General Working Memory Research Articles

Change in prefrontal activity and executive functions after action-based cognitive remediation in bipolar disorder: a randomized controlled trial.

Cognitive impairment is prevalent in bipolar disorder (BD) but treatments with pro-cognitive effects are lacking. Insight concerning the neurocircuitry of cognitive improvement could provide a biomarker for pro-cognitive effects to advance treatment development. The dorsal prefrontal cortex (dPFC) is a promising region for such treatment target engagement. The aim of this functional magnetic resonance imaging (fMRI) study was to examine the effects of action-based cognitive remediation (ABCR) on early change in the dPFC blood-oxygen-level-dependent response in patients with BD in remission, and whether the observed neural change predicted improved executive functions following 10 weeks of treatment. Forty-five participants with remitted BD (ABCR: n = 26, control treatment: n = 19) completed a spatial n-back working memory task during fMRI and executive function tasks outside the scanner before and after two weeks of ABCR/control treatment, and an additional assessment of executive function at treatment completion. Thirty-four healthy controls underwent a single fMRI and executive function assessment for baseline comparisons. We found an early reversal of pretreatment hypo-activity in the dorsolateral prefrontal cortex (dlPFC) following ABCR vs. control during both high-load (2-back > 1-back) working memory (WM) (F(1,43) = 5.69, p = 0.02, η2 = 0.12) and general WM (2-back > 0-back) (F(1,43) = 5.61, p = 0.02, η2 = 0.12). This dlPFC activity increase predicted improved executive functions at treatment completion (high-load WM: B = -0.45, p = 0.01, general WM: B = -0.41, p < 0.01), independent of changes in subsyndromal symptoms. In conclusion, early dPFC increase may provide a neurocircuitry-based biomarker for pro-cognitive effects. Future cognition trials should include fMRI assessments to confirm the validity of this putative biomarker model across disorders with cognitive impairment.

Training-induced improvement in working memory tasks results from switching to efficient strategies

It is debated whether training with a working memory (WM) task, particularly n-back, can improve general WM and reasoning skills. Most training studies found substantial improvement in the trained task, with little to no transfer to untrained tasks. We hypothesized that training does not increase WM capacity, but instead provides opportunities to develop an efficient task-specific strategy. We derived a strategy for the task that optimizes WM resources and taught it to participants. In two sessions, 14 participants who were taught this strategy performed as well as fourteen participants who trained for 40 sessions without strategy instructions. To understand the mechanisms underlying the no-instruction group’s improvement, participants answered questionnaires during their training period. Their replies indicate that successful learners discovered the same strategy and their improvement was associated with this discovery. We conclude that n-back training allows the discovery of strategies that enable better performance with the same WM resources.

Neurocognitive impairment following proton therapy for paediatric brain tumour: a systematic review of post-therapy assessments.

Proton therapy (PT), frequently utilised to treat paediatric brain tumour (PBT) patients, eliminates exit dose and minimises dose to healthy tissues that theoretically can mitigate treatment-related effects including cognitive deficits. As clinical outcome data are emerging, we aimed to systematically review current evidence of cognitive changes following PT of PBT. We searched PubMed and Scopus electronic databases to identify eligible reports on cognitive changes following PT of PBT according to PRISMA guidelines. Reports were extracted for information on demographics and cognitive outcomes. Then, they were systematically reviewed based on three themes: (1) comparison with photon therapy, (2) comparison with baseline cognitive measures, to population normative mean or radiotherapy-naïve PBT patients and (3) effects of dose distribution to cognition. Thirteen reports (median size (range): 70 (12-144)) were included. Four reports compared the cognitive outcome between PBT patients treated with proton to photon therapy and nine compared with baseline/normative mean/radiotherapy naïve from which two reported the effects of dose distribution. Reports found significantly poorer cognitive outcome among patients treated with photon therapy compared with proton therapy especially in general cognition and working memory. Craniospinal irradiation (CSI) was consistently associated with poorer cognitive outcome while focal therapy was associated with minor cognitive change/difference. In limited reports available, higher doses to thehippocampus and temporal lobes were implicated to larger cognitive change. Available evidence suggests that PT causes less cognitive deficits compared with photon therapy. Children who underwent focal therapy with proton were consistently shown to have low risk of cognitive deficit suggesting the need for future studies to separate them from CSI. Evidence on the effect of dose distribution to cognition in PT is yet to mature.

Meta-analysis: Resistance Training Improves Cognition in Mild Cognitive Impairment.

This study investigated the benefits of resistance training on cognition in patients with mild cognitive impairment. We searched the PubMed, Embase and Cochrane Library databases, and seven randomized controlled trials were reviewed. We evaluated the risk of bias using the Cochrane Collaboration's bias assessment tool. Standard mean differences with 95% confidence intervals were calculated for statistical analysis. This meta-analysis assessed three variables: general cognitive function, executive function and working memory. The results indicate that general cognitive function improved significantly (standardized mean difference: 0.53, P=0.04), and further subgroup analyses on frequency and duration per session showed that the subgroups 'twice a week' (P=0.01) and 'duration per session >60 min' (P=0.0006) exhibited better performance than the subgroups 'three time a week' (P=0.47) and 'duration per session <60 min' (P=0.53). Additionally, a moderate effect size was found in executive function (standardized mean difference: 0.50, P=0.0003), and there was non-significant effect in working memory (P=0.14). In summary, resistance training may mitigate mild cognitive impairment by improving cognition. Larger-scale studies are recommended to demonstrate the relationship between resistance training and cognition in mild cognitive impairment.

Emotional working memory training reduces rumination and alters the EEG microstate in anxious individuals

Rumination is an important etiological factor of anxiety pathology, with its mechanism related to the deficit of working memory. The current study examined whether working memory training (WM-T) and emotional working memory training (EWM-T) could reduce rumination in anxious individuals. The participants with high trait anxiety underwent 21 days of mobile applications-based WM-T (n = 34), EWM-T (n = 36) or placebo control (n = 36), with questionnaires, cognitive tasks, and resting electroencephalogram (EEG) as the pre-post-test indicators. The results revealed that two training groups obtained comparable operation span increases (WM-T: d = 0.53; EWM-T: d = 0.65), updating improvement (WM-T: d = 0.43; EWM-T: d = 0.60) and shifting improvement (WM-T: d = 0.49; EWM-T: d = 0.72). Furthermore, compared to the control group, the EWM-T showed significant self-reported rumination reduction (d = 0.69), increased inhibition ability (d = 0.72), as well as modification of resting EEG microstate C parameters (Duration C: d = 0.42, Coverage C: d = 0.39), which were closely related to rumination level (r ~ 0.4). The WM-T group also showed the potential to reduced self-reported rumination (d = 0.45), but with the absence of the observable inhibition improvement and resting EEG changes. The correlation analysis suggested that the emotional benefits of WM-T depending more on improved updating and shifting, and that of EWM-T depending more on improved inhibition ability. The advantage to add emotional distractions into general working memory training for targeting rumination related anxiety has been discussed.

Changes in Working Memory Performance Over an Academic Semester in Student Pharmacists

Objective. To preliminarily assess changes in Doctor of Pharmacy students' working memory performance over the course of an academic semester and to determine whether any observed changes were associated with fluctuations in stress and fatigue. Methods. Twenty-three PharmD students were recruited for this pilot study. At baseline, data were collected on students' personality, stress, fatigue, and working memory performance using two measures, the operation span and the symmetry span. Approximately every four weeks throughout the semester students' fatigue and stress levels were reassessed and they completed the two measures of working memory. A repeated measures analysis of variance was used to assess trends over time, and correlation analysis was used to assess potential relationships between working memory and other variables. Results. The operation span, a measure of general working memory resources, showed a significant quadratic trend over time. Irrespective of time, some associations between working memory performance and fatigue were seen. Significant correlations between fatigue and the extraversion personality trait were identified. The symmetry span, a measure of visuospatial resources, did not show trends over time nor did it correlate with fatigue, stress, or personality factors. Conclusion. Pharmacy students' working memory performance may fluctuate over the course of a semester, but more research is needed to identify factors that may influence this fluctuation.

Replacing tDCS with theta tACS provides selective, but not general WM benefits

Working memory (WM) can be improved after repeated training sessions paired with noninvasive neurostimulation techniques. Previously, we reported that WM training paired with tDCS succeeded behaviorally by enhancing anterior-posterior theta phase coherence and reducing alpha power. Here, in two experiments we tested several theta and alpha frequencies and two transcranial alternating current stimulation (tACS) montages in an effort to shortcut WM training while preserving behavioral gains. In Experiment 1, in separate sessions participants received online tACS at two frequencies derived from the previous study with the respective goal of improving and impairing WM performance. We selected the mean group peak value theta (7 Hz) to benefit WM and alpha (11 Hz) to impair WM. Stimulation (tACS) over right frontoparietal sites (F4-P4) during 3-back WM tasks (object, spatial) produced no behavioral consequences. In Experiment 2 we stimulated at a slower theta frequency (4.5 Hz), which was also significant in our prior study, and tested whether frontoparietal or bifrontal montages would be more effective at improving WM. This experiment revealed selectively improved object WM after right frontoparietal tACS alone. In summary, one session of tACS failed to produce the magnitude or breadth of WM gains observed after 4–10 tDCS-WM training sessions. In short, despite looking for loopholes we found little tACS savings.

The nature of morphosyntactic processing during language perception. Evidence from an additional-task study in Spanish and German

The present study investigates in how far morphosyntactic processing is affected by an additional non-verbal task and whether this effect differs between German and Spanish, two languages with differences in processing grammatical gender (lexical vs. cue-based processing). By manipulating task load and language we aimed at getting an insight into subprocesses of morphosyntax and their dependence on resources of general and verbal working memory, respectively. In more general terms, this study contributes to the debate on the modularity of morphosyntax. Written German or Spanish sentences with or without gender violations were presented word by word to native speakers. The critical words temporally overlapped in different degrees with a non-linguistic stimulus (a high or low tone). In a single task (Experiment 1) participants judged sentence acceptability and ignored the tones. Experiment 2 required a response to the tones. Left-anterior negativity (LAN) and P600 components were analyzed in the ERPs to critical words. Whereas the LAN was not affected by any of the experimental manipulations, the P600 was modulated as a function of language during the single task conditions (Experiment 1). In Experiment 2 the additional task did not add up with this effect; instead, the differences between language groups vanished. This may indicate that the processes reflected in the P600 draw on resources of general working memory. The LAN data seem to be in line with modularity of first pass morphosyntactic processing, although this interpretation contradicts findings from other studies. The P600 results may highlight the flexibility of sentence-based syntactic processing.

The Predictive role of Cognitive Factors and Academic Self-efficacy on Academic Functioning of Children at Risk for Specific Learning Disabilities

&lt;p style="text-align:justify"&gt;The goals of the study were to examine the predictive power of general cognitive ability, working memory, and self-efficacy in first grade for academic functioning of children at risk for learning disabilities in second grade. The study involved 82 children (age 6-7 years) from five local public elementary schools in middle-class neighborhoods in Jerusalem, including 41 children at risk for specific learning disabilities and 41 typically developing peers. In the first stage of the study, (performed at the end of first grade), general cognitive ability and working memory were assessed using subtests from the Wechsler Intelligence Scale for Children (the subtests consisted of: Vocabulary and Block Design for general cognitive ability; Arithmetic and Digit Span for working memory). Academic self-efficacy was rated using a structural interview. At follow-up, academic functioning was assessed at the end of second grade. A serial-multiple mediation analysis revealed significant mediating roles for levels of performance in the Arithmetic subtest and for academic self-efficacy in predicting the academic functioning in second grade. The significance of the Arithmetic subtest, based on contemporary research on the structure of the intelligence was proposed. Educational implications call for sensitizing teachers to the unique role of academic self-efficacy in shaping trajectories of academic functioning development among children with RLD and in using effective strategies of promoting self-efficacy.&lt;/p&gt;

Positivity Effect and Working Memory Performance Remains Intact in Older Adults After Sleep Deprivation.

Background: Older adults perform better in tasks which include positive stimuli, referred to as the positivity effect. However, recent research suggests that the positivity effect could be attenuated when additional challenges such as stress or cognitive demands are introduced. Moreover, it is well established that older adults are relatively resilient to many of the adverse effects of sleep deprivation. Our aim was to investigate if the positivity effect in older adults is affected by one night of total sleep deprivation using an emotional working memory task.Methods: A healthy sample of 48 older adults (60-72 years) was either sleep deprived for one night (n = 24) or had a normal night’s sleep (n = 24). They performed an emotional working memory n-back (n = 1 and 3) task containing positive, negative and neutral pictures.Results: Performance in terms of accuracy and reaction times was best for positive stimuli and worst for negative stimuli. This positivity effect was not altered by sleep deprivation. Results also showed that, despite significantly increased sleepiness, there was no effect of sleep deprivation on working memory performance. A working memory load × valence interaction on the reaction times revealed that the beneficial effect of positive stimuli was only present in the 1-back condition.Conclusion: While the positivity effect and general working memory abilities in older adults are intact after one night of sleep deprivation, increased cognitive demand attenuates the positivity effect on working memory speed.

Therapeutic and prophylactic role of cognitive enhancers in electroconvulsive therapy-induced cognitive deficits.

Objectives:The objective is to evaluate the pattern of cognitive deficits after electroconvulsive therapy (ECT); to ascertain the role of various psychosocial, illness and treatment-related parameters on cognitive functions after ECT; and to evaluate the effect of donepezil on various cognitive deficits.Materials and Methods:A triple-blind randomized controlled trial was undertaken. Ninety patients undergoing ECT were included into study after due consent and institutional ethical approval. They were randomized into two groups: one using donepezil with ECT and the other using placebo with ECT. Various cognitive parameters were studied before ECT, after a course of ECT and after 4 weeks of last ECT. Findings were assessed in the light of available socialdemographic and clinical parameters and existing literature.Results:ECT was found to be an effective therapeutic modality. Immediate memory worsened over the course of ECT till after 4 weeks of ECT. Augmentation of donepezil was found useful. It sped up the improvement of general memory and working memory during ECT.Conclusion:Donepezil has therapeutic and prophylactic benefit on cognition of patients undergoing ECT over the course of treatment till 4 weeks after the ECT.

Association of physical activity on changes in cognitive function: Boston Puerto Rican Health Study

ABSTRACTObjective: To evaluate the association of habitual physical activity engagement on changes in cognitive function among Puerto Rican adults.Methods: Longitudinal data (2-year follow-up) from the Boston Puerto Rican Health Study were analyzed (n = 862; mean age = 56.5 year). A daily energy expenditure score was calculated using the number of hours over a 24-h period engaged in various activities, including sleeping, light activity, and moderate-to-vigorous exercise. Energy expenditure estimates were weighted based on the rate of oxygen consumption associated with each activity. Seven cognitive function outcomes were evaluated, including an assessment of general cognitive function, episodic memory, attention and working memory, cognitive flexibility, response inhibition, processing speed, and visuo-spatial organization. From these, overall executive function and memory capacity were derived using principal components analysis.Results: Physical activity was not associated with changes in overall executive function. However, compared to those with low baseline physical activity, those with moderate physical activity had 48% reduced odds of having ≥1 standard deviation decline in memory function (OR = 0.52; 95% CI: 0.32, 0.84; p = 0.008) in 2 years.Conclusion: Among Puerto Rican adults, physical activity may help attenuate memory decline.

Effects of the experimental administration of oral estrogen on prefrontal functions in healthy young women.

17-Beta-estradiol (E2) stimulates neural plasticity and dopaminergic transmission in the prefrontal cortex, which is critically involved in attentional control, working memory, and other executive functions. Studies investigating E2's actions on prefrontally mediated behavior in the course of the menstrual cycle or during hormone replacement therapy are inconclusive, with numerous null findings as well asbeneficial and detrimental effects. The current study focused on the effect of E2 on attentional performance, as animal studies indicate that supraphysiological doses (i.e., above estrous cycle levels) of E2 have beneficial effects on measures of attention in female rodents. To translate these findings to humans, we administered 12mg E2-valerate or placebo orally to 34 naturally cycling women in the low-hormone early follicular phase using a randomized, double-blinded, pre-post design. Behavioral performance was tested twice during baseline and E2 peak, where E2 levels reached mildly supraphysiological levels in the E2 group. Aside from mainly prefrontally mediated tasks of attention, working memory, and other executive functions, we employed tasks of affectively modulated attention, emotion recognition, and verbal memory. E2 administration had a significant, but subtle negative impact on general processing speed and working memory performance. These effects could be related to an overstimulation of dopaminergic transmission. The negative effect of supraphysiological E2 on working memory connects well to animal literature. There were no effects on attentional performance or any other measure. This could be explained by different E2 levels being optimal for changing behavioral performance in specific tasks, which likely depends on the brain regions involved.

Tracing the evolutionary trajectory of verbal working memory with neuro-archaeology

AbstractWe used optical neuroimaging to explore the extent of functional overlap between working memory (WM) networks involved in language and Early Stone Age toolmaking behaviors. Oldowan tool production activates two verbal WM areas, but the functions of these areas are indistinguishable from general auditory WM, suggesting that the first hominin toolmakers relied on early precursors of verbal WM to make simple flake tools. Early Acheulian toolmaking elicits activity in a region bordering on Broca’s area that is involved in both visual and verbal WM tasks. The sensorimotor and mirror neurons in this area, along with enhancement of general WM capabilities around 1.8 million years ago, may have provided the scaffolding upon which a WM network dedicated to processing exclusively linguistic information could evolve. In the road map going forward, neuro-archaeologists should investigate the trajectory of WM over the course of human evolution to better understand its contribution to language origins.

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.

Multivariate Relationships Between Cognition and Brain Anatomy Across the Psychosis Spectrum

BackgroundCognitive and structural brain abnormalities range from mild to severe in psychosis. The relationships of specific cognitive functions to specific brain structures across the psychosis spectrum is less certain. MethodsParticipants (n = 678) with bipolar, schizoaffective, or schizophrenia psychoses and healthy control subjects were recruited via the Bipolar-Schizophrenia Network for Intermediate Phenotypes. The Schizo-Bipolar Scale was used to create a psychosis continuum (from purely affective to purely nonaffective). Canonical correlation between 14 cognitive measures and structural brain measures (gray matter volume, cortical thickness, cortical surface area, and local gyrification indices) for 68 neocortical regions yielded constructs that defined shared cognition–brain structure relationships. Canonical discriminant analysis was used to integrate these constructs and efficiently summarize cognition–brain structure relationships across the psychosis continuum. ResultsGeneral cognition was associated with larger gray matter volumes and thicker cortices but smaller cortical surface area in frontoparietal regions. Working memory was associated with larger volume and surface area in frontotemporal regions. Faster response speed was associated with thicker frontal cortices. Constructs that captured general cognitive ability and working memory and their relationship to cortical volumes primarily defined an ordered psychosis spectrum (purely affective, least abnormal through purely nonaffective, and most abnormal). A construct that captured general cognitive ability and its relationship to cortical surface area differentiated purely affective cases from other groups. ConclusionsGeneral cognition and working memory with cortical volume deviations characterized more nonaffective psychoses. Alternatively, affective psychosis cases with general cognitive deficits had deviations in cortical surface area, perhaps accounting for heterogeneous findings across previous studies.

Eficacia ejecutiva en tareas de interferencia tipo Stroop. Estudio de validación de una versión numérica y manual (CANUM)

&lt;p style="margin: 0cm 0cm 0pt; text-align: justify; line-height: normal;"&gt;&lt;span style="font-family: 'Times New Roman',serif; font-size: 10pt; mso-ansi-language: EN-US;" lang="EN-US"&gt;This paper presents CANUM, a new numerical and manual version of Stroop interference task. The stimulus used replaces the classical color-word conflict by the numerosity-number conflict considering the interference generated between the symbolic value of the number and the amount of times it is repeated. CANUM also replaces the vocal answer by a simple right-left typing. The aim was twofold: first, to ensure a general measure of attentional control capacity not linked to the verbal factor; and second, to extent the population to whom the test would be applied, avoiding the restrictions on reading ability inherent to the classical Stroop task. The results obtained in a sample of school children reveal a high reliability in terms of internal consistency, as well as a significant predictive validity in relation to two criterial measures: general intelligence and working memory. This supports its usefulness as an instrument for the assessment of executive function and controlled attention applicable in a wide age range, both for research purposes as for clinical and educational goals.&lt;/span&gt;&lt;/p&gt;

The contribution of general language ability, reading comprehension and working memory to mathematics achievement among children with English as additional language (EAL): an exploratory study

ABSTRACTAn increasing number of high-stakes mathematics standardised tests around the world place an emphasis on using mathematical word problems to assess students’ mathematical understanding. Not only do these assessments require children to think mathematically, but making sense of these tests’ mathematical word problems also brings children’s language ability, reading comprehension and working memory into play. The nature of these test items places a great deal of cognitive demand on all mathematics learners, but particularly on children completing the assessments in a second language that is still developing. This paper reports findings from an exploratory study on the contribution of language to mathematics achievement among 35 children with English as an Additional Language (EAL) and 31 children with English as their first language (FLE). The findings confirm the prominent role of general language ability in the development and assessment of mathematical ability. This variable explained more variance than working memory in word-based mathematics scores for all learners. Significant differences were found between the performance of FLE learners and EAL learners on solving mathematical word-based problems, but not on wordless problems. We conclude that EAL learners need to receive more targeted language support, including help with specific language knowledge needed to understand and solve mathematical word problems.

Sleep and cognitive functioning in childhood: Ethnicity, socioeconomic status, and sex as moderators.

We examined children's sleep at age 9 as a predictor of developmental trajectories of cognitive performance from ages 9 to 11 years. The effects of sleep on cognition are not uniform and thus we tested race/ethnicity, socioeconomic status (SES), and sex as moderators of these associations. At the first assessment, 282 children aged 9.44 years (52% boys, 65% European American [EA], 35% African American [AA]) participated. Two more waves of data collection spaced 1 year apart followed. The majority of children (63%) were living at or below the poverty line. Children's sleep was measured objectively with actigraphy and 2 well-established sleep parameters were derived: duration, indexed by sleep minutes between sleep onset and wake time, and quality, indexed by efficiency. Multiple cognitive functioning domains were examined with the Woodcock Johnson Tests of Cognitive Abilities (WJ III). Across the sample, higher sleep efficiency, but not duration, was associated with better cognitive performance. Significant moderation effects emerged. Controlling for SES, AA children scored lower on general intellectual ability and working memory (WM) at age 11 only if they experienced lower sleep efficiency at age 9. Further, boys scored lower on general abilities and processing speed (PS) at age 11 only if their sleep efficiency was lower at age 9. Findings indicate that lower sleep efficiency may contribute to lower cognitive functioning especially for AA children and boys. These vulnerabilities appear to emerge early in development and are maintained over time. Results underscore the importance of individual differences in explicating relations between sleep and children's cognitive performance. (PsycINFO Database Record

A Latent Factor Analysis of Working Memory Measures Using Large-Scale Data.

Working memory (WM) is a key cognitive system that is strongly related to other cognitive domains and relevant for everyday life. However, the structure of WM is yet to be determined. A number of WM models have been put forth especially by factor analytical studies. In broad terms, these models vary by their emphasis on WM contents (e.g., visuospatial, verbal) vs. WM processes (e.g., maintenance, updating) as critical, dissociable elements. Here we conducted confirmatory and exploratory factor analyses on a broad set of WM tasks, half of them numerical-verbal and half of them visuospatial, representing four commonly used task paradigms: simple span, complex span, running memory, and n-back. The tasks were selected to allow the detection of both content-based (visuospatial, numerical-verbal) and process-based (maintenance, updating) divisions. The data were collected online which allowed the recruitment of a large and demographically diverse sample of adults (n = 711). Both factor analytical methods pointed to a clear division according to task content for all paradigms except n-back, while there was no indication for a process-based division. Besides the content-based division, confirmatory factor analyses supported a model that also included a general WM factor. The n-back tasks had the highest loadings on the general factor, suggesting that this factor reflected high-level cognitive resources such as executive functioning and fluid intelligence that are engaged with all WM tasks, and possibly even more so with the n-back. Together with earlier findings that indicate high variability of process-based WM divisions, we conclude that the most robust division of WM is along its contents (visuospatial vs. numerical-verbal), rather than along its hypothetical subprocesses.