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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).

通说认为工作记忆容量有限，一个对短期记忆的早期量化是1956年米勒 Miller提出的“神奇数字7”。他主张年轻人的信息处理能力大约是7个元素，称之为组块（chunk），组块内容可以是数字、字母、单词或其他单元。后续的研究发现，这个数字的大小取决于所用组块的类别（例如规模可能在约7个数字、6个字母、5个单词）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）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）。还有其他若干因素会影响可测量的记忆规模，因此难以确定短期记忆或工作记忆的组块数。尽管如此，考恩 Cowan主张年轻成人的工作记忆容量大约是4个组块（儿童和老年人则更少）。

通说认为工作记忆容量有限，一个对短期记忆的早期量化是1956年米勒 Miller提出的“'''<font color="#ff8000">神奇数字7 The Magical Number Seven</font>'''”。他主张年轻人的信息处理能力大约是7个元素，称之为组块（chunk），组块内容可以是数字、字母、单词或其他单元。后续的研究发现，这个数字的大小取决于所用组块的类别（例如规模可能在约7个数字、6个字母、5个单词）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）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）。还有其他若干因素会影响可测量的记忆规模，因此难以确定短期记忆或工作记忆的组块数。尽管如此，考恩 Cowan主张年轻成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大约7个数字，但有些个体显示出显著增加的数字记忆规模——高达80个数字。这种技术可以通过对编码策略的广泛训练来实现。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，参与者必须能够将组块识别为某些已知的数字字符串。例如，埃里克森 Ericsson 和他的同事研究的一位研究对象利用了体育历史中比赛时间的广泛知识来编写代码组块: 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，必须保持在工作记忆中的只有层次结构最高级别的一些组块，且这些组块是打开的用于检索。也就是说，工作记忆中的组块作为提取线索发挥作用，提取它们所指向的数字内容。埃里克森 Ericsson 和 金茨 Kintsch (1995; 参见 Gobet & Simon，2000)认为，练习这种记忆技术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)信息的容量。

大多数成年人能够正确地重复大约7个数字，但有些个体显示出显著增加的数字记忆规模——高达80个数字。这种技术可以通过对编码策略的广泛训练来实现。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，参与者必须能够将组块识别为某些已知的数字字符串。例如，埃里克森 Ericsson 和他的同事研究的一位研究对象利用了体育历史中比赛时间的广泛知识来编写代码组块: 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，必须保持在工作记忆中的只有层次结构最高级别的一些组块，且这些组块是打开的用于检索。也就是说，工作记忆中的组块作为提取线索发挥作用，提取它们所指向的数字内容。埃里克森 Ericsson 和 金茨 Kintsch （1995; 参见 Gobet & Simon，2000）认为，练习这种记忆技术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）信息的容量。

工作记忆容量可以通过一系列任务来测试。一个常用的度量方法是双任务范例，它将记忆规模测度与并发处理任务(有时称为“复杂规模”)结合起来。1980年，丹曼 Daneman 和 卡朋特 Carpenter 发明了这类任务的第一个版本——“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。句子阅读完后他们按照自己认为正确的顺序复述单词。还有一些其他非双重任务性质的任务也是测量工作记忆容量的好办法。丹曼 Daneman 和 卡朋特 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即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。用于测量工作记忆容量的好的任务应当具备那些特征，是一个尚在研究中的课题。

工作记忆容量可以通过一系列任务来测试。一个常用的度量方法是双任务范例，它将'''<font color="#ff8000">记忆广度测度 Memory Span Measure</font>'''与并发处理任务(有时称为“复杂规模”)结合起来。1980年，丹曼 Daneman 和 卡朋特 Carpenter 发明了这类任务的第一个版本——“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。句子阅读完后他们按照自己认为正确的顺序复述单词。还有一些其他非双重任务性质的任务也是测量工作记忆容量的好办法。丹曼 Daneman 和 卡朋特 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即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。用于测量工作记忆容量的好的任务应当具备那些特征，是一个尚在研究中的课题。

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.

一些研究人员主张，工作记忆容量反映执行功能效率，其中在面对分散注意力的不相关信息时维持多个任务相关表征的能力最具代表性; 且这样的任务似乎也反映出个体在集中注意力和保持注意力方面的能力差异，特别是当其他事件在吸引注意力时。工作记忆和执行功能都非常依赖（但不限于）额叶大脑区域。

一些研究人员主张，工作记忆容量反映出执行功能的效率，其中最具代表性的是在面对分散注意力的不相关信息时维持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.

其他研究人员主张，用心理上形成或抓取元素间关系的能力来描述工作记忆容量更佳。Graeme Halford 格雷姆 · 哈尔福德在用我们理解变量之间统计交互作用的有限能力时形成并提出了这个想法。这些发起人要求人们把关于几个变量之间关系的书面陈述与相应的图示（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) ，这是大多数人能够理解的最大值。这里的容量限制显然不是记忆量限制(所有相关信息都可连续看到) ，而是同时识别关系量的限制。

另一些研究人员主张，用心理上形成或抓取元素间关系的能力来描述工作记忆容量更佳。Graeme Halford 格雷姆 · 哈尔福德在用我们理解变量之间统计交互作用的有限能力时形成并提出了这个想法。这些发起人要求人们把关于几个变量之间关系的书面陈述与相应的图示（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） ，这是大多数人能够理解的最大值。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） ，而是同时识别关系量的限制。

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.

短期记忆或工作记忆的内容会随着时间的推移而衰退，除非通过复述来防止衰退，这种假设可追溯到短期记忆早期的实验研究。这也是工作记忆多分量理论中的一个重要假设。迄今为止，最详尽的基于衰减假设的工作记忆理论是“基于时间的资源共享模型”。这个理论假设工作记忆中不断衰退的表征需要刷新维持，而刷新需要注意力机制，而注意力又对于任何并发进程任务都是必需的。当进程任务存在不需要注意力的微小时间间隔时，该时间可刷新记忆痕迹。因此，该理论预测遗忘量取决于进程任务临时所需注意力的密度，这种密度叫做“认知负荷”。认知负荷取决于两个变量，一是进程任务需要单个步骤执行的速率，二是每个步骤的持续时间。例如，如果处理任务包括添加数字，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更大的认知负荷。在一系列的实验中，巴鲁耶 Barrouillet 及其同事已证明字母列表的记忆并不取决于处理步骤数量或者处理总时间，而是取决于认知负荷。

短期记忆或工作记忆的内容会随着时间的推移而衰退，除非通过刷新来防止衰退，这种假设可追溯到短期记忆早期的实验研究。这也是工作记忆多分量理论中的一个重要假设。迄今为止，最详尽的基于衰减假设的工作记忆理论是“基于时间的资源共享模型”。这个理论假设工作记忆中不断衰退的表征需要刷新维持，而刷新需要注意力机制，而注意力又对于任何并发进程任务都是必需的。当进程任务存在不需要注意力的微小时间间隔时，该时间可刷新记忆痕迹。因此，该理论预测遗忘量取决于进程任务临时所需注意力的密度，这种密度叫做“认知负荷”。认知负荷取决于两个变量，一是进程任务需要单个步骤执行的速率，二是每个步骤的持续时间。例如，如果处理任务包括添加数字，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更大的认知负荷。在一系列的实验中，巴鲁耶 Barrouillet 及其同事已证明字母列表的记忆并不取决于处理步骤数量或者处理总时间，而是取决于认知负荷。