Working memory and language comprehension: A meta-analysis

Are working memory and behavioral attention equally important for both reading and listening comprehension? A developmental comparison

We investigated the extent to which working memory and behavioral attention predicted reading and listening comprehension in grades 1 through 3 and, whether their relative contributions differed by modality and grade. Separate grade samples (N = 370; ns = 125, 123, and 122 for grades 1, 2, and 3 respectively) completed multiple measures of word reading, working memory, and parallel measures of reading and listening comprehension. Teachers and parents provided behavioral attention ratings. Concurrently, working memory was more important for listening than for reading comprehension and predicted significant variance in both modalities across grades, after controlling for background measures and behavioral attention ratings. For both modalities, working memory explained the greatest proportion of variance in grade 3. Behavioral attention predicted variance in grades 1 and 2 for reading comprehension and all grades for listening comprehension. Subsidiary analyses demonstrated that the influence of working memory and behavioral attention on reading comprehension was indirect, through word reading and listening comprehension both concurrently and also longitudinally between grades 1-3. These findings indicate that delivery of classroom materials orally will not always be beneficial to the young beginner reader or one who struggles with word decoding, and that children with poor working memory/attention may require additional support to access meaning from both written and spoken text.

Are there multiple ways to direct attention in working memory?

In visual working memory tasks, memory for an item is enhanced if participants are told that the item is relatively more valuable than others presented within the same trial. Experiment 1 explored whether these probe value boosts (termed prioritization effects in previous literature) are affected by probe frequency (i.e., how often the more valuable item is tested). Participants were presented with four colored shapes sequentially and asked to recall the color of one probed item following a delay. They were informed that the first item was more valuable (differential probe value) or as valuable as the other items (equal probe value), and that this item would be tested more frequently (differential probe frequency) or as frequently (equal probe frequency) as the other items. Probe value and probe frequency boosts were observed at the first position, though both were accompanied by costs to other items. Probe value and probe frequency boosts were additive, suggesting the manipulations yield independent effects. Further supporting this, experiment 2 revealed that probe frequency boosts are not reliant on executive resources, directly contrasting with previous findings regarding probe value. Taken together, these outcomes suggest there may be several ways in which attention can be directed in working memory.

Alignment of alpha-band desynchronization with syntactic structure predicts successful sentence comprehension

Sentence comprehension requires the encoding of phrases and their relationships into working memory. To date, despite the importance of neural oscillations in language comprehension, the neural-oscillatory dynamics of sentence encoding are only sparsely understood. Although oscillations in a wide range of frequency bands have been reported both for the encoding of unstructured word lists and for working-memory intensive sentences, it is unclear to what extent these frequency bands subserve processes specific to the working-memory component of sentence comprehension or to general verbal working memory. In our auditory electroencephalography study, we isolated the working-memory component of sentence comprehension by adapting a subsequent memory paradigm to sentence comprehension and assessing oscillatory power changes during successful sentence encoding. Time-frequency analyses and source reconstruction revealed alpha-power desynchronization in left-hemispheric language-relevant regions during successful sentence encoding. We further showed that sentence encoding was more successful when source-level alpha-band desynchronization aligned with computational measures of syntactic-compared to lexical-semantic-difficulty. Our results are a preliminary indication of a domain-general mechanism of cortical disinhibition via alpha-band desynchronization superimposed onto the language-relevant cortex, which is beneficial for encoding sentences into working memory.

Explicit Performance in Girls and Implicit Processing in Boys: A Simultaneous fNIRS-ERP Study on Second Language Syntactic Learning in Young Adolescents

Learning a second language (L2) proceeds with individual approaches to proficiency in the language. Individual differences including sex, as well as working memory (WM) function appear to have strong effects on behavioral performance and cortical responses in L2 processing. Thus, by considering sex and WM capacity, we examined neural responses during L2 sentence processing as a function of L2 proficiency in young adolescents. In behavioral tests, girls significantly outperformed boys in L2 tests assessing proficiency and grammatical knowledge, and in a reading span test (RST) assessing WM capacity. Girls, but not boys, showed significant correlations between L2 tests and RST scores. Using functional near-infrared spectroscopy (fNIRS) and event-related potential (ERP) simultaneously, we measured cortical responses while participants listened to syntactically correct and incorrect sentences. ERP data revealed a grammaticality effect only in boys in the early time window (100–300 ms), implicated in phrase structure processing. In fNIRS data, while boys had significantly increased activation in the left prefrontal region implicated in syntactic processing, girls had increased activation in the posterior language-related region involved in phonology, semantics, and sentence processing with proficiency. Presumably, boys implicitly focused on rule-based syntactic processing, whereas girls made full use of linguistic knowledge and WM function. The present results provide important fundamental data for learning and teaching in L2 education.

Neural mechanisms of two different verbal working memory tasks: A VLSM study

Currently, a distributed bilateral network of frontal-parietal areas is regarded as the neural substrate of working memory (WM), with the verbal WM network being more left-lateralized. This conclusion is based primarily on functional magnetic resonance imaging (fMRI) data that provides correlational evidence for brain regions involved in a task. However, fMRI cannot differentiate the areas that are fundamentally required for performing a task. These data can only come from brain-injured individuals who fail the task after the loss of specific brain areas. In addition to the lack of complimentary data, is the issue of the variety in the WM tasks used to assess verbal WM. When different tasks are assumed to measure the same behavior, this may mask the contributions of different brain regions. Here, we investigated the neural substrate of WM by using voxel-based lesion symptom mapping (VLSM) in 49 individuals with stroke-induced left hemisphere brain injuries. These participants completed two different verbal WM tasks: complex listening span and a word 2-back task. Behavioral results indicated that the two tasks were only slightly related, while the VLSM analysis revealed different critical regions associated with each task. Specifically, significant detriments in performance on the complex span task were found with lesions in the inferior frontal gyrus, while for the 2-back task, significant deficits were seen after injury to the superior and middle temporal gyri. Thus, the two tasks depend on the structural integrity of different, non-overlapping frontal and temporal brain regions, suggesting distinct neural and cognitive mechanisms triggered by the two tasks: rehearsal and cue-dependent selection in the complex span task, versus updating/auditory recognition in the 2-back task. These findings call into question the common practice of using these two tasks interchangeably in verbal WM research and undermine the legitimacy of aggregating data from studies with different WM tasks. Thus, the present study points out the importance of lesion studies in complementing functional neuroimaging findings and highlights the need to consider task demands in neuroimaging and neuropsychological investigations of WM.

Verbal short-term memory capacities and executive function in semantic and syntactic interference resolution during sentence comprehension: Evidence from aphasia

This study examined the role of verbal short-term memory (STM) and executive function (EF) underlying semantic and syntactic interference resolution during sentence comprehension for persons with aphasia (PWA) with varying degrees of STM and EF deficits. Semantic interference was manipulated by varying the semantic plausibility of the intervening NP as subject of the verb and syntactic interference was manipulated by varying whether the NP was another subject or an object. Nine PWA were assessed on sentence reading times and on comprehension question performance. PWA showed exaggerated semantic and syntactic interference effects relative to healthy age-matched control subjects. Importantly, correlational analyses showed that while answering comprehension questions, PWA' semantic STM capacity related to their ability to resolve semantic but not syntactic interference. In contrast, PWA' EF abilities related to their ability to resolve syntactic but not semantic interference. Phonological STM deficits were not related to the ability to resolve either type of interference. The results for semantic interference are consistent with prior findings indicating a role for semantic but not phonological STM in sentence comprehension, specifically with regard to maintaining semantic information prior to integration. The results for syntactic interference are consistent with the recent findings suggesting that EF is critical for syntactic processing.

Modern Speed-Reading Apps Do Not Foster Reading Comprehension

New computer apps are gaining popularity by suggesting that reading speeds can be drastically increased when eye movements that normally occur during reading are eliminated. This is done using rapid serial visual presentation (RSVP), where words are presented 1 at a time, thus preventing natural eye movements such as saccades, fixations, and regressions from occurring. Al- though the companies producing these apps suggest that RSVP reading does not yield comprehension deficits, research investigating the role of eye movements in reading documents shows the necessity of natural eye movements for accurate comprehension. The current study explored variables that may affect reading comprehension during RSVP reading, including text difficulty (6th grade and 12th grade), text presentation speed (static, 700 wpm, and 1,000 wpm), and working memory capacity (WMC). Consistent with recent work showing a tenuous relationship between comprehension and WMC, participants' WMC did not predict comprehension scores. Instead, comprehension was most affected by reading speed: Static text was associated with superior performance, relative to either RSVP reading condition. Furthermore, slower RSVP speeds yielded better verbatim comprehension, and faster speeds benefited inferential comprehension.

The Role of Interference Control in Working Memory: A Study with Children at Risk of Adhd

The study aimed to test whether the impairment in a working memory task observed in children at risk of ADHD was due to a lack of control of interfering information being processed whilst carrying out the memory task. Two groups of children at risk of ADHD with or without a learning disability (reading impairment) were compared to a control group in a working memory task. Activation of irrelevant items was tested with a lexical decision task presented immediately after the final recall in about half of the trials. Results showed a poor working memory performance in children at risk of ADHD and reading disability associated with a larger activation of irrelevant information than that of control children. Results indicated that the to-be-excluded and interfering items are still highly accessible to working memory in children that fail the working memory task. The examination of working memory and interference control of children at risk of ADHD with a learning disability revealed a counterintuitive picture of children with poor working memory showing better recall/activation of processed information. This picture is consistent with a view of working memory related to an efficient inhibitory control that influences cognitive functioning.

Phonological similarity effects in verbal complex span

Phonological similarity effects were used to assess the role of acoustic coding in verbal complex span, a processing-plus-storage measure found to correlate significantly with aspects of complex cognition. Three experiments demonstrated consistent effects of phonological similarity on listening span. These effects appeared relatively insensitive to manipulations of task materials (Experiment 1) and differences in processing task demands (Experiments 2 and 3). The results were interpreted as reflecting a significant role for the phonological loop in supporting verbal complex span and a multicomponent view of working memory, as tapped by these tests. Phonological similarity did not significantly interact with aspects of the tasks varied across Experiments 1 to 3, suggesting a relative robustness of the effect. However, variation in the phonological similarity effect sizes across Experiments 1 to 3 supports the suggestion that task demands and characteristics have the potential to disrupt the phonological similarity effect and, by implication, the reliance on a phonological code.

The Contributions of Strategy Use to Working Memory Span: A Comparison of Strategy Assessment Methods

In two experiments, we tested whether individual differences in strategy production account for individual differences in performance on a working memory span task. We measured the strategies used during a standard experimenter-paced operation span (OSPAN) task by having participants make both set-by-set reports of strategy use for individual item sets and global reports of strategy use. In Experiment 1, although normatively effective strategies were self-reported on only a small proportion of OSPAN sets, individual differences in effective strategy use correlated with span performance. Experiment 2 replicated this outcome using a sample of 100 participants but, as important, it demonstrated that individual differences in effective strategy use did not mediate the relationship between OSPAN and measures of verbal ability. Discussion focuses on the interpretation of strategy–span relationships and the relative utility of general reports of strategy use versus the set-by-set reports introduced here for the OSPAN task.

What Happens to Information to be Suppressed in Working–Memory Tasks? Short and Long Term Effects

The study explored, from an individual differences point of view, what happens to information to be suppressed in a working–memory task at short and long term. In particular, it was examined whether control mechanisms of irrelevant information in working memory imply their complete elimination from working memory or just the modulation of their activation. To this end, we compared the fate of irrelevant information in groups of subjects with high and low reading comprehension (Experiments 1 and 2) and subjects with high and low working memory (Experiments 1, 2, 3, and 4). All the experiments presented a working–memory task devised by De Beni, Palladino, Pazzaglia, and Cornoldi (1998), which required participants to process lists of words, to tap when a word from a particular category was presented, and then to recall only the last items in each list. Results confirmed that participants with high reading comprehension also have higher working memory and make less intrusion errors due to irrelevant items that have to be processed but then discarded. Furthermore, it was found that participants with low working memory have slightly better implicit (Experiment 1) and explicit memory (Experiments 3 and 4) of highly activated irrelevant information. Nevertheless, in a long–term recognition test, participants with high and low reading comprehension/working memory presented a similar pattern of memory for different types of irrelevant information (Experiment 2), whereas in a short–term memory recognition test, low–span participants presented a facilitation effect in the time required for the recognition of highly activated irrelevant information (Experiment 4). It was concluded that efficient working–memory performance is related to the temporary reduction of activation of irrelevant information but does not imply its elimination from memory.

The Effects of Cognitive Demand upon Relationships between Working Memory and Cognitive Skills

The present study explored the effects of cognitive demand upon relationships between working memory and cognitive skills. Both children and adults were tested on a measure of short-term memory and three measures of counting span, which varied in cognitive demand. When statistically controlling for short-term memory and the speed of counting operations, the more demanding the counting-span task, the closer its relationship with cognitive skills. The results are discussed in terms of practical and theoretical implications for working memory research.

Working memory capacity and the construction of spatial mental models in comprehension and deductive reasoning

We asked 149 high-school students who were pretested for their working memory capacity (WMC) to read spatial descriptions relating to five objects and to evaluate conclusions asserting an unmentioned relationship between two of the objects. Unambiguous descriptions were compatible with a single spatial arrangement, whereas ambiguous descriptions permitted two arrangements; a subset of the ambiguous descriptions still determined the relation asserted in the conclusion, whereas another subset did not. Two groups of participants received different instructions: The deduction group should accept conclusions only if they followed with logical necessity from the description, whereas the comprehension group should accept a conclusion if it agreed with their representation of the arrangement. Self-paced reading times increased on sentences that introduced an ambiguity, replicating previous findings in deductive reasoning experiments. This effect was also found in the comprehension group, casting doubt on the interpretation that people consider multiple possible arrangements online. Responses to conclusions could be modelled by a multinomial processing model with four parameters: the probability of constructing a correct mental model, the probability of detecting an ambiguity, and two guessing parameters. Participants with high and with low WMC differed mainly in the probability of successfully constructing a mental model.

Working Memory Period: The Endurance of Mental Representations

Working memory span assesses the maximum number of items that can be remembered in the face of concurrent processing. Models of working memory differ on several dimensions, yet many rely exclusively on this span procedure for their evidence. Three experiments consider an alternative paradigm that attempts to capture the endurance limits for remembering a fixed number of items during concurrent processing. Eight-year-old children performed two versions of this working memory period measure—operation period and reading period. Period scores show healthy test–retest reliability and external validity for scholastic attainment, comparing well with span scores in these respects. In addition, period is highly correlated with span and shows similar effects of varying the order in which stimuli are presented. We conclude that the durability of representations is an important factor in both span and period.

Working memory and syllogistic reasoning

The purpose of this study was to examine the relation between working memory span and syllogistic reasoning performance. In addition, performance for the reasoning task was compared to predictions made by mental model theory and the probability heuristics model. According to mental model theory, syllogisms that require the use of more mental models are more difficult. According to the probability heuristics model difficulty is related to the number of probabilistic heuristics that must be applied, or (for invalid syllogisms) inconsistencies between the derived and correct conclusion. The predictions of these theories were examined across two experiments. In general, people with larger working memory capacities reasoned better. Also, the responses made by people with larger capacities were more likely to correspond to the predictions made by both mental model theory and the probability heuristics model. Relations between working memory span and performance were also consistent with both theories.

Receptive Vocabulary, Cognitive Flexibility, and Inhibitory Control Differentially Predict Older and Younger Adults' Success Perceiving Speech by Talkers With Dysarthria

PURPOSE

Previous research has demonstrated equivocal findings related to the effect of listener age on intelligibility ratings of dysarthric speech. The aim of the present study was to investigate the mechanisms that support younger and older adults' perception of speech by talkers with dysarthria.

METHOD

Younger and older adults identified words in phrases produced by talkers with dysarthria. Listeners also completed assessments on peripheral hearing, receptive vocabulary, and executive control functions.

RESULTS

Older and younger adults did not differ in their ability to perceive speech by talkers with dysarthria. Younger adults' success in identifying words produced by talkers with dysarthria was associated only with their hearing acuity. In contrast, older adults showed effects of working memory and cognitive flexibility and interactions between hearing acuity and receptive vocabulary and between hearing acuity and inhibitory control.

CONCLUSIONS

Although older and younger adults had equivalent performance identifying words produced by talkers with dysarthria, older adults appear to utilize more cognitive support to identify those words.

Working Memory Training for Schoolchildren Improves Working Memory, with No Transfer Effects on Intelligence

Working memory contributes to many higher-order cognitive processes and predicts general cognitive skills. It is therefore important to know if its functions are trainable. In this study we investigated the malleability of working memory processes in schoolchildren whose cognitive functions are still developing. We also analyzed transfer effects to both general and specific intellectual skills. To address these issues, we examined the effectiveness of working memory training (10 training sessions) in terms of practice effects (trained tasks), near-transfer effects (working memory capacity), and far-transfer effects (psychometric intelligence). Sixty-nine children aged 8–10 participated in the study. The experimental group (42 children) participated in working memory training that intensely engaged the updating function of working memory. The training tasks, implemented as computer games, were based on the n-back and keep track paradigms. There was also an active control group (27 children). The results suggest that the experimental group improved their working memory capacity, as measured with both trained and untrained tasks. Regarding intelligence, far-transfer effects were weak and may be attributed to mere repetition of measurements. Moreover, whereas improvement in the training tasks could be observed after 15 months, the far-transfer effects disappeared in the delayed assessment.

Cognitive and Behavioral Consequences of Sleep Disordered Breathing in Children

There is now a plethora of evidence that children with sleep disordered breathing (SDB) show deficits in neurocognitive performance, behavioral impairments, and school performance. The following review will focus on the neurobehavioral impacts of SDB, pediatric sleep investigation challenges, potential mechanisms of behavioral and cognitive deficits in children with SDB, and the impact of SDB treatment.

Comprehension in Proficient Readers: The Nature of Individual Variation

Individual-difference research on reading comprehension is challenging because reader characteristics are as correlated with each other as they are with comprehension. This study was conducted to determine which abilities are central to explaining comprehension and which are secondary to other abilities. A battery of psycholinguistic and cognitive tests was administered to community college and university students. Seven constructs were identified: word decoding, working-memory capacity (WMC), general reasoning, verbal fluency, perceptual speed, inhibition, and language experience. Only general reasoning and language experience had direct effects; these two variables accounted for as much variance in comprehension as did the complete set. Direct effects of WMC and decoding were found only when general reasoning and language experience were deleted from the models. The authors question the need to include WMC in our theories of variability in adult reading comprehension and highlight the need to understand precisely how vocabulary facilitates comprehension.

Working Memory and Speech Comprehension in Older Adults With Hearing Impairment

PURPOSE

This study examined the relationship between working memory (WM) and speech comprehension in older adults with hearing impairment (HI). It was hypothesized that WM would explain significant variance in speech comprehension measured in multitalker babble (MTB).

METHOD

Twenty-four older (59-73 years) adults with sensorineural HI participated. WM capacity (WMC) was measured using 3 complex span tasks. Speech comprehension was assessed using multiple passages, and speech identification ability was measured using recall of sentence final-word and key words. Speech measures were performed in quiet and in the presence of MTB at + 5 dB signal-to-noise ratio.

RESULTS

Results suggested that participants' speech identification was poorer in MTB, but their ability to comprehend discourse in MTB was at least as good as in quiet. WMC did not explain significant variance in speech comprehension before and after controlling for age and audibility. However, WMC explained significant variance in low-context sentence key words identification in MTB.

CONCLUSIONS

These results suggest that WMC plays an important role in identifying low-context sentences in MTB, but not when comprehending semantically rich discourse passages. In general, data did not support individual variability in WMC as a factor that predicts speech comprehension ability in older adults with HI.

Differently confident: Susceptibility to bias in perceptual judgments of size interacts with working memory capacity

Much prior research has shown that retrieval of information from long-term memory (LTM) can influence many aspects of complex cognition in situ. However, research also has shown that not all individuals manage information retrieved from LTM in equivalent fashions. Specifically, high working memory capacity (WMC) individuals have been shown to be better able to manage not only what information is retrieved from LTM, but also whether it is applied to the task-at-hand. As such, it is likely that WMC will interact with the biasing influences of prior knowledge on current task performance. In this series of studies, high and low WMC individuals were asked to make perceptual judgments of size that either did or did not activate biasing prior knowledge. Results indicate that when retrieving information from LTM, high WMC individuals are actually more susceptible to perceptual bias and also are erroneously more confident in the accuracy of their response. However, when no retrieval from LTM is necessary, this effect reverses. This suggests that high WMC individuals are indeed able to inhibit such biasing information; however, their overconfidence in the quality of information retrieved from their own LTM can make them susceptible to making errors in perceptual judgments.

Atypical neuronal activation during a spatial working memory task in 13-year-old very preterm children

Children born very preterm (VP; <32 weeks' gestational age) are at risk for unfavorable outcomes in several cognitive domains, including spatial working memory (WM). The underlying neural basis of these cognitive impairments is poorly understood. We investigated differences in neuronal activation during spatial WM using a backward span (BS) task relative to a control (C) task in 45 VP children and 19 term-born controls aged 13 years. VP children showed significantly more activation in the bilateral superior frontal gyrus and significantly less activation in the left parahippocampal gyrus compared with controls. We further explored the distinct contributions of maintenance and manipulation processes of WM using forward span (FS)>C and BS > FS, respectively. There were no significant group differences in neuronal activation for FS > C. However, BS > FS revealed that VP children had significantly greater activation in the left middle frontal gyrus, in the left superior parietal gyrus and right cerebellar tonsil, and significantly less activation in the right precentral and postcentral gyrus and left insula compared with controls. Taken together these results suggest that VP children at 13 years of age show an atypical neuronal activation during spatial WM, specifically related to manipulation of spatial information in WM. It is unclear whether these findings reflect delayed maturation and/or recruitment of alternative neuronal networks as a result of neuroplasticity. Hum Brain Mapp 38:6172-6184, 2017. © 2017 Wiley Periodicals, Inc.

The Effects of Home-Based Cognitive Training on Verbal Working Memory and Language Comprehension in Older Adulthood

Effective language understanding is crucial to maintaining cognitive abilities and learning new information through adulthood. However, age-related declines in working memory (WM) have a robust negative influence on multiple aspects of language comprehension and use, potentially limiting communicative competence. In the current study (N = 41), we examined the effects of a novel home-based computerized cognitive training program targeting verbal WM on changes in verbal WM and language comprehension in healthy older adults relative to an active component-control group. Participants in the WM training group showed non-linear improvements in performance on trained verbal WM tasks. Relative to the active control group, WM training participants also showed improvements on untrained verbal WM tasks and selective improvements across untrained dimensions of language, including sentence memory, verbal fluency, and comprehension of syntactically ambiguous sentences. Though the current study is preliminary in nature, it does provide initial promising evidence that WM training may influence components of language comprehension in adulthood and suggests that home-based training of WM may be a viable option for probing the scope and limits of cognitive plasticity in older adults.

Theorization and an Empirical Investigation of the Component-Based and Developmental Text Writing Fluency Construct

We discuss a component-based, developmental view of text writing fluency, which we tested using data from children in Grades 2 and 3. Text writing fluency was defined as efficiency and automaticity in writing connected texts, which acts as a mediator between text generation (oral language), transcription skills, and writing quality. We hypothesized that in the beginning phase, text writing fluency would be largely constrained by transcription skills (spelling and handwriting), while at a later phase, oral language would make an independent contribution to text writing fluency. Furthermore, we hypothesized that text writing fluency would have a stronger relationship with writing quality at a later phase than at an earlier phase. We operationalized text writing fluency using two curriculum-based measurement writing scores: percentage correct word sequences and correct minus incorrect word sequences. Results revealed that in Grade 2, only transcription skills were uniquely related to text writing fluency, whereas in Grade 3, oral language was also related to text writing fluency. Text writing fluency was weakly related to writing quality in Grade 2 but strongly related to writing quality in Grade 3, over and above oral language and transcription skills. In both grades, oral language and handwriting fluency were independently related to writing quality. Theoretical and practical implications are discussed.

The relation between working memory and language comprehension in signers and speakers

This study investigated the relation between linguistic and spatial working memory (WM) resources and language comprehension for signed compared to spoken language. Sign languages are both linguistic and visual-spatial, and therefore provide a unique window on modality-specific versus modality-independent contributions of WM resources to language processing. Deaf users of American Sign Language (ASL), hearing monolingual English speakers, and hearing ASL-English bilinguals completed several spatial and linguistic serial recall tasks. Additionally, their comprehension of spatial and non-spatial information in ASL and spoken English narratives was assessed. Results from the linguistic serial recall tasks revealed that the often reported advantage for speakers on linguistic short-term memory tasks does not extend to complex WM tasks with a serial recall component. For English, linguistic WM predicted retention of non-spatial information, and both linguistic and spatial WM predicted retention of spatial information. For ASL, spatial WM predicted retention of spatial (but not non-spatial) information, and linguistic WM did not predict retention of either spatial or non-spatial information. Overall, our findings argue against strong assumptions of independent domain-specific subsystems for the storage and processing of linguistic and spatial information and furthermore suggest a less important role for serial encoding in signed than spoken language comprehension.

Executive Function Buffers the Association between Early Math and Later Academic Skills

Extensive evidence has suggested that early academic skills are a robust indicator of later academic achievement; however, there is mixed evidence of the effectiveness of intervention on academic skills in early years to improve later outcomes. As such, it is clear there are other contributing factors to the development of academic skills. The present study tests the role of executive function (EF) (a construct made up of skills complicit in the achievement of goal-directed tasks) in predicting 5th grade math and reading ability above and beyond math and reading ability prior to school entry, and net of other cognitive covariates including processing speed, vocabulary, and IQ. Using a longitudinal dataset of N = 1292 participants representative of rural areas in two distinctive geographical parts of the United States, the present investigation finds EF at age 5 strongly predicts 5th grade academic skills, as do cognitive covariates. Additionally, investigation of an interaction between early math ability and EF reveals the magnitude of the association between early math and later math varies as a function of early EF, such that participants who have high levels of EF can “catch up” to peers who perform better on assessments of early math ability. These results suggest EF is pivotal to the development of academic skills throughout elementary school. Implications for further research and practice are discussed.

Auditory Verbal Working Memory as a Predictor of Speech Perception in Modulated Maskers in Listeners With Normal Hearing

PURPOSE

Background noise can interfere with our ability to understand speech. Working memory capacity (WMC) has been shown to contribute to the perception of speech in modulated noise maskers. WMC has been assessed with a variety of auditory and visual tests, often pertaining to different components of working memory. This study assessed the relationship between speech perception in modulated maskers and components of auditory verbal working memory (AVWM) over a range of signal-to-noise ratios.

METHOD

Speech perception in noise and AVWM were measured in 30 listeners (age range 31-67 years) with normal hearing. AVWM was estimated using forward digit recall, backward digit recall, and nonword repetition.

RESULTS

After controlling for the effects of age and average pure-tone hearing threshold, speech perception in modulated maskers was related to individual differences in the phonological component of working memory (as assessed by nonword repetition) but only in the least favorable signal-to-noise ratio. The executive component of working memory (as assessed by backward digit) was not predictive of speech perception in any conditions.

CONCLUSIONS

AVWM is predictive of the ability to benefit from temporal dips in modulated maskers: Listeners with greater phonological WMC are better able to correctly identify sentences in modulated noise backgrounds.

Effects of Working Memory Capacity and Tasks in Processing L2 Complex Sentence: Evidence from Chinese-English Bilinguals

Two experiments aimed at investigating how working memory capacity (WMC) related to processing wh-extractions in both a grammatical judgment and a translation task by using the Operation Span task. A self-paced paradigm was used to collect response times and accuracy rates. In Experiment 1, results showed that high WMC was related to faster grammatical judgment of the critical region in subject- and object-extractions. In Experiment 2, high WMC was only related to high accuracy in translating wh-extractions. These results indicate that individual differences in WMC play a certain role during L2 sentence processing, and experimental tasks can modulate this effect.

Resolving Conflicts Between Syntax and Plausibility in Sentence Comprehension

Comprehension of plausible and implausible object- and subject-relative clause sentences with and without prepositional phrases was examined. Undergraduates read each sentence then evaluated a statement as consistent or inconsistent with the sentence. Higher acceptance of consistent than inconsistent statements indicated reliance on syntactic analysis. Higher acceptance of plausible than implausible statements reflected reliance on semantic plausibility. There was greater reliance on semantic plausibility and lesser reliance on syntactic analysis for more complex object-relatives and sentences with prepositional phrases than for less complex subject-relatives and sentences without prepositional phrases. Comprehension accuracy and confidence were lower when syntactic analysis and semantic plausibility yielded conflicting interpretations. The conflict effect on comprehension was significant for complex sentences but not for less complex sentences. Working memory capacity predicted resolution of the syntax-plausibility conflict in more and less complex items only when sentences and statements were presented sequentially. Fluid intelligence predicted resolution of the conflict in more and less complex items under sequential and simultaneous presentation. Domain-general processes appear to be involved in resolving syntax-plausibility conflicts in sentence comprehension.

Disentangling Working Memory Functioning in Mood States of Bipolar Disorder: A Systematic Review

Working memory (WM) deficits are often reported in patients with Bipolar Disorder (BD). However, it is not clear about the nature of these WM deficits (update or serial order processes) and their association with each BD states (euthymic, mania, and depressive). This review investigated the association between BD patient's states and the functioning of WM components. For this purpose, we carried out a systematic review fulfilling a search in the databases Medline, Scopus, SciELO, and Web of Science using specific terms in the abstracts of the articles that generated 212 outcomes in the restricted period from 2005 to 2016. Twenty-three papers were selected, completely read, and analyzed using PICOS strategy. The mood episodes predicted deficits in different components of WM in BD patients (the phonological loop or visuospatial sketchpad) and were associated with different WM processes (updating and serial recall). Lower cognitive scores persist even in remission of symptoms. This result suggests that WM deficit apparently is stage-independent in BD patients. Furthermore, findings suggest that the neutral point on Hedonic Detector component of WM could be maladjusted by BD.

Planning sentences while doing other things at the same time: effects of concurrent verbal and visuospatial working memory load

This study investigated to what extent advance planning during sentence production is affected by a concurrent cognitive load. In two picture–word interference experiments in which participants produced subject–verb–object sentences while ignoring auditory distractor words, we assessed advance planning at a phonological (lexeme) and at an abstract–lexical (lemma) level under visuospatial or verbal working memory (WM) load. At the phonological level, subject and object nouns were found to be activated before speech onset with concurrent visuospatial WM load, but only subject nouns were found to be activated with concurrent verbal WM load, indicating a reduced planning scope as a function of type of WM load (Experiment 1). By contrast, at the abstract–lexical level, subject and object nouns were found to be activated regardless of type of concurrent load (Experiment 2). In both experiments, sentence planning had a more detrimental effect on concurrent verbal WM task performance than on concurrent visuospatial WM task performance. Overall, our results suggest that advance planning at the phonological level is more affected by a concurrently performed verbal WM task than advance planning at the abstract–lexical level. Also, they indicate an overlap of resources allocated to phonological planning in speech production and verbal WM.

The role of speed in ADHD-related working memory deficits: A time-based resource-sharing and diffusion model account

Several recent commentaries suggest that, for psychological science to move beyond "homuncular" explanations for cognitive control, it is critically important to examine the role of basic and computationally well-defined processes (e.g. cognitive processing speed). Correlational evidence has previously linked slow speed to working memory (WM) deficits in ADHD, but the directionality of this relationship has not been investigated experimentally and the mechanisms through which speed may influence WM are unclear. Herein, we demonstrate in school-aged children with and without ADHD, that manipulating speed (indexed with the diffusion model) within a WM paradigm reduces WM capacity due to an increase in cognitive load, in a manner that is consistent with predictions of the time-based resource-sharing model of WM. Results suggest slow speed is a plausible cause of WM deficits in ADHD, provide a mechanistic account of this relationship, and urge the exploration of non-executive neurocognitive processes in clinical research on etiology.

Semantic and Syntactic Interference in Sentence Comprehension: A Comparison of Working Memory Models

This study investigated the nature of the underlying working memory system supporting sentence processing through examining individual differences in sensitivity to retrieval interference effects during sentence comprehension. Interference effects occur when readers incorrectly retrieve sentence constituents which are similar to those required during integrative processes. We examined interference arising from a partial match between distracting constituents and syntactic and semantic cues, and related these interference effects to performance on working memory, short-term memory (STM), vocabulary, and executive function tasks. For online sentence comprehension, as measured by self-paced reading, the magnitude of individuals' syntactic interference effects was predicted by general WM capacity and the relation remained significant when partialling out vocabulary, indicating that the effects were not due to verbal knowledge. For offline sentence comprehension, as measured by responses to comprehension questions, both general WM capacity and vocabulary knowledge interacted with semantic interference for comprehension accuracy, suggesting that both general WM capacity and the quality of semantic representations played a role in determining how well interference was resolved offline. For comprehension question reaction times, a measure of semantic STM capacity interacted with semantic but not syntactic interference. However, a measure of phonological capacity (digit span) and a general measure of resistance to response interference (Stroop effect) did not predict individuals' interference resolution abilities in either online or offline sentence comprehension. The results are discussed in relation to the multiple capacities account of working memory (e.g., Martin and Romani, 1994; Martin and He, 2004), and the cue-based retrieval parsing approach (e.g., Lewis et al., 2006; Van Dyke et al., 2014). While neither approach was fully supported, a possible means of reconciling the two approaches and directions for future research are proposed.

EEG correlates of working memory performance in females

Background

The study investigates oscillatory brain activity during working memory (WM) tasks. The tasks employed varied in two dimensions. First, they differed in complexity from average to highly demanding. Second, we used two types of tasks, which required either only retention of stimulus set or retention and manipulation of the content. We expected to reveal EEG correlates of temporary storage and central executive components of WM and to assess their contribution to individual differences.

Results

Generally, as compared with the retention condition, manipulation of stimuli in WM was associated with distributed suppression of alpha1 activity and with the increase of the midline theta activity. Load and task dependent decrement of beta1 power was found during task performance. Beta2 power increased with the increasing WM load and did not significantly depend on the type of the task. At the level of individual differences, we found that the high performance (HP) group was characterized by higher alpha rhythm power. The HP group demonstrated task-related increment of theta power in the left anterior area and a gradual increase of theta power at midline area. In contrast, the low performance (LP) group exhibited a drop of theta power in the most challenging condition. HP group was also characterized by stronger desynchronization of beta1 rhythm over the left posterior area in the manipulation condition. In this condition, beta2 power increased in the HP group over anterior areas, but in the LP group over posterior areas.

Conclusions

WM performance is accompanied by changes in EEG in a broad frequency range from theta to higher beta bands. The most pronounced differences in oscillatory activity between individuals with high and low WM performance can be observed in the most challenging WM task.

Effects of proactive interference on non-verbal working memory

Working memory (WM) is a cognitive system responsible for actively maintaining and processing relevant information and is central to successful cognition. A process critical to WM is the resolution of proactive interference (PI), which involves suppressing memory intrusions from prior memories that are no longer relevant. Most studies that have examined resistance to PI in a process-pure fashion used verbal material. By contrast, studies using non-verbal material are scarce, and it remains unclear whether the effect of PI is domain-general or whether it applies solely to the verbal domain. The aim of the present study was to examine the effect of PI in visual WM using both objects with high and low nameability. Using a Directed-Forgetting paradigm, we varied discriminability between WM items on two dimensions, one verbal (high-nameability vs. low-nameability objects) and one perceptual (colored vs. gray objects). As in previous studies using verbal material, effects of PI were found with object stimuli, even after controlling for verbal labels being used (i.e., low-nameability condition). We also found that the addition of distinctive features (color, verbal label) increased performance in rejecting intrusion probes, most likely through an increase in discriminability between content-context bindings in WM.

Kognitive Fähigkeiten und Lesekompetenz

Zusammenfassung. In der vorliegenden Studie wird der Zusammenhang zwischen kognitiven Fähigkeiten und der Lesefertigkeit bei Schulkindern untersucht. Anhand einer Stichprobe von 101 deutschsprachigen Kindern im Alter zwischen 7 und 16 Jahren wurden Zusammenhänge zwischen den verschiedenen Indizes der Wechsler Intelligence Scale for Children-4th Edition, WISC-IV ( Petermann & Petermann, 2011 ), und den Leistungen in zwei standardisierten Lesetests analysiert. Die Ergebnisse deuten auf einen umschriebenen Einfluss bestimmter Intelligenzbereiche auf die Qualität der Lesefertigkeit hin. Dies unterstützt die in den Leitlinien der Deutschen Gesellschaft für Kinder- und Jugendpsychiatrie und -psychotherapie et al. ( DGKJP; 2015 ) empfohlene Verwendung eines IQ-Diskrepanzkriteriums, auch unter der Verwendung differenzierter Intelligenztests, wie der aktuellen Version des Wechsler Intelligenztests für Kinder und Jugendliche, WISC-IV.

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.

Expanding the developmental models of writing: A direct and indirect effects model of developmental writing (DIEW)

We investigated direct and indirect effects of component skills on writing (DIEW) using data from 193 children in Grade 1. In this model, working memory was hypothesized to be a foundational cognitive ability for language and cognitive skills as well as transcription skills, which, in turn, contribute to writing. Foundational oral language skills (vocabulary and grammatical knowledge) and higher-order cognitive skills (inference and theory of mind) were hypothesized to be component skills of text generation (i.e., discourse-level oral language). Results from structural equation modeling largely supported a complete mediation model among four variations of the DIEW model. Discourse-level oral language, spelling, and handwriting fluency completely mediated the relations of higher-order cognitive skills, foundational oral language, and working memory to writing. Moreover, language and cognitive skills had both direct and indirect relations to discourse-level oral language. Total effects, including direct and indirect effects, were substantial for discourse-level oral language (.46), working memory (.43), and spelling (.37), followed by vocabulary (.19), handwriting (.17), theory of mind (.12), inference (.10), and grammatical knowledge (.10). The model explained approximately 67% of variance in writing quality. These results indicate that multiple language and cognitive skills make direct and indirect contributions, and it is important to consider both direct and indirect pathways of influences when considering skills that are important to writing.

Attention and Reading Skills

Attention plays a critical role in information processing. Its adequate functioning is required for correct development of complex cognitive abilities and regular scholastic progress. Children with attention deficits often have difficulties in reading, writing, and arithmetic. The present study investigated interactions among reading skills, overall scholastic performance as rated by teachers, and components of attention: visual reaction time, simple immediate span of attention, and selectivity. The sample was 98 students in the first and second years of public junior high school (age range 11–14 years, M = 12.6, SD = 1.2), i.e., with expected already well-established reading. Reading was evaluated using Comprehension, Accuracy, and Speed tests. Overall scholastic performance was obtained by means of teachers' ratings. Simple Reaction Time, Digit Span, and Color-Word Interference, included in a multitask computerized test, assessed attention. Analysis confirmed the hypothesis that the reading skills are strongly predictive of the Scholastic Assessment rated by the teachers. High scholastic ratings were correlated with Reading Speed and Accuracy rather than Reading Comprehension. Poor readers showed worse performances on the Digit Span test which measures simple immediate span of attention. Good and poor readers obtained a similar score on the Color-Word Interference task. This observation seems to contrast with the more common interpretation of this effect, suggesting that reading is an automatic process and, therefore, the semantic dimension overcomes the controlled perceptual one. According to other studies, an alternative explanation is suggested. In conclusion, present results confirm the hypothesis of a strong link among reading speed and accuracy, scholastic assessment as rated by teachers, simple immediate span of attention, and visual reaction time.