The separability of working memory resources for spatial thinking and language processing: An individual differences approach.

The current study demonstrates the separability of spatial and verbal working memory resources among college students, In Experiment 1, we developed a spatial span task that taxes both the processing and storage components of spatial working memory. This measure correlated with spatial ability (spatial visualization) measures, but not with verbal ability measures. In contrast, the reading span test, a common test of verbal working memory, correlates with verbal ability measures, but not with spatial ability measures. Experiment 2, which uses an interference paradigm to cross the processing and storage demands of span tasks, replicates this dissociation and further demonstrates that both the processing and storage components of working memory tasks are important for predicting performance on spatial thinking and language processing tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term working memory.

To account for the large demands on working memory during text comprehension and expert performance, the traditional models of working memory involving temporary storage must be extended to include working memory based on storage in long-term memory. In the proposed theoretical framework cognitive processes are viewed as a sequence of stable states representing end products of processing. In skilled activities, acquired memory skills allow these end products to be stored in long-term memory and kept directly accessible by means of retrieval cues in short-term memory, as proposed by skilled memory theory. These theoretical claims are supported by a review of evidence on memory in text comprehension and expert performance in such domains as mental calculation, medical diagnosis, and chess. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Word knowledge and working memory as predictors of reading skill.

Three measures of working memory capacity and three measures of word knowledge were used as predictors of three different measures of reading skill. The results demonstrated that the size of a reader's vocabulary and the speed of accessing it are independent of a "depth" measure of word knowledge and that reading comprehension, reading speed, and text inferencing ability are all independent measures of reading skill. A series of regression analyses were conducted to derive a causal model of the three reading performance measures. The results indicated that working memory efficiency during reading was related to comprehension, whereas a more passive working memory capacity measure was related to reading speed. Moreover, text inferencing ability was related only to word knowledge. We conclude that concepts such as "reading skill," "working memory," and "word knowledge" are multidimensional constructs that cannot be captured by a single variable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new tool for measuring and understanding individual differences in the component processes of reading comprehension.

We propose a new measure of individual differences in reading comprehension ability that is theoretically motivated, is easy to administer, and that has high predictive power. Participants read 3-sentence paragraphs that describe the relations among a set of real and artificial terms, and then they respond to true–false statements that assess their ability to access and integrate long-term memory knowledge with text information, to make text-based inferences, and to recall text. The components of our task predict performance on a test of global reading comprehension and on a range of specific comprehension tests, each of which draws more heavily on one particular component. Our task is better at predicting reading comprehension than is a typical working memory span task and has the potential for advancing researchers' understanding and measurement of a range of linguistic and cognitive tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How prior knowledge, WMC, and relevance of information affect eye fixations in expository text.

This study examined how prior knowledge and working memory capacity (WMC) influence the effect of a reading perspective on online text processing. In Experiment 1, 47 participants read and recalled 2 texts of different familiarity from a given perspective while their eye movements were recorded. The participants' WMC was assessed with the reading span test. The results suggest that if the reader has prior knowledge related to text contents and a high WMC, relevant text information can be encoded into memory without extra processing time. In Experiment 2, baseline processing times showed whether readers slow down their processing of relevant information or read faster through the irrelevant information. The results are discussed in the light of different working memory theories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inferred goals in narratives: Evidence from self-paced reading, recall, and eye movements.

Three convergent methodologies were used to investigate the generation and reinstatement of goals not explicitly stated in a text. Readers read paragraphs adapted from J. S. Huitema, S. Dopkins, C. M. Klin, and J. L. Myers's (1993) study, which conveyed a character's goal early in the text. The goal was either stated explicitly or implied. An event was described later in the text that was either consistent or inconsistent with the goal. Line-by-line reading data, recall for the narratives, and eye-movement data were collected. Evidence is presented that readers infer a character's goal online at the time the information is presented, and the inferred goal functions like an explicitly stated goal in online comprehension processes and in the resulting memory representation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visuospatial cues for reinstating mental models in working memory during interrupted reading.

Reading involves constructing a mental representation in long-term working memory of the world described by the text. Disrupting short-term working memory can interfere with the maintenance of mental models (sets of retrieval cues) needed to access these representations, producing detrimental effects on reading time. In two experiments, subjects read passages that included pairs of coreferential sentences interrupted by unrelated text. As in previous research, reading times increased for the first sentence after the interruption, likely reflecting a reinstatement process for mental models in working memory. In the present research, pictures were provided as visuospatial cues to aid the reinstatement process. The interruption effect was found to be smaller with pictures related to the passages than with unrelated pictures (Experiment 1) or titles (Experiment 2); however, both of these effects occurred only for slow readers. The authors hypothesize that slow readers take the time needed to integrate visuospatial information into their mental models, providing more resilient access to long-term working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual Differences in the Inference of Word Meanings From Context: The Influence of Reading Comprehension, Vocabulary Knowledge, and Memory Capacity.

Two studies investigated the ability to use contextual information in stories to infer the meanings of novel vocabulary by 9-10-year-olds with good and poor reading comprehension. Across studies, children with poor reading comprehension were impaired when the processing demands of the task were greatest. In Study 2, working memory capacity was related to performance, but short-term memory span and memory for the literal content of the text were not. Children with poor reading comprehension were not impaired in learning novel vocabulary taught through direct instruction, but children with both weak reading comprehension and vocabulary were. Implications for the relation between vocabulary development and text comprehension are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging, memory load, and resource allocation during reading.

To test the notion that aging brings an inability to self-initiate processing, the authors investigated the effects of memory load on online sentence understanding. Younger and older adults read a series of short passages with or without a simultaneous updating task, which would be expected to deplete resources by consuming memory capacity. Regression analyses of word-by-word reading times onto text variables within each condition were used to decompose reading times into resources allocated to the array of word-level and textbase-level processes needed for comprehension. Among neither the young nor the old were word-level processes disrupted by a simultaneous memory load. However, older readers showed relatively greater levels of resource allocation to conceptual integration than the younger adults when under load, regardless of working-memory span or task priority. These results suggest that the ability to self-initiate the allocation of processing resources during reading is preserved among older readers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigation of functional working memory in the reading span test.

Two issues were investigated in 2 experiments: (1) the validity of a reading span test that combined a knowledge verification task with a secondary task of word memorization and (2) the hypothesis that word recall reflects the amount of working memory that is functional in reading. In Exp 1, the validity and reliability of the reading span measure were determined. In Exp 2, it was reasoned that if word recall reflected functional working memory in reading, then 2 results should be observed. The 1st predicted result was that prior exposure to sentences used in the reading span test would release working memory resources and improve word recall. The 2nd was that word recall, though correlated with general working memory and verbal knowledge measures, would add to these scores in predicting comprehension. Both sets of results were obtained, supporting the hypothesis that the reading span test measures functional working memory in reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory short-term memory and digit span: Normal versus poor readers.

Investigated the relationship between reading comprehension level, digit span, and short-term memory for Morse codelike temporal patterns in 3 experiments. Consistent with previous research on children, Exp I using 60 undergraduates demonstrated that Ss performed better when the 1st pattern was auditory than when it was visual or tactual. In Exps II and III with 36 undergraduates and 98 5th graders, respectively, no relationship was found between digit span and accuracy in comparing patterns of tones presented a few seconds apart. However, both tasks discriminated between children with normal and poor reading comprehension scores on a standardized test (Reading Comprehension subtest of the California Achievement Tests). It appears that these 2 tasks index fundamental processes that underlie reading comprehension. Digit span seems to assess an individual's ability to rapidly develop meaningful codes in memory for incoming verbal stimuli. The auditory pattern comparison procedure appears to measure ability to maintain information in short-term memory. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Text comprehension in Chinese children: Relative contribution of verbal working memory, pseudoword reading, rapid automated naming, and onset-rime phonological segmentation.

The present study examined the role of verbal working memory (memory span, tongue twister), 2-character Chinese pseudoword reading, rapid automatized naming (letters, numbers), and phonological segmentation (deletion of rimes and onsets) in inferential text comprehension in Chinese in 518 Chinese children in Hong Kong in Grades 3 to 5. It was hypothesized that verbal working memory, together with a small contribution from the other constructs, would explain individual variation in the children's text comprehension. Structural equation modeling and hierarchical multiple regression analyses generally upheld the hypotheses. Though Chinese pseudoword reading did not play an important mediating role in the effect of verbal working memory on text comprehension, verbal working memory had strong effects on pseudoword reading and text comprehension. The findings on the Chinese language support current Western literature as well as display the differential role of the constructs in Chinese reading comprehension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depression in multiple sclerosis: Relationship to working memory capacity.

Recent research has shown that depression in multiple sclerosis (MS) is associated with deficits on cognitively demanding tasks. One explanation for this relationship is that depressed NIS patients may have reduced working memory capacity. The present study was designed to test this hypothesis. Depressed NIS patients were compared with nondepressed MS patients and nondepressed healthy controls on a task of working memory capacity (reading span) and a short-term memory task not taxing working memory capacity (word span). In support of the capacity-reduction model, compared with the nondepressed groups, depressed MS patients performed significantly worse on reading span but not on word span. Additionally, reading span was significantly correlated with capacity-demanding tasks shown to be impaired in depressed NIS patients in previous reports. Results suggest that depressed MS patients are characterized by limited working memory capacity and that the central executive component of the working memory system may be most affected. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory skill.

Argues that acquired memory skills best account for individual differences in memory performance. W. G. Chase and K. A. Ericsson's (1982) theory that improved memory or memory skills are due to the acquisition of more efficient storage and retrieval processes using long-term memory (LTM) is presented. This theory specifies 3 principles that characterize the structure of memory skills: (1) Information rapidly stored in LTM is encoded in terms of knowledge structures in semantic memory (meaningful encoding); (2) during storage in LTM, special retrieval cues are explicitly associated with the memory encoding of the presented information (retrieval structure); and (3) encoding and retrieval operations using LTM can be dramatically sped up by practice, making the rate of information storage in LTM comparable to that of short-term memory. Empirical evidence of the exceptional performance of a large number of memory experts is examined in the light of these principles. It is contended that strong evidence for these principles has also been found for normal Ss, when they are given more than a couple of hours of practice or training on memory tasks. It is concluded that expert memory skill is related to normal Ss' superior memory for meaningful information. (French abstract) (4? p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The complexities of complex span: Explaining individual differences in working memory in children and adults.

Two studies are presented that investigated the constraints underlying working memory performance in children and adults. In each case, independent measures of processing efficiency and storage capacity are assessed to determine their relative importance in predicting performance on complex span tasks, which measure working memory capacity. Results show that complex span performance was independently constrained by individual differences in dornain-general processing efficiency and domain-specific storage capacity. Residual variance, which may reflect the ability to coordinate storage and processing, also predicted academic achievement. These results challenge the view that complex span taps, a limited-capacity resource pool shared between processing and storage operations. Rather, they are consistent with a multiple-component model in which separate resource pools support the processing and storage functions of working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of inferior parietal and inferior frontal cortex in working memory.

Verbal working memory involves two major components: a phonological store that holds auditory-verbal information very briefly and an articulatory rehearsal process that allows that information to be refreshed and thus held longer in short-term memory (A. Baddeley, 1996, 2000; A. Baddeley & G. Hitch, 1974). In the current study, the authors tested two groups of patients who were chosen on the basis of their relatively focal lesions in the inferior parietal (IP) cortex or inferior frontal (IF) cortex. Patients were tested on a series of tasks that have been previously shown to tap phonological storage (span, auditory rhyming, and repetition) and articulatory rehearsal (visual rhyming and a 2-back task). As predicted, IP patients were disproportionately impaired on the span, rhyming, and repetition tasks and thus demonstrated a phonological storage deficit. IF patients, however, did not show impairment on these storage tasks but did exhibit impairment on the visual rhyming task, which requires articulatory rehearsal. These findings lend further support to the working memory model and provide evidence of the roles of IP and IF cortex in separable working memory processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relation among error detection, sentence verification, and low-level reading skills of fourth graders.

The author explored the relation among low-level reading skills, sentence verification, and error detection in 4th graders. Literal text comprehension was measured with the Sentence Verification Technique (J. M. Royer, in press) procedure. A higher (strategic) level of text comprehension was assessed with the error detection paradigm. Thus low- and high-level text comprehension were correlated with low-level reading skill: decoding, lexical access, verbal working memory span, and each other. Although literal text comprehension and low-level reading measures were correlated, both were uncorrelated with error detection. A second study deomonstrated that 4th graders' error detection was best predicted by their tendency to generate inferences while reading. These data suggest that although literal text comprehension is dependent on low-level reading processes, strategic reading competence reflects the 4th grader's tendency to go beyond literal information in a text. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What limits children's working memory span? Theoretical accounts and applications for scholastic development.

Explanations of working memory span in children were studied in a longitudinal follow-up of J. N. Towse, G. J. Hitch, and U. Hutton (1998). Reading span and operation span were lower when within-task retention intervals were lengthened. For each task, variation in span between test waves and age cohorts was systematically related to changes in processing speed. The two spans explained substantial shared variance in both reading and arithmetic scores, with some evidence for domain specificity. Combined span scores predicted unique variance in scholastic attainment over a 1-year interval. The authors concluded that working memory span is constrained by rapid loss of active codes and is not simply a measure of capacity for resource sharing. Working memory is also implicated in scholastic development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences in memory for mathematical story problems: Memory span and problem perception.

The purpose of this study was to investigate individual differences in the recall of propositional units from algebra story problems as a function of memory span and problem perception. Consistent with predictions derived from a processing efficiency view of short-term memory, memory span was inversely related to the recall of extraneous information, positively related to the recall of relational statements, and unrelated to the recall of assignment statements and questions. As predicted by the schema hypothesis, problem perception was inversely related to the recall of extraneous information; however, this relationship was not statistically significant when memory span scores were partialed out. It was concluded that the elementary cognitive processes underlying memory span are important sources of individual differences in problem perception, the ability to eliminate extraneous information from the mental representation of mathematical story problems, and the ability to integrate relational information into a problem representation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)