Scientific claims are selected in part for their ability to survive. Scientists can pursue an r-strategy of broad, easy-to-spread ideas, or a K-strategy of stress-tested, bulletproof statements. The “generalizability crisis” is an exquisite mutation that allows dull, K-strategic methodology articles to spread nearly as quickly as the fast-breeding, r-strategic memes of pop-psychology.

Adaptive training adjusts a training task with the goal of improving learning outcomes. Adaptive training has been shown to improve human performance in attention, working memory capacity, and motor control tasks. Additionally, correlations have been observed between neural EEG spectral features and the performance of some cognitive tasks. This relationship suggests some EEG features may be useful in adaptive training regimens. Here, we anticipated that adding a neural measure into a behavioral-based adaptive training system would improve human performance on a (...) subsequent transfer task. We designed, developed, and conducted a between-subjects study of 44 participants comparing three training regimens: Single Item Fixed Difficulty, Behaviorally Adaptive Training, and Combined Adaptive Training using both behavioral and EEG measures. Results showed a statistically significant transfer task performance advantage of the CAT-based system relative to SIFD and BAT systems of 6 and 9 percentage points, respectively. Our research shows a promising pathway for designing closed-loop BCI systems based on both users' behavioral performance and neural signals for augmenting human performance. (shrink)

The framework of plateaus, dips, and leaps shines light on periods when individuals may be inventing new methods of skilled performance. We begin with a review of the role performance plateaus have played in experimental psychology, human–computer interaction, and cognitive science. We then reanalyze two classic studies of individual performance to show plateaus and dips which resulted in performance leaps. For a third study, we show how the statistical methods of Changepoint Analysis plus a few simple heuristics may direct our (...) focus to periods of performance change for individuals. For the researcher, dips become the marker of exploration where performance suffers as new methods are invented and tested. Leaps mark the implementation of a successful new method and an incremental jump above the path plotted by smooth and steady log–log performance increments. The methods developed during these dips and leaps are the key to surpassing one's teachers and acquiring extreme expertise. (shrink)

Research over the past few decades has shown the positive influence that cognitive, social, and physical activities have on older adults’ cognitive and affective health. Especially interventions in health-related behaviors, such as cognitive activation, physical activity, social activity, nutrition, mindfulness, and creativity, have shown to be particularly beneficial. Whereas most intervention studies apply unimodal interventions, such as cognitive training, this study investigates the potential to foster cognitive and affective health factors of older adults by means of an autonomy-supportive multimodal intervention. (...) The intervention integrates everyday life recommendations for six evidence-based areas combined with psychoeducational information. This randomized controlled trial study compares the effects of a MMI and CT on those of a waiting control group on cognitive and affective factors, everyday life memory performance, and activity in everyday life. Three groups, including a total of 119 adults aged 65–86 years, attended a 5- or 10-week intervention. Specifically, one group completed a 10-week MMI, the second group completed 5-week of computer-based CT followed by a 5-week MMI, whereas the third group paused before completing the MMI for the last 5 weeks. All participants completed online surveys and cognitive tests at three test points. The findings showed an increase in the number and variability of activities in the everyday lives of all participants. Post hoc analysis on cognitive performance of MMI to CT indicate similar or better effects. Furthermore, results on far transfer variables showed interesting trends in favor of the MMI, such as increased well-being and attitude toward the aging brain. Also, the MMI group showed the biggest perceived improvements out of all groups for all self-reported personal variables. The results implicate a positive trend toward MMI on cognitive and affective factors of older adults. These tendencies show the potential of a multimodal approach compared to training a specific cognitive function. Moreover, the findings suggest that information about MMI motivates participants to increase activity variability and frequency in everyday life. Finally, the results could also have implications for the primary prevention of neurocognitive deficits and degenerative diseases. (shrink)

Non-invasive transcranial electrical brain stimulation (tES) techniques, including transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS), can alter neuronal activity and related brain functions. However, tES effects seem to be modulated by various influencing factors, leading to high inter-individual variability in tES effects and often only low effect sizes, or even no effects. The present thesis therefore aimed to investigate methodological and physiological influencing factors of tDCS, tACS and tRNS that have not (...) been sufficiently examined so far. A first study investigated the influence of montage and individual functional performance level on the effects of anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC) in healthy adults. Compared with sham stimulation, a multichannel montage led to stronger effects than a bipolar montage. For both montages the effects of stimulation were dependent on the functional performance level of participants. A second study investigated the effects of multichannel tDCS over the left DLPFC in healthy children and adolescents, considering the influence of concurrent target task performance during stimulation and individual head anatomy. tDCS did not influence the target outcome but led to transfer effects on non-target task performance and neurophysiological activity, that were only partly influenced by task performance during stimulation. The individual head anatomy had no influence on stimulation effects. A third study investigated tACS and tRNS effects on motor cortex excitability in healthy children and adolescents in comparison to adults. The individual response to sham stimulation was investigated as marker for the individual physiological brain state. Motor cortex excitability was not modulated by age but by individual response to sham stimulation. All studies provide important insights into the modulatory factors of stimulation effects. Based on these results, future studies should aim at individualising tES application. (shrink)

Multitasking behavior and working memory training are important topics in psychological science. The present thesis systematically investigated the underlying cognitive constructs of multitasking behavior and the cognitive strategies related to transfer effects of working memory training, which were described in two empirical studies. In the first study, we examined the underlying cognitive constructs associated with the concept of multitasking behavior. Although prior investigations have revealed cognitive abilities to be important predictors of multitasking behavior, few studies have been conducted on the (...) relation between executive functions and multitasking behavior. In this regard, the current investigation explored the importance of EFs, working memory capacity, relational integration, and divided attention to multitasking behavior. A sample of 202 young adults completed a battery of EFs, three WMC tests, three relational integration tests, two divided attention tests, and a multitasking scenario. Our study provided several key findings. First, in direct replication attempts, we could replicate the multitasking behavior model and partially replicate the three-factor and nested factors EFs models. Second, the regression analyses revealed that updating, inhibition, relational integration, and divided attention had strong contributions in explaining multitasking behavior variance, whereas shifting and WMC did not show any explanatory power beyond these constructs. Finally, using structural equation modeling, we found that the general EF ability representing variance common to shifting, updating, and inhibition highly overlapped with multitasking behavior. Our results are of value not only to shed light on the relevant cognitive correlates of multitasking behavior but also to position multitasking behavior in an established framework of cognitive abilities. Additionally, by providing strong empirical evidence in favor of cognitive constructs of multitasking behavior, this study builds the necessary groundwork for steering future research to elucidate the etiology of underlying relations between these specific cognitive correlates and multitasking behavior. The second study inspected how transfer occurs on material-specific tasks, rather than other task types within the working memory training framework. Despite numerous attempts of using training interventions to increase WMC, the role of cognitive strategy in explaining the transfer effects is not yet experimentally investigated. We hypothesized that transfer would occur when a similar cognitive strategy is applied in solving both the trained and transfer tasks. According to this idea, we examined the strategic approach by directly using tasks that allow for specific strategies and tasks that do not. In particular, training with verbal and numerical materials should show transfer to figural material, and the other way around. Additionally, differences between visual and verbal cognitive strategies could lead to differential transfer effects on working memory tasks. Eighty young adults received training on two working memory operations: storage and processing, and relational integration with four different materials verbal/numerical/figural /figural, and another 17 served as active control group and 8 as passive group. Before and after 12 days of adaptive training, performance on the storage and processing, and on the relational integration tasks was assessed. Linear-mixed effects modeling revealed four important findings. First, following training, there were reliable improvements on the performance of trained storage and processing, and relational integration tasks, compared to the active control group. However, such training did not generalize to measures of the same working memory operation with different materials in most cases. Second, the only transfer effect was observed between numerical and figural material within relational integration tasks, thereby confirming our hypothesis. Third, no transfer was detected between storage and processing, and relational integration. Finally, there was no direct evidence supporting the influence of cognitive strategies on transfer effects. Together, the present findings provide strong evidence for growing theories of multitasking behavior and working memory training, emphasizing the importance of cognitive underpinnings of multitasking behavior and specifying the efficacy of working memory intervention only on material-specific tasks, which may be emerged from the acquisition of task-specific cognitive strategies. Although the current investigation did not yet provide clear evidence about the strategic approach, the combination of material-specific mechanisms with a general boost in the underlying cognitive strategies provides an important and interesting perspective for future work. (shrink)