Working Memory Research Articles

Dysgraphia and Memory: Insights into the Cognitive Mechanisms, Neural Correlates, and Intervention Strategies.

Studies regarding dysgraphia, an impairment in writing, have been receiving more attention in recent research. Most studies have broadly discussed the multiple cognitive mechanisms involved in writing and its disruption leading to dysgraphia. However, little attention has been paid to the involvement of different memory systems integral to writing and its disruption in individuals with dysgraphia. Orthographic long-term memory and orthographic working memory are the two memory systems predominantly involved in the production of written expressions, and the subsequent interruption of these memory systems often leads to varied deficit profiles of dysgraphia. These disruptions have resulted from damage in the brain caused by neural injuries, neurological disorders, or epigenetic factors. The existing studies did not probe into the nuances of the disruptions of these two memory systems in dysgraphia and associated neural pathways. In order to fill this gap, the review attempts to provide a comprehensive account of dysgraphia and its association with orthographic long-term memory and orthographic working memory by comparing and contrasting their workings and patterns of disruption in the deficit profiles of dysgraphia by probing into the underlying neural correlates. Such a detailed account brings insights into pertinent intervention strategies for improving memory systems and dysgraphia. It also helps identify the limitations of the existing intervention methods like CART, ACT, or Spell-Study-Spell, leading to the proposal of improvised neuro-targeted interventions for dysgraphia.

COVID-19 Traumatic Stress, Working Memory Deficits, and Mindfulness

Stress is known to be a risk factor for deficits in working memory creating profound cognitive disturbances resulting in lingering impairments and losses in social and occupational functioning. Although a body of research has identified mindfulness as a potential means of mitigating deficits in working memory, there is a paucity of studies on the association between mindfulness and deficits in working memory among those who have experienced COVID-19 traumatic stress. This exploratory cross-sectional study sought to examine the mitigating effect of mindfulness on COVID-19 stress impacting working memory. The sample included 484 college students in Israel and the USA. Correlation and multiple regression analyses indicated that COVID-19 stress had a modest, inverse association with both a self-report and task-based indicator of working memory. In separate models predicting the different operationalizations of working memory, results revealed different effects for Israeli and USA students. Mindfulness was significantly associated with task-based but not self-reported working memory. The results offered evidence for a small but significant effect of mindfulness as moderating the impact of COVID-19 stress on working memory deficits. This exploratory, cross-­sectional study, used a convenience sample limiting the generalizability and its ability to test causal effects, calling for replication.

Alpha Traveling Waves during Working Memory: Disentangling Bottom-up Gating and Top-down Gain Control.

While previous works established the inhibitory role of alpha oscillations during working memory maintenance, it remains an open question whether such an inhibitory control is a top-down process. Here, we attempted to disentangle this issue by considering the spatio-temporal component of waves in the alpha band, i.e., alpha traveling waves. We reanalyzed two pre-existing and open-access EEG datasets (N = 180, 90 males, 80 females, 10 unknown) where participants performed lateralized, visual delayed match-to-sample working memory tasks. In the first dataset, the distractor load was manipulated (2, 4, or 6), whereas in the second dataset, the memory span varied between 1, 3, and 6 items. We focused on the propagation of alpha waves on the anterior-posterior axis during the retention period. Our results reveal an increase in alpha-band forward waves as the distractor load increased, but also an increase in forward waves and a decrease in backward waves as the memory set size increased. Our results also showed a lateralization effect: alpha forward waves exhibited a more pronounced increase in the hemisphere contralateral to the distractors, whereas the reduction in backward waves was stronger in the hemisphere contralateral to the targets. In short, the forward waves were regulated by distractors, whereas targets inversely modulated backward waves. Such a dissociation of goal-related and goal-irrelevant physiological signals suggests the co-existence of bottom-up and top-down inhibitory processes: alpha forward waves might convey a gating effect driven by distractor load, while backward waves may represent direct top-down gain control of downstream visual areas.Significance Statement When exploring the functional role of alpha band neural oscillations during working memory, mostly amplitude modulations have been considered so far, with relatively limited exploration of spatial-temporal dynamics of this rather global brain oscillatory signature. The present study seeks to address this gap by examining the directionality of alpha wave propagation during working memory retention. Our findings offer novel insights into the well-established inhibitory role of alpha waves, demonstrating that this function is manifested differently according to their propagation directions: forward waves seem to facilitate bottom-up gating, while backward waves might mediate top-down gain control.

Differential association between childhood trauma subtypes and neurocognitive performance in adults with major depression.

Neurocognitive impairment is one of the prominent manifestations of major depressive disorder (MDD). Childhood trauma enhances vulnerability to developing MDD and contributes to neurocognitive dysfunctions. However, the distinct impacts of different types of childhood trauma on neurocognitive processes in MDD remain unclear. This study comprised 186 individuals diagnosed with MDD and 268 healthy controls. Childhood trauma was evaluated using the 28-item Childhood Trauma Questionnaire-Short Form. Neurocognitive abilities, encompassing sustained attention, vigilance, visual memory, and executive functioning, were measured by the Cambridge Neuropsychological Testing Automated Battery. Multivariable linear regressions revealed that childhood trauma and MDD diagnosis were independently associated with neurocognitive impairment. Physical neglect was associated with impaired visual memory and working memory. MDD diagnosis is associated with working memory and planning. Interactive analysis revealed that physical/sexual abuse was associated with a high level of vigilance and that emotional neglect was linked with better performance on cognitive flexibility in MDD patients. Furthermore, childhood emotional abuse, physical abuse, and emotional neglect were revealed to be risk factors for developing early-onset, chronic depressive episodes. Thus, specific associations between various childhood traumas and cognitive development in depression are complex phenomena that need further study.

Transcranial direct current stimulation for Parkinson's disease: systematic review and meta-analysis of motor and cognitive effects.

Transcranial direct current stimulation (tDCS) is a promising noninvasive intervention for Parkinson's disease (PD). However, studies of its motor and cognitive effect have produced mixed results. We conducted a systematic review including 38 studies and meta-analysis of 12 randomized sham-controlled trials with 263 PD patients. No significant differences were found between active and sham tDCS in motor function (UPDRS-III: SMD = -0.14, p = 0.74), gait (SMD = 0.10, p = 0.513), attention and working memory (SMD = 0.24, p = 0.13), executive function (SMD = 0.03, p = 0.854), and memory and learning (SMD: -0.07, p = 0.758). The prediction intervals indicated substantial heterogeneity among studies. Meta-regression showed small positive effects in younger PD patients with milder symptoms. These findings are preliminary but suggest tDCS may benefit some PD patients while being neutral or harmful to others.

EXPRESS: What are the benefits of directed attention within verbal working memory?

Information that is particularly relevant for upcoming behavior can be prioritized within working memory, by directing attention to it. Receiving focused attention during retention is assumed to be associated with specific benefits, such as increased memory performance and reduced vulnerability to perceptual distractions. This has been demonstrated in visuospatial working memory. Given the domain-general nature of the focus of attention, these benefits should extend to verbal working memory as well. This was tested in the current study. In particular, we examined and compared the effects of cue-based and reward-based prioritization in verbal working memory across a series of five preregistered experiments. These experiments varied in their memory materials, set size, interference, and memory task. Our results collectively revealed several key findings. Firstly, both cue-based and reward-based prioritization led to a clear and consistent memory boost for prioritized information in verbal working memory. Secondly, the memory boost induced by cue-based prioritization was mostly comparable to that induced by reward-based prioritization. Thirdly, memory for verbal information did not drastically suffer when exposed to perceptual interference. And lastly, the effect of perceptual interference on verbal information was not drastically influenced by whether the information was prioritized or not. Overall, this series of experiments contributes to understanding the consequences of directed attention in verbal working memory and highlights similarities and differences from findings in visuospatial working memory.

Can neurocognitive performance account for dimensional paranoid ideation?

Paranoid ideation underlies numerous psychological disorders and has debilitating effects on daily life. Deficits in neurocognition are highlighted as a contributing factor to paranoid-related disorders, but the impact on the symptom-level experience of paranoid ideation is unclear. This study aimed to employ a dimensional approach to understand the association between neurocognition and the severity and presence of paranoid ideation. 400 participants, representative of the general population of the USA, completed an online questionnaire consisting of the Brief Symptom Inventory-53, and demographic and clinical questions. The participants then completed four computerised neurocognitive tasks measuring working memory, shifting, inhibition, and speed of processing. Speed of processing accounted for unique variance in the severity of paranoid ideation with a small effect size, after controlling for covariates. Working memory, shifting, and inhibition could not uniquely or collectively, account for paranoid ideation. Neurocognitive performance could not distinguish between individuals with and without paranoid ideation experiences. This research supports the body of literature that speed of information processing may be a key feature of paranoid ideation. Future research should employ non-linear dynamic methods to better understand the potential interactions between neurocognitive components and how this may relate to paranoid ideation.

Psychophysiological and Performance Effects of Biofeedback and Neurofeedback Interventions in a Top 100 Female Chess Player

(1) Background: Previous studies showed that neurofeedback and biofeedback could improve stress levels, enhance self-control over physiological factors, improve behavioral efficiency, and increase reaction speed to stimuli. Specifically, the sensorimotor rhythm stimulation (12–15 Hz) can enhance cognitive functions such as selective attention and working memory. However, there is no study that analyzes the effect of these interventions in chess players. (2) Methods: A Chess Woman Grandmaster and Chess International Master, with an ELO ranking higher than 2350 points, was selected to participate in this case study. The participant conducted a total of 14 sessions of biofeedback and neurofeedback, training in breathing, sensorimotor rhythm stimulation in Cz, skin conductance, temperature, and heart rate variability combined with chess work. Specific and non-specific tasks were designed to evaluate the intervention. (3) Results: The chess player enhanced the heart rate variability during specific and non-specific chess tasks: chess problems, 15 + 10 games, and puzzle rush games. In addition, the sensorimotor rhythm power decreased during the chess problem and increased during the 15 + 10 game and puzzle rush. Also, chess performance and anxiety levels improved after the intervention. (4) Conclusions: Neurofeedback and biofeedback training combined with chess training could improve the performance of chess players.

Transcranial Direct Current Stimulation over the Posterior Parietal Cortex Increases Non-target Retrieval during Visual Working Memory.

Visual working memory (VWM) requires precise feature binding. Previous studies have revealed a close relationship between the posterior parietal cortex (PPC) and feature binding during VWM, this study further examined their causal relationship through three transcranial direct current stimulation (tDCS) experiments. In Experiment 1 (N = 57), participants underwent three sessions of tDCS separately, including PPC stimulation, occipital cortex stimulation, and sham stimulation, and completed delayed estimation tasks for orientations before and after stimulation. Results showed that tDCS over PPC selectively prolonged recall response time (RT) and increased the probability of non-target responses (a.k.a. failure of feature binding, pNT). In Experiment 2 (N = 29), combining metacognition estimation, we further investigated whether the effects of PPC stimulation were attributed to mis-binding (i.e., participants self-reported "remembered" in non-target responses) or informed guessing trials (participants self-reported "forgotten" in non-target responses). We replicated the main findings in Experiment 1, and observed greater tDCS effects of PPC on RT in informed guessing trials while comparable effects on pNT in these two types of trials. In Experiment 3 (N = 28), we then examined whether the tDCS effects over PPC specifically influenced the memory retrieval process by using a change detection task. We found that PPC stimulation did not influence the recognition RT or accuracy. Together, this study provided direct causal evidence supporting the specific involvement of PPC in feature binding during VWM retrieval, from both aspects of speed and response preference, expanding our understanding of the neural basis of feature binding in VWM.Significance Statement Visual working memory (VWM) enables humans to temporarily store and process visual information, which requires accurate binding of items to their unique context. Accumulating studies posited that the posterior parietal cortex (PPC) is closely related to this binding process, the current study further examined their causal relationship. Through three strictly within-subject well-designed non-invasive neural stimulation experiments, we found that PPC stimulation selectively increased response time (RT) and binding error during VWM. Moreover, we found these changes were modulated by individual metacognition and only occurred during memory recall instead of recognition. Together, our results provided strong evidence that PPC is causally involved in the binding process during visual working memory retrieval.

Plasma neurofilament light chain in fibromyalgia: A case control study exploring correlation with clinical and cognitive features.

Plasma neurofilament light chain (NFL) has been measured as a biomarker of neuronal damage in various neurological disorders. Elevated tau and β-amyloid levels have been found in patients with fibromyalgia (FM). The aim of the present study was to compare plasma neurofilament levels in fibromyalgia patients with normal controls and to investigate the correlation with clinical features and cognitive tests. Plasma NFL levels were assessed in 33 FM patients and compared with 22 age-matched controls. All patients were also assessed with clinical scales examining fibromyalgia disability, sleep quality and duration, fatigue, anxiety, and depression, and a neuropsychological battery examining executive function, verbal short-term memory, and working memory, as well as attentional executive function and selective attention, interference sensitivity, and inhibition of automatic responses. NFL levels were higher in FM patients (controls 6.19± 1.92; FM 17.28± 15.94 pg/mL ANOVA p 0.002). Working memory was the most impaired cognitive function significantly correlated with high NFL scores (Pearson p 0.034). Short sleep times also correlated with higher NFL scores (Pearson p 0.02) and poorer working memory performance (Pearson p 0.02). No correlation was found with indices of disease severity and duration. Plasma NFL levels are elevated in fibromyalgia patients, suggesting neuronal damage and correlating with a slight decrease in working memory and short sleep duration. Plasma neurofilament levels are elevated in patients with fibromyalgia, regardless of disease severity and duration. Neurofilament levels are higher in patients with mild working memory impairment and sleep disorders. Subgroups of patients with primary neuronal damage phenomena could be individualized for prospective evaluation with regard to the possible development of cognitive decline and sleep disturbances, which would justify a tailored therapeutic approach.

Effects of home-based exercise alone or combined with cognitive training on cognition in community-dwelling older adults: A randomized clinical trial

BackgroundStructured and supervised physical exercise and cognitive training are two efficient ways to enhance cognition in older adults. Performing both within a combined intervention could maximize their effect on cognition due to their potential synergy on brain functions. During the COVID-19 pandemic, these interventions were particularly relevant due to the collateral impact of social restrictions regarding physical activity and the level of cognitive stimulation. However, the benefits of remotely monitored intervention combining physical exercise and cognitive training for older adult cognition remain to be demonstrated. Methods127 older adults (age: 65.20 ± 7.95) were randomized in two arms, encouraging self-engagement in six months of home-based physical exercise alone or combined with cognitive training, monitored by phone once a week. Neuropsychological assessment was performed under videoconference supervision at baseline and after three and six months. Composite Z-scores were calculated for processing speed, executive functioning, working, and episodic memory to assess changes after three and six months of training. The weekly metabolic expenditure of self-reported activities was estimated using the compendium of physical activity to distinguish participants performing higher and lower doses of exercise (median split). Results106 participants (83.46 %) completed the 6-month training. Results showed a greater Z-score change in executive functioning for participants in the combined arm than those who only exercised (F = 4.127, p = 0.046, ηp2 = 0.050). Group x Exercise dose interaction was observed for episodic memory Z-score change (F = 6.736, p = 0.011, ηp2 = 0.070), with a greater improvement for participants performing higher doses of exercise compared to those who performed a lower dose, only in exercise alone arm. Performing a higher dose of exercise increased the working memory Z-score change in both intervention arms compared to a lower dose (F = 7.391, p = 0.008, η p2 = 0.076). ConclusionRemote combined training may lead to larger improvement in executive functioning than exercise alone. Physical exercise showed a dose-related improvement in working and episodic memory performances. The combination of cognitive interventions mitigated the effects of exercise on episodic memory. These results suggest that home-based exercise and cognitive training may help improve older adults' cognition. Trial registrationCOVEPIC was retrospectively registered on December 03, 2020. Clinical trials Identifier: NCT04635462 - https://clinicaltrials.gov/ct2/show/record/NCT04635462?term=NCT04635462&draw=2&rank=1

Disabled Cinematic Technologies or the Crisis of the Image’s Register in Pedro Almodóvar’s Los abrazos rotos (2009)

The human body – and, by extension, the social corpus – has been the main subject of the critical apparatus of Disability Studies. However, I explore here how a ‘disabled technology’ might impact the works of memory and even the constitution of such bodies in Pedro Almodóvar’s film Los abrazos rotos (2009). Although the development of filmmaking technologies has traditionally been thought to serve the enhancement of the image’s readability, theorists such as Jean-Louis Comolli and Lev Manovich have pointed out the way in which these accomplishments reveal the medium’s flawed nature. Thus, this paper analyses the precarity of works of memory as resulting from the coalescence of the protagonist’s sensorial disability and from visual technologies’ impaired rendition of reality. I argue that the notion of disabled technologies not only expresses the crisis of the image’s legibility in the film but, furthermore, it entails a posthuman conception of the body itself as a (disabled?) technology.

Using an app-based screening tool to predict deficits in written word spelling at school entry

IntroductionThe first year of schooling is crucial for the further development of spelling abilities in children, which makes early assessment and intervention essential. The aim of this study was to develop and validate an efficient and cost-free screening tool for identifying spelling problems in community school settings around the time of school entry.MethodsA broad range of precursors of spelling (vocabulary, grammar, letter knowledge, phonological awareness, phonological working memory, rapid automatized naming) were assessed in 522 Austrian first graders (6–7 years of age) in the first weeks of schooling. At the end of first grade, spelling abilities were assessed by newly developed spelling tasks based on the trochaic foot. By applying logistic regression with the least absolute shrinkage and selection operator (LASSO), we aimed to select a set of important predictors of spelling problems at the end of grade 1 (i.e., scoring below the 16th percentile in the spelling test).ResultsOur analysis identified letter knowledge (i.e., an aspect of phonological information processing) and sentence repetition (i.e., a measure of grammatical knowledge) as important predictors of spelling problems. The screening tool has acceptable diagnostic accuracy [area under the curve (AUC) = 0.0.725 and DeLong 95% CI (0.666, 0.784)]. Further analyses indicated that the AUC differs neither between boys and girls nor between children with and without German as their first language.DiscussionThese results suggest that administering the screening tool during the first weeks of schooling is a valid approach to identifying spelling deficits, which in turn enables early targeted pedagogical interventions. Practical implications for spelling instructions are discussed.

Formal Thought Disorders and Neurocognition in Treatment-Resistant Schizophrenia: Trouble du cours de la pensée et neurocognition dans la schizophrénie réfractaire.

Formal thought disorders (FTDs), a core feature of schizophrenia, have been subdivided into positive and negative types, and are clinically assessed by examining speech (objective) or patient introspection (subjective). Despite being associated with poorer treatment response and worse outcomes, FTDs have been understudied in patients with schizophrenia, in particular treatment-resistant schizophrenia (TRS) or schizoaffective disorder. We aimed to explore the relationship between the severity of positive and negative FTDs and neurocognition as well as social/occupational functioning in this clinical subgroup. This was a retrospective chart review conducted at the Clozapine Clinic at the Centre for Addiction and Mental Health, Toronto, Canada. We reviewed charted standardized assessment of FTDs using the Thought and Language Disorder (TALD) scale, neurocognition using the Brief Cognitive Assessment Tool for Schizophrenia (B-CATS), and functioning using the Social and Occupational Functioning Assessment Scale (SOFAS) between October 2022 and June 2023. Following the original factor structure of the TALD, we computed 4- factor scores that combined positive or negative and objective or subjective FTDs. We then explored the correlation between the scores from each TALD factor and the neurocognition and functioning scores. We analysed data for 23 outpatients on clozapine. After the Bonferroni adjustment, total TALD scores, indicating overall severity of FTDs, were strongly and inversely correlated with SOFAS scores (p < 0.001). A strong inverse correlation was found between the objective positive TALD factor and Letter-Number Span verbal working memory scores, r(21) = -0.63, p < 0.001. Our results demonstrate the strong relationship between FTDs, neurocognition, and social/occupational functioning in a sample of TRS outpatients. Within the cognitive domains assessed, verbal working memory impairment had the strongest correlation with positive FTDs, such as derailment or tangentiality. These findings highlight the value of employing standardized psychopathological scales for FTDs in clinical practice.

Theta Transcranial Alternating Current Stimulation Is Not Effective in Improving Working Memory Performance.

There is an extensive body of research showing a significant relationship between frontal midline theta activity in the 4- to 8-Hz range and working memory (WM) performance. Transcranial alternating current stimulation (tACS) is recognized for inducing lasting changes in brain oscillatory activity. Across two experiments, we tested whether WM could be improved through tACS of dorsomedial pFC and ACC, by affecting executive control networks associated with frontal midline theta. In Experiment 1, after either a 20-min verum or sham stimulation applied to Fpz-CPz at 1 mA and 6 Hz, 31 participants performed WM tasks, while EEG was recorded. The tasks required participants to either mentally manipulate memory items or retain them in memory as they were originally presented. No significant effects were observed in behavioral performance, and we found no change in theta activity during rest and task after stimulation. However, alpha activity during retention or manipulation of information in WM was less strongly enhanced during the delay period after verum stimulation as compared with sham. In Experiment 2 (n = 25), tACS was administered during the task in two separate sessions. Here, we changed the order of the stimulation blocks: A 25-min task block was either accompanied first by sham stimulation and then by verum stimulation, or vice versa. Again, we found no improvements in WM through either tACS after-effects or online stimulation. Taken together, our results demonstrate that theta frequency tACS applied at the midline is not an effective method for enhancing WM.

Parallel maturation of rodent hippocampal memory and CA1 task representations.

Hippocampal-dependent memory is known to emerge late in ontogeny, and its full development is protracted. Yet the changes in hippocampal neuronal function that underlie this delayed and gradual maturation remain relatively unexplored. To address this gap, we recorded ensembles of CA1 neurons while charting the development of hippocampal-dependent spatial working memory (WM) in rat pups (∼2-4weeks of age). We found a sharp transition in WM development, with age of inflection varying considerably between individual animals. In parallel with the sudden emergence of WM, hippocampal spatial representations became abruptly task specific, remapping between encoding and retrieval phases of the task. Further, we show how the development of task-phase remapping could partly be explained by changes in place-field size during this developmental period as well as the onset of precise temporal coordination of CA1 excitatory input. Together, these results suggest that a hallmark of hippocampal memory development may be the emergence of contextually specific CA1 representations driven by the maturation of CA1 micro-circuits.

Attentional Refreshing in Working Memory and Its Interplay with Long-term Memory: A Behavioral and EEG Study.

Despite the growing interest in the study of attentional refreshing, the functioning of this working memory maintenance mechanism, including its cerebral underpinnings, is still debated. In particular, it remains unclear whether refreshing promotes long-term memory and whether it, in return, depends on long-term memory content to operate. Here, we used direct maintenance instructions and measured brain activity to investigate working memory maintenance with two objectives: (1) test if different behavioral and oscillatory patterns could be observed when participants were instructed to use attentional refreshing versus verbal rehearsal, and (2) observe whether and how refreshing is modulated when maintaining novel (pseudowords) versus familiar (words) memoranda. We conducted an EEG experiment using a modified Brown-Peterson task, in which we manipulated the type of maintenance engaged through explicit instructions (verbal rehearsal vs. refreshing), the type of memoranda (words vs. pseudowords), and the memory load (2 vs. 6). Using scalp EEG, we measured both neural oscillations during working memory maintenance and ERPs during the concurrent parity judgment task. For words, we showed that verbal rehearsal benefited more short-term recall whereas refreshing benefited more delayed recall. In keeping with these behavioral differences between maintenance instructions, frontal-midline theta power increased with memory load only when using verbal rehearsal, whereas occipito-parietal alpha desynchronization was larger with refreshing than verbal rehearsal. When maintaining pseudowords, verbal rehearsal also benefitted short-term recall more than refreshing. However, no long-term memory benefit of refreshing was observed for pseudowords, and oscillatory activity was not different under the two maintenance instructions. Our results provide new evidence supporting the independence between attentional refreshing and verbal rehearsal, and bring new insight into refreshing functioning. We discuss the possible interpretations of these results and the implications for the attentional refreshing literature.

Encoding colors and tones into working memory concurrently: A developmental investigation.

Working memory serves as a means to accumulate information and reorganize it. Researchers have long assumed that the natural organization of information is one stream at a time. This logic leads to the expectation that, when two different series of stimuli are to be remembered, performance should be superior if the series are presented one before the other in succession, rather than concurrently. Moreover, different accounts of attentional limits lead to different expectations for the change in the ability to encode two sets across age groups in childhood. Testing children from first grade (6-7years) to adulthood, we presented sequences of colored objects and tones in succession or concurrently (with one color accompanying an unrelated tone) and found that performance was equally good no matter which presentation method was used. The results for both presentation methods closely matched the intricate pattern of development observed by Cowan etal. (2018), who used successive presentation only. We found marked developmental improvement in the ability to retain materials in each modality without an increasing cost of attention-sharing between modalities. Humans at least from the elementary school years through young adulthood thus display an ability to accommodate and organize two concurrent streams of information. RESEARCH HIGHLIGHTS: Memory for stimuli from multiple modalities is relevant to school performance and learning; here we investigate how attention is shared between remembering colors and tones. Participants received four colors and/or four tones for subsequent recognition on a trial, with dual modalities presented successively (0.5s per stimulus) or concurrently (0.5s per pair). Successive versus concurrent presentation had little effect on recognition, and the marked increase in memory performance with age did not come from dividing attention during encoding or maintenance. Children as young as first grade thus can encode and organize for later recognition colors and concurrently-presented, but unrelated, tones.

Similarity Distractors Increase the Burden of Chinese Character Selection and Updating in Working Memory.

Attentional mechanisms are the primary processes for performing working memory (WM) tasks and can prevent distractors from interfering with the content representations stored in WM. However, our understanding of the mechanisms by which attention affects WM remains limited. As such, we analyzed ERPs of the character n-back task to investigate Chinese character selection, updating, and maintenance in WM. In Experiment 1, we collected electroencephalography data from 27 participants aged 18-25 years to explore the influence of false-character interference and symbol interference on a neural activity in the character n-back task. The results suggest that RT was longer in the false-character interference condition. The N2pc and P300 amplitudes were smaller; however, the slow wave amplitude did not differ significantly. In Experiment 2, we used a single-symbol interference and a multiple-symbol interference to establish whether the number of interferences affected the neural activity in the character n-back task. Thirty participants (aged 19-25 years) took part in the experiment. The findings imply that a longer RT and a larger N2pc amplitude occurred in the multiple-symbol interference condition, but not in the P300 and slow wave conditions. Our findings indicate that distractors that are similar to characters may produce greater interference in character recognition and affect the subsequent updating, whereas the number of distractors may only interfere with early character selection, but not with updating and maintenance phases.

Comparison of Cognitive Functions between Healthy Controls and Individuals with Chronic Low Back Pain with High and Low Pain Catastrophizing: A Cross-sectional Study.

Researchers suggested that the interruptive effects of chronic pain on cognitive functions may be modulated by the level of pain catastrophizing (PC). However, in individuals with chronic low back pain (CLBP), domains of cognitive function that may be affected by the level of PC remain largely unclear. Therefore, this study was aimed to compare cognitive functions between healthy controls and individuals with CLBP with high and low PC. This cross-sectional study examined cognitive functions of 42 individuals with CLBP and 21 healthy controls. The PC scale was used to stratify participants with CLBP into high and low PC. Participants performed 5 cognitive tests from the Cambridge Neuropsychological Test Automated Battery, namely five-choice reaction time, rapid visual processing, spatial working memory, attention switching task, and stop signal task. The statistical analyses revealed that compared to individuals with CLBP with low PC and healthy controls, individuals with high PC demonstrated greater values of the between errors (P=0.01), reaction latency (P<0.001), and stop signal reaction time variables (P=0.004, P=0.003, respectively) but lower values of probability of hit (P=0.02, P=0.01, respectively), A' (P=0.01, P<0.001, respectively), and percent correct trials variables (P=0.002, P<0.001, respectively). The results of the current study showed deficits in sustained attention, working memory, cognitive flexibility, and inhibitory control in individuals with CLBP with high PC. From a clinical perspective, therapeutic interventions targeting PC should be considered to decrease catastrophic thinking about pain in individuals with CLBP. Additional research is warranted to explore cognitive functioning as an outcome of these interventions in individuals with CLBP.