The relationship between age,processing speed,working memory capacity,and language comprehension

A total of 50 elderly individuals and 48 college students were tested on several measures of processing speed and of working memory capacity. Language processing was tested with an on‐line measure of sentence processing efficiency, an end‐of‐sentence acceptability judgement task, and a paragraph comprehension test. Elderly individuals performed more poorly than college students on the speed of processing and working memory measures and had longer listening times overall on the sentence processing measures. Elderly individuals did not, however, have overall longer listening times at the most capacity‐demanding regions of the harder sentence types. Correlational analyses failed to establish a relationship between the increase in syntactic processing load at the capacity‐demanding region of the harder sentence type and the measures of working memory capacity, but did establish a relationship between paragraph comprehension and working memory capacity. The data are argued to provide evidence that the WM system used to structure sentences syntactically is separate from that used in other aspects of language comprehension.     

Effects of acoustic degradation on syntactic processing: implications for the nature of the resource system used in language processing

This study investigated the effect of noise masking on on-line syntactic processing. Ninety college students were tested on measures of working memory and on-line sentence comprehension. Subjects were divided equally into three listening conditions: no noise masking, -3 dB signal-to-noise ratio (S:N), -4.5 dB S:N. The auditory moving windows (AMW) paradigm was used to measure on-line sentence processing. In the AMW paradigm, subjects pressed a button for the successive presentation of each phrase in two types of sentences (syntactically simple and complex), and listening times were recorded for each phrase. Previous studies have shown that the verb in the more complex sentence type is the most capacity demanding portion of the sentence. Listening times were longer overall with increased noise masking, and listening times were longer overall at the verb of the harder sentence type. However, the increase at the verb was not larger with increased noise masking. All three groups showed similar effects of syntactic structure in the on-line data. The on-line syntactic effects were not due to problems in word recognition. Correlational analyses did not indicate a relationship between the increase in processing time at the capacity demanding region of the harder sentence types and any of the measures of working memory capacity in any of the three listening conditions. Results indicate that on-line sentence processing is not affected by noise masking if lexical access (e.g., word recognition) remains intact.     

Effects of age, speed of processing, and working memory on comprehension of sentences with relative clauses

Two hundred participants, 50 in each of four age ranges (19-29, 30-49, 50-69, 70-90) were tested for working memory, speed of processing, and the processing of sentences with relative clauses. In Experiment 1, participants read four sentence types (cleft subject, cleft object, subject-subject, subject-object) in a word-by-word, non-cumulative, self-paced reading task and made speeded plausibility judgments about them. In Experiment 2, participants read two types of sentences, one of which contained a doubly center embedded relative clause. Older participants' comprehension was less accurate and there was age-related slowing of online processing times in all but the simplest sentences, which increased in syntactically complex sentences in Experiment 1. This pattern suggests an age-related decrease in the efficiency of parsing and interpretation. Slower speed of processing and lower working memory were associated with longer online processing times only in Experiment 2, suggesting that task-related operations are related to general speed of processing and working memory. Lower working memory was not associated with longer reading times in more complex sentences, consistent with the view that general working memory is not critically involved in online syntactic processing. Longer online processing at the most demanding point in the most demanding sentence was associated with better comprehension, indicating that it reflects effective processing under some certain circumstances. However, the poorer comprehension performance of older individuals indicates that their slower online processing reflects inefficient processing even at these points.     

Role of Working Memory in Typically Developing Children’s Complex Sentence Comprehension

The influence of three mechanisms of working memory (phonological short-term memory (PSTM capacity), attentional resource control/allocation, and processing speed) on children's complex (and simple) sentence comprehension was investigated. Fifty two children (6-12 years) completed a nonword repetition task (indexing PSTM), concurrent verbal processing-storage task (indexing resource control/allocation), auditory-visual reaction time (RT) task (indexing processing speed), and a sentence comprehension task that included complex and simple sentences. Correlation and regression analyses were run to determine the association between the memory variables and sentence comprehension accuracy. Results revealed: (1) none of the memory variables correlated with simple sentence comprehension, (2) resource control/allocation and processing speed correlated significantly with complex sentence comprehension, even after covarying for age, and (3) attentional functioning and processing speed predicted complex sentence comprehension (after accounting for age). Results were interpreted to suggest that working memory is significantly involved in school age children's comprehension of familiar complex sentence structures.     

Use of Memory-Load Interference in Processing Spoken Chinese Relative Clauses

The processing advantage of Subject-gapped relative clause (SRC) versus Object-gapped relative clause (ORC) has been advocated by competing processing accounts. Using a self-paced listening paradigm, this study investigates what Chinese RC online processing asymmetry looks like under concurrent memory load manipulation. Both On-line listening times and Post-online measures of Chinese SRCs and ORCs are estimated and compared. The on-line results show that ORCs and SRCs demonstrate no differential processing patterns under the interfering conditions. At the relativizer-DE marker region, under 0-digt-load, SRCs show processing advantage, while under 5-digit-load condition, SRCs display greater listening times than ORCs. Furthermore, the Post-online RTs and accuracy of post-sentence comprehension and digit recalls show that processing of SRCs had worse performance. These results lead to the conjecture that there may be no intrinsic processing asymmetry in Chinese RCs, and underscore the necessity that future studies in exploring the processing metrics of sentence complexity should consider the working memory involvement.     

The measurement of reading comprehension: How not to trade construct validity for predictive power

This paper proposes a way to measure and understand individual differences in reading comprehension. The measure is based on the theory that individual differences in reading skill reflect differences in the processing capacity of working memory. The measure of processing capacity, called the reading span test, requires subjects to read aloud increasingly longer sets of sentences and to recall the final word of each sentence in the set. Reading span, the number of final words recalled, varies from two to five for university students. According to the proposed theory, poor readers devote so much capacity to processing the sentences, that they have less residual capacity for storing and producing the final words. The ability to keep information accessible in working memory is particularly crucial for the processes that integrate each ne word with previously read information. And, indeed, reading span is highly correlated with integration processes such as computing pronominal reference, monitoring and revising comprehension errors, and making inferences. The theoretical and predictive value of the reading span measure can be contrasted with the relatively limited value of existing atheoretical and theoretical measures of reading comprehension.     

Is phonological short-term memory related to phonological analysis stages in auditory sentence processing?

Despite extensive research, the role of phonological short-term memory (STM) during oral sentence comprehension remains unclear. We tested the hypothesis that phonological STM is involved in phonological analysis stages of the incoming words, but not in sentence comprehension per se. We compared phonological STM capacity and processing times for natural sentences and sentences containing phonetically ambiguous words. The sentences were presented for an auditory sentence anomaly judgement task and processing times for each word were measured. STM was measured via nonword and word immediate serial recall tasks, indexing phonological and lexicosemantic STM capacity, respectively. Significantly increased processing times were observed for phonetically ambiguous words, relative to natural stimuli in same sentence positions. Phonological STM capacity correlated with the size of this phonetic ambiguity effect. However, phonological STM capacity did not correlate with measures of later semantic integration processes while lexicosemantic STM did. This study suggests that phonological STM is associated with phonological analysis processes during sentence processing.     

On-line syntactic processing under concurrent memory load

Thirty-six university students were tested in a plausibility judgment task using a self-paced listening paradigm under no-interference and two-digit load conditions. Listening times were longer at syntactically more complex portions of syntactically more complex sentences, and greater loads led to increased listening times. However, listening times at syntactically more complex positions in syntactically more complex sentences did not increase more than listening times at comparable positions in syntactically simple sentences under digit load conditions. The results indicate that a concurrent memory load does not reduce the availability of working memory resources used for on-line syntactic processing and, thus, provide evidence that the working memory system used for assigning syntactic structure is separate from that measured by standard working memory tasks.     

Working memory and language comprehension: A meta-analysis

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. A primary goal of the meta-analysis was to compare the predictive power of the measures of working memory developed by Daneman and Carpenter (1980) with the predictive power of other measures of working memory. The results of the meta-analysis support Daneman and Carpenter’s (1980) 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.     

The Measurement of Verbal Working Memory Capacity and Its Relation to Reading Comprehension

Ninety-four subjects were tested on the Daneman and Carpenter (1980) reading span task, four versions of a related sentence span task in which reaction times and accuracy on sentence processing were measured along with sentence-final word recall, two number generation tasks designed to test working memory, digit span, and two shape-generation tasks designed to measure visual-spatial working memory. Forty-four subjects were retested on a subset of these measures at a 3-month interval. All subjects were tested on standard vocabulary and reading tests. Correlational analyses showed better internal consistency and test-retest reliability of the sentence span tasks than of the Daneman-Carpenter reading span task. Factor analysis showed no factor that could be related to a central verbal working memory; rotated factors suggested groupings of tests into factors that correspond to digitrelated tasks, spatial tasks, sentence processing in sentence span tasks, and recall in sentence span tasks. Correlational analyses and regression analyses showed that the sentence processing component of the sentence span tasks was the best predictor of performance on the reading test, with a small independent contribution of the recall component. The results suggest that sentence span tasks are unreliable unless measurements are made of both their sentence processing and recall components, and that the predictive value of these tasks for reading comprehension abilities lies in the overlap of operations rather than in limitations in verbal working memory that apply to both.     

The relationship between age, verbal working memory, and language comprehension

A structural modeling approach was used to examine the relationships between age, verbal working memory (vWM), and 3 types of language measures: online syntactic processing, sentence comprehension, and text comprehension. The best-fit model for the online-processing measure revealed a direct effect of age on online sentence processing, but no effect mediated through vWM. The best-fit models for sentence and text comprehension included an effect of age mediated through vWM and no direct effect of age. These results indicate that the relationship among age, vWM, and comprehension differs depending on the measure of language processing and support the view that individual differences in vWM do not affect individuals' online syntactic processing.     

Sentence Comprehension Deficits in Alzheimer''s Disease: A Comparison of Off-Line vs. On-Line Sentence Processing

Two studies explored whether sentence comprehension impairments in Alzheimer's disease (AD) are due to deficits in syntactic processing or memory. Study 1 used a picture-pointing sentence comprehension task to measure the final outcome of comprehension in an off-line fashion. It showed the comprehension of 30 patients with AD to be impaired, but suggested that the deficits could not be attributed solely to syntactic impairments. Study 2 investigated the effects of memory on sentence comprehension by comparing off-line (grammaticality judgment) with on-line (cross-modal naming) language processing in 11 AD and 9 control subjects. The results revealed impaired performance in the off-line task but normal performance in the on-line task using the same sentences. Performance on the off-line task correlated with independent measures of verbal working memory. These data are used to argue that sentence comprehension impairments are related to verbal working memory deficits in AD.     

Low working memory capacity is only spuriously related to poor reading comprehension

Accounts of comprehension failure, whether in the case of readers with poor skill or when syntactic complexity is high, have overwhelmingly implicated working memory capacity as the key causal factor. However, extant research suggests that this position is not well supported by evidence on the span of active memory during online sentence processing, nor is it well motivated by models that make explicit claims about the memory mechanisms that support language processing. The current study suggests that sensitivity to interference from similar items in memory may provide a better explanation of comprehension failure. Through administration of a comprehensive skill battery, we found that the previously observed association of working memory with comprehension is likely due to the collinearity of working memory with many other reading-related skills, especially IQ. In analyses which removed variance shared with IQ, we found that receptive vocabulary knowledge was the only significant predictor of comprehension performance in our task out of a battery of 24 skill measures. In addition, receptive vocabulary and non-verbal memory for serial order—but not simple verbal memory or working memory—were the only predictors of reading times in the region where interference had its primary affect. We interpret these results in light of a model that emphasizes retrieval interference and the quality of lexical representations as key determinants of successful comprehension.     

Information processing and reasoning with premises that are empirically false: Interference,working memory,and processing speed

In this study, we looked at the contributions of individual differences in susceptibility to interference and working memory to logical reasoning with premises that were empirically false (i.e., not necessarily true). A total of 97 university students were given a sentence completion task for which a subset of stimuli was designed to generate inappropriate semantic activation that interfered with the correct response, a measure of working memory capacity, and a series of logical reasoning tasks with premises that were not always true. The results indicate that susceptibility to interference, as measured by the error rate on the relevant subset of the sentence completion task, and working memory independently account for variation in reasoning performance. The participants who made more errors in the relevant portion of the sentence completion task also showed more empirical intrusions in the deductive reasoning task, even when the effects of working memory were partialed out. Working memory capacity was more clearly related to processes involved in generating uncertainty responses to inferences for which there was no certain conclusion. A comparison of the results of this study with studies of children's reasoning suggests that adults are capable of more selective executive processes than are children. An analysis of latency measures on the sentence completion task indicated that high working memory participants who made no errors on the sentence completion task used a strategy that involved slower processing speed, as compared with participants with similar levels of working memory who did make errors. In contrast, low working memory participants who made no errors on the sentence completion task had relatively shorter reaction times than did comparable participants who did make errors.     

Verbal working memory and on-line syntactic processing: Evidence from self-paced listening

Two experiments investigated the relationship between performance on standard tests of verbal working-memory and the on-line construction of syntactic form. In Experiment 1, working-memory was measured in 100 college students on a version of the Daneman and Carpenter (1980) reading-span task, and online syntactic processing was assessed using a self-paced listening task with four sentence types. In Experiment 2, working-memory was measured in 48 college students on two versions of the reading-span task and two other tests of verbal working-memory, and on-line syntactic processing was assessed using the self-paced listening task with an additional sentence type. In both experiments, there was no relationship between working-memory capacity and the increase in processing time seen for the on-line construction of syntactic form for either syntactically more complex or syntactically simpler sentences. The results indicate that the capacity of the working-memory system that is measured by standard working-memory tests does not determine the efficiency of on-line syntactic processing. They are consistent with the view that the working-memory system used for parsing is at least partially separate from that measured by traditional measures of working-memory capacity.     

信息加工效率与阅读的关系研究

对23名大学生进行知觉广度、记忆广度和阅读理解的多项测验,探求知觉、记忆加工效率与不同语言阅读成绩和阅读眼动特性之间的关系。结果发现：低水平的视觉符号方向信号知觉广度与阅读不存在明显的关系,从眼跳幅度指标上反映出右侧知觉广度大的被试对第二语言加工难度更为敏感。短时记忆和工作记忆能力对阅读的影响主要反映在眼跳幅度方面,与单个注视点获取的信息量有关,但与课文理解水平的关系不明显。短时记忆能力强的被试在眼跳幅度上以及第二语言言语工作记忆弱的被试在注视时间上均出现语言差异效应。     

言语工作记忆、句子理解与句法依存关系加工

言语工作记忆在句子理解中作用的机制和性质,是当前认知神经科学研究的一个中心课题。文章首先回顾了与支撑语言理解的工作记忆资源的性质有关的理论争论和实验证据,然后回顾了填充语-空位依存关系加工这一能够揭示言语工作记忆与句子理解之间关系的重要领域,最后简要展望了今后应该进一步研究的几个问题     

Differential constraints on the working memory and reading abilities of individuals with learning difficulties and typically developing children

This study examined the factors that constrain the working memory span performance and reading ability of individuals with generalized learning difficulties. In the study, 50 individuals with learning difficulties (LD) and 50 typically developing children (TD) matched for reading age completed two working memory span tasks. Participants also completed independent measures of the processing and storage operations involved in each working memory span task and Raven's Coloured Progressive Matrices. The results showed that despite an equivalent level of working memory span, the relative importance of the constraints on working memory differed between the groups. In addition, working memory span was not closely related to word recognition or sentence comprehension performance in the LD group. These results suggest that the working memory span performance of LD and TD individuals may reflect different working memory limitations and that individuals with generalized learning difficulties may approach cognitive tasks in a qualitatively different way from that of typically developing individuals.     

Executive control is shared between sentence processing and digit maintenance: Evidence from a strictly timed dual-task paradigm

We investigated whether the comprehension of syntactically difficult sentences taxes the executive control component of working memory more than the comprehension of their easier counterparts. To that end, we tested the effect of sharing executive control between sentence comprehension and the maintenance of a digit load in two dual-task experiments with strictly controlled timing (Barrouillet, Bernardin, & Camos, 2004). Recall was worse after participants had processed one (Experiment 2) or two (Experiment 1) difficult sentences than after they had processed one or two easy sentences, respectively. This finding suggests that sentence processing and the maintenance of a digit load share executive control. Processing syntactically difficult sentences seems to occupy executive control for a longer time than processing their easy counterparts, thereby blocking refreshments of the memory traces of the digits so that these traces decay more and recall is worse. There was no effect of the size of the digit load on sentence-processing performance (Experiment 2), suggesting that sentence processing completely occupied executive control until processing was complete.     

Processing resource capacity and the comprehension of garden path sentences

Three experiments explored the relationship between verbal working memory capacity and the comprehension of garden path sentences. In Experiment 1, subjects with high, medium, and low working memory spans made acceptability judgments about garden path and control sentences under whole sentence and rapid serial visual presentation (RSVP) conditions. There were no significant differences between subjects with different working memory spans in the comprehension of garden path sentences in either condition. In Experiments 2A and 2B, subjects with high and low working memory spans were tested on the same materials at three RSVP rates. There were no significant differences between subjects with different working memory spans in the magnitude of the effect of garden path sentences at any presentation rate. The results suggest that working memory capacity, as measured by the Daneman and Carpenter (1980) reading span task, is not a major determinant of individual differences in the processing of garden path sentences.