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Two experiments using the materials of the Revised Speech Perception in Noise (SPIN-R) Test [Bilger et al., J. Speech Hear. Res. 27, 32-48 (1984)] were conducted to investigate age-related differences in the identification and the recall of sentence-final words heard in a babble background. In experiment 1, the level of the babble was varied to determine psychometric functions (percent correct word identification as a function of S/N ratio) for presbycusics, old adults with near-normal hearing, and young normal-hearing adults, when the sentence-final words were either predictable (high context) or unpredictable (low context). Differences between the psychometric functions for high- and low-context conditions were used to show that both groups of old listeners derived more benefit from supportive context than did young listeners. In experiment 2, a working memory task [Daneman and Carpenter, J. Verb. Learn. Verb. Behav. 19, 450-466 (1980)] was added to the SPIN task for young and old adults. Specifically, after listening to and identifying the sentence-final words for a block of n sentences, the subjects were asked to recall the last n words that they had identified. Old subjects recalled fewer of the items they had perceived than did young subjects in all S/N conditions, even though there was no difference in the recall ability of the two age groups when sentences were read. Furthermore, the number of items recalled by both age groups was reduced in adverse S/N conditions. The resutls were interpreted as supporting a processing model in which reallocable processing resources are used to support auditory processing when listening becomes difficult either because of noise, or because of age-related deterioration in the auditory system. Because of this reallocation, these resources are unavailable to more central cognitive processes such as the storage and retrieval functions of working memory, so that "upstream" processing of auditory information is adversely affected.

This paper presents a meta-analysis of the data from 6,179 participants in 77 studies that investigated the association between working-memory capacity and language comprehension ability. Aprimary goal of the meta-analysis was to compare the predictive power of the measures of working memory developed by with the predictive power of other measures of working memory. The results of the meta-analysis support claim that measures that tap the combined processing and storage capacity of working memory (e.g., reading span, listening span) are better predictors of comprehension than are measures that tap only the storage capacity (e.g., word span, digit span). The meta-analysis also showed that math process plus storage measures of working memory are good predictors of comprehension. Thus, the superior predictive power of the process plus storage measures is not limited to measures that involve the manipulation of words and sentences.In this paper we present a meta-analysis ofthe research investigating the association between working-memory capacity and language comprehension ability. Much ofthe research was stimulated by a 1980 paper in which Daneman and Carpenter claimed to have developed a measure of working-memory capacity that was an excellent predictor of language comprehension ability. First we will describe claims, and then we will present our meta-analysis ofthe research findings. THE BACKGROUNDIn their 1980 paper, Daneman and Carpenter claimed to have resolved a paradox in the literature on individual differences in comprehension ability. Many theorists had suggested that short-term memory capacity plays a crucial role in reading and listening comprehension, and that short-term memory should therefore be an important source of individual differences in comprehension ability (cf. Just & Carpenter, 1980; Kintsch & van Dijk, 1978;Perfetti & Lesgold, 1977). After all, reading and listening involve much more than comprehending a stream of isolated words. A major component of skilled comprehension is the ability to compute the semantic and syntactic relations among successive words, phrases, and senThis research was supported by grants from the Natural Sciences and Engineering Research Council of Canada to M. Daneman and P. M. Merikle. We thank Monica Davidson for her help with data search and categorization, Lee Sechrest for statistical consultation, and Akira Miyake for his useful comments and suggestions. Correspondence concerning this article should be addressed to M. Daneman, Department of Psychology, University of Toronto, Mississauga, ON, Canada L5L IC6 (e-mail: daneman@psych.utoronto.ca).tences, thereby constructing a coherent and meaningful representation ofthe discourse. Integrating newly encountered information with the previously processed information means that readers and listeners must have access to the results ofearlier processes. Otherwise, how could they compute the referent for he in the following sentence?-Although he spoke softly, yesterday sspeaker could hear the little boy:S question (Jus...

Individual differences in working memory capacity affect the probability of resolving apparent inconsistencies as in There is a sewer near our home who makes terrific suits. Resolution was less likely for readers with small working memories, as assessed by the reading span test that taxes both processing and storage functions of working memory. The theory proposes that readers with small spans devote so many resources to reading processes that they have less capacity for retaining earlier verbatim wording in working memory. Readers with small spans had particular difficulty recovering from inconsistencies when a sentence boundary intervened, as in There is a sewer near our home. He makes terrific suits. This suggests that end-of-sentence processes taxed the poor reader more. Reading times were used to model the time course of integration. Detection and recovery increased processing time. Furthermore, detection was apparent on the first inconsistent word, suggesting that readers attempt to integrate a word immediately and do not buffer several words before processing them semantically. This article examines individual differences found a bat that was very large and brown and was flying in how readers integrate successive words into ba <* ^ f °rth '" the "to"* room -Now he dkta ' t need their current representation of a text. It focuses to ta 9fraid any longet on the role of working memory in integration Most readers initially interpret the ambiguous and how it interacts with the characteristics wor( j b at & "baseball bat" because this is the of the text being read. The integration pro-interpretation that was primed by the precedcesses were studied by embedding inconsis-j ng sentence. However, "baseball bat" is intencies in simple "garden path" passages such compatible with the subsequent phrase flying as the following:back and forth in the gloomy room, and the There was a strange noise emanating from the dark house, resolution requires a reinterpretation of bat to Bob had to venture in to find what was there. He was mean "a kind of animal." Such inconsistencies terrified; rumor had it that the house was haunted. He ma y be detected as soon as the reader attempts would feel more secure with a stick to defend himself and t mteg rate the new information, say flying, so he went and looked among his baseball equipment. He , . , T . " , ' ..£ which is semantically anomalous given the _.~ ~ r~~;7T. representation of the earlier text. To recoverThe research was supported in part by Natural Sciences .

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