digit—separate processing is required for each digit since most individuals cannot perform several mathematical processes in parallel. Oberauer's attentional component selects one of the digits for processing and then shifts the attentional focus to the next digit, continuing until all digits have been processed.

Oberauer has extended Cowan's model by adding a third component, a more narrow focus of attention that holds only one chunk at a time. The one-element focus is embedded in the four-element focus and serves to select a single chunk for processing. For example, four digits can be held in mind at the same time in Cowan's "focus of attention". When the individual wishes to perform a process on each of these digits—for example, adding the number two to each digit—separate processing is required for each digit since most individuals cannot perform several mathematical processes in parallel. Oberauer's attentional component selects one of the digits for processing and then shifts the attentional focus to the next digit, continuing until all digits have been processed.

奥伯奥尔 Oberauer 在Cowan模型的基础上又添加了一个组件——一个更窄的注意力焦点，一次只能容纳一个组块chunk。单元素焦点系统嵌在四元素焦点系统之中，用于挑选要处理的单个块。例如，根据Cowan 的“注意力焦点”理论，四个数字可以同时出现在脑海中。当个体要加工所有数字时（例如，将数字2加到每个数字）必须要先对每个数字进行独立加工（因为大多数人不能同时处理多个数学问题）。此时Oberauer 的注意力组件将选择其中一个数字进行处理，结束后就把焦点转到下一个数字，直到处理完毕。

容量 Capacity

Working memory is widely acknowledged as having limited capacity. An early quantification of the capacity limit associated with short-term memory was the "magical number seven" suggested by Miller in 1956. He claimed that the information-processing capacity of young adults is around seven elements, which he called "chunks", regardless of whether the elements are digits, letters, words, or other units. Later research revealed this number depends on the category of chunks used (e.g., span may be around seven for digits, six for letters, and five for words), and even on features of the chunks within a category. For instance, span is lower for long than short words. In general, memory span for verbal contents (digits, letters, words, etc.) depends on the phonological complexity of the content (i.e., the number of phonemes, the number of syllables), and on the lexical status of the contents (whether the contents are words known to the person or not). Several other factors affect a person's measured span, and therefore it is difficult to pin down the capacity of short-term or working memory to a number of chunks. Nonetheless, Cowan proposed that working memory has a capacity of about four chunks in young adults (and fewer in children and old adults).

Working memory is widely acknowledged as having limited capacity. An early quantification of the capacity limit associated with short-term memory was the "magical number seven" suggested by Miller in 1956. He claimed that the information-processing capacity of young adults is around seven elements, which he called "chunks", regardless of whether the elements are digits, letters, words, or other units. Later research revealed this number depends on the category of chunks used (e.g., span may be around seven for digits, six for letters, and five for words), and even on features of the chunks within a category. For instance, span is lower for long than short words. In general, memory span for verbal contents (digits, letters, words, etc.) depends on the phonological complexity of the content (i.e., the number of phonemes, the number of syllables), and on the lexical status of the contents (whether the contents are words known to the person or not). Several other factors affect a person's measured span, and therefore it is difficult to pin down the capacity of short-term or working memory to a number of chunks. Nonetheless, Cowan proposed that working memory has a capacity of about four chunks in young adults (and fewer in children and old adults).

工作记忆通常被认为容量有限。1956年，米勒 Miller提出了“神奇数字7 The Magical Number Seven”来量化短期记忆。他认为年轻人的信息处理能力容量大约是7个元素，称之为组块。组块内容可以是数字、字母、单词等。后续的研究发现，这个数字的大小取决于所用组块的类别（例如，数字对应7个，字母对应6个，单词对应5个）甚至取决于该类别中组块的特征。例如，长词的组块数会低于短词的组块数。一般而言，口头内容（数字、字母、单词）的记忆规模取决于内容的音系复杂度（即音素、音节的量）以及所用词汇状态（内容所用单词是否为主体所知）。除此之外，还有其他若干因素也会影响人的记忆规模，因此难以确定短期记忆或工作记忆的组块数。尽管如此，Cowan还是认为年轻人的工作记忆容量大约是4个组块（儿童和老年人则更少） 。

Whereas most adults can repeat about seven digits in correct order, some individuals have shown impressive enlargements of their digit span—up to 80 digits. This feat is possible by extensive training on an encoding strategy by which the digits in a list are grouped (usually in groups of three to five) and these groups are encoded as a single unit (a chunk). For this to succeed, participants must be able to recognize the groups as some known string of digits. One person studied by Ericsson and his colleagues, for example, used an extensive knowledge of racing times from the history of sports in the process of coding chunks: several such chunks could then be combined into a higher-order chunk, forming a hierarchy of chunks. In this way, only some chunks at the highest level of the hierarchy must be retained in working memory, and for retrieval the chunks are unpacked. That is, the chunks in working memory act as retrieval cues that point to the digits they contain. Practicing memory skills such as these does not expand working memory capacity proper: it is the capacity to transfer (and retrieve) information from long-term memory that is improved, according to Ericsson and Kintsch (1995; see also Gobet & Simon, 2000).

Whereas most adults can repeat about seven digits in correct order, some individuals have shown impressive enlargements of their digit span—up to 80 digits. This feat is possible by extensive training on an encoding strategy by which the digits in a list are grouped (usually in groups of three to five) and these groups are encoded as a single unit (a chunk). For this to succeed, participants must be able to recognize the groups as some known string of digits. One person studied by Ericsson and his colleagues, for example, used an extensive knowledge of racing times from the history of sports in the process of coding chunks: several such chunks could then be combined into a higher-order chunk, forming a hierarchy of chunks. In this way, only some chunks at the highest level of the hierarchy must be retained in working memory, and for retrieval the chunks are unpacked. That is, the chunks in working memory act as retrieval cues that point to the digits they contain. Practicing memory skills such as these does not expand working memory capacity proper: it is the capacity to transfer (and retrieve) information from long-term memory that is improved, according to Ericsson and Kintsch (1995; see also Gobet & Simon, 2000).

大多数成年人能够正确地重复7个数字，但有些个体的记忆规模则得到了显著扩充——高达80个数字。这可以通过编码策略培训来实现。按编码策略将列表中的数字分组（通常分3到5组）并将这些组编码为一个独立单元（一个组块）。要实现这一点，参与者必须要将组识别为某些已知的数字字符串。例如，埃里克森 Ericsson 和他同事的一位研究对象利用了体育史中各大比赛的时间来编写代码组块: 几个这样的组块可组合成一个更高级的组块，形成组块层次结构。如此，只要层次结构最高级别的组块保持在工作记忆中即可——当然这些组块是可检索的。也就是说，工作记忆中的组块是提取数字内容的指向性线索。埃里克森 Ericsson 和 金茨 Kintsch （1995; 参见 Gobet & Simon，2000）认为，练习这种记忆技巧并不能真正提高工作记忆容量，所提高的是从长期记忆中传递（和检索）信息的能力。

测量和关联 Measures and correlates

Working memory capacity can be tested by a variety of tasks. A commonly used measure is a dual-task paradigm, combining a memory span measure with a concurrent processing task, sometimes referred to as "complex span". Daneman and Carpenter invented the first version of this kind of task, the "reading span", in 1980. Subjects read a number of sentences (usually between two and six) and tried to remember the last word of each sentence. At the end of the list of sentences, they repeated back the words in their correct order. Other tasks that do not have this dual-task nature have also been shown to be good measures of working memory capacity. Whereas Daneman and Carpenter believed that the combination of "storage" (maintenance) and processing is needed to measure working memory capacity, we know now that the capacity of working memory can be measured with short-term memory tasks that have no additional processing component. Conversely, working memory capacity can also be measured with certain processing tasks that don't involve maintenance of information. The question of what features a task must have to qualify as a good measure of working memory capacity is a topic of ongoing research.

Working memory capacity can be tested by a variety of tasks. A commonly used measure is a dual-task paradigm, combining a memory span measure with a concurrent processing task, sometimes referred to as "complex span". Daneman and Carpenter invented the first version of this kind of task, the "reading span", in 1980. Subjects read a number of sentences (usually between two and six) and tried to remember the last word of each sentence. At the end of the list of sentences, they repeated back the words in their correct order. Other tasks that do not have this dual-task nature have also been shown to be good measures of working memory capacity. Whereas Daneman and Carpenter believed that the combination of "storage" (maintenance) and processing is needed to measure working memory capacity, we know now that the capacity of working memory can be measured with short-term memory tasks that have no additional processing component. Conversely, working memory capacity can also be measured with certain processing tasks that don't involve maintenance of information. The question of what features a task must have to qualify as a good measure of working memory capacity is a topic of ongoing research.

我们可以通过一系列任务来测量工作记忆的容量。其中一个方法是双任务范例，它将记忆广度测度 memory span measure与并发处理任务concurrent processing task（有时称为“复杂规模”）结合起来。1980年，丹曼 Daneman 和 卡朋特 Carpenter 发明了该方法的第一个版本——“阅读广度”。受试者阅读大量的句子（通常2至6个），并努力记住每个句子的最后一个单词。阅读完后他们按照自己认为正确的顺序复述单词。其他一些不具备双任务性质的任务同样也是测量工作记忆容量的好办法。Daneman 和Carpenter 相信“存储”（维护）和加工的结合是测量工作记忆容量所必须的，现在我们知道工作记忆的容量既可以用没有额外处理组件的短时记忆任务来测量，也可以用不涉及信息维护的某些处理任务来衡量。至于用于测量工作记忆容量的好的任务方案应当具备哪些特征，这仍是一个待研究的课题。

Measures of working-memory capacity are strongly related to performance in other complex cognitive tasks, such as reading comprehension, problem solving, and with measures of intelligence quotient.

Measures of working-memory capacity are strongly related to performance in other complex cognitive tasks, such as reading comprehension, problem solving, and with measures of intelligence quotient.

工作记忆容量的测量与其他复杂认知任务中的表现有密切联系，例如阅读理解 reading comprehension、问题解决 problem solving和智商测量intelligence quotient。。

Some researchers have argued that working-memory capacity reflects the efficiency of executive functions, most notably the ability to maintain multiple task-relevant representations in the face of distracting irrelevant information; and that such tasks seem to reflect individual differences in the ability to focus and maintain attention, particularly when other events are serving to capture attention. Both working memory and executive functions rely strongly, though not exclusively, on frontal brain areas.

Some researchers have argued that working-memory capacity reflects the efficiency of executive functions, most notably the ability to maintain multiple task-relevant representations in the face of distracting irrelevant information; and that such tasks seem to reflect individual differences in the ability to focus and maintain attention, particularly when other events are serving to capture attention. Both working memory and executive functions rely strongly, though not exclusively, on frontal brain areas.

一些研究人员认为，工作记忆容量能够反映执行功能的效率，其中最具代表性的是面对不相关信息时协调多个任务相关表征的能力; 且这样的任务似乎也反映出在集中注意力和保持注意力方面的个体能力差异（特别是当其他事件能吸引注意力时）。工作记忆和执行功能都非常依赖（但不限于）额叶大脑区域 。

Other researchers have argued that the capacity of working memory is better characterized as the ability to mentally form relations between elements, or to grasp relations in given information. This idea has been advanced, among others, by Graeme Halford, who illustrated it by our limited ability to understand statistical interactions between variables. These authors asked people to compare written statements about the relations between several variables to graphs illustrating the same or a different relation, as in the following sentence: "If the cake is from France, then it has more sugar if it is made with chocolate than if it is made with cream, but if the cake is from Italy, then it has more sugar if it is made with cream than if it is made of chocolate". This statement describes a relation between three variables (country, ingredient, and amount of sugar), which is the maximum most individuals can understand. The capacity limit apparent here is obviously not a memory limit (all relevant information can be seen continuously) but a limit to how many relationships are discerned simultaneously.

Other researchers have argued that the capacity of working memory is better characterized as the ability to mentally form relations between elements, or to grasp relations in given information. This idea has been advanced, among others, by Graeme Halford, who illustrated it by our limited ability to understand statistical interactions between variables. These authors asked people to compare written statements about the relations between several variables to graphs illustrating the same or a different relation, as in the following sentence: "If the cake is from France, then it has more sugar if it is made with chocolate than if it is made with cream, but if the cake is from Italy, then it has more sugar if it is made with cream than if it is made of chocolate". This statement describes a relation between three variables (country, ingredient, and amount of sugar), which is the maximum most individuals can understand. The capacity limit apparent here is obviously not a memory limit (all relevant information can be seen continuously) but a limit to how many relationships are discerned simultaneously.

另一些研究人员主张，用个体构建元素间关系或获取信息的能力来测量工作记忆容量更佳。格雷姆 · 哈尔福德Graeme Halford用我们理解变量之间统计交互作用的有限能力来解释这个想法。这些发起人要求人们把陈述几个变量之间关系的书面表达与相应的图示（说明相同或不同关系）进行比较，例如: ”如果蛋糕来自法国，那么用巧克力做的比用奶油做的含糖量高。但如果蛋糕来自意大利，那么用奶油做的比用巧克力做的含糖量高”。这个陈述描述了三个变量之间的关系（国家、成分和糖量）——这是大多数人理解能力的上限。这里的容量限制显然不是记忆量限制（所有相关信息都可完整看到），而是可同时识别关系量的限制。

工作记忆容量的试验研究 Experimental studies of working-memory capacity

There are several hypotheses about the nature of the capacity limit. One is that a limited pool of cognitive resources is needed to keep representations active and thereby available for processing, and for carrying out processes. Another hypothesis is that memory traces in working memory decay within a few seconds, unless refreshed through rehearsal, and because the speed of rehearsal is limited, we can maintain only a limited amount of information. Yet another idea is that representations held in working memory interfere with each other.

There are several hypotheses about the nature of the capacity limit. One is that a limited pool of cognitive resources is needed to keep representations active and thereby available for processing, and for carrying out processes. Another hypothesis is that memory traces in working memory decay within a few seconds, unless refreshed through rehearsal, and because the speed of rehearsal is limited, we can maintain only a limited amount of information. Yet another idea is that representations held in working memory interfere with each other.

关于容量极限capacity limit的性质有几种假设。一种观点认为其性质是一种有限认知资源池，作为激活记忆表征以及处理记忆表征的前提，另一种观点认为工作记忆若不反复刷新将会在几秒内衰退。又因为刷新速率是有限的，所以我们只能维持一定的信息量。还有观点认为容量极限是工作记忆中的表征互相干涉的结果。

衰变理论 Decay theories

The assumption that the contents of short-term or working memory decay over time, unless decay is prevented by rehearsal, goes back to the early days of experimental research on short-term memory. It is also an important assumption in the multi-component theory of working memory. The most elaborate decay-based theory of working memory to date is the "time-based resource sharing model". This theory assumes that representations in working memory decay unless they are refreshed. Refreshing them requires an attentional mechanism that is also needed for any concurrent processing task. When there are small time intervals in which the processing task does not require attention, this time can be used to refresh memory traces. The theory therefore predicts that the amount of forgetting depends on the temporal density of attentional demands of the processing task—this density is called "cognitive load". The cognitive load depends on two variables, the rate at which the processing task requires individual steps to be carried out, and the duration of each step. For example, if the processing task consists of adding digits, then having to add another digit every half second places a higher cognitive load on the system than having to add another digit every two seconds. In a series of experiments, Barrouillet and colleagues have shown that memory for lists of letters depends neither on the number of processing steps nor the total time of processing but on cognitive load.

The assumption that the contents of short-term or working memory decay over time, unless decay is prevented by rehearsal, goes back to the early days of experimental research on short-term memory. It is also an important assumption in the multi-component theory of working memory. The most elaborate decay-based theory of working memory to date is the "time-based resource sharing model". This theory assumes that representations in working memory decay unless they are refreshed. Refreshing them requires an attentional mechanism that is also needed for any concurrent processing task. When there are small time intervals in which the processing task does not require attention, this time can be used to refresh memory traces. The theory therefore predicts that the amount of forgetting depends on the temporal density of attentional demands of the processing task—this density is called "cognitive load". The cognitive load depends on two variables, the rate at which the processing task requires individual steps to be carried out, and the duration of each step. For example, if the processing task consists of adding digits, then having to add another digit every half second places a higher cognitive load on the system than having to add another digit every two seconds. In a series of experiments, Barrouillet and colleagues have shown that memory for lists of letters depends neither on the number of processing steps nor the total time of processing but on cognitive load.

该理论假设短期记忆或工作记忆的内容会随着时间的推移而衰退 decay，这种衰退只能通过不断刷新来遏制。这种理论来自短期记忆的早期研究。它同样是工作记忆多元理论中的一个重要假设。迄今为止，基于衰减假设的最详尽的工作记忆理论是“基于时间的资源共享模型 time-based resource sharing model” 。该理论假设工作记忆中的表征不断衰退，需要持续刷新来维持。而刷新需要注意力机制——对于任何平行任务都是必需的——的保障。当任务进程中存在不需要注意力的微小时间间隔时，刷新记忆路径的任务可以在此时完成。因此，该理论推测遗忘量取决于任务进程所需即时注意力的密度，这种密度叫做“认知负荷”。认知负荷取决于两个变量，一是任务进程中各个步骤执行的速率，二是每个步骤的持续时间。例如，如果处理的任务内容是数字添加，那么每半秒添加一个数字会比每两秒添加一个数字给系统带来的认知负荷更大。在一系列的实验中，巴鲁耶 Barrouillet 及其同事证明字母列表的记忆并不取决于处理步骤的数量或者处理的总时间，而是取决于认知负荷。

资源理论 Resource theories

Resource theories assume that the capacity of working memory is a limited resource that must be shared between all representations that need to be maintained in working memory simultaneously. Some resource theorists also assume that maintenance and concurrent processing share the same resource; this can explain why maintenance is typically impaired by a concurrent processing demand. Resource theories have been very successful in explaining data from tests of working memory for simple visual features, such as colors or orientations of bars. An ongoing debate is whether the resource is a continuous quantity that can be subdivided among any number of items in working memory, or whether it consists of a small number of discrete "slots", each of which can be assigned to one memory item, so that only a limited number of about 3 items can be maintained in working memory at all.

Resource theories assume that the capacity of working memory is a limited resource that must be shared between all representations that need to be maintained in working memory simultaneously. Some resource theorists also assume that maintenance and concurrent processing share the same resource;

资源理论 resource theories认为工作记忆容量是一种由储存于工作记忆中的全部表征所共享的有限资源。一些资源理论学者同时还假设维护和并行处理会占用同样的资源;

干涉理论 Interference theories

Several forms of interference have been discussed by theorists. One of the oldest ideas is that new items simply replace older ones in working memory. Another form of interference is retrieval competition. For example, when the task is to remember a list of 7 words in their order, we need to start recall with the first word. While trying to retrieve the first word, the second word, which is represented in proximity, is accidentally retrieved as well, and the two compete for being recalled. Errors in serial recall tasks are often confusions of neighboring items on a memory list (so-called transpositions), showing that retrieval competition plays a role in limiting our ability to recall lists in order, and probably also in other working memory tasks. A third form of interference is the distortion of representations by superposition: When multiple representations are added on top of each other, each of them is blurred by the presence of all the others. A fourth form of interference assumed by some authors is feature overwriting. The idea is that each word, digit, or other item in working memory is represented as a bundle of features, and when two items share some features, one of them steals the features from the other. The more items are held in working memory, and the more their features overlap, the more each of them will be degraded by the loss of some features.

Several forms of interference have been discussed by theorists. One of the oldest ideas is that new items simply replace older ones in working memory. Another form of interference is retrieval competition. For example, when the task is to remember a list of 7 words in their order, we need to start recall with the first word. While trying to retrieve the first word, the second word, which is represented in proximity, is accidentally retrieved as well, and the two compete for being recalled. Errors in serial recall tasks are often confusions of neighboring items on a memory list (so-called transpositions), showing that retrieval competition plays a role in limiting our ability to recall lists in order, and probably also in other working memory tasks. A third form of interference is the distortion of representations by superposition: When multiple representations are added on top of each other, each of them is blurred by the presence of all the others. A fourth form of interference assumed by some authors is feature overwriting. The idea is that each word, digit, or other item in working memory is represented as a bundle of features, and when two items share some features, one of them steals the features from the other. The more items are held in working memory, and the more their features overlap, the more each of them will be degraded by the loss of some features.

理论家们讨论过多种形式的干涉。最初的观点之一是，新事物只是单纯地取代了工作记忆中的旧事物。另一种干涉形式是检索竞争 retrieval competition。例如当任务是按照一定顺序记住7个单词时，我们需要从第一个单词开始回忆。而在试图检索第一个单词时，我们往往会意外地检索到第二个单词，至于我们最终会回忆起哪个单词，这就得看它们竞争的结果了。回忆中出现的错误通常表现为记忆列表中相邻项目的混淆(即所谓的换位) ，这表明检索竞争限制了我们按照正确顺序回忆列表的能力，这种限制也可能发生在其他工作记忆任务中。另一种形式的干涉是叠表征的变形: 当多重表征叠加在一起时，每一表征都因其他表征的相互作用而模糊不清。一些人认为特征覆盖也是一种干涉形式。该观点认为工作记忆中的每个单词、数字或其他项目都被表现为一系列特征，当两个项目共享某些特征时，其中一个就会窃取另一个的特征。工作记忆中保存的条目越多则重叠的特征越多，因此每个条目丢失的特征越多，减损也就越多。

极限 Limitations

None of these hypotheses can explain the experimental data entirely. The resource hypothesis, for example, was meant to explain the trade-off between maintenance and processing: The more information must be maintained in working memory, the slower and more error prone concurrent processes become, and with a higher demand on concurrent processing memory suffers. This trade-off has been investigated by tasks like the reading-span task described above. It has been found that the amount of trade-off depends on the similarity of the information to be remembered and the information to be processed. For example, remembering numbers while processing spatial information, or remembering spatial information while processing numbers, impair each other much less than when material of the same kind must be remembered and processed. Also, remembering words and processing digits, or remembering digits and processing words, is easier than remembering and processing materials of the same category. These findings are also difficult to explain for the decay hypothesis, because decay of memory representations should depend only on how long the processing task delays rehearsal or recall, not on the content of the processing task. A further problem for the decay hypothesis comes from experiments in which the recall of a list of letters was delayed, either by instructing participants to recall at a slower pace, or by instructing them to say an irrelevant word once or three times in between recall of each letter. Delaying recall had virtually no effect on recall accuracy. The interference theory seems to fare best with explaining why the similarity between memory contents and the contents of concurrent processing tasks affects how much they impair each other. More similar materials are more likely to be confused, leading to retrieval competition.

None of these hypotheses can explain the experimental data entirely. The resource hypothesis, for example, was meant to explain the trade-off between maintenance and processing: The more information must be maintained in working memory, the slower and more error prone concurrent processes become, and with a higher demand on concurrent processing memory suffers. This trade-off has been investigated by tasks like the reading-span task described above. It has been found that the amount of trade-off depends on the similarity of the information to be remembered and the information to be processed. For example, remembering numbers while processing spatial information, or remembering spatial information while processing numbers, impair each other much less than when material of the same kind must be remembered and processed. Also, remembering words and processing digits, or remembering digits and processing words, is easier than remembering and processing materials of the same category. These findings are also difficult to explain for the decay hypothesis, because decay of memory representations should depend only on how long the processing task delays rehearsal or recall, not on the content of the processing task. A further problem for the decay hypothesis comes from experiments in which the recall of a list of letters was delayed, either by instructing participants to recall at a slower pace, or by instructing them to say an irrelevant word once or three times in between recall of each letter. Delaying recall had virtually no effect on recall accuracy. The interference theory seems to fare best with explaining why the similarity between memory contents and the contents of concurrent processing tasks affects how much they impair each other. More similar materials are more likely to be confused, leading to retrieval competition.

这些假说都不能完全解释实验数据。例如，资源理论旨在解释维护和加工之间的平衡: 工作记忆中需要保存的信息越多，并发进程就变得越慢、越容易出错，且对并发加工记忆的要求也越高。先前叙述的阅读广度任务等被应用于此现象的研究。研究发现，平衡量取决于所要记忆或处理的信息的相似性。例如，在处理空间信息时去记忆数字，或者在处理数字时去记忆空间信息，这些任务的偏差程度要低于记忆并处理同类材料所造成的损失。此外，记忆单词时处理数字，或记忆数字时处理单词，也要比记忆和处理同一类别材料更容易。这些发现同样也很难解释衰退假说，因为记忆表征的衰退应该只取决任务处理进程中刷新延迟的时间，而不取决于任务处理的内容。衰退假说 decay theories的另一个问题来自于延迟回忆字母列表的实验——通过要求参与者以较慢的速度回忆或在回忆每个字母的间隔说一个不相关单词一至三次来实现延迟效果。但延迟回忆对回忆准确率几乎没有影响。干扰理论 interference theories似乎最好地解释了为何记忆内容相似或并发进程内容相似就会造成记忆效果减损。材料越相似就越容易混淆，进而引起检索竞争。

发展 Development

The capacity of working memory increases gradually over childhood and declines gradually in old age.

The capacity of working memory increases gradually over childhood and declines gradually in old age.

工作记忆的容量在儿童时期逐渐增加，在老年时期逐渐下降 and declines gradually in old age.。

儿童期 Childhood

Main article: Neo-Piagetian theories of cognitive development

Measures of performance on tests of working memory increase continuously between early childhood and adolescence, while the structure of correlations between different tests remains largely constant. theorists have argued that the growth of working-memory capacity is a major driving force of cognitive development. This hypothesis has received substantial empirical support from studies showing that the capacity of working memory is a strong predictor of cognitive abilities in childhood. Particularly strong evidence for a role of working memory for development comes from a longitudinal study showing that working-memory capacity at one age predicts reasoning ability at a later age. Studies in the Neo-Piagetian tradition have added to this picture by analyzing the complexity of cognitive tasks in terms of the number of items or relations that have to be considered simultaneously for a solution. Across a broad range of tasks, children manage task versions of the same level of complexity at about the same age, consistent with the view that working memory capacity limits the complexity they can handle at a given age. Although neuroscience studies support the notion that children rely on prefrontal cortex for performing various working memory tasks, an fMRI meta-analysis on children compared to adults performing the n back task revealed lack of consistent prefrontal cortex activation in children, while posterior regions including the insular cortex and cerebellum remain intact.

Measures of performance on tests of working memory increase continuously between early childhood and adolescence, while the structure of correlations between different tests remains largely constant. theorists have argued that the growth of working-memory capacity is a major driving force of cognitive development. This hypothesis has received substantial empirical support from studies showing that the capacity of working memory is a strong predictor of cognitive abilities in childhood. Particularly strong evidence for a role of working memory for development comes from a longitudinal study showing that working-memory capacity at one age predicts reasoning ability at a later age. Studies in the Neo-Piagetian tradition have added to this picture by analyzing the complexity of cognitive tasks in terms of the number of items or relations that have to be considered simultaneously for a solution. Across a broad range of tasks, children manage task versions of the same level of complexity at about the same age, consistent with the view that working memory capacity limits the complexity they can handle at a given age. Although neuroscience studies support the notion that children rely on prefrontal cortex for performing various working memory tasks, an fMRI meta-analysis on children compared to adults performing the n back task revealed lack of consistent prefrontal cortex activation in children, while posterior regions including the insular cortex and cerebellum remain intact.

从儿童到青少年这段时间里，人们在针对工作记忆的测试中表现会越来越好，而不同测试之间的相关性结构基本保持不变。理论学者认为工作记忆容量的增长是认知发展的主要驱动力之一。这一假设得到了大量研究的支持，研究表明工作记忆能力是童年认知能力的一个强预测因子。工作记忆对认知发展起作用的有力证明来自一项追踪研究。该研究表明，根据人在某一年龄上的工作记忆能力可以预测其之后的推理能力。 对新皮亚杰传统的的研究也支持了这一观点。该研究分析了认知任务复杂性（情境下需要同时考虑的项目及关系的数量）的问题。在一系列任务之中，相同年龄段的儿童可处理难度近似的任务，这与特定年龄下的工作记忆容量会限制人能够处理的问题的复杂度的观点一致。虽然神经科学研究认为儿童依靠脑前额叶皮层来完成各种工作记忆任务，但一项功能性磁共振成象元在分析对比了儿童和成人在n back任务中的表现之后，发现儿童相对来说较难做到持续激活脑前额叶皮层，反而是后部区域包括到叶皮质和小脑都表现正常。

老化 Aging

Working memory is among the cognitive functions most sensitive to decline in old age. Several explanations have been offered for this decline in psychology. One is the processing speed theory of cognitive aging by Tim Salthouse. Drawing on the finding of general slowing of cognitive processes as people grow older, Salthouse argues that slower processing leaves more time for working-memory contents to decay, thus reducing effective capacity. However, the decline of working-memory capacity cannot be entirely attributed to slowing because capacity declines more in old age than speed. Another proposal is the inhibition hypothesis advanced by Lynn Hasher and Rose Zacks. This theory assumes a general deficit in old age in the ability to inhibit irrelevant, or no-longer relevant, information. Therefore, working memory tends to be cluttered with irrelevant contents that reduce the effective capacity for relevant content. The assumption of an inhibition deficit in old age has received much empirical support but, so far, it is not clear whether the decline in inhibitory ability fully explains the decline of working-memory capacity. An explanation on the neural level of the decline of working memory and other cognitive functions in old age has been proposed by West. She argued that working memory depends to a large degree on the pre-frontal cortex, which deteriorates more than other brain regions as we grow old. Age related decline in working memory can be briefly reversed using low intensity transcranial stimulation, synchronizing rhythms in bilateral frontal and left temporal lobe areas.

Working memory is among the cognitive functions most sensitive to decline in old age. Several explanations have been offered for this decline in psychology. One is the processing speed theory of cognitive aging by Tim Salthouse. Drawing on the finding of general slowing of cognitive processes as people grow older, Salthouse argues that slower processing leaves more time for working-memory contents to decay, thus reducing effective capacity. However, the decline of working-memory capacity cannot be entirely attributed to slowing because capacity declines more in old age than speed. Another proposal is the inhibition hypothesis advanced by Lynn Hasher and Rose Zacks. This theory assumes a general deficit in old age in the ability to inhibit irrelevant, or no-longer relevant, information. Therefore, working memory tends to be cluttered with irrelevant contents that reduce the effective capacity for relevant content. The assumption of an inhibition deficit in old age has received much empirical support but, so far, it is not clear whether the decline in inhibitory ability fully explains the decline of working-memory capacity. An explanation on the neural level of the decline of working memory and other cognitive functions in old age has been proposed by West. She argued that working memory depends to a large degree on the pre-frontal cortex, which deteriorates more than other brain regions as we grow old. Age related decline in working memory can be briefly reversed using low intensity transcranial stimulation, synchronizing rhythms in bilateral frontal and left temporal lobe areas.

人进入老年期后，一系列认知功能都会有所衰退，其中最严重的就是工作记忆。心理学对此有几种解释。一个是提姆 · 萨尔特豪斯 Tim Salthouse 提出的关于认知老化的加工速度理论 processing speed theory。普遍而言，人的认知过程随着年龄增长而滞缓。所以Salthouse 认为工作记忆会有更多的衰减机会，从而使其有效容量降低。然而，工作记忆容量的下降不能完全归因于此，因为老年时期记忆容量的下降速度比速度本身下降的更快。另一个是琳恩·哈什尔 Lynn Hasher 和 罗丝·扎克 Rose Zacks 提出的抑制假说 inhibition hypothesis。该理论假设老年人排除不相关信息的能力不足。因此，工作记忆往往会被不相关内容所干扰，从而降低记忆内容的有效容量。老年抑制能力缺失的假设得到了大量研究的支持，但抑制能力的下降能否完全解释为何工作记忆能力下降，目前为止还不清楚。韦斯特 West对老年工作记忆及其他认知功能的衰退则提出了一种神经层面的解释。她认为前额叶皮层对工作记忆有着很大的影响，而随着年龄的增长，前额叶皮与其他大脑区域相比更容易衰退。由衰老引发的工作记忆衰退可通过低强度经颅刺激同步化额叶或左侧颞叶节律来短期逆转。

训练 Training

Torkel Klingberg was the first to investigate whether intensive training of working memory has beneficial effects on other cognitive functions. His pioneering study suggested that working memory can be improved by training in ADHD patients through computerized programs. This study has found that a period of working memory training increases a range of cognitive abilities and increases IQ test scores. Another study of the same group has shown that, after training, measured brain activity related to working memory increased in the prefrontal cortex, an area that many researchers have associated with working memory functions. It has been shown in one study that working memory training increases the density of prefrontal and parietal dopamine receptors (specifically, DRD1) in test persons. However, subsequent work with the same training program has failed to replicate the beneficial effects of training on cognitive performance. A meta-analytic summary of research with Klingberg's training program up to 2011 shows that this training has at best a negligible effect on tests of intelligence and of attention.

Torkel Klingberg was the first to investigate whether intensive training of working memory has beneficial effects on other cognitive functions. His pioneering study suggested that working memory can be improved by training in ADHD patients through computerized programs. This study has found that a period of working memory training increases a range of cognitive abilities and increases IQ test scores. Another study of the same group has shown that, after training, measured brain activity related to working memory increased in the prefrontal cortex, an area that many researchers have associated with working memory functions. It has been shown in one study that working memory training increases the density of prefrontal and parietal dopamine receptors (specifically, DRD1) in test persons. However, subsequent work with the same training program has failed to replicate the beneficial effects of training on cognitive performance. A meta-analytic summary of research with Klingberg's training program up to 2011 shows that this training has at best a negligible effect on tests of intelligence and of attention.

托克尔 · 克林伯格 Torkel Klingberg 是第一个研究工作记忆强化训练是否对其他认知功能有益的人。他实施的开创性研究表明ADHD患者在经过电脑程序训练后工作记忆得到改善。该研究发现，工作记忆训练 Working Memory Training可以提高人的一系列认知能力及 IQ 测试成绩。针对同一群体的另一项研究表明，训练之后脑前额叶外皮层——被许多研究人员认为与工作记忆功能相关——的大脑活动测度有所增加。还有一项研究表明，工作记忆训练能增加受试者前额叶和顶叶多巴胺受体(特别是 DRD1)的密度。然而，同一训练方案的后续工作却未能再现这些有益影响。一份荟萃分析报告显示，持续至2011年的Klingberg 训练对智力和注意力的提升只有微乎其微的影响。

In another influential study, training with a working memory task (the dual n-back task) has improved performance on a fluid intelligence test in healthy young adults. The improvement of fluid intelligence by training with the n-back task was replicated in 2010, but two studies published in 2012 failed to reproduce the effect. The combined evidence from about 30 experimental studies on the effectiveness of working-memory training has been evaluated by several meta-analyses. The authors of these meta-analyses disagree in their conclusions as to whether or not working-memory training improves intelligence. Yet, these meta-analyses agree in their estimate of the size of the effect of working-memory training: If there is such an effect, it is likely to be small.

In another influential study, training with a working memory task (the dual n-back task) has improved performance on a fluid intelligence test in healthy young adults. The improvement of fluid intelligence by training with the n-back task was replicated in 2010, but two studies published in 2012 failed to reproduce the effect. The combined evidence from about 30 experimental studies on the effectiveness of working-memory training has been evaluated by several meta-analyses. The authors of these meta-analyses disagree in their conclusions as to whether or not working-memory training improves intelligence. Yet, these meta-analyses agree in their estimate of the size of the effect of working-memory training: If there is such an effect, it is likely to be small.

在另一项有影响力的研究中，工作记忆(双 n-back 任务 The Dual n-back Task)训练使健康青年在流体智力测试中的表现有所提升。2010年时，通过 n-back 任务训练提高流体智力的实验被再次实施，但2012年发表的两项研究未能重现那一结果。在运用元分析对约30个关于工作记忆训练有效性的研究进行评估之后，分析者并不认为训练可以提高智力。不过，这些元分析在某点上达成了一致: 训练大概率只会有很微弱的影响。

脑内 In the brain

信息维持的神经机制 Neural mechanisms of maintaining information

The first insights into the neuronal and neurotransmitter basis of working memory came from animal research. The work of Jacobsen and Fulton in the 1930s first showed that lesions to the PFC impaired spatial working memory performance in monkeys. The later work of Joaquin Fuster recorded the electrical activity of neurons in the PFC of monkeys while they were doing a delayed matching task. In that task, the monkey sees how the experimenter places a bit of food under one of two identical-looking cups. A shutter is then lowered for a variable delay period, screening off the cups from the monkey's view. After the delay, the shutter opens and the monkey is allowed to retrieve the food from under the cups. Successful retrieval in the first attempt – something the animal can achieve after some training on the task – requires holding the location of the food in memory over the delay period. Fuster found neurons in the PFC that fired mostly during the delay period, suggesting that they were involved in representing the food location while it was invisible. Later research has shown similar delay-active neurons also in the posterior parietal cortex, the thalamus, the caudate, and the globus pallidus. The work of Goldman-Rakic and others showed that principal sulcal, dorsolateral PFC interconnects with all of these brain regions, and that neuronal microcircuits within PFC are able to maintain information in working memory through recurrent excitatory glutamate networks of pyramidal cells that continue to fire throughout the delay period. These circuits are tuned by lateral inhibition from GABAergic interneurons. The neuromodulatory arousal systems markedly alter PFC working memory function; for example, either too little or too much dopamine or norepinephrine impairs PFC network firing and working memory performance.

The first insights into the neuronal and neurotransmitter basis of working memory came from animal research. The work of Jacobsen and Fulton in the 1930s first showed that lesions to the PFC impaired spatial working memory performance in monkeys. The later work of Joaquin Fuster recorded the electrical activity of neurons in the PFC of monkeys while they were doing a delayed matching task. In that task, the monkey sees how the experimenter places a bit of food under one of two identical-looking cups. A shutter is then lowered for a variable delay period, screening off the cups from the monkey's view. After the delay, the shutter opens and the monkey is allowed to retrieve the food from under the cups. Successful retrieval in the first attempt – something the animal can achieve after some training on the task – requires holding the location of the food in memory over the delay period. Fuster found neurons in the PFC that fired mostly during the delay period, suggesting that they were involved in representing the food location while it was invisible. Later research has shown similar delay-active neurons also in the posterior parietal cortex, the thalamus, the caudate, and the globus pallidus. The work of Goldman-Rakic and others showed that principal sulcal, dorsolateral PFC interconnects with all of these brain regions, and that neuronal microcircuits within PFC are able to maintain information in working memory through recurrent excitatory glutamate networks of pyramidal cells that continue to fire throughout the delay period. These circuits are tuned by lateral inhibition from GABAergic interneurons. The neuromodulatory arousal systems markedly alter PFC working memory function; for example, either too little or too much dopamine or norepinephrine impairs PFC network firing and working memory performance.

最初，关于工作记忆神经元和神经递质基础的见解来自于对动物的研究。20世纪30年代，雅各布森 Jacobsen 和富尔顿 Fulton在研究中首次证明了猴子的空间工作记忆能力会因PFC而减损。华金 · 福斯特 Joaquin Fuster 的后续工作记录了猴子在完成延迟匹配任务时 PFC 中神经元的电活动。在该任务中有两个相同的杯子，猴子看到实验人员把一点食物放在其中一个下面。然后一个挡板降下，暂时挡住猴子看向杯子的视线（延迟变量）。之后挡板打开，允许猴子从杯子下面取出食物。在第一次尝试中它成功地得到了食物——这是动物经过特定训练后应该能够完成的任务——要求动物在延迟期内维持对食物位置的记忆。Fuster发现在延迟期间，PFC中的大部分神经元被激活了，表明它们参与了在隔离期间对食物位置的记忆维持。后来的研究发现后顶叶皮层posterior parietal cortex、丘脑thalamus、尾状核caudate和苍白球globus pallidus也有类似的延迟活动神经元。高德马・拉齐克 Goldman-Rakic 等人的研究表明，脊髓背外侧的PFC与这些大脑区域相互连接，PFC内的神经元微回路凭借反复兴奋的锥体细胞谷氨酸网络来维持工作记忆中的信息——这些神经元网络在延迟期间是持续激活的。这些回路由GABA能中间神经元的侧抑制调节。神经调节性唤起系统对PFC工作记忆功能产生了显著影响; 例如，过多或过少的多巴胺或去甲肾上腺素会减损PFC神经网络放电功能和工作记忆表现。

The research described above on persistent firing of certain neurons in the delay period of working memory tasks shows that the brain has a mechanism of keeping representations active without external input. Keeping representations active, however, is not enough if the task demands maintaining more than one chunk of information. In addition, the components and features of each chunk must be bound together to prevent them from being mixed up. For example, if a red triangle and a green square must be remembered at the same time, one must make sure that "red" is bound to "triangle" and "green" is bound to "square". One way of establishing such bindings is by having the neurons that represent features of the same chunk fire in synchrony, and those that represent features belonging to different chunks fire out of sync. In the example, neurons representing redness would fire in synchrony with neurons representing the triangular shape, but out of sync with those representing the square shape. So far, there is no direct evidence that working memory uses this binding mechanism, and other mechanisms have been proposed as well. It has been speculated that synchronous firing of neurons involved in working memory oscillate with frequencies in the theta band (4 to 8 Hz). Indeed, the power of theta frequency in the EEG increases with working memory load, and oscillations in the theta band measured over different parts of the skull become more coordinated when the person tries to remember the binding between two components of information.

The research described above on persistent firing of certain neurons in the delay period of working memory tasks shows that the brain has a mechanism of keeping representations active without external input. Keeping representations active, however, is not enough if the task demands maintaining more than one chunk of information. In addition, the components and features of each chunk must be bound together to prevent them from being mixed up. For example, if a red triangle and a green square must be remembered at the same time, one must make sure that "red" is bound to "triangle" and "green" is bound to "square". One way of establishing such bindings is by having the neurons that represent features of the same chunk fire in synchrony, and those that represent features belonging to different chunks fire out of sync. In the example, neurons representing redness would fire in synchrony with neurons representing the triangular shape, but out of sync with those representing the square shape. So far, there is no direct evidence that working memory uses this binding mechanism, and other mechanisms have been proposed as well. It has been speculated that synchronous firing of neurons involved in working memory oscillate with frequencies in the theta band (4 to 8 Hz). Indeed, the power of theta frequency in the EEG increases with working memory load, and oscillations in the theta band measured over different parts of the skull become more coordinated when the person tries to remember the binding between two components of information.

上述关于工作记忆任务延迟期间某些神经元持续放电的研究表明，大脑有一种机制能使在无外部输入的情况下表征依旧保持活跃。但这不足以应对维护多个信息块的任务。此外，每个组块的组件和特性必须绑定在一起，以防止混淆。例如，如果必须同时记住一个红色三角形和一个绿色正方形，就必须确保“红色”与“三角形”绑定，而“绿色”与“正方形”绑定。实现该目标的一种方法是让表现同一组块特征的神经元同步激活，那些表现不同组块特征的神经元则不同步激活。在这个例子中，代表红色的神经元会与代表三角形的神经元同步激活，与代表正方形的神经元不同步激活。不过目前还没有直接的证据表明工作记忆使用这种结合机制，因此学界也提出了其他一些观点。据推测，工作记忆相关神经元的同步激活是在θ波段 theta band (4ー8赫兹)振荡。脑电图θ频率的能量确实随工作记忆负荷的增加而增加，当受试者试图记住信息的两个组成部分之间的联系时，在头骨不同部位测量到的 θ 波段的振荡变得更加协调。

脑内定位 Localization in the brain

Localization of brain functions in humans has become much easier with the advent of brain imaging methods (PET and fMRI). This research has confirmed that areas in the PFC are involved in working memory functions. During the 1990s much debate has centered on the different functions of the ventrolateral (i.e., lower areas) and the dorsolateral (higher) areas of the PFC. A human lesion study provides additional evidence for the role of the dorsolateral prefrontal cortex in working memory. One view was that the dorsolateral areas are responsible for spatial working memory and the ventrolateral areas for non-spatial working memory. Another view proposed a functional distinction, arguing that ventrolateral areas are mostly involved in pure maintenance of information, whereas dorsolateral areas are more involved in tasks requiring some processing of the memorized material. The debate is not entirely resolved but most of the evidence supports the functional distinction.

Localization of brain functions in humans has become much easier with the advent of brain imaging methods (PET and fMRI). This research has confirmed that areas in the PFC are involved in working memory functions. During the 1990s much debate has centered on the different functions of the ventrolateral (i.e., lower areas) and the dorsolateral (higher) areas of the PFC. A human lesion study provides additional evidence for the role of the dorsolateral prefrontal cortex in working memory. One view was that the dorsolateral areas are responsible for spatial working memory and the ventrolateral areas for non-spatial working memory. Another view proposed a functional distinction, arguing that ventrolateral areas are mostly involved in pure maintenance of information, whereas dorsolateral areas are more involved in tasks requiring some processing of the memorized material. The debate is not entirely resolved but most of the evidence supports the functional distinction.

脑成像brain imaging方法（PET和fMRI）的出现让人脑功能定位更加容易。一项研究证实PFC中的一些区域确实影响了工作记忆功能。在20世纪90年代，讨论大多集中在腹外侧区（即较低区域）和背外侧区（较高区域）的不同功能上。一项关于人体损伤的研究为背外侧脑前额叶外皮在工作记忆中发挥作用提供了额外的证据。一种观点认为，背外侧区负责空间工作记忆，腹外侧区负责非空间工作记忆。另一种观点则是功能区分说functional distinction，认为腹外侧区域主要负责纯粹的信息维护，而背外侧区域则更倾向于负责记忆材料的处理。虽然分歧并没有彻底解决，但功能区分说还是得到了大多数证据的支持。

Brain imaging has revealed that working memory functions are not limited to the PFC. A review of numerous studies shows areas of activation during working memory tasks scattered over a large part of the cortex. There is a tendency for spatial tasks to recruit more right-hemisphere areas, and for verbal and object working memory to recruit more left-hemisphere areas. The activation during verbal working memory tasks can be broken down into one component reflecting maintenance, in the left posterior parietal cortex, and a component reflecting subvocal rehearsal, in the left frontal cortex (Broca's area, known to be involved in speech production).

Brain imaging has revealed that working memory functions are not limited to the PFC. A review of numerous studies shows areas of activation during working memory tasks scattered over a large part of the cortex. There is a tendency for spatial tasks to recruit more right-hemisphere areas, and for verbal and object working memory to recruit more left-hemisphere areas. The activation during verbal working memory tasks can be broken down into one component reflecting maintenance, in the left posterior parietal cortex, and a component reflecting subvocal rehearsal, in the left frontal cortex (Broca's area, known to be involved in speech production).

脑成像已经证明工作记忆功能并不局限于PFC。大量研究表明，工作记忆任务中的激活区域广泛分布于大脑皮层。其中，空间任务倾向于使用右半球区域，言语和物体工作记忆倾向于使用左半球区域。非文字工作记忆任务中的激活可以分解为在左后顶叶皮层反映维持的组件，以及在左额叶皮层的反映次声练习的组件（已知与语言产生有关的Broca区域） 。

There is an emerging consensus that most working memory tasks recruit a network of PFC and parietal areas. A study has shown that during a working memory task the connectivity between these areas increases. Another study has demonstrated that these areas are necessary for working memory, and not simply activated accidentally during working memory tasks, by temporarily blocking them through transcranial magnetic stimulation (TMS), thereby producing an impairment in task performance.

There is an emerging consensus that most working memory tasks recruit a network of PFC and parietal areas. A study has shown that during a working memory task the connectivity between these areas increases. Another study has demonstrated that these areas are necessary for working memory, and not simply activated accidentally during working memory tasks, by temporarily blocking them through transcranial magnetic stimulation (TMS), thereby producing an impairment in task performance.

人们逐渐达成共识，认为大多数工作记忆任务使用的是PFC顶叶区域组成的网络。一项研究表明，这些区域之间的连通性在工作记忆任务的执行过程中有所增加。另一项研究表明，这些区域是工作记忆所必备的，并非是被意外激活的。通过经颅磁刺激（TMS）暂时阻止它们，从而导致任务性能受损。

A current debate concerns the function of these brain areas. The PFC has been found to be active in a variety of tasks that require executive functions. This has led some researchers to argue that the role of PFC in working memory is in controlling attention, selecting strategies, and manipulating information in working memory, but not in maintenance of information. The maintenance function is attributed to more posterior areas of the brain, including the parietal cortex. Other authors interpret the activity in parietal cortex as reflecting executive functions, because the same area is also activated in other tasks requiring attention but not memory.

A current debate concerns the function of these brain areas. The PFC has been found to be active in a variety of tasks that require executive functions. Other authors interpret the activity in parietal cortex as reflecting executive functions, because the same area is also activated in other tasks requiring attention but not memory.

目前的争论集中于大脑各个区域功能的研究。研究发现，在许多需要执行功能的任务中，PFC都具有活性。这使得一些研究人员认为，PFC在工作记忆中的作用是控制注意力，选择策略以及操纵信息，而非信息维护。信息维护功能更多的由大脑后部区域负责——包括顶叶皮层。其他研究者把顶叶皮层的活动理解为对执行功能的反映，因为在其他需要注意力而不是记忆的任务中该区域同样被激活 。

A 2003 meta-analysis of 60 neuroimaging studies found left frontal cortex was involved in low-task demand verbal working memory and right frontal cortex for spatial working memory. Brodmann's areas (BAs) 6, 8, and 9, in the superior frontal cortex was involved when working memory must be continuously updated and when memory for temporal order had to be maintained. Right Brodmann 10 and 47 in the ventral frontal cortex were involved more frequently with demand for manipulation such as dual-task requirements or mental operations, and Brodmann 7 in the posterior parietal cortex was also involved in all types of executive function.

A 2003 meta-analysis of 60 neuroimaging studies found left frontal cortex was involved in low-task demand verbal working memory and right frontal cortex for spatial working memory. Brodmann's areas (BAs) 6, 8, and 9, in the superior frontal cortex was involved when working memory must be continuously updated and when memory for temporal order had to be maintained. Right Brodmann 10 and 47 in the ventral frontal cortex were involved more frequently with demand for manipulation such as dual-task requirements or mental operations, and Brodmann 7 in the posterior parietal cortex was also involved in all types of executive function.

在2003年，一份对60项神经成像研究结果的元分析发现，左额叶皮层参与低任务需求的语言工作记忆，而右额叶皮层参与空间工作记忆。罗德曼大脑上额叶皮层区域(BAs)的6、8、9号参与需要不断更新的以及需要维持特定顺序的工作记忆。腹侧额叶皮层的右布罗德曼10和47号区域较频繁地参与需要双重任务或心理操作的工作记忆，其中后顶叶皮层的罗德曼7号区域参与了全部的执行功能。

Working memory has been suggested to involve two processes with different neuroanatomical locations in the frontal and parietal lobes. First, a selection operation that retrieves the most relevant item, and second an updating operation that changes the focus of attention made upon it. Updating the attentional focus has been found to involve the transient activation in the caudal superior frontal sulcus and posterior parietal cortex, while increasing demands on selection selectively changes activation in the rostral superior frontal sulcus and posterior cingulate/precuneus.

Working memory has been suggested to involve two processes with different neuroanatomical locations in the frontal and parietal lobes. First, a selection operation that retrieves the most relevant item, and second an updating operation that changes the focus of attention made upon it. Updating the attentional focus has been found to involve the transient activation in the caudal superior frontal sulcus and posterior parietal cortex, while increasing demands on selection selectively changes activation in the rostral superior frontal sulcus and posterior cingulate/precuneus.

我们一般认为，工作记忆包括两种过程——两类过程发生于额叶和顶叶两个不同位置。首先是检索最相关项的选择操作，其次是更改关注焦点的更新操作。更新操作包括额上沟superior frontal sulcus尾部和后顶叶皮质posterior parietal cortex的短暂激活，选择操作随选择的需求增加而选择性地发生额上沟和后扣带回/楔前叶激活。

Articulating the differential function of brain regions involved in working memory is dependent on tasks able to distinguish these functions. Most brain imaging studies of working memory have used recognition tasks such as delayed recognition of one or several stimuli, or the n-back task, in which each new stimulus in a long series must be compared to the one presented n steps back in the series. The advantage of recognition tasks is that they require minimal movement (just pressing one of two keys), making fixation of the head in the scanner easier. Experimental research and research on individual differences in working memory, however, has used largely recall tasks (e.g., the reading span task, see below). It is not clear to what degree recognition and recall tasks reflect the same processes and the same capacity limitations.

Articulating the differential function of brain regions involved in working memory is dependent on tasks able to distinguish these functions. Most brain imaging studies of working memory have used recognition tasks such as delayed recognition of one or several stimuli, or the n-back task, in which each new stimulus in a long series must be compared to the one presented n steps back in the series. The advantage of recognition tasks is that they require minimal movement (just pressing one of two keys), making fixation of the head in the scanner easier. Experimental research and research on individual differences in working memory, however, has used largely recall tasks (e.g., the reading span task, see below). It is not clear to what degree recognition and recall tasks reflect the same processes and the same capacity limitations.

要想阐明与工作记忆相关的大脑区域功能，首先需要区分这些功能的任务。大多数关于工作记忆的脑成像研究都使用了识别任务，比如延迟识别一个或多个刺激，或 n-back 任务，即一个长系列中的每个新刺激都需与该系列中的一个n步后的刺激进行比较。识别任务的优势在于只需要最低限度的运动（只需二选一按键），这使头部扫描的定位更加容易。然而，关于工作记忆个体差异的实验研究大量使用的是回忆任务（例如阅读广度任务，见下文）。不过我们目前尚不清楚识别任务和回忆任务能在多大程度上反映相同过程和相同能力极限。

Brain imaging studies have been conducted with the reading span task or related tasks. Increased activation during these tasks was found in the PFC and, in several studies, also in the anterior cingulate cortex (ACC). People performing better on the task showed larger increase of activation in these areas, and their activation was correlated more over time, suggesting that their neural activity in these two areas was better coordinated, possibly due to stronger connectivity.

Brain imaging studies have been conducted with the reading span task or related tasks. Increased activation during these tasks was found in the PFC and, in several studies, also in the anterior cingulate cortex (ACC). People performing better on the task showed larger increase of activation in these areas, and their activation was correlated more over time, suggesting that their neural activity in these two areas was better coordinated, possibly due to stronger connectivity.

脑成像研究已用于进行阅读广度任务或相关任务。任务过程中，PFC的活跃性增加，前扣带皮层anterior cingulate cortex (ACC)的活性也有所增强。那些在任务中表现更好的人的这些区域活性显著提升，且随着时间的推移变得更强。这表明这两个区域的神经活动协调度更高——可能是因为区域间有更强的关联性 。

神经模型 Neural models

One approach to modeling the neurophysiology and the functioning of working memory is prefrontal cortex basal ganglia working memory (PBWM). In this model, the prefrontal cortex works hand-in-hand with the basal ganglia to accomplish the tasks of working memory. Many studies have shown this to be the case. One used ablation techniques in patients who had suffered from seizures and had damage to the prefrontal cortex and basal ganglia. Researchers found that such damage resulted in decreased capacity to carry out the executive function of working memory. Additional research conducted on patients with brain alterations due to methamphetamine use found that training working memory increases volume in the basal ganglia.

One approach to modeling the neurophysiology and the functioning of working memory is prefrontal cortex basal ganglia working memory (PBWM). In this model, the prefrontal cortex works hand-in-hand with the basal ganglia to accomplish the tasks of working memory. Many studies have shown this to be the case. One used ablation techniques in patients who had suffered from seizures and had damage to the prefrontal cortex and basal ganglia. Researchers found that such damage resulted in decreased capacity to carry out the executive function of working memory .Additional research conducted on patients with brain alterations due to methamphetamine use found that training working memory increases volume in the basal ganglia.

前额叶皮质基底节工作记忆记忆模型 Prefrontal Cortex Basal Ganglia Working Memory (PBWM)是模拟神经生理学和工作记忆功能模型的一种。 在该模型中，脑前额叶外皮与基底神经节协力完成工作记忆任务，并得到许多研究证明支持，例如使用消融技术ablation techniques治疗脑前额叶外皮和基底神经节受损、癫痫发作患者等。研究人员发现，这种损害使得工作记忆的执行功能受损。此外还有对因服用甲基苯丙胺 methamphetamine而导致大脑改变的病人进行工作记忆训练后成功增加其基底神经节容量的案例。

神经生理学的压力效果 Effects of stress on neurophysiology

Working memory is impaired by acute and chronic psychological stress. This phenomenon was first discovered in animal studies by Arnsten and colleagues, who have shown that stress-induced catecholamine release in PFC rapidly decreases PFC neuronal firing and impairs working memory performance through feedforward, intracellular signaling pathways. Exposure to chronic stress leads to more profound working memory deficits and additional architectural changes in PFC, including dendritic atrophy and spine loss, which can be prevented by inhibition of protein kinase C signaling. fMRI research has extended this research to humans, and confirms that reduced working memory caused by acute stress links to reduced activation of the PFC, and stress increased levels of catecholamines. Imaging studies of medical students undergoing stressful exams have also shown weakened PFC functional connectivity, consistent with the animal studies. The marked effects of stress on PFC structure and function may help to explain how stress can cause or exacerbate mental illness.

Working memory is impaired by acute and chronic psychological stress. This phenomenon was first discovered in animal studies by Arnsten and colleagues, who have shown that stress-induced catecholamine release in PFC rapidly decreases PFC neuronal firing and impairs working memory performance through feedforward, intracellular signaling pathways. Exposure to chronic stress leads to more profound working memory deficits and additional architectural changes in PFC, including dendritic atrophy and spine loss, which can be prevented by inhibition of protein kinase C signaling. fMRI research has extended this research to humans, and confirms that reduced working memory caused by acute stress links to reduced activation of the PFC, and stress increased levels of catecholamines. Imaging studies of medical students undergoing stressful exams have also shown weakened PFC functional connectivity, consistent with the animal studies. The marked effects of stress on PFC structure and function may help to explain how stress can cause or exacerbate mental illness.

急性和慢性心理压力都会损害工作记忆。这最早由安斯登 Arnsten 和他的同事们在动物实验中发现。他们发现应激诱导PFC中儿茶酚胺 catecholamine的释放可迅速降低PFC神经元的放电频率，并通过前馈和细胞内信号通路损害工作记忆。长期暴露在压力下会导致更深层次的工作记忆缺陷和额外的PFC结构变化——包括树突萎缩和脊柱丧失——这些都可以通过抑制蛋白激酶C信号来预防。功能磁共振成像研究已经将这项研究进一步扩展到人类，并证实了急性压力导致的工作记忆减少会降低PFC的活性，同时，压力还会导致儿茶酚胺水平提高。在经历紧张的考试后，医学院学生的成像研究也表明其PFC功能减弱，与动物实验的结果一致。压力对PFC结构和功能的显著影响可能有助于解释为何压力会加重甚至导致精神疾病。

The more stress in one's life, the lower the efficiency of working memory in performing simple cognitive tasks. Students who performed exercises that reduced the intrusion of negative thoughts showed an increase in their working memory capacity. Mood states (positive or negative) can have an influence on the neurotransmitter dopamine, which in turn can affect problem solving.

The more stress in one's life, the lower the efficiency of working memory in performing simple cognitive tasks. Students who performed exercises that reduced the intrusion of negative thoughts showed an increase in their working memory capacity. Mood states (positive or negative) can have an influence on the neurotransmitter dopamine, which in turn can affect problem solving.

人在生活中的压力越大工作记忆在完成简单认知任务时的效率就会越低。接受过限制负面思想入侵练习的学生，其工作记忆容量明显有所增加。因此我们说，情绪状态(积极或消极)会影响神经递质多巴胺，进而影响问题解决效果。

神经生理学的酒精效果 Effects of alcohol on neurophysiology

Alcohol abuse can result in brain damage which impairs working memory. Alcohol has an effect on the blood-oxygen-level-dependent (BOLD) response. The BOLD response correlates increased blood oxygenation with brain activity, which makes this response a useful tool for measuring neuronal activity. The BOLD response affects regions of the brain such as the basal ganglia and thalamus when performing a working memory task. Adolescents who start drinking at a young age show a decreased BOLD response in these brain regions. Alcohol dependent young women in particular exhibit less of a BOLD response in parietal and frontal cortices when performing a spatial working memory task. Binge drinking, specifically, can also affect one's performance on working memory tasks, particularly visual working memory. Additionally, there seems to be a gender difference in regards to how alcohol affects working memory. While women perform better on verbal working memory tasks after consuming alcohol compared to men, they appear to perform worse on spatial working memory tasks as indicated by less brain activity. Finally, age seems to be an additional factor. Older adults are more susceptible than others to the effects of alcohol on working memory.

Alcohol abuse can result in brain damage which impairs working memory. Alcohol has an effect on the blood-oxygen-level-dependent (BOLD) response. The BOLD response correlates increased blood oxygenation with brain activity, which makes this response a useful tool for measuring neuronal activity. The BOLD response affects regions of the brain such as the basal ganglia and thalamus when performing a working memory task. Adolescents who start drinking at a young age show a decreased BOLD response in these brain regions. Alcohol dependent young women in particular exhibit less of a BOLD response in parietal and frontal cortices when performing a spatial working memory task. Binge drinking, specifically, can also affect one's performance on working memory tasks, particularly visual working memory. Additionally, there seems to be a gender difference in regards to how alcohol affects working memory. While women perform better on verbal working memory tasks after consuming alcohol compared to men, they appear to perform worse on spatial working memory tasks as indicated by less brain activity. Finally, age seems to be an additional factor. Older adults are more susceptible than others to the effects of alcohol on working memory.

酗酒会损伤大脑，进而损害工作记忆。酒精会影响血氧水平依赖性 Blood-Oxygen-Level-Dependent（BOLD）反应。BOLD反应把血氧含量增加与大脑活动联系起来，这使得其成为测量神经元活动的有效指标。在执行工作记忆任务时，BOLD反应影响大脑的基底神经节和丘脑等区域。从小就喝酒的青少年BOLD反应相应较低。特别的，有酒精依赖的年轻女性在执行空间工作记忆任务时顶叶和额叶皮层的BOLD反应较弱。酗酒工作记忆任务表现有显著影响——特别是视觉工作记忆。此外，酒精对工作记忆的影响似乎也存在性别差异。与男性相比，女性酒后的非文字工作记忆任务完成得更好，但空间工作记忆任务完成得似乎更差（大脑活动迟缓）。最后，年龄似乎也是一个可考虑的因素。老年人更容易受到酒精的影响 。

基因 Genetics

行为基因 Behavioral genetics

Individual differences in working-memory capacity are to some extent heritable; that is, about half of the variation between individuals is related to differences in their genes. The genetic component of variability of working-memory capacity is largely shared with that of fluid intelligence.

Individual differences in working-memory capacity are to some extent heritable; that is, about half of the variation between individuals is related to differences in their genes. The genetic component of variability of working-memory capacity is largely shared with that of fluid intelligence.

工作记忆能力的个体差异在某种程度上是遗传的，即个体间约一半的差异与基因差异有关。工作记忆能力变异的遗传成分与流体智力的遗传成分大致相同 。

识别个别基因的尝试 Attempts to identify individual genes

Little is known about which genes are related to the functioning of working memory. Within the theoretical framework of the multi-component model, one candidate gene has been proposed, namely ROBO1 for the hypothetical phonological loop component of working memory.

Little is known about which genes are related to the functioning of working memory. Within the theoretical framework of the multi-component model, one candidate gene has been proposed, namely ROBO1 for the hypothetical phonological loop component of working memory.

我们对哪些基因与工作记忆的功能有关知之甚少。多成分模型的理论框架提出了一个候选基因——即工作记忆的语音回路ROBO1。

在学术成就方面的角色 Role in academic achievement

Working memory capacity is correlated with learning outcomes in literacy and numeracy. Initial evidence for this relation comes from the correlation between working-memory capacity and reading comprehension, as first observed by Daneman and Carpenter (1980) and confirmed in a later meta-analytic review of several studies. Subsequent work found that working memory performance in primary school children accurately predicted performance in mathematical problem solving. One longitudinal study showed that a child's working memory at 5 years old is a better predictor of academic success than IQ.

Working memory capacity is correlated with learning outcomes in literacy and numeracy. Initial evidence for this relation comes from the correlation between working-memory capacity and reading comprehension, as first observed by Daneman and Carpenter (1980) and confirmed in a later meta-analytic review of several studies. Subsequent work found that working memory performance in primary school children accurately predicted performance in mathematical problem solving. One longitudinal study showed that a child's working memory at 5 years old is a better predictor of academic success than IQ.

工作记忆容量与识字和算术能力的学习成果相关。1980年Daneman 和卡朋特 Carpenter首次从工作记忆容量和阅读理解的相关性研究中获得证据——这在后来几项研究的元分析中也得到了证实。随后的研究发现，小学生的工作记忆能力能够精确地反映在数学问题解决上。一项后续研究表明，孩子5岁时的工作记忆能力与智商相比，是我们预测其未来学术成就地更好依据。

In a large-scale screening study, one in ten children in mainstream classrooms were identified with working memory deficits. The majority of them performed very poorly in academic achievements, independent of their IQ. Similarly, working memory deficits have been identified in national curriculum low-achievers as young as seven years of age. Without appropriate intervention, these children lag behind their peers. A recent study of 37 school-age children with significant learning disabilities has shown that working memory capacity at baseline measurement, but not IQ, predicts learning outcomes two years later. This suggests that working memory impairments are associated with low learning outcomes and constitute a high risk factor for educational underachievement for children. In children with learning disabilities such as dyslexia, ADHD, and developmental coordination disorder, a similar pattern is evident.

In a large-scale screening study, one in ten children in mainstream classrooms were identified with working memory deficits. The majority of them performed very poorly in academic achievements, independent of their IQ. Similarly, working memory deficits have been identified in national curriculum low-achievers as young as seven years of age. Without appropriate intervention, these children lag behind their peers. A recent study of 37 school-age children with significant learning disabilities has shown that working memory capacity at baseline measurement, but not IQ, predicts learning outcomes two years later. This suggests that working memory impairments are associated with low learning outcomes and constitute a high risk factor for educational underachievement for children. In children with learning disabilities such as dyslexia, ADHD, and developmental coordination disorder, a similar pattern is evident.

在一项大规模的筛查研究中，大班教学模式中十分之一的儿童被认为患有工作记忆缺陷。他们中的大多数人在学术成就上乏善可陈——这与智商无关。同样，国家课程标准把最早在7岁就表现出工作记忆缺陷的儿童定性为低成就学生。如果没有适当的干预，这些孩子就会落后于同龄人。最近，一项针对37名具有显著学习障碍的学龄儿童的研究表明，基线测量的工作记忆能力（而非智商）可预测两年后的学习结果。这表明低分与工作记忆障碍有关，甚至成为导致教育失败的高风险因素。在有学习障碍的儿童中(如诵读困难dyslexia、多动症ADHD和失用症)，类似模式是显而易见的。

与注意力的关系 Relation to attention

There is some evidence that optimal working memory performance links to the neural ability to focus attention on task-relevant information and to ignore distractions, and that practice-related improvement in working memory is due to increasing these abilities. One line of research suggests a link between the working memory capacities of a person and their ability to control the orientation of attention to stimuli in the environment. Such control enables people to attend to information important for their current goals, and to ignore goal-irrelevant stimuli that tend to capture their attention due to their sensory saliency (such as an ambulance siren). The direction of attention according to one's goals is assumed to rely on "top-down" signals from the pre-frontal cortex (PFC) that biases processing in posterior cortical areas. Capture of attention by salient stimuli is assumed to be driven by "bottom-up" signals from subcortical structures and the primary sensory cortices. The ability to override "bottom-up" capture of attention differs between individuals, and this difference has been found to correlate with their performance in a working-memory test for visual information. Another study, however, found no correlation between the ability to override attentional capture and measures of more general working-memory capacity.

There is some evidence that optimal working memory performance links to the neural ability to focus attention on task-relevant information and to ignore distractions, and that practice-related improvement in working memory is due to increasing these abilities. One line of research suggests a link between the working memory capacities of a person and their ability to control the orientation of attention to stimuli in the environment. Such control enables people to attend to information important for their current goals, and to ignore goal-irrelevant stimuli that tend to capture their attention due to their sensory saliency (such as an ambulance siren). The direction of attention according to one's goals is assumed to rely on "top-down" signals from the pre-frontal cortex (PFC) that biases processing in posterior cortical areas. Capture of attention by salient stimuli is assumed to be driven by "bottom-up" signals from subcortical structures and the primary sensory cortices. The ability to override "bottom-up" capture of attention differs between individuals, and this difference has been found to correlate with their performance in a working-memory test for visual information. Another study, however, found no correlation between the ability to override attentional capture and measures of more general working-memory capacity.

有证据表明，较佳的工作记忆表现与能否忽略干扰集中注意力于任务相关信息的神经能力有关，也就是说训练之后的工作记忆之所以能够改善，是因为上述能力得到了改善。一项研究表明，工作记忆能力和面对环境刺激人能否控制注意力方向之间存在联系。因为这种控制会引导人关注相关的信息而忽略与目标无关的刺激——这些刺激往往因其感官显著性（如救护车警报器）而吸引人的注意力。个体的注意力方向被认为取决于前额叶皮质(PFC)“自上而下”发出的信号，这种信号偏好于在后皮质区处理任务。皮层下结构和初级感觉皮层发出的“自下而上”的信号驱动着由显著刺激引发的注意力。然而，另一项研究发现，注意力过度集中对在工作记忆能力测量过程中没有起到预期作用 。

与神经系统疾病的关系 Relationship with neural disorders

An impairment of working memory functioning is normally seen in several neural disorders:

An impairment of working memory functioning is normally seen in several neural disorders:

工作记忆功能障碍通常见于以下神经系统疾病:

ADHD: Several authors have proposed that symptoms of ADHD arise from a primary deficit in a specific executive function (EF) domain such as working memory, response inhibition or a more general weakness in executive control. A meta-analytical review cites several studies that found significant lower group results for ADHD in spatial and verbal working memory tasks, and in several other EF tasks. However, the authors concluded that EF weaknesses neither are necessary nor sufficient to cause all cases of ADHD.

ADHD: Several authors have proposed that symptoms of ADHD arise from a primary deficit in a specific executive function (EF) domain such as working memory, response inhibition or a more general weakness in executive control. A meta-analytical review cites several studies that found significant lower group results for ADHD in spatial and verbal working memory tasks, and in several other EF tasks. However, the authors concluded that EF weaknesses neither are necessary nor sufficient to cause all cases of ADHD.

注意力缺陷多动障碍（ADHD）: 一些研究者提出，ADHD 源于特定 执行功能（EF） Executive Function (EF)领域——如工作记忆、反应抑制或执行控制方面——的原发性缺陷。引用了几项研究之后，研究人员得出一份元分析报告，发现在空间和语言工作记忆任务及其他几项EF任务中，ADHD群体有较低的成绩。然而，研究者的结论是EF缺陷既不必然也不足以引发所有的ADHD病例 。

Several neurotransmitters, such as dopamine and glutamate may be both involved in ADHD and working memory. Both are associated with the frontal brain, self-direction and self-regulation, but cause–effect have not been confirmed, so it is unclear whether working memory dysfunction leads to ADHD, or ADHD distractibility leads to poor functionality of working memory, or if there is some other connection.

Several neurotransmitters, such as dopamine and glutamate may be both involved in ADHD and working memory. Both are associated with the frontal brain, self-direction and self-regulation, but cause–effect have not been confirmed, so it is unclear whether working memory dysfunction leads to ADHD, or ADHD distractibility leads to poor functionality of working memory, or if there is some other connection.

多巴胺和谷氨酸盐等多种神经递质可能都与ADHD和工作记忆有关。两者都与额叶大脑、自我定向self-direction和自我调节self-regulation有关，但其中的因果关系尚未得到确认。所以目前不清楚是工作记忆功能障碍导致 ADHD，还是注意力分散导致ADHD工作记忆功能低下，亦或存在着其他联系。

Parkinson's disease: Patients with Parkinson's show signs of a reduced verbal function of working memory. They wanted to find if the reduction is due to a lack of ability to focus on relevant tasks, or a low amount of memory capacity. Twenty-one patients with Parkinson's were tested in comparison to the control group of 28 participants of the same age. The researchers found that both hypotheses were the reason working memory function is reduced which did not fully agree with their hypothesis that it is either one or the other.

Parkinson's disease: Patients with Parkinson's show signs of a reduced verbal function of working memory. They wanted to find if the reduction is due to a lack of ability to focus on relevant tasks, or a low amount of memory capacity. Twenty-one patients with Parkinson's were tested in comparison to the control group of 28 participants of the same age. The researchers found that both hypotheses were the reason working memory function is reduced which did not fully agree with their hypothesis that it is either one or the other.

帕金森病 Parkinson's Disease: 帕金森病患者表现出工作记忆语言功能的减退。研究者想知道这种减少是因为缺乏专注于相关任务的能力，还是因为记忆容量太小。他们对21名帕金森病患者与28名同龄对照组进行了测试。研究人员发现二者都是工作记忆功能减退的原因，而非他们先前假设的原因在二者之一。

Alzheimer's disease: As Alzheimer's disease becomes more serious, less working memory functions. There is one study that focuses on the neural connections and fluidity of working memory in mice brains. Half of the mice were given an injection that is similar to Alzheimer's effects, and the other half were not. Then they were expected to go through a maze that is a task to test working memory. The study help answer questions about how Alzheimer's can deteriorate the working memory and ultimately obliterate memory functions.

Alzheimer's disease: As Alzheimer's disease becomes more serious, less working memory functions. There is one study that focuses on the neural connections and fluidity of working memory in mice brains. Half of the mice were given an injection that is similar to Alzheimer's effects, and the other half were not. Then they were expected to go through a maze that is a task to test working memory. The study help answer questions about how Alzheimer's can deteriorate the working memory and ultimately obliterate memory functions.

阿尔茨海默病 Alzheimer's Disease: 工作记忆功能随着阿尔茨海默症病情的加重而降低。在一项针对老鼠大脑中的神经连接和工作记忆流动性的研究中，一半的老鼠注射了可以引发类阿尔茨海默症的药物，另一半则不注射药物。然后让它们穿越一个迷宫，即完成一个工作记忆测试任务。这项研究有助于回答阿尔兹海默症是如何损害工作记忆并最终消除记忆功能的。

Huntington's disease: A group of researchers hosted a study that researched the function and connectivity of working memory over a 30-month longitudinal experiment. It found that there were certain places in the brain where most connectivity was decreased in pre-Huntington diseased patients, in comparison to the control group that remained consistently functional.

Huntington's disease: A group of researchers hosted a study that researched the function and connectivity of working memory over a 30-month longitudinal experiment. It found that there were certain places in the brain where most connectivity was decreased in pre-Huntington diseased patients, in comparison to the control group that remained consistently functional.

亨廷顿氏病 Huntington's Disease: 一组研究人员进行了为期30个月的纵向实验，研究工作记忆的功能和关联性。研究发现，亨廷顿症患者大脑中特定部位的关联性降低，而对照组功能正常 。

参见 See also

• 多重记忆模型 Atkinson–Shiffrin memory model

• 模板:Section link

• 孤独症与工作记忆 Autism and working memory

• 模糊痕迹理论 Fuzzy-trace theory

• 中期记忆 Intermediate-term memory

• 记忆与老化 Memory and aging

• 前额叶基底节工作记忆 Prefrontal cortex basal ganglia working memory (PBWM)

• 意识结构 Cognitive architecture

• 提姆・沙丽斯 Tim Shallice

外部链接 External links

• Models of Working Memory (Mechanisms of Active Maintenance and Executive Control)

Category:Memory processes

分类: 记忆过程

Category:Problem solving

分类: 解决问题

Category:Human behavior

分类: 人类行为

This page was moved from wikipedia:en:Working memory. Its edit history can be viewed at 工作记忆/edithistory