A subgroup analysis of working memory in children with reading disabilities: domain-general or domain-specific deficiency?

The purpose of this study was to investigate whether changes in working memory (WM) of children with reading disabilities (RD) were related to a domain-specific or a domain-general system. Based on Daneman and Carpenter's (1980) Sentence Listening Span task, children were subgrouped into a group of high executive processing (high listening span) children without RD, a group of low executive processing (low listening span) children with RD, and a group of children with and without RD matched on executive processing (moderate listening span). Subgroups were compared on phonological, visual-spatial, and semantic WM tasks across initial (no probes or cues), gain (cues that bring performance to an asymptotic level), and maintenance conditions (asymptotic conditions without cues). The results showed that (a) children without RD high in executive processing ability outperformed all other subgroups, (b) the RD subgroup low in executive processing performed poorly relative to all other subgroups across task and memory conditions, (c) children with and without RD matched on executive processing were comparable in WM span and changes in WM for all tasks, and (d) WM performance of children with RD was a strong linear function of the high executive processing group, suggesting that the nature or the specific componential makeup of the tasks are not the main contributors to WM performance. Taken together, the results suggest that a domain-general system may partially contribute to poor WM in children with RD, and that this system may operate independently of their reading deficits.     

Intrusion errors in working memory tasks: Are they related to reading comprehension ability?

The purpose of the present research was to investigate whether inefficient suppression mechanisms cause overload and interference in working memory and, consequently, influence reading comprehension. Two groups of children, matched for intelligence but differing in inferential comprehension ability, were compared on measures of short-term (passive storage) and working memory (maintenance and processing) and memory for relevant and irrelevant information after reading a passage. Poor comprehenders produced more intrusion errors in a working memory task and recalled more irrelevant information from the passage. The presence of irrelevant information in recall suggests that poor comprehenders are less efficient in reducing the activation (suppression) of information, which is no longer relevant. A year-long longitudinal study was conducted to investigate the influence of suppression efficiency in reading comprehension. Intrusion errors were shown to be a good predictor of comprehension performance 1 year later. Suppression mechanisms seem to play an important role in working memory by reducing interference and improving the processing and maintenance of relevant information in order to build a coherent representation during reading comprehension.     

Does strategy knowledge influence working memory in children with mathematical disabilities?

This study investigated the relationship between working memory (WM), declarative strategy knowledge, and math achievement in children with and without mathematical disabilities (MD). Experiment 1 examined the relationship between strategy knowledge, verbal WM, and visual-spatial WM in children with MD as a function of initial, gain, and maintenance conditions. The results showed that after partialing the influence of reading, stable strategy choices rather than specific strategy knowledge was related to verbal and visual-spatial WM span in high demand (maintenance) conditions. Experiment 2 compared children with MD to a group of chronological age-matched children and a group of math ability-matched children on the same conditions as Experiment 1. Age-matched children's verbal and visual-spatial WM performance was superior to that of children with MD, whereas WM performance was statistically comparable between children with MD and younger children matched on math ability. The selection of expert strategies was related to high WM span scores in the initial conditions. After controlling for reading achievement in a regression analysis, verbal and visual-spatial WM, stable verbal strategy choices, and expert strategy choices related to visual-spatial processing all contributed independent variance to math achievement. Overall, these results suggest that WM and math achievement are related to strategy knowledge.     

Do different components of working memory underlie different subgroups of reading disabilities?

The purpose of this study was to determine the components of working memory (WM) that underlie less skilled readers' comprehension and word recognition difficulties. Performance of 3 less skilled reading subgroups---children with reading disabilities (RD) in both word recognition and comprehension; children with comprehension deficits only; and children with low verbal IQ, word recognition, and comprehension (poor readers)--was compared to that of skilled readers on WM, short-term memory (STM), processing speed, executive, and phonological processing measures. Ability group comparisons showed that (a) skilled readers outperformed all less skilled readers on measures of WM, updating, and processing speed; (b) children with comprehension deficits only outperformed children with RD on measures of WM, STM, phonological processing, and processing speed; and (c) children with RD outperformed poor readers on WM and phonological processing measures. A hierarchical regression analysis showed that (a) subgroup differences on WM tasks among less skilled readers were moderated by a storage system not specific to phonological skills, and (b) STM and updating contributed significant variance to WM beyond what was contributed by reading group classification. The latter finding suggested that some differences in storage and executive processing emerged between skilled and less skilled readers that were not specific to reading.     

Are working memory deficits in readers with learning disabilities hard to change?

This study investigated whether changes in the working memory (WM) performance of readers with learning disabilities (LD) is related to a general or domain-specific system. The study compared readers with LD, chronologically age-matched (CA-M), and reading level-matched (RL-M) children's WM performance for phonological, visual-spatial, and semantic information under initial (no probes or cues), gain (cues that bring performance to an asymptotic level), and maintenance (asymptotic conditions without cues) conditions. The main findings indicated that (a) CA-M children were superior in performance to readers with LD across initial, gain, and maintenance conditions, (b) readers with LD showed less change (as reflected in effect size scores, slopes for the quadratic curve) on both visual-spatial and verbal (phonological and semantic) WM tasks across gain and maintenance conditions than the CA-matched children, and (c) the performance of readers with LD was superior to the RL-M children's performance on initial conditions, but inferior on gain and maintenance conditions. Taken together, the results suggest that a general system moderated the changes in retrieval of phonological, visual-spatial, and semantic information in readers with LD.     

Does domain experience compensate for working memory capacity in second language reading comprehension?

Reading comprehension in a second language (L2) is a complex task involving knowledge of vocabulary and grammar as well as controlled attention for continuous updating of information. The purpose was to examine the relative contributions of working memory capacity (WMC), first language (L1) comprehension, and domain experience on L2 reading comprehension in Spanish. Three hypotheses of the relationship between ability and experience were examined. The “knowledge is power” model predicts that with enough experience, WMC differences are eliminated. The “independent influences” model predicts that experience and ability separately influence L2 reading comprehension. Finally, the “rich get richer” model, predicts that high WMC individuals benefit more from experience. Results provide evidence for independent influences of experience and ability.     

Remedial interventions for children with reading disabilities: speech perception--an effective component in phonological training?

The effects of two types of phonological training in children with reading disabilities (RD) were examined. One of the programs (SP/LPA) trained children in speech discrimination, letter-sound correspondence, and phonemic awareness. The other program (LPA) trained children only in letter-sound correspondence and phonemic awareness. The effects of these programs were compared with a control group. Thirty-five children with RD were trained in small groups five times a week for 4 weeks. The results indicated that both experimental groups improved in phonemic awareness compared to the control group but that only the SP/LPA group scored higher than the control group in reading.     

Are mathematics disabilities due to a domain-general or a domain-specific working memory deficit?

The relationship between verbal and visual-spatial working memory and mathematical computation skill was examined in children and adults with and without disabilities in mathematics. A hierarchical regression analysis showed that, when partialing for the influence of reading ability, age, and gender, mathematical computation was better predicted by verbal than by visual-spatial working memory. Furthermore, the results showed that the relationship between mathematics ability and working memory were not significantly moderated by age but were stable across a broad age span. We concluded that, regardless of age, deficits in mathematics are mediated by both a domain-general and a domain-specific working memory system.     

What is not working in working memory of children with literacy disorders? Evidence from a three-year-longitudinal study

The goals of this study were to explore the deficits in working memory associated with literacy disorders (i.e. developmental disorders of reading and/or spelling) and the developmental trajectories of these working memory deficits. The performance of 28 children with literacy disorders was compared to a non-disabled control group with the same group size at five bi-annual times of measurement in a three-year-longitudinal study beginning at the end of primary school (9.5 years of age). Storage capacity and central-executive working memory were assessed in phonological and visual-spatial modalities, the latter under static and dynamic conditions. Overall, children with literacy disorders were outperformed by their typical developing peers in all phonological and in dynamic visual-spatial storage and central-executive tasks except for the static visual-spatial storage task. Results at single times of measurement revealed that the most consistent deficit was found in the storage capacity of the phonological loop. An additional central-executive impairment is supported by low backward spans. The causes for output deficits in dynamic visual-spatial tasks and good performance under static visual-spatial condition are discussed.     

Summary versus argument tasks when working with multiple documents: Which is better for whom?

This article reports on two experiments where undergraduates read five documents on a scientific topic and afterwards answered comprehension questions and wrote either summaries or argument essays on the topic. In the first experiment, students who were instructed to work with the documents for the purpose of summarizing their contents displayed better comprehension and integration of document contents than did students instructed to construct arguments from the documents. In the second experiment, focusing on whether the effects of task instructions on multiple-documents comprehension and integration could be moderated by students’ prior knowledge, it was found that only students with high prior knowledge were able to take advantage of instructions to construct arguments while reading, whereas low-knowledge readers seemed to be more hindered than helped by such task instructions. Theoretical as well as educational implications of these findings are discussed.     

Does previewing answer choice options improve performance on reading tests?

Previewing answer-choice options before finishing reading the text is a widely employed test-taking behavior. In the present study we examined whether previewing is related to item response accuracy and response time, using data from Chinese learners of varying English proficiency levels and English native speakers. We examined eye movement patterns of participants who completed online multiple-choice sentence completion tasks, and how previewing was related to reading performance and whether the relation varied as a function of English proficiency level. The results showed that, relative to no previewing, previewing was associated with a significantly lower probability of answering an item correctly but not with significantly longer response time. Importantly, these relations varied across English proficiency levels such that participants with higher proficiency performed better without previewing, but there was no difference for lower-intermediate learners of English. These findings suggest that previewing does not facilitate performance on a sentence comprehension task, but instead interferes with the comprehension process, particularly for individuals with relatively high language proficiency.     

How working memory relates to children’s reading comprehension: the importance of domain-specificity in storage and processing

Working memory is considered a well-established predictor of individual variation in reading comprehension in children and adults. However, how storage and processing capacities of working memory in both the phonological and semantic domain relate to reading comprehension is still unclear. In the current study, we investigated the contribution of phonological and semantic storage, and phonological and semantic processing to reading comprehension in 123 Dutch children in fifth grade. We conducted regression and mediation analyses to find out to what extent variation in reading comprehension could be explained by storage and processing capacities in both the phonological and the semantic domain, while controlling for children’s decoding and vocabulary. The analyses included tasks that reflect storage only, and working memory tasks that assess processing in addition to storage. Regression analysis including only storage tasks as predictor measures, revealed semantic storage to be a better predictor of reading comprehension than phonological storage. Adding phonological and semantic working memory tasks as additional predictors to the model showed that semantic working memory explained individual variation in reading comprehension over and above all other memory measures. Additional mediation analysis made it clear that semantic storage contributed indirectly to reading comprehension via semantic working memory, indicating that semantic storage tapped by working memory, in addition to processing capacities, explains individual variation in reading comprehension. It can thus be concluded that semantic storage plays a more important role in children’s reading comprehension than previously thought.     

Verbal and visuospatial short-term and working memory in children: are they separable?

This study explored the structure of verbal and visuospatial short-term and working memory in children between ages 4 and 11 years. Multiple tasks measuring 4 different memory components were used to capture the cognitive processes underlying working memory. Confirmatory factor analyses indicated that the processing component of working memory tasks was supported by a common resource pool, while storage aspects depend on domain-specific verbal and visuospatial resources. This model is largely stable across this developmental period, although some evidence exists that the links between the domain-specific visuospatial construct and the domain-general processing construct were higher in the 4- to- 6-year age group. The data also suggest that all working memory components are in place by 4 years of age.     

Does visual redundancy inhibit older persons’ information processing in learning?

ABSTRACT

This study investigated the redundancy effect on older and younger persons’ cognitive performance in a caregiver video training. Participants (N = 92) were recruited from one research-intensive university and three senior centers in a midsize city in the western United States. The mixed within- and between-subjects design was used. Participants watched the caregiving video with caption followed by a video without caption or vice versa depending on the condition. The results showed that older persons benefited from the redundancy learning whereas younger persons suffered from the redundancy learning. Implications of the findings are discussed with suggestions for future research.     

Does students’ heritage matter in their performance on and perceptions of historical reasoning tasks?

This mixed methods study explores how high school students (N = 35) enrolled in a US charter school with a high Latino/a population perform on and perceive (in terms of interest and relevance) document-based type historical reasoning tasks: one about the Dust Bowl in the 1930s and the other about the experiences of Mexicans and Mexican Americans in the 1920s. Students wrote essay responses and completed perception inventories about the tasks. We also interviewed 10 focal students to delve more deeply into students’ thinking regarding the tasks and their interest levels in the two topics. We scored students’ responses along the criteria of historical claims, substantiation of claims, use of evidence from documents, sourcing of documents and contextualization. Our hypotheses were that students would perform better on, and be more interested in, tasks that were culturally relevant to them. We found that although students did not perform differently on the two tasks overall, students’ perceptions of the tasks differed, with a significantly greater interest in the task about Mexicans and Mexican Americans. We address the complexity of these findings and discuss implications for curriculum and practise.     

Language problems in children with learning disabilities: do they interfere with maternal communication?

In this study, parent-child interaction in two carefully matched subgroups-school-age boys with learning disabilities (LD) who showed a discrepancy between their verbal IQ and performance IQ and had more extensive difficulties in higher-level language abilities (VIQ < PIQ, n = 8) and boys with LD who did not manifest a discrepancy between verbal IQ and performance IQ (VIQ = PIQ, n = 8), were investigated. The effects of the child's language problems on child task performance and on the quality of maternal communication were analyzed in a mother-child problem solving task. Children in the VIQ < PIQ group were found to be less successful on the task than children in the VIQ = PIQ group, and their mothers exhibited lower communication clarity in their instructions than the mothers of the children in the VIQ = PIQ group. An interesting interaction effect was found for communication deviances. For mothers in the VIQ < PIQ group the extent of deficient communication increased from the monologue to the dialogue situation, whereas communication deviances decreased for mothers in the VIQ = PIQ group. Three possible models are discussed in light of the differences between the subgroups.     

Which components of working memory are important in the writing process?

This study investigated the relationship between components of working memory (WM) and the macrostructure (e.g., planning, writing, and revision) and microstructure (e.g., grammar, punctuation) of writing. A battery of WM and writing measures were administered to 160 high-school students. Overall, hierarchical regression analyses showed that the central executive component of WM significantly predicted planning, writing, and revision as well the majority of microstructure measures. The results further validate the importance of WM in the writing process, but indicate that writing process is more intricately tied to the controlled attention component of WM when compared to storage of information.

Do PDAs enhance the organization and memory skills of students with cognitive disabilities?

The project studied the on‐time behavior of 35 students with intellectual disabilities (ID) or traumatic brain injury (TBI) under three conditions – times and tasks list, paper planner, and two different personal data assistants (PDAs). Students participated for two 4‐week periods, receiving one morning reminder during Period 1 and no reminders during Period 2. Students were on time more often using a PDA compared to a list (p < .024) or a planner (p < .002). Students were on time 50% more often in Period 1 with a single daily morning reminder as compared to no reminder across all conditions. When applying results, clinicians and researchers should note that only the alarm function prompting on‐time behavior was studied, and the influence of the small sample size and short time frame. Future researchers will find a framework for studying PDAs and cell phones with larger samples, over longer time periods, and with a wider range of functions. © 2008 Wiley Periodicals, Inc.