Working memory and language comprehension: A meta-analysis

Longitudinal relations between verbal working memory and reading in students from diverse linguistic backgrounds

The current research tracked kindergarteners into Grade 4 to investigate the longitudinal relations between reading and verbal working memory (VWM). The samples for investigation included the overall weighted sample, English monolingual (EL1) learners, language minority learners with high English proficiency (HP-LM), and language minority learners with persistently low English proficiency (LP-LM). We first investigated the growth factor relation between VWM and reading and then examined the cross-lagged relations between the two skills in different groups. Results suggested that VWM and reading growth could be separated into the initial phase (kindergarten to Grade 1) and the consolidation phase (end of Grade 1 to Grade 4). Despite the growth rate relation between VWM and reading starting to decline at the consolidation phase for EL1 and HP-LM learners, a moderate growth rate relation was able to remain for LP-LM learners. However, the effects of early VWM on later reading were either small (βs ≤ 0.15) or nonsignificant. In addition, the earlier reading skills were not predictive of later VWM. We suggest that the bidirectional relation between VWM and reading is a codevelopment process rather than a causal factor of each other. However, the process of acquiring basic reading skills and the shaping of VWM influence each other irrespective of linguistic background. Implications for intervention and suggestions for future research are provided.

Syntax and working memory in typically-developing children

A growing trend in developmental psycholinguistics is to relate linguistic development to the development of other cognitive systems. Jakubowicz (2005, 2011) in particular argued that the processing of a complex sentence requires considerable working memory (WM) resources and that these resources are limited in young children, which would explain their non-adult grammar. The present research aims to clarify the relationship between WM and complex syntax, in comprehension, repetition, and spontaneous production, in 48 typically-developing children aged 5 to 12. Our results demonstrate a strong age effect for all measures of WM and syntax. They also reveal strong correlations between scores on simple and complex spans and syntactic performance. Finally, we show the highly predictive value of WM capacities on the acquisition of syntactic skills in both comprehension and production. In particular, the complex-span task, measuring counting span, explains the largest part of the variance in the spontaneous production of embedded clauses.

Cognitive-motor exergaming for reducing fall risk in people with chronic stroke: A randomized controlled trial

BACKGROUND

Dual-task (simultaneous motor and cognitive task) (DT) training via virtual-reality exergaming is known to benefit balance control post-stroke. However, the efficacy of such training on DT balance control (volitional and reactive) and cognitive (executive function and attention) domains associated with fall risk remains unclear.

OBJECTIVE

We evaluated the efficacy of cognitive-motor exergame training (CMT) (Wii-fit games in conjunction with cognitive tasks) for improving balance control (volitional and reactive) and cognition (executive function and attention) among people with chronic stroke (PwCS).

METHODS

Hemiparetic, ambulatory PwCS were randomly assigned to either CMT (n = 12) or conventional training (CT) (n = 12) and underwent six weeks of high-intensity, tapered balance training. The CMT group performed Wii-fit games in conjunction with cognitive tasks, while CT group underwent customized, progressive balance training. Performance under DT conditions on Limits of Stability (volitional) and Slip-Perturbation (reactive) tests, and letter-number sequencing (cognition) determined the efficacy of CMT.

RESULTS

Post-intervention, under DT reactive conditions, CMT group improved both motor and cognition, while the CT group improved motor alone. Under DT volitional conditions, motor performance improved only in CMT group.

CONCLUSION

Cognitive-motor exergaming appears to be effective for improving balance control and cognition and could be implemented in clinical stroke rehabilitation settings.

Differences in Working Memory Capacity Affect Online Spoken Word Recognition: Evidence From Eye Movements

Individual differences in working memory capacity have been gaining recognition as playing an important role in speech comprehension, especially in noisy environments. Using the visual world eye-tracking paradigm, a recent study by Hadar and coworkers found that online spoken word recognition was slowed when listeners were required to retain in memory a list of four spoken digits (high load) compared with only one (low load). In the current study, we recognized that the influence of a digit preload might be greater for individuals who have a more limited memory span. We compared participants with higher and lower memory spans on the time course for spoken word recognition by testing eye-fixations on a named object, relative to fixations on an object whose name shared phonology with the named object. Results show that when a low load was imposed, differences in memory span had no effect on the time course of preferential fixations. However, with a high load, listeners with lower span were delayed by ∼550 ms in discriminating target from sound-sharing competitors, relative to higher span listeners. This follows an assumption that the interference effect of a memory preload is not a fixed value, but rather, its effect is greater for individuals with a smaller memory span. Interestingly, span differences affected the timeline for spoken word recognition in noise, but not offline accuracy. This highlights the significance of using eye-tracking as a measure for online speech processing. Results further emphasize the importance of considering differences in cognitive capacity, even when testing normal hearing young adults.

Working Memory Capacity Limits Memory for Bindings

I propose that the capacity of working memory places a specific limit on the maintenance of temporary bindings. Two experiments support this binding hypothesis: Participants remembered word lists of varying length. When tested on a randomly selected word, their error rates increased with the length of the list, reflecting a limited capacity for short-term maintenance. This increase in errors was predominantly due to binding errors: People confused the correct word with other words of the current memory list, but very rarely with words not in the list. The frequencies of response choices were analyzed through two measurement models – one based on the assumption of discrete memory states, one on the assumption of continuous memory strength – that capture memory for items and for bindings in separate parameters. Increasing memory set size impaired binding memory but not item memory, supporting the binding hypothesis.

Not All Factors Contribute Equally to European-American and Hispanic Students' SAT Scores

This exploratory study shows that the contributions of cognitive, metacognitive awareness, performance avoidance, test anxiety, and socioeconomic family background factors to SAT scores (i.e., overall SAT, SAT-V, SAT-M) may vary as a function of ethnicity (i.e., European-American, Hispanic). Four hundred and fifty-seven students, 282 European-American and 175 Hispanic, completed multiple measures of cognitive, metacognitive awareness, social/personality (i.e., test anxiety, performance avoidance, academic self-efficacy), and socioeconomic family background factors, which were used in regression analyses predicting overall SAT, SAT-V, and SAT-M scores. The results show that most factors contributed significantly to overall SAT, SAT-M, and SAT-V scores. In addition, the ethnicity X test anxiety interaction was significant for all three SAT measures, a finding that suggests ethnic differences in the contributions of test anxiety to overall SAT, SAT-M, and SAT-V scores. For European-American students, test anxiety had no influence on overall SAT and SAT-M scores, whereas for Hispanic students test anxiety had a negative influence on overall SAT and SAT-M scores. For SAT-V scores, interpreting the ethnicity X test anxiety interaction was more complicated because both the significant main effect of test anxiety and the ethnicity X test anxiety interaction must be interpreted together. Whereas test anxiety negatively influenced European-Americans' SAT-V scores, this negative influence was less than the influence it had on Hispanic students' SAT-V scores. Indeed, for Hispanic students with high test anxiety, this negative influence was profound. Taken as a whole, these results suggest that any theory explaining the SAT may need to take into account multiple predictors as well as the possibility that the contributions of these predictors may vary as a function of ethnicity.

Interactions between visual working memory and visual attention among survivors of pediatric acute lymphoblastic leukemia (ALL) and their healthy peers

Introduction: There is increasing concern for adverse cognitive late effects among survivors of pediatric acute lymphoblastic leukemia (ALL) given the widespread impact they have on academic achievement, particularly working memory and attention. We assessed performance among survivors and their healthy peers on a dual task paradigm measuring visual working memory (VWM) and visual attention independently and the dynamic relationship between the two. Assessing specific subsets within cognitive domains allows for understanding the distinct nature of cognitive impairments. Method: Participants were 34 survivors of ALL who have been off-treatment and disease free for 7.5 years; and 20 healthy controls, all between the ages of 10 and 18 years. We utilized behavioral single- and dual-task paradigms. In the dual tasks, participants maintained several items in VWM while performing a visual attention task (Eriksen Flanker Task) that required processing of a target stimulus while inhibiting the processing of distractor stimuli. The single tasks involved performing only the VWM task or only the visual attention task. Results: Results revealed survivors of ALL performed significantly worse than their healthy peers on the single visual attention task but not the single VWM task. Of particular interest, group differences were obtained on the dual VWM and visual attention tasks, such that the VWM and attention tasks reciprocally interfered with each other only among survivors and not their healthy peers. Conclusions: Our results highlight a core deficit in visual attention that is exacerbated by VWM demands among survivors of ALL. The implementation of tasks from cognitive neuroscience paradigms may be sensitive to cognitive impairments experienced by cancer survivors. Assessment and intervention practices among survivors of pediatric ALL are discussed.

DHH Students' Comprehension of Irony in Self-paced Reading

Irony comprehension can be a kind of challenge to those who are relatively less skillful in reading. To examine how DHH college students (DCSs) were different from hearing college students (HCSs) in the reading of ironic discourses, we conducted two experiments in the self-paced reading task. In Experiment 1, the statement was either literally congruent with the preceding context or had to be understood in an ironic way in each trial; In Experiment 2, the statement was the same but the context was not across the two levels of discourse type. The DCSs generally had a poorer performance than the hearing participants. Although able to comprehend ironies, they had a significantly lower efficiency than their hearing counterparts. The results were consistently in agreement with the prediction of the graded salience hypothesis (Giora, R. (1997). Understanding figurative and literal language: The graded salience hypothesis. Cognitive Linguistics, 7, 183-206. doi:10.1515/cogl.1997.8.3.183) and the parallel-constraint-satisfaction framework (Pexman, P. M. (2008). It's fascinating research. Current Directions in Psychological Science, 17(4)286-290. doi:10.1111/j.1467-8721.2008.00591.x), and the DCSs' performance appears to indicate an amplified version of this support. It is implied that educational environments should be created in which deaf and DHH students are encouraged to do as much reading as possible. Exercises should be designed in helping them to improve vocabulary and syntactic skills in general and to improve skills of inference-making in particular.

Individual differences in lexical learning across two language modalities: Sign learning, word learning, and their relationship in hearing non-signing adults

A considerable amount of research has been devoted to understanding individual differences in lexical learning, however, the majority of this research has been conducted with spoken languages rather than signed languages and thus we know very little about the cognitive processes involved in sign learning or the extent to which lexical learning processes are specific to word learning. The present study was conducted to address this gap. Two-hundred thirty-six non-signing adults completed 25 tasks assessing word learning and sign learning (via associative learning paradigms) as well as modality-specific phonological short-term memory, working memory capacity, crystallized intelligence, and fluid intelligence. Latent variable analyses indicated that, when other variables were held constant, fluid intelligence was predictive of both word and sign learning, however, modality-specific phonological short-term memory factors were only predictive of lexical learning within modality-none of the other variables made significant independent contributions. It was further observed that sign and word learning were strongly correlated. Exploratory analyses revealed that all lexical learning tasks loaded onto a general factor, however, sign learning tasks loaded onto an additional specific factor. As such, this study provides insight into the cognitive components that are common to associative L2 lexical learning regardless of language modality and those that are unique to either signed or spoken languages. Results are further discussed in light of established and more recent theories of intelligence, short-term memory, and working memory.

Person-based organisation in working memory

Working memory (WM) helps maintain information during a variety of cognitive activities in scholastic and social situations. This study focused on a social aspect of WM, specifically, how it maintains information related to people. We investigated person-based organisation of information across four experiments using the reading span task (RST). Person information (i.e., an occupational title) was provided with sentences manipulated across conditions. In Experiment 1, consistent with the assumption that person-based organisation exists in WM, participants performed better when they could easily organise target items in a person-based manner (person-based organisation) than when they were prevented from using such information. Experiments 2 and 3 investigated the process of person-based organisation using alphabetical letters as targets (unlike words in Experiment 1), which prevented possible semantic associations between person information and target items. Experiment 2 replicated Experiment 1, suggesting that contextual retrieval is critical in person-based organisation. Experiment 3 showed the person-based organisation effect even after controlling for the difficulty of the process component in the RST. The results of Experiments 2 and 3 suggest that person information could serve as contextual retrieval cues in WM. Experiment 4, which did not show the organisation effect based on information about an object (i.e., a fruit name), suggests along with Experiments 1 to 3 that the observed organisation effect in Experiments 1 to 3 was specific to person information. In addition to showing the enhanced WM performance by person-based organisation, we have suggested contextual cue-dependent retrieval as the underlying cognitive process.

Characterizing and decomposing the neural correlates of individual differences in reading ability among adolescents with task-based fMRI

To better characterize the neural correlates of the full spectrum of reading ability, this fMRI study examined how variations in reading ability correlate with task-based brain activity during reading among a large community sample of adolescents (N = 234). In addition, complimentary approaches taking advantage of empirical as well as independent meta-analytic information were employed to isolate neural substrates of domain-general executive processes that are predictive of reading ability. Age-related differences in brain activity were also examined. Better reading was associated with increased activation in left anterior and inferior temporal regions and parts of orbitofrontal cortex, along with reduced activation in the thalamus and left frontal eye field (FEF). Converging evidence suggests that FEF activity corresponds to executive processes during reading. In contrast, activity in temporal regions is likely to reflect cognitive processes specific to reading. Older adolescents also demonstrated increased activation in an orbitofrontal region that overlaps with the aforementioned age-independent, reading-related regions, along with reduced activity in parietal and occipital regions. These results suggest that comparedto poor readers, proficient readers benefit from efficient reading-specific processes and require less executive effort, implemented via the FEF, during a reading comprehension task.

The Role of Short Vowels in Arabic Listening Comprehension

The goal of the present study was to investigate the effect of short Arabic vowels on listening comprehension. It is well documented that short vowels affect reading and reading comprehension in Arabic literacy. Since reading comprehension and listening comprehension share many commonalities, it is assumed that short vowels will positively affect listening comprehension too. Two listening conditions were presented to students in three grade levels, 7th, 10th and 12th grades: a fully vowelized text and the second without short vowels (on ends of words). Students had to listen and answer multiple choice comprehension questions about the read aloud texts. Further, interviews were conducted with 10 volunteered students from each grade level to get their feedback about their experience. The results indicated significant differences between the two listening conditions in favor of the fully vowelized condition. The results are discussed in relation to different orthographies, reading comprehension, phonology, working memory and comprehension.

Dissociation among preserved resistance to proactive interference and impaired behavioral inhibition in a patient with bilateral lesions in the inferior frontal gyrus: A single-case study

Inhibition is not a unitary construct, as different inhibition-related functions have been disentangled. The present single-case study compares performance of a patient with bilateral lesions in the inferior frontal gyrus (IFG) and anterior insula to healthy age-matched controls in different inhibition-related tasks. Particular focus was on the resolution of proactive interference that is supposed to rely on bilateral IFG and anterior insula. Two working memory tasks previously proven sensitive to deficits in proactive interference (recent-probes, n-back) and two tasks measuring behavioral inhibition (verb generation task, Stroop task) were administered. Against expectations, the patient did not show any deficits in measures of proactive interference. However, compared to controls, she demonstrated considerably reduced performance in both measures of behavioral inhibition, thus resulting in a classical dissociation between proactive interference and behavioral inhibition. Although performance improved during the chronic phase post stroke, the overall pattern of a classical dissociation between proactive interference and behavioral inhibition remained stable across time. Taken together, the present data support the role of the IFG in inhibition-related functions, but a direct relationship between lesions in the IFG and difficulties in resolution of proactive interference could not be corroborated.

Individual differences in children's comprehension of temporal relations: Dissociable contributions of working memory capacity and working memory updating

In two experiments, we examined 9- to 12-year-old children's comprehension and processing of two-clause sentences with a temporal connective (before or after) in the sentence-medial or sentence-initial position. We obtained measures of individual differences in working memory (WM) capacity and WM updating to test their contributions to comprehension. We measured the accuracy of children's responses to the questions "What happened first?" (Experiment 1; N = 74) and "What happened last?" (Experiment 2; N = 50) as well as their sentence reading times. Together, these experiments show continued development of comprehension of temporal relations in children in upper elementary school and suggest that children's comprehension difficulties (i.e., more comprehension errors and longer reading times) were influenced by clause salience and recency effects rather than sentence chronology or the familiarity of the connective. Our findings are consistent with a memory resource-limited account and suggest that individual differences in WM updating and WM capacity make dissociable contributions to processing and comprehension of sentences with temporal order information.

Listening back in time: Does attention to memory facilitate word-in-noise identification?

The ephemeral nature of spoken words creates a challenge for oral communications where incoming speech sounds must be processed in relation to representations of just-perceived sounds stored in short-term memory. This can be particularly taxing in noisy environments where perception of speech is often impaired or initially incorrect. Usage of prior contextual information (e.g., a semantically related word) has been shown to improve speech in noise identification. In three experiments, we demonstrate a comparable effect of a semantically related cue word placed after an energetically masked target word in improving accuracy of target-word identification. This effect persisted irrespective of cue modality (visual or auditory cue word) and, in the case of cues after the target, lasted even when the cue word was presented up to 4 seconds after the target. The results are framed in the context of an attention to memory model that seeks to explain the cognitive and neural mechanisms behind processing of items in auditory memory.

The role of proactive interference in working memory training and transfer

Recent work on working memory training has produced conflicting results regarding the degree and generality of transfer to other cognitive processes. However, few studies have investigated possible mechanisms underlying transfer. The current study was designed to test the role of proactive interference in working memory training and transfer. Eighty-six young adults participated in a pretest-posttest design, with ten training sessions in between. In the two working memory training conditions, subjects performed an operation span task, with one condition requiring recall of letters on every trial (operation-letters), whereas the other condition alternated between letters, digits, and words as the to-be-remembered items across trials (operation-mix). These groups were compared to an active-control group (visual-search). Working memory, verbal fluency, and reading comprehension measures were administered in pretest and posttest sessions. All groups significantly increased their performance over the ten training sessions. There was evidence of strategy-specific benefits on transfer, such that transfer to working memory measures was higher for the operation-letters group on tasks specifically involving letters, and no differential transfer to working memory tests without letters, to verbal fluency, or to reading comprehension. The results indicate that proactive interference does not appear to play a causal role in determining transfer from working memory training, and instead a strategy account based on stimulus content provides a more parsimonious explanation for the pattern of training and transfer.

Effects of backpack weight on the performance of basic short-term/working memory tasks during flat-surface standing

This study empirically investigated the effects of backpack weight on the performance of three basic short-term/working memory (STM/WM) tasks during flat-surface standing. Four levels of backpack weight were considered: 0, 15, 25 and 40% of the body weight. The three STM/WM tasks were the Corsi block, digit span and 3-back tasks, corresponding to the visuo-spatial sketchpad, phonological loop and central executive of WM, respectively. Thirty participants conducted the STM/WM tasks while standing with loaded backpack. Major study findings were that (1) increased backpack weight adversely affected the scores of all three STM/WM tasks; and, (2) the adverse effect of backpack weight was less pronounced for the phonological loop STM task than the other STM/WM tasks. The study findings may help understand and predict the impacts of body-worn equipment weight on the worker's mental task performance for various work activities requiring simultaneous performance of mental and physical tasks. Practitioner summary: The current study empirically examined the effects of backpack weight on the performance of three basic STM/WM tasks. The study findings entail that reduces the weight of body-worn equipment can positively impact the worker's mental task performance in addition to reducing the worker's bodily stresses. Abbreviations: ACC: anterior cingulate cortex; AP: anterior-posterior; BW: body weight; CoP: centre of pressure; C-S: central executive working memory task and standing; DLPFC: dorsolateral prefrontal cortex; HIP: human information processing; ML: medio-lateral; PMC: premotor cortex; P-S: phonological loop short-term memory task and standing; SMA: supplementary motor area; STM: short-term memory; VLPFC: ventrolateral prefrontal cortex; V-S: visuo-spatial short-term memory task and standing; WM: working memory.

Does Exposure to Code-Switching Influence Language Performance in Bilingual Children?

This study investigated whether the effect of exposure to code-switching on bilingual children's language performance varied depending on verbal working memory (WM). A large sample of school-aged Spanish-English bilingual children (N = 174, M_age  = 7.78) was recruited, and children were administered language measures in English and Spanish. The frequency with which the children were exposed to code-switching was gathered through parent report. For children with high verbal WM, greater exposure to code-switching was associated with higher levels of language ability. In contrast, for children with lower verbal WM, greater exposure to code-switching was associated with lower levels of language ability. These findings indicate that children's cognitive processing capacity dictates whether exposure to code-switching facilitates or hinders language skills.

Neural mechanisms of internal distraction suppression in visual attention

When performing a demanding cognitive task, internal distraction in the form of task-irrelevant thoughts and mind wandering can shift our attention away from the task, negatively affecting task performance. Behaviorally, individuals with higher executive function indexed by higher working memory capacity (WMC) exhibit less mind wandering during cognitive tasks, but the underlying neural mechanisms are unknown. To address this problem, we recorded functional magnetic resonance imaging (fMRI) data from subjects performing a cued visual attention task, and assessed their WMC in a separate experiment. Applying machine learning and time-series analysis techniques, we showed that (1) higher WMC individuals experienced lower internal distraction through stronger suppression of posterior cingulate cortex (PCC) activity, (2) higher WMC individuals had better neural representations of attended information as evidenced by higher multivoxel decoding accuracy of cue-related activities in the dorsal attention network (DAN), (3) the positive relationship between WMC and DAN decoding accuracy was mediated by suppression of PCC activity, (4) the dorsal anterior cingulate (dACC) was a source of top-down signals that regulate PCC activity as evidenced by the negative association between Granger-causal influence dACC→PCC and PCC activity levels, and (5) higher WMC individuals exhibiting stronger dACC→PCC Granger-causal influence. These results shed light on the neural mechanisms underlying the executive suppression of internal distraction in tasks requiring externally oriented attention and provide an explanation of the individual differences in such suppression.

The word order of languages predicts native speakers' working memory

The relationship between language and thought is controversial. One hypothesis is that language fosters habits of processing information that are retained even in non-linguistic domains. In left-branching (LB) languages, modifiers usually precede the head, and real-time sentence comprehension may more heavily rely on retaining initial information in working memory. Here we presented a battery of working memory and short-term memory tasks to adult native speakers of four LB and four right-branching (RB) languages from Africa, Asia and Europe. In working memory tasks, LB speakers were better than RB speakers at recalling initial stimuli, but worse at recalling final stimuli. Our results show that the practice of parsing sentences in specific directions due to the syntax and word order of our native language not only predicts the way we remember words, but also other non-linguistic stimuli.

Urinary tetrahydrocannabinol is associated with poorer working memory performance and alterations in associated brain activity

Worldwide, cannabis is one of the most widely used psychoactive substances and cannabis use has been implicated in poorer performance in several cognitive domains, including working memory (WM). However, the neural mechanisms underlying these WM decrements are not well understood and the current study investigated the association of cannabis involvement with WM performance and associated neural activation in the Human Connectome Project (N = 1038). Multiple indicators of cannabis involvement were examined in relation to behavioral performance and brain activity in a visual N-back task using functional magnetic resonance imaging. A positive urine drug screen for tetrahydocannabinol (THC+ status), the principal psychoactive constituent in cannabis, was associated with worse WM performance and differential brain response in areas previously linked to WM performance. Furthermore, decreases in blood-activation-level-dependent (BOLD) signal in WM task-positive brain regions and increases in task-negative regions mediated the relationship between THC+ status and WM performance. In contrast, WM performance and BOLD response during the N-back task were not associated with total lifetime cannabis use, age of first use, or other indicators of involvement, suggesting that the effects of cannabis on WM were short-term residual effects, rather than long-term persistent effects. These findings elucidate differential influences of cannabis involvement on neurocognition and have significant potential implications for occupational performance in diverse settings.

The Meeting Point: Where Language Production and Working Memory Share Resources

The interaction between working memory and language processing is widely discussed in cognitive research. However, those studies often explore the relationship between language comprehension and working memory (WM). The role of WM is rarely considered in language production, despite some evidence suggesting a relationship between the two cognitive systems. This study attempts to fill that gap by using a complex span task during language production. We make our predictions based on the reorganization of elementary functions neurocognitive model, a usage based theory about grammatical status, and language production models. In accordance with these theories, we expect an overlap between language production and WM at one or more levels of language planning. Our results show that WM is involved at the phonological encoding level of language production and that adding WM load facilitates language production, which leads us to suggest that an extra task-specific storage is being created while the task is performed.

Assessing Cognitive Abilities in High-Performing Cochlear Implant Users

Despite being considered one of the most successful neural prostheses, cochlear implants (CIs) provide recipients with a wide range of speech perception performance. While some CI users can understand speech in the absence of visual cues, other recipients exhibit more limited speech perception. Cognitive skills have been documented as a contributor to complex auditory processing, such as language understanding; however, there are no normative data for existing standardized clinical tests assessing cognitive abilities in CI users. Here, we assess the impact of modality of presentation (i.e., auditory-visual versus visual) for the administration of working memory tests in high-performing CI users in addition to measuring processing speed, cognitive efficiency and intelligence quotient (IQ). Second, we relate performance on these cognitive measures to clinical CI speech perception outcomes.

Methods: Twenty one post-lingually deafened, high-performing, adult CI users [age range: 52–88 years; 3 unilateral CI, 13 bimodal (i.e., CI with contralateral hearing aid), 5 bilateral CI] with clinical speech perception scores (i.e., AzBio sentences in quiet for the first-ear CI) of ≥60% were recruited. A cognitive test battery assessing auditory-visual working memory (AVWM), visual working memory (VWM), processing speed, cognitive efficiency and IQ was administered, in addition to clinical measures of speech perception in quiet (i.e., AzBio sentences in quiet). AzBio sentences were assessed in two conditions: first-ear CI only, and best-aided everyday wearing condition. Subjects also provided self-reported measures of performance and benefit from their CI using standardized materials, including the Glasgow Benefit Inventory (GBI) and the Nijmegen Cochlear Implant questionnaire (NCIQ).

Results: High-performing CI users demonstrated greater VWM than AVWM recall. VWM was positively related to AzBio scores when measured in the first-ear CI only. AVWM, processing speed, cognitive efficiency, and IQ did not relate to either measure of speech perception (i.e., first-ear CI or best-aided conditions). Subjects’ self-reported benefit as measured by the GBI predicted best-aided CI speech perception performance.

Conclusion: In high-performing CI recipients, visual presentation of working memory tests may improve our assessment of cognitive function.

Effects of intelligibility on within- and cross-modal sentence recognition memory for native and non-native listeners

The goal of the study was to examine whether enhancing the clarity of the speech signal through conversational-to-clear speech modifications improves sentence recognition memory for native and non-native listeners, and if so, whether this effect would hold when the stimuli in the test phase are presented in orthographic instead of auditory form (cross-modal presentation). Sixty listeners (30 native and 30 non-native English) participated in a within-modal (i.e., audio-audio) sentence recognition memory task (Experiment I). Sixty different individuals (30 native and 30 non-native English) participated in a cross-modal (i.e., audio-textual) sentence recognition memory task (Experiment II). The results showed that listener-oriented clear speech enhanced sentence recognition memory for both listener groups regardless of whether the acoustic signal was present during the test phase (Experiment I) or absent (Experiment II). Compared to native listeners, non-native listeners had longer reaction times in the within-modal task and were overall less accurate in the cross-modal task. The results showed that more cognitive resources remained available for storing information in memory during processing of easier-to-understand clearly produced sentences. Furthermore, non-native listeners benefited from signal clarity in sentence recognition memory despite processing speech signals in a cognitively more demanding second language.

Relationship between working memory and comprehension and expression of grammar in Farsi-speaking children with cochlear implants

OBJECTIVES

Grammar is one of the most fundamental components of language and working memory (WM) is one of the most important cognitive features. These two skills play a vital role in learning, literacy and communication. Children with cochlear implants (CIs) experience delays in both of these skills. The aim of this study was to investigate the relationship between these two skills in children with CIs.

SUBJECTS AND METHODS

The sample consisted of 20 Farsi-speaking children with CIs. WM was estimated by forward and backward auditory digit spans (FBS and BDS) from the Persian (Farsi) version of the Wechsler Intelligence Scale for Children, 4th edition. The comprehension of grammar by participants was evaluated using the Persian Syntax Comprehension Test. Grammar expression was assessed using the Photographic Expressive Persian Grammar Test. Pearson's correlation and simple linear regression were used for data analysis.

RESULTS

The results of linear regression and correlation showed a strong correlation between comprehension of grammar and FDS (r = 0.61; p = 0.004) was obtained, between BDS and comprehension of grammar (r = 0.161; p = 0.080). FDS and expression of grammar (r = 0.163; p = 0.222) showed a positive but insignificant correlation.

CONCLUSION

The results indicate that WM decisively effects grammar. Enhancement of the phonological loop can improve grammar, especially comprehension of grammar. The effect of the central executive in grammar requires further research.

Individual differences in syntactic processing: Is there evidence for reader-text interactions?

There remains little consensus about whether there exist meaningful individual differences in syntactic processing and, if so, what explains them. We argue that this partially reflects the fact that few psycholinguistic studies of individual differences include multiple constructs, multiple measures per construct, or tests for reliable measures. Here, we replicated three major syntactic phenomena in the psycholinguistic literature: use of verb distributional statistics, difficulty of object-versus subject-extracted relative clauses, and resolution of relative clause attachment ambiguities. We examine whether any individual differences in these phenomena could be predicted by language experience or general cognitive abilities (phonological ability, verbal working memory capacity, inhibitory control, perceptual speed). We find correlations between individual differences and offline, but not online, syntactic phenomena. Condition effects on reading time were not consistent within individuals, limiting their ability to correlate with other measures. We suggest that this might explain controversy over individual differences in language processing.

Reading Comprehension in Children With and Without ASD: The Role of Word Reading, Oral Language, and Working Memory

Word reading and oral language predict reading comprehension, which is generally poor, in individuals with autism spectrum disorder (ASD). However, working memory (WM), despite documented weaknesses, has not been thoroughly investigated as a predictor of reading comprehension in ASD. This study examined the role of three parallel WM N-back tasks using abstract shapes, familiar objects, and written words in children (8-14 years) with ASD (n = 19) and their typically developing peers (n = 24). All three types of WM were significant predictors of reading comprehension when considered alone. However, these relationships were rendered non-significant with the addition of age, word reading, vocabulary, and group entered into the models. Oral vocabulary emerged as the strongest predictor of reading comprehension.

Ending the Reading Wars: Reading Acquisition From Novice to Expert

There is intense public interest in questions surrounding how children learn to read and how they can best be taught. Research in psychological science has provided answers to many of these questions but, somewhat surprisingly, this research has been slow to make inroads into educational policy and practice. Instead, the field has been plagued by decades of "reading wars." Even now, there remains a wide gap between the state of research knowledge about learning to read and the state of public understanding. The aim of this article is to fill this gap. We present a comprehensive tutorial review of the science of learning to read, spanning from children's earliest alphabetic skills through to the fluent word recognition and skilled text comprehension characteristic of expert readers. We explain why phonics instruction is so central to learning in a writing system such as English. But we also move beyond phonics, reviewing research on what else children need to learn to become expert readers and considering how this might be translated into effective classroom practice. We call for an end to the reading wars and recommend an agenda for instruction and research in reading acquisition that is balanced, developmentally informed, and based on a deep understanding of how language and writing systems work.

Relations between Reading and Writing: A Longitudinal Examination from Grades 3 to 6

We investigated developmental trajectories of and the relation between reading and writing (word reading, reading comprehension, spelling, and written composition), using longitudinal data from students in Grades 3 to 6 in the US. Results revealed that word reading and spelling were best described as having linear growth trajectories whereas reading comprehension and written composition showed nonlinear growth trajectories with a quadratic function during the examined developmental period. Word reading and spelling were consistently strongly related (.73 ≤ rs ≤ .80) whereas reading comprehension and written composition were weakly related (.21 ≤ rs ≤ .37). Initial status and linear slope were negatively and moderately related for word reading (-.44) whereas they were strongly and positively related for spelling (.73). Initial status of word reading predicted initial status and growth rate of spelling; and growth rate of word reading predicted growth rate of spelling. In contrast, spelling did not predict word reading. When it comes to reading comprehension and writing, initial status of reading comprehension predicted initial status (.69), but not linear growth rate, of written comprehension. These results indicate that reading-writing relations are stronger at the lexical level than at the discourse level and may be a unidirectional one from reading to writing at least between Grades 3 and 6. Results are discussed in light of the interactive dynamic literacy model of reading-writing relations, and component skills of reading and writing development.

Is There a Processing Preference for Object Relative Clauses in Chinese? Evidence From ERPs

A consistent finding across head-initial languages, such as English, is that subject relative clauses (SRCs) are easier to comprehend than object relative clauses (ORCs). However, several studies in Mandarin Chinese, a head-final language, revealed the opposite pattern, which might be modulated by working memory (WM) as suggested by recent results from self-paced reading performance. In the present study, event-related potentials (ERPs) were recorded when participants with high and low WM spans (measured by forward digit span and operation span tests) read Chinese ORCs and SRCs. The results revealed an N400-P600 complex elicited by ORCs on the relativizer, whose magnitude was modulated by the WM span. On the other hand, a P600 effect was elicited by SRCs on the head noun, whose magnitude was not affected by the WM span. These findings paint a complex picture of relative clause processing in Chinese such that opposing factors involving structural ambiguities and integration of filler-gap dependencies influence processing dynamics in Chinese relative clauses.

Theories of Working Memory: Differences in Definition, Degree of Modularity, Role of Attention, and Purpose

Purpose

The purpose of this article is to review and discuss theories of working memory with special attention to their relevance to language processing.

Method

We begin with an overview of the concept of working memory itself and review some of the major theories. Then, we show how theories of working memory can be organized according to their stances on 3 major issues that distinguish them: modularity (on a continuum from domain-general to very modular), attention (on a continuum from automatic to completely attention demanding), and purpose (on a continuum from idiographic, or concerned with individual differences, to nomothetic, or concerned with group norms). We examine recent research that has a bearing on these distinctions.

Results

Our review shows important differences between working memory theories that can be described according to positions on the 3 continua just noted.

Conclusion

Once properly understood, working memory theories, methods, and data can serve as quite useful tools for language research.

The Comprehension Problems of Children with Poor Reading Comprehension despite Adequate Decoding: A Meta-Analysis

The purpose of this meta-analysis was to examine the comprehension problems of children who have a specific reading comprehension deficit (SCD), which is characterized by poor reading comprehension despite adequate decoding. The meta-analysis included 86 studies of children with SCD who were assessed in reading comprehension and oral language (vocabulary, listening comprehension, storytelling ability, and semantic and syntactic knowledge). Results indicated that children with SCD had deficits in oral language (d = -0.78, 95% CI [-0.89, -0.68], but these deficits were not as severe as their deficit in reading comprehension (d = -2.78, 95% CI [-3.01, -2.54]). When compared to reading comprehension age-matched normal readers, the oral language skills of the two groups were comparable (d = 0.32, 95% CI [-0.49, 1.14]), which suggests that the oral language weaknesses of children with SCD represent a developmental delay rather than developmental deviance. Theoretical and practical implications of these findings are discussed.

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.