Differences In Working Memory Research Articles

Working memory is related to perceptual processing: a case from color perception.

We explored the relation between individual differences in working memory (WM) and color constancy, the phenomenon of color perception that allows us to perceive the color of an object as relatively stable under changes in illumination. Successive color constancy (measured by first viewing a colored surface under a particular illumination and later recalling it under a new illumination) was better for higher WM individuals than for lower WM individuals. Moreover, the magnitude of this WM difference depended on how much contextual information was available in the scene, which typically improves color constancy. By contrast, simple color memory, measured by viewing and recalling a colored surface under the same illumination, showed no significant relation to WM. This study reveals a relation between WM and a low-level perceptual process not previously thought to operate within the confines of attentional control, and it provides a first account of the individual differences in color constancy known about for decades.

A working memory, not bilingual advantage, in controlled attention

We explored the relationship between working memory (WM) and visually controlled attention (CA) in young bilingual and monolingual children. Previous research has shown that balanced bilingual children outperform monolinguals in CA. However, it is unclear whether this advantage is truly associated with bilingualism or whether potential WM and/or language differences led to the observed effects. Therefore, we examined whether bilingual and monolingual children differ on a visual measure of CA after potential differences in verbal and visual WM had been accounted for. We also looked at the relationship between visually CA and visual WM. Fifteen French monolingual children, 15 English monolingual children, and 15 early simultaneous bilingual children completed verbal short-term memory, verbal WM, visual WM, and visual CA tasks. Detailed information regarding language exposure was collected and abilities in each language were evaluated. A bilingual advantage was not found; that is, monolingual and bilingual children were equally successful in ignoring the irrelevant perceptual distraction on the Simon Task. However, children with better visual WM scores were also more faster and more accurate on the Simon Task. Furthermore, visual WM correlated significantly with the visual CA task.

The concurrent validity of the N-back task as a working memory measure

The N-back task is used extensively in literature as a working memory (WM) paradigm and it is increasingly used as a measure of individual differences. However, not much is known about the psychometric properties of this task and the current study aims to shed more light on this issue. We first review the current literature on the psychometric properties of the N-back task. With three experiments using task variants with different stimuli and load levels, we then investigate the nature of the N-back task by investigating its relationship to WM, and its role as an inter-individual difference measure. Consistent with previous literature, our data suggest that the N-back task is not a useful measure of individual differences in WM, partly because of its insufficient reliability. Nevertheless, the task seems to be useful for experimental research in WM and also well predicts inter-individual differences in other higher cognitive functions, such as fluid intelligence, especially when used at higher levels of load.

Working memory demands impair skill acquisition in children with ADHD.

This study examined the process of cognitive skill acquisition under differential working memory (WM) load conditions in children with the primarily inattentive (n = 21) and the combined (n = 32) subtypes of childhood attention-deficit/hyperactivity disorder (ADHD) and compared the results with those of non-ADHD controls (n = 48). Children completed 2 tasks of cognitive skill acquisition: alphabet arithmetic and finger math. The tasks differed in the amount of WM required for execution (alphabet arithmetic required more) but were otherwise matched with respect to logical structure, design, and discriminatory power. As would be predicted if the WM of the to-be-learned task affected the ability of children with ADHD to develop automaticity for a complex cognitive skill, ADHD-related impairments in the development of automaticity were seen for alphabet arithmetic but not for finger math. Results not only are relevant to ongoing debate regarding the presence of effortful versus automatic cognitive deficits in ADHD but also have implications for the development of new psychoeducational interventions for children with ADHD.

Prospective memory in Parkinson disease and healthy aging during a Virtual Week

Event Abstract Back to Event Prospective memory in Parkinson disease and healthy aging during a Virtual Week E. T. Foster1, M. A. McDaniel2, P. G. Rendell3 and N. S. Rose2* 1 Washington University School of Medicine, United States 2 Washington University in St. Louis, United States 3 Australian Catholic University, Australia Healthy older adults and individuals with Parkinson’s disease (PD) played a computerized version of the Virtual Week game (Rendell & Craik, 2000), a prospective memory (PM) paradigm that simulates everyday PM tasks (e.g., taking medication). Participants also completed a working memory (WM) task. Previous research using Virtual Week has shown that non-repeated PM tasks with cues that are less focal to other ongoing activities produce age differences that are largely attributable to age-related differences in WM, suggesting these tasks are more demanding of executive control processes (Rose, Rendell, McDaniel, Aberle, & Kliegel, 2009). Individuals with PD have impaired executive control processes due to frontostriatal circuitry dysfunction. Accordingly, we expected that PD individuals would be especially challenged by non-repeated PM tasks with less focal cues. Confirming this prediction, results showed that individuals with PD were preferentially impaired on PM tasks that were not repeated and had less focal cues, and this deficit was reduced for repeated and more focally-cued PM tasks. Furthermore, WM may play a mediating role. These findings suggest that PD negatively impacts PM for tasks that are more demanding of executive control processes but that repetition and more focal cues may support spontaneous intention retrieval in this population. Conference: The 20th Annual Rotman Research Institute Conference, The frontal lobes, Toronto, Canada, 22 Mar - 26 Mar, 2010. Presentation Type: Poster Presentation Topic: Neurologic Citation: Foster ET, McDaniel MA, Rendell PG and Rose NS (2010). Prospective memory in Parkinson disease and healthy aging during a Virtual Week. Conference Abstract: The 20th Annual Rotman Research Institute Conference, The frontal lobes. doi: 10.3389/conf.fnins.2010.14.00158 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 01 Jul 2010; Published Online: 01 Jul 2010. * Correspondence: N. S Rose, Washington University in St. Louis, St Louis, United States, nrose@wustl.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers E. T Foster M. A McDaniel P. G Rendell N. S Rose Google E. T Foster M. A McDaniel P. G Rendell N. S Rose Google Scholar E. T Foster M. A McDaniel P. G Rendell N. S Rose PubMed E. T Foster M. A McDaniel P. G Rendell N. S Rose Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Working Memory, Strategy Knowledge, and Strategy Instruction in Children With Reading Disabilities

Two experiments investigated the effects of strategy knowledge and strategy training on the working memory (WM) performance in children (ages 10—11) with and without reading disabilities (RD). Experiment 1 examined the relationship between strategy knowledge (stability of strategy choices) and WM performance as a function of initial, gain (cued), and maintenance conditions. WM performance was significantly improved for both groups under cued conditions; however, the performances of children with RD were inferior to those of children without RD across all memory conditions. Measures of WM capacity rather than strategy stability or processing efficiency best predicted reading comprehension performance. Experiment 2 assessed the effects of strategy training on WM performance by randomly assigning children to strategy instruction or control conditions. Significant improvements in WM performance occurred as a function of training conditions, but the residual WM differences between the reading groups remained. Although the results showed that stable strategy choices, cued performance, and strategy instruction significantly bolstered WM performance in children with RD, their overall WM performance, however, was constrained by capacity limitations.

The Role of Working Memory and Fluency Practice on the Reading Comprehension of Students Who Are Dysfluent Readers

The authors investigated whether practice in reading fluency had a causal influence on the relationship between working memory (WM) and text comprehension for 155 students in Grades 2 and 4 who were poor or average readers. Dysfluent readers were randomly assigned to repeated reading or continuous reading practice conditions and compared with untreated dysfluent and fluent readers on posttest measures of fluency, word identification, vocabulary, and reading comprehension. Three main findings emerged: (a) The influence of WM on text comprehension was not related to fluency training, (b) dysfluent readers in the continuous-reading condition had higher posttest scores than dysfluent readers in the other conditions on measures of text comprehension but not on vocabulary, and (c) individual differences in WM better predicted posttest comprehension performance than word-attack skills. In general, the results suggested that although continuous reading increased comprehension, fluency practice did not compensate for WM demands. The results were interpreted within a model that viewed reading comprehension processes as competing for a limited supply of WM resources that operate independent of fluency.

When and how less is more: reply to Tharp and Pickering

In DeCaro et al. [DeCaro, M. S., Thomas, R. D., & Beilock, S. L. (2008). Individual differences in category learning: Sometimes less working memory capacity is better than more. Cognition, 107, 284–294] we demonstrated that sometimes less working memory (WM) has its advantages. The lower individuals’ WM, the faster they achieved success on an information-integration (II) category learning task adopted from Waldron and Ashby [Waldron, E. M., & Ashby, F. G. (2001). The effects of concurrent task interference on category learning: Evidence for multiple category learning systems. Psychonomic Bulletin & Review, 8, 168–176]. We attributed this success to the inability of lower WM individuals to employ explicit learning strategies heavily reliant on executive control. This in turn, we hypothesized, might push lower WM individuals to readily adopt procedural-based strategies thought to lead to success on the II task. Tharp and Pickering [Tharp, I. J., & Pickering, A. D. (2009). A note on DeCaro, Thomas, and Beilock (2008): Further data demonstrate complexities in the assessment of information-integration category learning. Cognition] recently questioned whether the II category learning task DeCaro et al. used really reflects procedural learning. In an effort to investigate Tharp and Pickering’s assertions with respect to individual differences in WM, we replicate and extend our previous work, in part by modeling participants’ response strategies during learning. We once again reveal that lower WM individuals demonstrate earlier II learning than their higher WM counterparts. However, we also show that low WM individuals’ initial success is not because of procedural-based responding. Instead, individuals lower in WM capacity perseverate in using simple rule-based strategies that circumvent heavy demands on WM while producing above-chance accuracy.

Working Memory, Short-Term Memory, and Reading Disabilities

The purpose of the present study was to synthesize research that compares children with and without reading disabilities (RD) on measures of short-term memory (STM) and working memory (WM). Across a broad age, reading, and IQ range, 578 effect sizes (ESs) were computed, yielding a mean ES across studies of —.89 (SD = 1.03). A total of 257 ESs were in the moderate range for STM measures (M = —.61, 95% confidence range of —.65 to —.58), and 320 ESs were in the moderate range for WM measures (M = —.67, 95% confidence range of —.68 to —.64). The results indicated that children with RD were distinctively disadvantaged compared with average readers on (a) STM measures requiring the recall of phonemes and digit sequences and (b) WM measures requiring the simultaneous processing and storage of digits within sentence sequences and final words from unrelated sentences. No significant moderating effects emerged for age, IQ, or reading level on memory ESs. The findings indicated that domain-specific STM and WM differences between ability groups persisted across age, suggesting that a verbal deficit model that fails to efficiently draw resources from both a phonological and executive system underlies RD.

Do sex differences affect prefrontal cortex associated cognition in schizophrenia?

Cognitive deficits in schizophrenia, especially those related to prefrontal cortex (PFC) functions, influence functional outcome. There is evidence for sex differences in cognition in schizophrenia, but the results in the literature are still controversial. Objective This study evaluated different modalities of working memory (WM) and executive control (EC), functions that are both associated with the PFC, between sexes in schizophrenic patients and controls. Methods We used a battery of neuropsychological tests for assessing auditory, spatial, and visual-matching WM and used a dual task for assessing EC. The study included 50 inpatients (25 female) partially remitted and taking atypical neuroleptics, as well as 40 controls (20 female) matched for age and education. Results Significant sex differences were found in the dual task; female patients detected fewer correct trials than male patients and controls did. Moreover, female patients performed significantly worse in the single visual subtest of the dual task. For the controls, no sex differences were found. Males showed higher positive symptoms than females, but no other differences in psychopathology, disease characteristics, or extrapyramidal symptoms were found between sexes. Conclusion The present study shows an absence of sex differences in WM in healthy subjects and in patients with schizophrenia. However, in the dual task and in the single visual subtest, female patients performed worse than males. This finding suggests that in contrast to males, nonacute female inpatients show an underlying attentional deficit that may contribute to impairment in higher-order functions such as EC.

Differential working memory impairment in bipolar disorder and schizophrenia: effects of lifetime history of psychosis

Although bipolar disorder and schizophrenia have long been viewed as distinct illnesses, there is growing evidence that these two complex diseases share some common genes, which may manifest as overlapping neuropsychological impairments. Although working memory dysfunction has been proposed to be central to the pathophysiology of schizophrenia, it has received less attention in studies of bipolar disorder. We applied measures of working memory to patients with schizophrenia (n = 15), patients with schizoaffective disorder (n = 15), patients with psychotic (n = 11) and non-psychotic (n = 15) bipolar disorder, and demographically matched healthy subjects (n = 32), in order to determine the extent to which these groups show common or unique impairments. While patients with bipolar disorder (with and without psychotic features) and those with schizophrenia/schizoaffective disorder were impaired on backward digit span, only patients with a lifetime history of psychotic features, regardless of diagnosis, were impaired on spatial delayed response task. Backward digit span performance is comparable in bipolar disorder and schizophrenia, and may be an appropriate endophenotypic marker that cuts across diagnostic categories. In contrast, spatial working memory performance clearly distinguishes non-psychotic bipolar disorder patients from patients with functional psychosis.

Explaining age differences in temporal working memory.

To determine the cognitive mechanisms underlying age differences in temporal working memory (WM), the authors examined the contributions of item memory, associative memory, simple order memory, and multiple item memory, using parallel versions of the delayed-matching-to-sample task. Older adults performed more poorly than younger adults on tests of temporal memory, but there were no age differences in nonassociative item memory, regardless of the amount of information to be learned. In contrast, a combination of associative and simple order memory, both of which were reduced in older adults, completely accounted for age-related declines in temporal memory. The authors conclude that 2 mechanisms may underlie age differences in temporal WM, namely, a generalized decline in associative ability and a specific difficulty with order information.

The roles of study-abroad experience and working-memory capacity in the types of errors made during translation

We examined the effects of study-abroad experience (SAE) and working-memory capacity (WMC) on the types of errors made during single-word translation from the first language to the second language, contrasting non-response with meaning errors (i.e. when individuals translate semantically-related words instead of the target word). SAE and WMC interacted; individuals with more SAE and higher WMC made as many meaning as non-response errors, whereas individuals in the other groups made more non-response than meaning errors. We conclude that SAE encourages the use of approximate translations to communicate, but only higher WMC learners can do so because this strategy requires multiple items to be maintained in memory simultaneously. A speech-production model is adapted to capture our results and demonstrate the effects of differential working memory demands on producing correct translations, meaning errors, and non-response errors.

Individual differences in the fan effect and working memory capacity

In opposition to conceptualizing working memory (WM) in terms of a general capacity, we present four experiments that favor the view that individual differences in WM depend on attentional control. High- and low-WM participants, as assessed by the operation span task, learned unrelated sentences for which the subject and predicate of the sentences shared concepts (fan). Sentences were learned in sets organized by subjects (Experiments 1A and 1B) or predicates (Experiments 2A and 2B). WM predicted accuracy and reaction times on a subsequent speeded verification task, but not learning. In Experiments 1A and 2A, low-WM participants had a steeper, positively sloped fan effect for reaction times to studied items than high-WM participants. In Experiments 1B and 2B, fan was eliminated across but not within memory sets, which eliminated individual differences but not slope to the fan effect. These effects suggest the crux of WM is attentional control, and competition across sets causes individual differences.

Matching Instructional Media with Instructional Demands

Video instruction is an effective support for audio instruction of visuospatial tasks; but how is effectiveness of this type of instruction moderated? We investigated the effects of age-related cognitive changes, audio versus audio-plus-video instructions, differential working memory instruction demands, and differential task difficulty on assembly task performance. Forty-eight young adults and 48 older adults completed an assembly task where accuracy, use of additional time, repetition of steps, and subjective mental workload were measured. Results indicated that participants receiving audio plus video instruction benefited most as task difficulty increased. Older adults performed more poorly compared to young adults; however, the findings indicate that video-based instruction was beneficial for both young and older adults for this class of task. Results are discussed from a training perspective in general and as they relate to telemedicine specifically. Guidelines for applying the correct instructional media as a function of the instructional demands are discussed.

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.

Training effects and working memory contributions to skill acquisition in a complex coordination task

Componential and contextual procedures were used to train separate groups in a coordination task that involved dynamic spatial and verbal information. Mean differences analyses indicated performance improved as a result of training, was localized in the more difficult items, and equivalent across groups. However, further analyses provided evidence of differential working memory contributions across groups. Thus, different training procedures fostered equivalent performance levels based on different resource requirements, an important consideration in tasks performed under attentional load. Likely, this difference was related to the functional consistency of information in the training procedures. The broader implications of this study include the importance of detailed task analyses to determine consistent task elements before training programs are enacted and the importance of combining mean and individual differences analyses in studies of human cognition.

Working memory and retrieval: a resource-dependent inhibition model.

Four experiments examined individual differences in working memory (WM) capacity and how those differences affect performance on retrieval from both primary and secondary memory. The results showed that WM differences appear only in retrieval from primary memory and then only under conditions that lead to interference or response competition within the task. This suggests that WM capacity is important to retrieval that is based on controlled effortful search but not search that is based on automatic activation. A view is presented suggesting that individual differences in attentional resources lead to differences in the ability to inhibit or suppress irrelevant information. The paradigm also allowed more general comparisons between the processes involved in retrieval from primary and secondary memory. As expected, it was found that retrieval from primary memory was a function of set size. However, for sets larger than 2 items, retrieval from secondary memory was independent of set size.

The Roman strains of rats as a psychogenetic tool for pharmacological investigation of working memory: example with RU 41656.

This study examined the effects of RU 41656, a dopaminergic D2 agonist, on the differential working memory performances and on the differential activities of the neurochemical systems of the Roman high (RHA) and Roman low (RLA) avoidance strains of rats. Compared with RLA, RHA performed worse in three tests of working memory (spontaneous alternation, radial maze and object recognition) and had higher levels of exploratory locomotor activity. Hippocampal and frontal cortex choline acetyltransferase (ChAT) activities were lower in RHA. Frontal cortex DA and DOPAC levels, hippocampal and striatal 5-HT and NA levels were higher in RHA. RU 41656 induced a significant improvement in working memory performance of RHA, whereas in RLA it had no effect. It decreased exploratory locomotor activity in both strains. ChAT activity in hippocampus was not affected by RU 41656 in either strain, whereas in frontal cortex it was increased in RHA but not in RLA. Hippocampal NA levels were decreased by RU 41656 in RHA but not in RLA. These results confirm previous data concerning the promnesic effect of RU 41656 and extend the finding that the Roman strains are a psychogenetic model for the behavioural, neurochemical and psychopharmacological study of the working memory in rats.