Tackling cognitive decline in late adulthood: Cognitive interventions.

Affordable and easy-to-administer interventions such as cognitive training, cognitively stimulating everyday leisure activities, and non-invasive brain stimulation techniques, are promising avenues to counteract age-related cognitive decline and support people in maintaining cognitive health into late adulthood. However, the same pattern of findings emerges across all three fields of cognitive intervention research: whereas improvements within the intervention context are large and often reliable, generalisation to other cognitive abilities and contexts are severely limited. These findings suggest that while cognitive interventions can enhance the efficiency with which people use their existing cognitive capacity, these interventions are unlikely to expand existing capacity limits. Therefore, future research investigating generalisation of enhanced efficiency constitutes a promising avenue for developing reliably effective cognitive interventions.

Mechanisms of Training-Related Change in Processing Speed: A Drift-Diffusion Model Approach.

Processing speed is a crucial ability that changes over the course of the lifespan. Training interventions on processing speed have shown promising effects and have been associated with improved cognitive functioning. While training-related changes in processing speed are often studied using reaction times (RTs) and error rates, these measures provide limited insight into the mechanisms underlying changes during training. The drift-diffusion model provides estimates of the cognitive processes underlying speeded decision tasks, such as the rate of evidence accumulation (drift rate), response strategies (boundary separation), as well as time for other processes such as stimulus encoding and motor response (non-decision time). In the current study, we analyzed existing data of an extensive multi-session training intervention (von Bastian & Oberauer, 2013) to disentangle changes in drift rate, boundary separation, and non-decision time during training of different speeded choice-RT tasks. During this training intervention, 30 participants performed 20 training sessions over the course of four weeks, completing three tasks each session: a face-matching, a pattern-matching, and a digit-matching task. Our results show that processing speed training increased drift rates throughout training. Boundary separation and non-decision time decreased mostly during the initial parts of training. This pattern of prolonged training-related changes in rate of evidence accumulation as well as early changes in response strategy and non-decision processes was observed across all three tasks. Future research should investigate how these training-related changes relate to improvements in cognitive functioning more broadly.

Mechanisms of Cognitive Change: Training Improves the Quality But Not the Quantity of Visual Working Memory Representations.

As of yet, visual working memory (WM) training has failed to yield consistent cognitive benefits to performance in untrained tasks, despite large improvements in trained tasks. Investigating the mechanisms underlying training effects can help explain these inconsistencies. In this pre-registered, pre-test/post-test online training study, we examined how training affects the quantity and quality of representations in visual WM using continuous-reproduction tasks. N = 64 young healthy adults were randomly assigned to an experimental group or an active control group to complete four training sessions of practce in an orientation-reproduction or a visual search task, respectively. We observed that, in the trained task, only the quality, but not the quantity, of visual WM representations significantly increased in the experimental group relative to the control group. These improvements did not generalise to untrained stimuli or paradigms. Therefore, our findings suggest that training gains are not driven by enhanced capacity. Instead, gains in the quality of visual WM representations that are tied to specific stimuli and paradigms may reflect enhanced efficiency in using the existing visual WM capacity.

The Psychological Science Accelerator's COVID-19 rapid-response dataset.

In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data.

Limits of near transfer: Content- and operation-specific effects of working memory training.

Working memory (WM) training typically leads to large performance gains in the practiced tasks, but transfer of these gains to other contexts is elusive. One possible explanation for the inconsistent findings of past research is that transfer may only occur when cognitive strategies acquired during training can also be applied in the transfer tasks. Therefore, we systematically varied the content domains and WM operations assessed by training and transfer tasks and, thereby, the extent to which similar cognitive strategies could be applied. We randomly assigned 171 young adults to one of eight experimental groups who trained one of two WM operations (storage and processing or relational integration) with materials from one of four content domains (verbal, numerical, figural-icon, or figural-pattern) to an active or to a passive control group. Before and after 12 sessions of adaptive training within 2-3 weeks, performance was assessed in all eight WM tasks. Bayesian generalized linear mixed-effects models revealed improved performance in the trained tasks compared to the active control group. However, these improvements did not generalize to tasks measuring the same WM operation with different materials. Moreover, the comparison of the training groups with an active and a passive control group showed considerable differences, thus highlighting the importance of distinguishing between active and passive control groups. Overall, the findings revealed no evidence for transfer between tasks assumed to afford the same strategies. Therefore, the adoption of specific cognitive strategies alone is unlikely to be responsible for transfer of WM training gains between tasks. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Elaboration by superposition: From interference in working memory to encoding in long-term memory.

Distraction embedded in working memory tasks leads to impaired performance. This impairment is mitigated when targets and distractors that follow them share common features-a signature effect of interference by superposition. Here we propose that target-distractor similarity modulates not only forgetting from working memory but also encoding into long-term memory. In five experiments, we test this elaboration-by-superposition hypothesis, demonstrating that semantic relatedness between targets and distractors benefits delayed category-cued recall performance (Experiments 1a and 1b), which is not due to carry-over effects from working memory testing (Experiment 2). Just as in the case of working memory, this long-term memory effect is reduced when distractors precede targets (Experiment 3). Finally, we show that while high target-distractor similarity reduces forgetting from working memory, it produces net benefits for long-term memory performance (Experiment 4). Together, the results suggest that common mechanisms underlie encoding into working and long-term memory, and that bindings between features of spatiotemporal context and features of to-be-remembered items play a crucial role. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Mechanisms of processing speed training and transfer effects across the adult lifespan: protocol of a multi-site cognitive training study.

BACKGROUND: In recent years, cognitive training has gained popularity as a cost-effective and accessible intervention aiming at compensating for or even counteracting age-related cognitive declines during adulthood. Whereas the evidence for the effectiveness of cognitive training in general is inconsistent, processing speed training has been a notable successful exception, showing promising generalized benefits in untrained tasks and everyday cognitive functioning. The goal of this study is to investigate why and when processing speed training can lead to transfer across the adult lifespan. Specifically, we will test (1) whether training-induced changes in the rate of evidence accumulation underpin transfer to cognitive performance in untrained contexts, and (2) whether these transfer effects increase with stronger attentional control demands of the training tasks. METHODS: We will employ a multi-site, longitudinal, double-blinded and actively controlled study design with a target sample size of N = 400 adult participants between 18 and 85 years old. Participants will be randomly assigned to one of three processing speed training interventions with varying attentional control demands (choice reaction time, switching, or dual tasks) which will be compared to an active control group training simple reaction time tasks with minimal attentional control demands. All groups will complete 10 home-based training sessions comprising three tasks. Training gains, near transfer to the untrained tasks of the other groups, and far transfer to working memory, inhibitory control, reasoning, and everyday cognitive functioning will be assessed in the laboratory directly before, immediately after, and three months after training (i.e., pretest, posttest, and follow-up, respectively). We will estimate the rate of evidence accumulation (drift rate) with diffusion modeling and conduct latent-change score modeling for hypothesis testing. DISCUSSION: This study will contribute to identifying the cognitive processes that change when training speeded tasks with varying attentional control demands across the adult lifespan. A better understanding of how processing speed training affects specific cognitive mechanisms will enable researchers to maximize the effectiveness of cognitive training in producing broad transfer to psychologically meaningful everyday life outcomes. Trial registration Open Science Framework Registries, registration https://doi.org/10.17605/OSF.IO/J5G7E ; date of registration: 9 May 2022.

Individual differences in updating are not related to reasoning ability and working memory capacity.

Previous research assumes that executive functions such as inhibition, shifting, and updating explain individual differences in cognitive abilities. Of these three executive functions, updating was previously found to relate most strongly to fluid intelligence. However, this relationship could be a methodological artifact: Measures of inhibition and shifting usually isolate the contribution of this executive function to performance by contrasting conditions with high and low demands on these processes, whereas updating is measured by overall accuracy in working memory tasks involving updating. This updating measure conflates updating-specific individual differences (e.g., removal of outdated information) with variance in working memory maintenance. Reanalyzing data (N = 111) from von Bastian et al. (2016), we separated updating-specific variance from working memory maintenance variance. Updating contributed only 15% to individual differences in performance in the updating tasks, and it correlated neither with fluid intelligence nor with independent working memory measures reflecting storage and processing or relational integration. In contrast, the working memory maintenance component of the updating task correlated with both abilities. These findings challenge the view that updating contributes to variance in higher cognitive abilities. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Development and validation of a stress response measure: the Daily Stress Response Scale (DSRS).

BACKGROUND: To date, there is a lack of measures for capturing a broad spectrum of psychophysiological stress reactions that can be administered on a daily basis and in different contexts. A need for such a measure is especially salient in settings where stress processes can unfold momentarily and substantially fluctuate daily. Therefore, the main aim of the current study was to develop and validate the Daily Stress Response Scale (DSRS), an instrument capturing a broad spectrum of psychophysiological stress reactions that can be administered in real time and in different contexts. PARTICIPANTS AND PROCEDURE: The study was conducted in the early stages of the COVID-19 pandemic in Europe. Participants were 7228 (81% female) Polish university students. The data were collected anonymously through self-completion questionnaires. The DSRS was subject to confirmatory factor analyses (CFA). RESULTS: The DSRS is a 30-item, easy-to-use stress response measure with excellent psychometric properties. Based on CFA results, the scale consists of two subscales, psychological and physiological stress response, which form associations with related external criteria. CONCLUSIONS: The DSRS is a reliable and valid measure of psychological and physiological stress reactions that can be used to assess the stress response to daily stressors, including those of an acute nature, such as a crisis, trauma, or surgery.

Storage and processing in working memory: A single, domain-general resource explains multitasking.

An ongoing major debate centers around whether multitasking in working memory, that is, performing several mental activities at once, is supported by multiple specialized domain-specific or by a single-purpose domain-general cognitive resources. Working memory theories differ in their explanations and predictions about when performing two mental tasks causes performance failures, versus when two processes can be carried out concurrently with negligible cognitive costs. In particular, the predictions of domain-specific and domain-general views on working memory are in conflict with one another when it comes to the cognitive cost associated with concurrent verbal and visuospatial processing and storage tasks. Previous tests of these predictions using traditional methods have led to ambiguous and inconsistent conclusions, however. To make critical progress in this theoretical debate, we used a radically different approach combining Bayesian state-trace analysis with an experimental design fully crossing processing and storage tasks differing only in the domain of representation (verbal vs. visuospatial). Across two experiments, we show unambiguously that a single, domain-general factor can account for briefly maintaining verbal and visuospatial information in a multitasking scenario. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Are there Reliable Qualitative Individual Differences in Cognition? Probably Not.

Rouder and Haaf (2021, this issue) propose a focus shift toward qualitative individual differences in cognition and present a research toolkit for doing so. In this invited commentary, I will argue that the observation of qualitative individual differences may be no more than an indicator that more theoretical and empirical work needs to be done to identify the mechanisms and abilities underlying these individual differences in directionality. I will then move on to discuss how the toolkit can be used though to investigate one of the currently most central current topics in cognitive differential psychology, that is, the question over the existence of true quantitative individual differences in attentional control experimental effects. I conclude that, while highly valuable, no toolkit can save us from facing the challenging theoretical and conceptual questions in this area.

In Search of the Executive Cognitive Processes Proposed by Process-Overlap Theory.

Process-Overlap Theory (POT) suggests that measures of cognitive abilities sample from sets of independent cognitive processes. These cognitive processes can be separated into domain-general executive processes, sampled by the majority of cognitive ability measures, and domain-specific processes, sampled only by measures within a certain domain. According to POT, fluid intelligence measures are related because different tests sample similar domain-general executive cognitive processes to some extent. Re-analyzing data from a study by De Simoni and von Bastian (2018), we assessed domain-general variance from executive processing tasks measuring inhibition, shifting, and efficiency of removal from working memory, as well as examined their relation to a domain-general factor extracted from fluid intelligence measures. The results showed that domain-general factors reflecting general processing speed were moderately and negatively correlated with the domain-general fluid intelligence factor (r = -.17--.36). However, domain-general factors isolating variance specific to inhibition, shifting, and removal showed only small and inconsistent correlations with the domain-general fluid intelligence factor (r = .02--.22). These findings suggest that (1) executive processing tasks sample only few domain-general executive processes also sampled by fluid intelligence measures, as well as (2) that domain-general speed of processing contributes more strongly to individual differences in fluid intelligence than do domain-general executive processes.

Effectiveness of cognitive stimulation for dementia: A systematic review and meta-analysis.

Cognitive stimulation (CS) is a nonpharmacological intervention often involving group activities and social interaction used to treat cognitive declines in people with dementia. This preregistered systematic review and meta-analysis evaluated the effectiveness of CS in producing benefits on cognition (primary outcome) and quality of life, activities of daily living, and psychological symptoms (secondary outcomes) across 44 randomized-controlled trials comprising 45 comparisons including 2,444 participants. A medium-sized effect (g = .49) on global cognition was found immediately after the intervention and was supported by decisive Bayesian evidence. Clinical relevance is defined as a reduction of 3 to 4 points on the Alzheimer's Disease Assessment Scale Cognitive subscale; the average attenuation of cognitive decline observed was 2.41 points (after removing 1 outlier). Therefore, the observed decline was of borderline clinical relevance. CS was also found to significantly improve memory, activities of daily living, depressive symptoms, and dementia ratings; most of these effects were supported by substantial and strong Bayesian evidence. No significant effects were found for global cognition at 1 to 10 months follow-up assessment for language, quality of life, anxiety, and behavior symptoms. However, evidence for the absence of these effects was ambiguous. A review of study bias highlighted that most studies lacked active, double-blinded controls, potentially leading to an overestimation of the effect, and making it difficult to conclusively attribute the observed improvements to the CS intervention. Hence, although effects are promising, the methodological issues highlight there is still a need for better controlled studies that provide more compelling evidence. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Working Memory Training Effects on White Matter Integrity in Young and Older Adults.

OBJECTIVES: Working memory is essential for daily life skills like reading comprehension, reasoning, and problem-solving. Healthy aging of the brain goes along with working memory decline that can affect older people's independence in everyday life. Interventions in the form of cognitive training are a promising tool for delaying age-related working memory decline, yet the underlying structural plasticity of white matter is hardly studied. METHODS: We conducted a longitudinal diffusion tensor imaging study to investigate the effects of an intensive four-week adaptive working memory training on white matter integrity quantified by global and tract-wise mean diffusivity. We compared diffusivity measures of fiber tracts that are associated with working memory of 32 young and 20 older participants that were randomly assigned to a working memory training group or an active control group. RESULTS: The behavioral analysis showed an increase in working memory performance after the four-week adaptive working memory training. The neuroanatomical analysis revealed a decrease in mean diffusivity in the working memory training group after the training intervention in the right inferior longitudinal fasciculus for the older adults. There was also a decrease in mean diffusivity in the working memory training group in the right superior longitudinal fasciculus for the older and young participants after the intervention. CONCLUSION: This study shows that older people can benefit from working memory training by improving their working memory performance that is also reflected in terms of improved white matter integrity in the superior longitudinal fasciculus and the inferior longitudinal fasciculus, where the first is an essential component of the frontoparietal network known to be essential in working memory.

Individual differences in task-unrelated thought in university classrooms.

This study investigated what academic traits, attitudes, and habits predict individual differences in task-unrelated thought (TUT) during lectures, and whether this TUT propensity mediates associations between academic individual differences and course outcomes (final grade and situational interest evoked by material). Undergraduates (N = 851) from ten psychology classes at two US universities responded to thought probes presented during two early-course lectures; they also indicated sitting in the front, middle, or back of the classroom. At each probe, students categorized their thought content, such as indicating on-task thought or TUT. Students also completed online, academic-self-report questionnaires at the beginning of the course and a situational interest questionnaire at the end. Average TUT rate was 24% but individuals' rates varied widely (SD = 18%). TUT rates also increased substantially from the front to back of the classroom, and modestly from the first to second half of class periods. Multiple-group analyses (with ten classroom groups) indicated that: (a) classroom media-multitasking habits, initial interest in the course topic, and everyday propensity for mind-wandering and boredom accounted for unique variance in TUT rate (beyond other predictors); (b) TUT rate accounted for unique (modest) variance in course grades and situational interest; and (c) classroom media multitasking and propensity for mind-wandering and boredom had indirect associations with course grades via TUT rate, and these predictor variables, along with initial interest, had indirect associations with end-of-term situational interest via TUT rate. Some academic traits and behaviors predict course outcomes in part because they predict off-task thought during class.

Lower general executive function is primarily associated with trait worry: A latent variable analysis of negative thought/affect measures.

This exploratory latent-variable study sought to identify common sources of variance between two multifaceted sets of constructs: executive functions (EFs) and negative thoughts/affect. One-hundred ninety-two college students completed nine tasks representing three types of EFs (inhibition, updating, and shifting) and a set of questionnaires assessing four facets of negative thought/affect (anxiety symptoms, depression symptoms, worry, and rumination). Results indicated that, although the four negative thought/affect constructs were substantially correlated with one another, trait worry was the construct uniquely associated with EFs. Specifically, worry was associated with general EF abilities underlying all three subtypes of EFs (common EF), but was not associated with specific EF abilities (i.e., shifting-specific and updating-specific). These findings highlight the importance of partitioning common and specific variances in both EFs and negative thought/affect when examining the associations between these two research domains. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Functional Ability in Everyday Life: Are Associations With an Engaged Lifestyle Mediated by Working Memory?

OBJECTIVES: An engaged lifestyle has been linked to measures of functional ability in everyday life. However, the underlying mechanism of this link is still understudied. We propose working memory as a potential mediator of this relation. METHODS: Modeling data of 158 older adults with a latent-variables approach, we examined whether working memory mediated the relation between an engaged lifestyle, that is, intellectual, social, and physical activities, and functional ability, that is, self-reported everyday failures and test-based everyday performance. RESULTS: Working memory was found to fully mediate the relation between gaming activities and test-based everyday performance. Furthermore, we found a negative association between sports activities and self-reported everyday failures not mediated through working memory, indicating that individuals who reported high levels of sports activities reported fewer everyday cognitive failures. All other lifestyle activities were, however, neither directly nor indirectly associated with functional ability. DISCUSSION: Working memory is one pathway by which gaming activities are related to test-based measures of functional ability in everyday life. Given the overlapping cognitive demands of working memory, gaming activities, and the test-based measure of functional ability, the findings suggest that while an engaged lifestyle can benefit functional ability, those benefits may be limited to highly similar domains.

Neural Correlates of Verbal Working Memory: An fMRI Meta-Analysis.

Verbal Working memory (vWM) capacity measures the ability to maintain and manipulate verbal information for a short period of time. The specific neural correlates of this construct are still a matter of debate. The aim of this study was to conduct a coordinate-based meta-analysis of 42 fMRI studies on visual vWM in healthy subjects (n = 795, males = 459, females = 325, unknown = 11; age range: 18-75). The studies were obtained after an exhaustive literature search on PubMed, Scopus, Web of Science, and Brainmap database. We analyzed regional activation differences during fMRI tasks with the anisotropic effect-size version of seed-based d mapping software (ES-SDM). The results were further validated by performing jackknife sensitivity analyses and heterogeneity analyses. We investigated the effect of numerous relevant influencing factors by fitting corresponding linear regression models. We isolated consistent activation in a network containing fronto-parietal areas, right cerebellum, and basal ganglia structures. Regarding lateralization, the results pointed toward a bilateral frontal activation, a left-lateralization of parietal regions and a right-lateralization of the cerebellum, indicating that the left-hemisphere concept of vWM should be reconsidered. We also isolated activation in regions important for response inhibition, emphasizing the role of attentional control in vWM. Moreover, we found a significant influence of mean reaction time, load, and age on activation associated with vWM. Activation in left medial frontal gyrus, left precentral gyrus, and left precentral gyrus turned out to be positively associated with mean reaction time whereas load was associated with activation across the PFC, fusiform gyrus, parietal cortex, and parts of the cerebellum. In the latter case activation was mainly detectable in both hemispheres whereas the influence of age became manifest predominantly in the left hemisphere. This led us to conclude that future vWM studies should take these factors into consideration.

Is executive control related to working memory capacity and fluid intelligence?

In the last two decades, individual-differences research has put forward 3 cognitive psychometric constructs: executive control (i.e., the ability to monitor and control ongoing thoughts and actions), working memory capacity (WMC, i.e., the ability to retain access to a limited amount of information in the service of complex tasks), and fluid intelligence (gF, i.e., the ability to reason with novel information). These constructs have been proposed to be closely related, but previous research failed to substantiate a strong correlation between executive control and the other two constructs. This might arise from the difficulty in establishing executive control as a latent variable and from differences in the way the 3 constructs are measured (i.e., executive control is typically measured through reaction times, whereas WMC and gF are measured through accuracy). The purpose of the present study was to overcome these difficulties by measuring executive control through accuracy. Despite good reliabilities of all measures, structural equation modeling identified no coherent factor of executive control. Furthermore, WMC and gF-modeled as distinct but correlated factors-were unrelated to the individual measures of executive control. Hence, measuring executive control through accuracy did not overcome the difficulties of establishing executive control as a latent variable. These findings call into question the existence of executive control as a psychometric construct and the assumption that WMC and gF are closely related to the ability to control ongoing thoughts and actions. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Bidialectalism and Bilingualism: Exploring the Role of Language Similarity as a Link Between Linguistic Ability and Executive Control.

The notion of bilingual advantages in executive functions (EF) is based on the assumption that the demands posed by cross-language interference serve as EF training. These training effects should be more pronounced the more cross-language interference bilinguals have to overcome when managing their two languages. In the present study, we investigated the proposed link between linguistic and EF performance using the similarity between the two languages spoken since childhood as a proxy for different levels of cross-language interference. We assessed the effect of linearly increasing language dissimilarity on linguistic and EF performance in multiple tasks in four groups of young adults (aged 18-33): German monolinguals (n = 24), bidialectals (n = 25; German and Swiss German dialect), bilinguals speaking two languages of the same Indo-European ancestry (n = 24; e.g., German-English), or bilinguals speaking two languages of different ancestry (n = 24; e.g., German-Turkish). Bayesian linear-mixed effects modeling revealed substantial evidence for a linear effect of language similarity on linguistic accuracy, with better performance for participants with more similar languages and monolinguals. However, we did not obtain evidence for the presence of a similarity effect on EF performance. Furthermore, language experience did not modulate EF performance, even when testing the effect of continuous indicators of bilingualism (e.g., age of acquisition, proficiency, daily foreign language usage). These findings question the theoretical assumption that life-long experience in managing cross-language interference serves as EF training.