Working Memory Research Articles

Cardiorespiratory fitness and working memory in persons with traumatic brain injury: a cross-sectional analysis

ABSTRACT Introduction Cognitive impairment is a highly impactful consequence of traumatic brain injury (TBI) and there are limited evidence-based treatment practices to combat these impairments. Evidence from other populations suggest that aerobic exercise training (AET) is beneficial for a variety of cognitive deficits, but the research in persons with TBI to date is equivocal. One potential reason is the heterogeneity of exercise prescriptions and outcome measures. This stems from the fact that studies have not been designed based on previous data supporting a specific AET prescription to target a cognitive domain. The primary purpose of this cross-sectional analysis was to examine the relationship between cardiorespiratory fitness (CRF), as a cross-sectional surrogate of AET, and cognition in persons with TBI to inform future research. Methods Cross-sectional analysis was conducted on baseline data of persons with TBI who completed neuropsychological assessments to evaluate several cognitive domains and a cardiopulmonary exercise test (CPET) to measure CRF. Based on the normal distribution of an outcome, Pearson’s r or Spearman’s ρ was calculated to measure the relationship between CRF and cognition. Results Data were analyzed for all participants who demonstrated valid CPETs (n = 21 of 29). Based on the cycle ergometer-based norms of CRF, males in this sample were in the 69th percentile and females in this sample were in the 56th percentile, with high variability across individuals. Higher CRF, as measured by peak power output (Wpeak), was significantly associated with greater working memory (ρ = 0.465, p = 0.017), even after post-hoc corrections. Conclusions These data suggest average and highly variable CRF in persons with TBI of all severity and support cycle ergometry-based CPET testing in this population. Further, these data provide support for future research applying AET to target working memory and possibly other executive functions in persons with TBI. This research is a small step toward large-scale randomized controlled trials that can directly impact clinical care to treat cognitive symptoms post-TBI.

Enhancing visual working memory in schizophrenia: effects of frontoparietal theta tACS in low-performing patients

Schizophrenia is a complex neuro-psychiatric disorder including positive symptoms, negative symptoms, and cognitive deficits. A key cognitive dysfunction in schizophrenia is a deficit in visual working memory (VWM). VWM involves three distinct stages: encoding, maintenance, and retrieval. The deficit in any one stage would produce the same symptom (i.e., poor VWM), although their causes are not the same. In this study, we used a retro-cue VWM task that provides helpful cues at different stages: early in maintenance (early cue), late in maintenance (late cue), or during retrieval (retrieval cue). This modification would help “tag” or identify the cognitive stage(s) most responsible for impaired VWM performance in schizophrenia. Additionally, we took advantage of this tagging feature and applied 6 Hz transcranial alternating current stimulation (tACS) over the right dorsolateral prefrontal cortex (DLPFC) and right posterior parietal cortex (PPC)—which has previously been shown to enhance VWM in low-performing healthy individuals—to examine whether tACS would improve a specific stage or all stages of VWM processing in schizophrenia. We observed that cues significantly enhanced performance in low-performing patients, who benefited equally from early and late maintenance cues, but not from retrieval cues. These low-performers also responded well to theta tACS in their overall VWM performance as opposed to a specific VWM stage. No improvement effect was observed in high-performing patients for both retro cue and tACS. Together, our data suggest that 1) low-performing patients’ VWM deficits likely stem from poor memory consolidation rather than retrieval, 2) right frontoparietal theta tACS can improve low-performing patients’ VWM performance, and 3) such facilitatory tACS effect is not selective of a specific VWM stage and thus is likely driven by an improvement in overall visual attention.

Is It Possible to Combine Non-Invasive Brain Stimulation and Evidence-Based Psychosocial Interventions in Schizophrenia? A Critical Review.

In schizophrenia, it was suggested that an integrated and multimodal approach, combining pharmacological and non-pharmacological interventions, could improve functional outcomes and clinical features in patients living with schizophrenia (PLWS). Among these alternatives, evidence-based psychosocial interventions (EBPIs) and Non-Invasive Brain Stimulation (NIBS) represent feasible treatment options targeting the clinical features that are unmet needs of PLWS (especially negative and cognitive symptoms). As no clear evidence is available on the combination of these non-pharmacological approaches, this review aimed to collect the available literature on the combination of EBPIs and NIBS in the treatment of PLWS. We demonstrated that the field of combining EBPIs and NIBS in schizophrenia is in its infancy, as only 11 studies were reviewed. In fact, only a few trials, with divergent results, combined these non-pharmacological modalities; while emerging evidence is available on the combination of cognitive remediation and rTMS/iTBS, inconclusive results were obtained. Conversely, albeit preliminary, more solid findings are available on the combination of HF-rTMS and family intervention. Moreover, despite the fact that cognitive activation could not be considered an EBPI, promising results are available in combination with tDCS to improve the working memory domain. To overcome these limitations, we considered several methodological issues to promote research in this field.

Phonological skills and executive functions: their effects on reading and arithmetic abilities across varied performance levels using quantile regression

ABSTRACT We aimed to investigate the effects of phonological awareness – PA, rapid automatised naming – RAN, visuospatial and verbal working memory – WM and executive functions – EF on the reading and arithmetic skills of children with low- to medium-performance levels. Participants were 472 Brazilian children from 3rd to 5th grades. Quantile Regression Analysis was employed. The PA, RAN and EF were shared main predictors of both reading and math. Verbal WM emerged as a unique main predictor for reading, while visuospatial WM and visuospatial short-term memory were the main predictors for arithmetic. Among children with very low reading proficiency, the effects of cognitive predictors were more pronounced, a trend not observed in arithmetic. The results suggest varying magnitudes of cognitive predictors for reading when considering different levels of performance/difficulties. We also corroborate unique and shared main predictors of reading and math that have implications for research, clinical and educational settings.

Clinical Utility of Virtual Kitchen Errand Task for Children (VKET-C) as a Functional Cognition Evaluation for Children with Developmental Disabilities.

This study evaluated the clinical utility of a virtual reality (VR)-based kitchen error task for children (VKET-C) to assess functional cognition in children. In total, 38 children aged 7-12 years were included, comprising 23 typically developing (TD) children and 15 children with developmental disabilities (DDs), including autism spectrum disorder, attention deficit hyperactivity disorder, and intellectual disability. While performing the VKET-C, performance errors were analyzed. The Stockings of Cambridge (SOC) and Spatial Working Memory (SWM) tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were used to assess cognitive function. The Brunner-Munzel test was performed to compare performance errors between the TD and DD groups, and correlations between performance errors and cognitive measures were analyzed. Omission and commission errors were significantly different between the groups (p < 0.001), with no significant difference in motor errors (p > 0.05). Omission errors were correlated with the initial thinking time mean (ITMN) in all items of the SOC task and the between errors (BE) of the SWM task. Commission errors were correlated with the ITMN in the difficult items of the SOC task and the BE of the SWM task. Additionally, motor errors were significantly correlated with problems solved in minimum moves (PSMM) and ITMN in the difficult items of the SOC task and BE in the SWM task. The VKET-C shows promise as an effective tool for assessing executive function and working memory in children with DDs, offering an engaging and ecologically valid alternative to traditional methods.

The Effects of the Complexity of 3D Virtual Objects on Visual Working Memory Capacity in AR Interface for Mobile Phones

The current study aims to investigate the effects of 3D virtual object complexity on visual working memory capacity in mobile augmented reality (MAR) interfaces. With the popularity of augmented reality technology in mobile applications, 3D virtual elements play a key role in interaction. However, prior studies ignored the correlation between virtual object presentation and visual working memory (VWM). Given that visual working memory capacity is closely related to overall cognitive ability, the current study explored the relationship between the complexity of 3D virtual objects and VWM capacity in AR interfaces. Sixty volunteers participated in a 5-point Likert scale rating to eliminate the interference factors of familiarity, concreteness and similarity in 3D virtual material objects. Then, we further conducted an MAR change detection paradigm experiment and successfully manipulated the complexity of 3D virtual objects and the set size. Thirty-one subjects completed the formal experiment. Three measurements (reaction time, proportion correct, and Cowan’s K) were analyzed for nine experimental conditions (three object complexity levels and three object set sizes). The results confirmed that the visual working memory capacity in mobile AR interfaces is modulated by the complexity of the 3D virtual objects and set size, which decreases with the increase in complexity and set size of the displayed 3D virtual objects. As the complexity of the 3D virtual objects increases, the amount of resources allocated to each item decreases, resulting in a decrease in memory capacity and memory accuracy. This study highlights the effectiveness of VWM capacity in MAR interface design research and provides valuable insights into determining the best way to present 3D virtual objects.

Understanding the influence of children’s mental health, cognitive development, and environmental factors on learning outcomes in Chile

Mental health, cognitive development, and social background are related to educational success. While growing evidence is available in cultural settings other than Western countries, more knowledge is needed, especially regarding interactions among these dimensions. Rather than studying isolated factors, we propose an integrated approach to consider the diverse interrelated dimensions influencing children’s learning. Life course theory supports this approach underlying the role of early events in subsequent life paths and the multidisciplinary nature of these events. The sample consisted of 610 children (49.1% male) attending first grade. The children completed reading, mathematics, and visuospatial working memory (VWM) assessments. Parents completed the Strengths and Difficulties Questionnaire (SDQ-P) and reported their demographic information. A multilevel path model was estimated, including direct relationships between (i) children’s socioemotional behavior (SEB) and learning, (ii) VWM and learning, and (iii) SEB and VWM. The effects of sex and maternal education were also controlled. School and student level variances were modeled. At the school level, VWM, reading, and mathematics have variance, whereas SEB does not. At the student level, VWM, SEB, and maternal education have significant and differential effects on learning. Hyperactivity and peer problems were negatively related to reading and mathematics, while emotional problems were not, and conduct problems exhibited mixed results. These results reinforce developmental life course approaches, that is, from the beginning of schooling, promoting positive mental health can improve children’s learning outcomes.

The Role of Cognitive Learner Prerequisites for Cognitive Load and Learning Outcomes in AR-Supported Lab Work

Augmented Reality (AR) can enhance student-centered lab work by bridging the spatial and temporal split between virtual information and observed real-world phenomena. While the Cognitive Theory of Multimedia Learning and the Cognitive Load Theory suggest that AR can reduce extraneous cognitive load (ECL) and foster learning, the empirical results remain inconsistent. This re-analysis of three related studies with different target groups and AR devices explores whether learners’ spatial abilities and verbal working memory capacity moderate the effect of AR support in lab work settings on ECL and conceptual knowledge gains. Although these moderators could not be confirmed consistently, the results indicate that tablet-based AR holds the potential to support learners with low spatial abilities. Moreover, low verbal working memory learners were demonstrated to be particularly vulnerable to the spatial contiguity failure that can be caused by smartglasses AR. Moderation effects were only observed for ECL but not for conceptual knowledge gains. The findings highlight that the benefit of AR support can depend on learners’ cognitive prerequisites and additional contextual factors, such as the AR device used and the age of the target group. The design and implementation of AR-supported lab work environments should account for these factors to optimize the learning outcomes.

Acute Administration of Edaravone Improves Cognitive Impairment in a Mouse Model of mPFC Ischemia: Crosstalk Between Necroptosis, Neuroinflammation, and Antioxidant Defense.

Edaravone (Eda), a well-known free radical scavenger, has been reported as a possible therapeutic agent for ischemic stroke patients' recovery. This study aimed to investigate the effects of time-dependent treatment with Eda on medial prefrontal cortex (mPFC) ischemia. Mice were randomly allocated into six groups: control, sham, normal saline, Eda-I, Eda-II, and Eda-III. After induction of a photothrombotic ischemia in the mPFC region, Eda-I, Eda-II, and Eda-III groups received 3mg/kg Eda intraperitoneally at the times of 0, 2, and 6h post-surgery. After 1day of recovery, the mice underwent behavioral tests (open field, novel object recognition, and T-maze). Next, necroptosis, NOD-like receptor protein 3 (NLRP3), and nuclear factor erythroid 2-related factor 2 (Nrf2) pathway-related protein levels were measured in the lesioned area using western blot analysis. For double confirmation, IL-1β and IL-18 were also assessed by immunofluorescence in the area. Further, histological evaluations were performed to measure tissue damage. The results showed that mPFC ischemia impaired recognition and spatial working memory without affecting locomotor activity, while immediate Eda administration improved cognitive impairments. Furthermore, acute Eda treatment reduced RIP1, RIP3, and MLKL levels, inhibited NLRP3 inflammasome proteins (NLRP3, ASC, and Cas1), decreased IL-1β and IL-18, upregulated Nrf2 and its targets (NQO-1 and HO-1), and diminished tissue damage. Our results highlighted the effects of acute administration of Eda post-stroke on improving cognitive impairments by suppressing necroptosis and NLRP3 inflammasome pathways and activating the Nrf2 antioxidant defense mechanism.

Ethnography of past happiness. Work in the yeast factory in Maszewo Lęborskie

For inhabitants of Maszewo Lęborskie, the memory of work in the yeast factory is an important point on which their local community is based. It is a memory of a strong integrating feature that unites the people of Maszewo. Theworkers’ lifestyle, shaped by the yeast factory after its collapse, was transformed into a community of memories. I present an outline of the history of the yeast factory in Maszewo and created examples of the discourse of memory around it.

No evidence that visual impulses enhance the readout of retrieved long-term memory contents from EEG activity

Abstract The application of multivariate pattern analysis (MVPA) to electroencephalography (EEG) data allows neuroscientists to track neural representations at temporally fine-grained scales. This approach has been leveraged to study the locus and evolution of long-term memory contents in the brain, but a limiting factor is that decoding performance remains low. A key reason for this is that processes such as encoding and retrieval are intrinsically dynamic across trials and participants, and this runs in tension with MVPA and other techniques that rely on consistently unfolding neural codes to generate predictions about memory contents. The presentation of visually perturbing stimuli may experimentally regularize brain dynamics, making neural codes more stable across measurements to enhance representational readouts. Such enhancements, which have repeatedly been demonstrated in working memory contexts, could offer a tool to improve decoding in long-term memory tasks. In this study, we evaluated whether visual perturbations—or pings—improve our ability to predict the category of retrieved images from EEG activity during cued recall. Overall, our findings suggest that while pings evoked a prominent neural response, they did not reliably produce improvements in MVPA-based classification across several analyses. We discuss possibilities that could explain these results, including the role of experimental and analysis parameter choices and mechanistic differences between working and long-term memory.

Competition during verbal creative processes influences on ERS/ERD

ABSTRACT Humans are social creatures, and many tasks in our daily lives are solved together. The two main forms of social interaction in problem solving could be defined as competition and cooperation. In our study, we compared the ERS/ERD when performing a creative task (Alternative Uses Test, AUT) and a control task (“naming the objects from the presented category”) under competitive conditions in dyads (22 dyads, m-m, f-f, 18–23 years old) compared to the performance of tasks individually. The number of answers given by subjects under competitive conditions was significantly lower than during the execution of the tasks individually. The solving of the creative task in competition versus individual performance was accompanied by EEG synchronization (9–30 hz) clusters: 140–1220 ms and 900–1780 ms after stimulus presentation; 13.5–30 hz (1800–1980 ms), reflecting the creative thinking mode, and expected cognitive, emotional answers’ assessment. The control task under competitive conditions was accompanied by pronounced synchronization of low frequencies in the frontal areas (2–7 hz, 0–1980 ms), due to a greater working memory load; synchronization clusters in broadband (10–30 hz, 100–320 ms, 400–860 ms) and in the beta EEG band (17–30 hz, 1140–1980 ms). The competitive conditions significantly modulated the brain activity underlying creative and non-creative cognitive task performance, and resulted in greater induced EEG synchronization.

Effects of a Functional Cone Mushroom (Termitomyces fuliginosus) Protein Snack Bar on Cognitive Function in Middle Age: A Randomized Double-Blind Placebo-Controlled Trial.

Background: Due to the rising prevalence of cognitive impairment in the middle-aged and elderly population, combined with consumer demand for functional foods to improve health and well-being. Objective: This study aimed to formulate a functional cone mushroom (Termitomyces fuliginosus) (FCM) protein snack bar and evaluate its amino acid profile, phytochemical contents, biological activity and impact on cognitive function. Methods: A total of 26 middle-aged male and female participants were randomized and divided into placebo, FCM1 and FCM2 groups. Continuous consumption was performed for 6 weeks. Demographic data, body composition, cognitive function and memory were evaluated at baseline and at the end of the study period (6 weeks). Results: The event-related potential (ERP) analysis results showed a significant increase in N100 and P300 amplitude at the Fz location in participants who consumed the functional cone mushroom protein snack bar at a dose of 1 g compared to the placebo group (p = 0.015). Additionally, subjects who consumed the functional cone mushroom protein snack bar at a dose of 2 g showed a significantly increased P300 amplitude and percent accuracy of numeric working memory (p = 0.048) compared to those in the placebo group (p = 0.044). The possible underlying mechanism may involve AChE and MAO suppression activity alongside antioxidant activity. Conclusions: These data suggest that FCM can improve cognitive function and memory and may be considered for use in natural supplementation products with possible health benefits.

Visual Working Memory in Adolescents with Autism Spectrum Disorder.

Previous research suggests that individuals with autism spectrum disorder (ASD) may experience working memory (WM) problems, but the nature of the underlying disruption remains unknown. A recent study (Bodner et al. 2019) found that young adults with ASD experienced intact WM capacity but disruptions in their ability to efficiently filter and allocate attention. The goal of the present study was to extend this work and evaluate potential disruptions in WM capacity and attentional allocation ability in adolescents with ASD. A sample of 38 adolescents with ASD and 39 adolescents without ASD aged 11-15 years completed a computerized WM task. In brief, participants were shown visual arrays consisting of four or six colored stimuli (circles and squares). After a short delay, memory for one of the stimuli was probed. Importantly, participants were informed beforehand that one of the shapes (e.g., circles) was more likely to be probed compared to the other shape (e.g., squares) - thus making it strategically beneficial to focus primarily on the high frequency shapes. The ASD group demonstrated overall lower WM capacity compared to the non-ASD group. However, no group differences were seen in attentional allocation. There was also no evidence of sex-related differences in WM performance in adolescents with ASD. Taken together with previous findings, the current results suggest that adolescents with ASD show disruptions in WM capacity that are resolved by adulthood. Future longitudinal research is needed to further disentangle the component processes of WM and the developmental trajectories of these components.

Exploring the influence of music on cognitive performance in female assembly line workers at a medical device manufacturing unit.

The significance of enhancing working conditions for the physical health and performance of workers, particularly female workers, underscores the need for research in this domain and the examination of interventions such as music. Previous studies have yielded diverse outcomes regarding the influence of music on individuals' performance; hence, further research in this area appears imperative. The aim of this study is to explore the impact of music on the cognitive and task performance of female assembly operation operators. This study is an interventional (quasi-experimental) study that involved 81 participants from the female workforce of the medical equipment assembly unit in Isfahan, Iran. The evaluation encompassed task performance, working memory using N-Back test, sustained attention using continues performance test (CPT), degree of sleepiness, and mental fatigue using Flicker Fusion test, along with physiological parameters such as heart rate and blood oxygen level. Participants underwent testing both in the presence of classical music and in a condition without music playback. The provision of background music enhanced the workers' sustained attention and working memory. It led to improved task performance and a reduction in drowsiness. Concerning physiological parameters, it resulted in a slight decrease in heart rate at the end of the work shift and a marginal increase in participants' blood oxygen levels. Background music enhanced working memory (p-value = 0.001), sustained attention (p-value = 0.001), and improved the task performance of workers(p-value = 0.005). Additionally, likely due to increased relaxation, it led to a decrease in heart rate (p-value = 0.001) and an increase in blood oxygen levels (p-value = 0.016). Music also played a role in reducing participants' sleepiness (p-value = 0.001).

A comparison of working memory abilities between children with intellectual disability with non-specific aetiology and children with Down syndrome in schools for intellectual development in Germany

Objectives The study compares the working memory performance of students with Down syndrome (DS) to that of matched controls with non-specific intellectual disability (NSID). Even though empirical evidence is somewhat mixed and inconclusive, previous research suggests that students with DS display a relative weakness in the phonological loop. In contrast, no differences are reported in the visuo-spatial sketchpad and the central executive. Methods The sample consisted of 23 students with DS and 23 matched controls with NSID. The phonological loop was assessed using nonword repetition and picture span. Measures of the visuo-spatial sketchpad included a corsi-block task and a pattern span. Finally, an odd-one-out task was used to assess the executive-loaded working memory (ELWM) as a part of the central executive. Results Supporting our hypotheses, students with DS significantly differed from their peers with NSID in the phonological loop, while we found no performance differences for the visuo-spatial sketchpad and the ELWM. Conclusions Weaknesses in the phonological loop in students with DS are documented in literature and supported by this study. Important conclusions can be drawn for teachers’ instruction and students’ reading development. However, the study’s limitations mean that any inferences must be drawn cautiously.

Effects of soccer instruction on the executive functions and agility of children in early childhood.

Studies have shown that in open-skill sports the executive function of high-performing players is significantly higher than that of the control group. However, whether participation in soccer effectively improves executive function is unclear because previous studies lacked baseline measurements of executive function. Furthermore, agility, mostly developed in early childhood, is the most demanding component of physical fitness in open-skill sports, requiring sudden changes in body direction while running at full speed. However, no studies have examined the improvement in agility of young children participating in open-skill sports through comparison with a control group. This study aimed to clarify whether instruction in soccer, an open-skill sport, can effectively improve the executive function and agility of kindergarteners compared to a control group. In April 2020, 31 five-year-old children enrolled in kindergarten K in H prefecture in Japan were targeted as the intervention group and received soccer instruction for 12 weeks. In April 2020, a control group was established, consisting of 39 five-year-old children enrolled at the same kindergarten. Participants in both groups were measured for agility, inhibition, and working memory before and after (pre-post) soccer instruction for the intervention group. For each item, a two-way ANOVA of the group (intervention group・control group) x measurement period (pre-post) was performed, showing no significant interactions for working memory and agility. Because only the inhibition effect was significant, simple main effects were tested. Regarding inhibition, although the intervention group (M = 0.18, SD = 0.01) and the control group (M = 0.17, SD = 0.01) did not differ significantly in performance pre-intervention, the intervention group (M = 0.23, SD = 0.01) showed significantly better performance post-intervention compared to the control group (M = 0.19, SD = 0.01) (p < .01). Thus, soccer instruction improved kindergarteners' inhibition, to a level significantly higher than that of the control group. Still, no differences were found between groups regarding working memory and agility.

Associations between AHA's Life's Essential 8 and cognition in midlife and older adults.

This study evaluated the associations between Life's Essential 8 (LE8) and cognitive performance, and compared the strength of the relationships of Life's Simple 7 (LS7) and LE8 to cognition in midlife and older adults. Participants (N=1539) were from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. Cross-sectional multivariable regression examined the associations between LE8 and cognition. Secondary analyses compared model performance between LE8 and LS7 measures on cognition from the same available sample. Higher LE8 scores were associated with better global cognitive performance, working memory, and attention. The LS7 model outperformed the LE8 model on global cognitive performance, but the LE8 model outperformed the LS7 model for the working memory domain. Better cardiovascular health (CVH) was associated with better cognitive performance among US middle-aged and older adults. However, the association between CVH and specific cognitive domains varies when using LE8 versus LS7. Cardiovascular health (CVH) is associated with cognitive performance. Life's Essential 8 (LE8) is a new construct to quantify CVH. Associations between LE8 and cognition were assessed. Higher LE8 was associated with better global cognitive performance. Higher LE8 was also associated with better working memory and attention.

Witnessing their mother’s acute and prolonged stress affects executive functioning in children

Stress can detrimentally affect physical and mental health, especially during childhood. During this critical period, parental bonds can foster resilience or amplify stress. This study explored whether mothers’ everyday stress can act as a source of childhood stress, affecting children’s executive functioning. 76 healthy mother-child dyads participated, with mothers assigned to a stress-inducing or stress-free condition. Children observed their mothers and were subsequently tested for cognitive flexibility and working memory. Subjective stress, heart rate, and cortisol were measured repeatedly in mothers and children, alongside everyday stress perceptions. Linear mixed models showed that children’s acute stress response was associated with impaired cognitive flexibility. Maternal stress, both acute and past-month, was a better predictor of children’s cognitive performance than children’s own stress. Quadratic relationships indicated the highest error rates at very low and high maternal stress. We found no evidence that children’s working memory was impaired by their own or their mothers’ stress. Although expected covariations of acute or prolonged stress between mothers and children were not observed, an interaction between maternal past-month stress and acute stress condition provided insights into adaptive mechanisms in children. These findings underscore the significant impact of maternal stress on children’s executive functioning, illustrating how parental experiences shape children’s everyday outcomes.

Long-term cognitive training enhances fluid cognition and brain connectivity in individuals with MCI

Amnestic mild cognitive impairment (aMCI) is a risk factor for Alzheimer’s disease (AD). Multi-domain cognitive training (CT) may slow cognitive decline and delay AD onset. However, most work involves short interventions, targeting single cognitive domains or lacking active controls. We conducted a single-blind randomized controlled trial to investigate the effect of a 6-month, multi-domain CT on Fluid Cognition, functional connectivity in memory and executive functioning networks (primary outcomes), and white matter microstructural properties (secondary outcome) in aMCI. Sixty participants were randomly assigned to either a multi-domain CT or crossword training (CW) group, and thirty-four participants completed the intervention. We found a significant group-by-time interaction in Fluid Cognition (p = 0.007, F (1,28) = 8.26, Cohen’s d = 0.38, 95% confidence interval [CI]: 2.45–14.4), with 90% of CT patients showing post-intervention improvements (p < 0.01, Cohen’sd = 0.7). The CT group also showed better post-intervention Fluid Cognition than healthy controls (HCs, N = 45, p = 0.045). Functional connectivity analyses showed a significant group-by-time interaction (Cohen’s d ≥ 0.8) in the dorsolateral prefrontal cortex (DLPFC) and inferior parietal cortex (IPC) networks. Specifically, CT displayed post-intervention increases whereas CW displayed decreases in functional connectivity. Moreover, increased connectivity strength between the left DLPFC and medial PFC was associated with improved Fluid Cognition. At a microstructural level, we observed a decline in fiber density (FD) for both groups, but the CT group declined less steeply (1.3 vs. 2%). The slower decline in FD for the CT group in several tracts, including the cingulum-hippocampus tract, was associated with better working memory. Finally, we identified regions in cognitive control and memory networks for which baseline functional connectivity and microstructural properties were associated with changes in Fluid Cognition. Long-term, multi-domain CT improves cognitive functioning and functional connectivity and delays structural brain decline in aMCI (ClinicalTrials.gov number: NCT03883308).