A Capacity Theory of Comprehension: Individual Differences in Working Memory
Psychological Review 1992, Vol. 99, No. 1,122-149
Copyright 1992 by the American Psychological Association, Inc. 0033-295X/92/J3.00
A Capacity Theory of Comprehension: Individual Differences in Working Memory
Marcel Adam Just and Patricia A. Carpenter Carnegie Mellon University
A theory of the way working memory capacity constrains comprehension is proposed. The theory proposes that both processing and storage are mediated by activation and that the total amount of activation available in working memory varies among individuals. Individual differences in working memory capacity for language can account for qualitative and quantitative differences among college-age adults in several aspects of language comprehension. One aspect is syntactic modularity: The larger capacity of some individuals permits interaction among syntactic and pragmatic information, so that their syntactic processes are not informationally encapsulated. Another aspect is syntactic ambiguity: The larger capacity of some individuals permits them to maintain multiple interpretations. The theory is instantiated as a production system model in which the amount of activation available to the model affects how it adapts to the transient computational and storage demands that occur in comprehension.
Working memory plays a central role in all forms of complex thinking, such as reasoning, problem solving, and language comprehension. However, its function in language comprehension is especially evident because comprehension entails processing a sequence of symbols that is produced and perceived over time. Working memory plays a critical role in storing the intermediate and final products of a reader 's or listener 's computations as she or he constructs and integrates ideas from the stream of successive words in a text or spoken discourse. In addition to its role in storage, working memory can also be viewed as the pool of operational resources that perform the symbolic computations and thereby
Copyright 1992 by the American Psychological Association, Inc. 0033-295X/92/J3.00
A Capacity Theory of Comprehension: Individual Differences in Working Memory
Marcel Adam Just and Patricia A. Carpenter Carnegie Mellon University
A theory of the way working memory capacity constrains comprehension is proposed. The theory proposes that both processing and storage are mediated by activation and that the total amount of activation available in working memory varies among individuals. Individual differences in working memory capacity for language can account for qualitative and quantitative differences among college-age adults in several aspects of language comprehension. One aspect is syntactic modularity: The larger capacity of some individuals permits interaction among syntactic and pragmatic information, so that their syntactic processes are not informationally encapsulated. Another aspect is syntactic ambiguity: The larger capacity of some individuals permits them to maintain multiple interpretations. The theory is instantiated as a production system model in which the amount of activation available to the model affects how it adapts to the transient computational and storage demands that occur in comprehension.
Working memory plays a central role in all forms of complex thinking, such as reasoning, problem solving, and language comprehension. However, its function in language comprehension is especially evident because comprehension entails processing a sequence of symbols that is produced and perceived over time. Working memory plays a critical role in storing the intermediate and final products of a reader 's or listener 's computations as she or he constructs and integrates ideas from the stream of successive words in a text or spoken discourse. In addition to its role in storage, working memory can also be viewed as the pool of operational resources that perform the symbolic computations and thereby