Visual-spatial Working Memory Measures Research Articles

Decoding: It's Not All About the Letters

Reading requires the ability to decode and comprehend. Impairments in working memory (WM) are often implicated in students who are poor decoders. It is unclear whether this is a domain-specific issue or a task-specific issue. Therefore, this study examined how auditory-verbal (AV) WM, visual-spatial (VS) WM, and cognitive load affected the decoding skills of students identified as poor readers. Twenty-five 2nd-grade and 23 fifth-grade students completed 3 different measures requiring various levels of cognitive demand for each domain of WM, and their decoding skills were assessed with word identification and word attack measures. AV WM measures with moderate and high cognitive demands were correlated with 2nd-grade students' abilities to decode words. AV WM measures also predicted their performance on decoding tasks. For 5th-grade students, the AV WM measure with simple cognitive load was correlated with ability to decode words. The VS WM measures were not correlated with word identification or word attack at either level. This study has implications for training instruction in reading. Because the AV WM measures and not the VS WM measures predicted decoding performance in second graders, a greater emphasis on language-rich reading programs could be beneficial in scaffolding early academic achievement and reading performance.

Developmental Trajectories of Verbal, Static Visual-Spatial, and Dynamic Visual-Spatial Working Memory

Working memory (WM) measures are routinely integrated into comprehensive diagnostic evaluations. However, there is little research regarding the underlying components of WM and their developmental trajectories. The current study examined the developmental trajectories of distinct WM components in a sample of 303 individuals ages 6 through 25 years. Consistent with previous research, results indicated an overall linear trajectory from childhood to adolescence; however, trajectories differed across specific content domains. Verbal working memory scores continued to increase linearly through at least early adulthood, and static visual-spatial working memory tapered off in late adolescence or early adulthood. In addition, dynamic visual-spatial working memory showed a slight decline in mid-adolescence before increasing again in early adulthood. The current findings regarding different trajectories for static vs. dynamic visual-spatial working memory provide suggestive evidence for expanding WM conceptualizations and assessments beyond verbal and visual tests. Applications of expanded WM assessments, including separate static and dynamic visual-spatial working memory measures in the comprehensive assessment, are discussed.

Verbal and visual-spatial working memory: What develops over a life span?

This study investigates whether age-related changes in the structure of 5 complex working memory (WM) tasks (a) reflect a general or domain specific system, (b) follows a similar trajectory across different age spans, and (c) contribute domain general or domain specific resources to achievement measures. The study parsed the sample (N = 2,471) into 11 age groups (mean ages of 6, 7, 8, 9, 11, 13, 15, 18, 26, 41, and 66 years), and compared their performances on verbal and visuospatial WM measures. Three important findings emerged: (a) a confirmatory factor analysis and Schmid-Leiman transformation to a high-order model solution supported a domain general factor model for the total sample as well as separately for children and adults, (b) performance on visual-spatial WM tasks as a function of age decreased at a faster rate than verbal WM tasks, and (c) both verbal and visual-spatial WM measures in concert with each other uniquely predicted reading and math measures, suggesting that a domain general WM system contributed to performance on achievement measures. The results support the notion that (a) complex WM tasks function as a domain general system and (b) the factor structure for children and adults on complex WM tasks was highly similar, even though there was evidence of differentiation among verbal and visual-spatial WM measures at certain age groups. (PsycINFO Database Record

Sex differences in visual-spatial working memory: A meta-analysis.

Visual-spatial working memory measures are widely used in clinical and experimental settings. Furthermore, it has been argued that the male advantage in spatial abilities can be explained by a sex difference in visual-spatial working memory. Therefore, sex differences in visual-spatial working memory have important implication for research, theory, and practice, but they have yet to be quantified. The present meta-analysis quantified the magnitude of sex differences in visual-spatial working memory and examined variables that might moderate them. The analysis used a set of 180 effect sizes from healthy males and females drawn from 98 samples ranging in mean age from 3 to 86years. Multilevel meta-analysis was used on the overall data set to account for non-independent effect sizes. The data also were analyzed in separate task subgroups by means of multilevel and mixed-effects models. Results showed a small but significant male advantage (mean d = 0.155, 95% confidence interval = 0.087-0.223). All the tasks produced a male advantage, except for memory for location, where a female advantage emerged. Age of the participants was a significant moderator, indicating that sex differences in visual-spatial working memory appeared first in the 13-17years age group. Removing memory for location tasks from the sample affected the pattern of significant moderators. The present results indicate a male advantage in visual-spatial working memory, although age and specific task modulate the magnitude and direction of the effects. Implications for clinical applications, cognitive model building, and experimental research are discussed.

A Pilot Study of Working Memory and Academic Achievement in College Students With ADHD

Objective: To investigate working memory (WM), academic achievement, and their relationship in university students with attention-deficit/hyperactivity disorder (ADHD). Method: Participants were university students with previously confirmed diagnoses of ADHD (n = 16) and normal control (NC) students (n = 30). Participants completed 3 auditory—verbal WM measures, 2 visual—spatial WM measures, and 1 control executive function task. Also, they self-reported grade point averages (GPAs) based on university courses. Results: The ADHD group displayed significant weaknesses on auditory—verbal WM tasks and 1 visual—spatial task. They also showed a nonsignificant trend for lower GPAs. Within the entire sample, there was a significant relationship between GPA and auditory—verbal WM. Conclusion: WM impairments are evident in a subgroup of the ADHD population attending university. WM abilities are linked with, and thus may compromise, academic attainment. Parents and physicians are advised to counsel university-bound students with ADHD to contact the university accessibility services to provide them with academic guidance. (J. of Att. Dis. 2008; 12(6) 574-581)

Cognitive processes in children's reading and attention: The role of working memory, divided attention, and response inhibition

Children experiencing attention difficulties have documented cognitive deficits in working memory (WM), response inhibition and dual tasks. Recent evidence suggests however that these same cognitive processes are also closely associated with reading acquisition. This paper therefore explores whether these variables predicted attention difficulties or reading among 123 children with and without significant attention problems sampled from the school population. Children were screened using current WM and attention task measures. Three factors explained variance in WM and attention tasks. Response inhibition tasks loaded mainly with central executive measures, but a dual processing task loaded with the visual-spatial WM measures. Phonological loop measures loaded independently of attention measures. After controls for age, IQ and attention-group membership, phonological loop and 'central processing' measures both predicted reading ability. A 'visual memory/dual-task' factor predicted attention group membership after controls for age, IQ and reading ability. Results thus suggest that some of the processes previously assumed to be predictive of attention problems may reflect processes involved in reading acquisition. Visual memory and dual-task functioning are, however, purer indices of cognitive difficulty in children experiencing attention problems.

Individual differences in children's writing: A function of working memory or reading or both processes?

The purpose of this study was to investigate whether a general or specific working memory (WM) system is related to writing and whether individual differences in reading and/or processing efficiency underlie the correlations between WM and writing. Two studies correlated WM with writing (Test of Written Language-TOWL) and reading measures. In Study 1, WM was correlated significantly with a number of writing measures, particularly to those measures related to text generation. Working-memory also contributed unique variance to writing, beyond what is predicted by reading comprehension. Study 2 compared the correlations of verbal and visual-spatial WM measures with the TOWL under initial and enhanced memory processing (dynamic assessment) conditions. The coefficients were statistically comparable between initial and enhanced processing conditions, suggesting that individual differences in processing efficiency do not account for the correlations between WM and writing. Overall, the results indicated that (a) WM measures contribute unique variance to writing, especially text generation, and (b) working memory performance improves under gain conditions, but this enhanced processing efficiency did not appear to mediate the links between WM and writing. Taken together, the two studies support a general capacity explanation for the relationship between working memory and text generation.

Individual and age-related differences in children's working memory.

The purpose of this study was to investigate the degree to which age-related and individual differences in children's working memory (WM) are due to a general or task-specific capacity system. Experiment 1 correlated children's (N = 146; age range 5-19 years) verbal and visual-spatial working memory performance with various intelligence and achievement measures. The results supporting a general system were that (1) visual-spatial and verbal WM measures were significantly intercorrelated with and without age partialed out and (2) both verbal and visual-spatial WM measures were significantly correlated with diverse achievement and intelligence measures. Experiment 2 compared three age groups (N = 192; 7-, 10-, and 13-year-olds) on working-memory performance tasks under initial, enhanced (cued), and maintenance conditions. The results supporting a general capacity system were that (1) age-related performance differences in WM were found on all conditions and not isolated to specific processes, (2) the maintenance measures (high-load condition) predicted the variance better in age-related performance than process measures, and (3) although individual differences in WM performance reflected two independent operations, these operations produced similar correlations to achievement within age groups. Overall, the results support a general capacity explanation of age-related and individual differences in children's WM performance.

The role of working memory in skilled and less skilled readers' comprehension

The purpose of this study was to investigate (a) whether limitations in less skilled reader's comprehension are related to specific or general working memory (WM) deficiencies and (b) whether WM and short-term memory (STM) independently contribute to the reading comprehension deficits in less skilled readers. For Experiment 1, performance of less skilled readers with learning disabilities (LD), chronological-age (CA)-matched, and reading comprehension level-matched children was compared on verbal and visual- spatial WM measures. The results indicated that (a) less skilled readers' WM performance was comparable on visual-spatial WM measures but inferior to CA-matched children on verbal WM measures and (b) less skilled readers' performance on visual-spatial and verbal WM measures was superior to reading comprehension-matched counterparts, with and without reading recognition scores partialed out in the analysis. Experiment 2 compared children, subgrouped into high and low reading comprehension and high and low reading recognition on WM and phonological STM tasks. The results indicated that the comorbid group (low word recognition and low comprehension) had combined WM and STM deficits. The poor comprehension-only group had low WM but average phonological STM performance, whereas the opposite profile occurred for the poor reading recognition-only group. The results support the hypothesis that less skilled readers suffer WM deficits that contribute to comprehension problems, independent of their problems in phonological coding. The results also support the notion that constraints in an executive system may contribute to the reading comprehension deficits in less skilled readers.

Working Memory in Learning Disability Subgroups

The purpose of this study was to investigate (a) the degree to which working memory differences between learning-disabled and nondisabled children reflect a specific or generalized deficit, and (b) whether limitations in the enhancement of learning-disabled student′s working memory performance are attributable to process or storage functions. To this end, performances of reading-disabled, math-disabled, chronological age (CA)-matched, and achievement-matched children were compared on verbal and visual-spatial working memory measures under initial, gain, and maintenance conditions. The results indicated that: (a) learning-disabled subtypes were not differentiated by their performance on verbal and visual-spatial working memory measures; and (b) learning-disabled children′s working memory performance was inferior to CA-matched and superior to achievement-matched counterparts across initial, gain, and maintenance conditions. The results suggest that learning-disabled children suffer generalized working memory deficits, possibly due to storage constraints in the executive system.