The effects of computerized cognitive training in older adults' cognitive performance and biomarkers of structural brain aging.

OBJECTIVES: Cognitive Training (CT) has been investigated as a means of delaying age-related cognitive decline in older adults. However, its impact on biomarkers of age-related structural brain atrophy has rarely been investigated, leading to a gap in our understanding of the linkage between improvements in cognition and brain plasticity. This study aimed to explore the impact of CT on cognitive performance and brain structure in older adults. METHODS: 124 cognitively normal older adults recruited from two study sites were randomly assigned to either an adaptive CT (n=60) or a casual game training (Active Control, AC, n= 64). RESULTS: After 10 weeks of training, CT participants showed greater improvements in the overall cognitive composite score (Cohen's d=.66, p<.01) with non-significant benefits after 6 months from the completion of training (Cohen's d=.36, p=.094). The CT group showed significant maintenance of the caudate volume as well as significant maintained fractional anisotropy (FA) in the left Internal Capsule (IC) and in left Superior Longitudinal Fasciculus (SLF) compared to the AC group. The AC group displayed an age-related decrease in these metrics of brain structure. DISCUSSION: Results from this multi-site clinical trial demonstrate that the CT intervention improves cognitive performance and helps maintain caudate volume and integrity of white matter regions that are associated with cognitive control, adding to our understanding of the changes in brain structure contributing to changes in cognitive performance from adaptive CT.

A game-factors approach to cognitive benefits from video-game training: A meta-analysis.

This current study is a meta-analysis conducted on 63 studies on video-game based cognitive interventions (118 investigations, N = 2,079), which demonstrated a moderate and significant training effect on overall gains in cognition, g = 0.25, p < .001. Significant evidence of transfer was found to overall cognition, as well as to attention/perception and higher-order cognition constructs. Examination of specific gameplay features however showed selective and differential transfer to these outcome measures, whereas the genre labels of "action", "strategy", "casual", and "non-casual" were not similarly predictive of outcomes. We therefore recommend that future video-game interventions targeting cognitive enhancements should consider gameplay feature classification approach over existing genre classification, which may provide more fruitful training-related benefits to cognition.

Influence of Strenuous Physical Activity and Cardiorespiratory Fitness on Age-Related Differences in Brain Activations During Varieties of Cognitive Control.

While there is extensive literature on the beneficial effects of physical activity on age differences in cognitive control, limited research exists on comparing the contributions of strenuous physical activity (sPA) and cardiorespiratory fitness (CRF) to fluctuations in the blood oxygen level-dependent (BOLD) signals during varieties of cognitive control. The current study addresses this gap in knowledge by investigating BOLD signal differences between high-fit and low-fit older adults, determined by their sPA or CRF, during a novel fMRI task with a hybrid block and event-related design that included transient activations (during switching, updating and their combination trials) and sustained activations (during proactive and reactive control blocks). fBOLD signals from older (n = 25) were compared to more functionally efficient younger (n = 15) adults. High-sPA old showed higher task accuracy than Low-sPA old and similar accuracy as young. Whole-brain fMRI analyses identified higher BOLD activations (esp. dlPFC/MFG) in high-fit old during updating and combination trials that were similar to young, suggesting maintenance of BOLD signals in higher fit older adults during working memory updating. Additionally, both High-sPA and High-CRF related compensatory overactivation were observed in left parietal and occipital areas during sustained activations, which were positively correlated with older adults' accuracy. These results suggest that physical fitness is a modifier of age-related changes in BOLD signal modulation elicited in response to increasing cognitive control demands, with higher fitness in old contributing to both compensatory overactivations and maintenance of task-related brain activations during cognitive control, whereas lower fitness contributed to maladaptive overactivations during lower cognitive demands.

Cognitive and structural predictors of novel task learning, and contextual predictors of time series of daily task performance during the learning period.

Investigation into methods of addressing cognitive loss exhibited later in life is of paramount importance to the field of cognitive aging. The field continues to make significant strides in designing efficacious cognitive interventions to mitigate cognitive decline, and the very act of learning a demanding task has been implicated as a potential mechanism of augmenting cognition in both the field of cognitive intervention and studies of cognitive reserve. The present study examines individual-level predictors of complex skill learning and day-to-day performance on a gamified working memory updating task, the BirdWatch Game, intended for use as a cognitive intervention tool in older adults. A measure of verbal episodic memory and the volume of a brain region involved in verbal working memory and cognitive control (the left inferior frontal gyrus) were identified as predictors of learning rates on the BirdWatch Game. These two neuro-cognitive measures were more predictive of learning when considered in conjunction than when considered separately, indicating a complementary effect. Additionally, auto-regressive time series forecasting analyses were able to identify meaningful daily predictors (that is, mood, stress, busyness, and hours of sleep) of performance-over-time on the BirdWatch Game in 50% of cases, with the specific pattern of contextual influences on performance being highly idiosyncratic between participants. These results highlight the specific contribution of language processing and cognitive control abilities to the learning of the novel task examined in this study, as well as the variability of subject-level influences on task performance during task learning.

Fitness and arterial stiffness in healthy aging: Modifiable cardiovascular risk factors contribute to altered default mode network patterns during executive function.

Increases in cardiovascular risks such as high blood pressure and low physical fitness have been independently associated with altered default mode network (DMN) activation patterns in healthy aging. However, cardiovascular risk is a multidimensional health problem. Therefore, we need to investigate multiple cardiovascular risk factors and their contributions to cognition and DMN activations in older adults, which has not yet been done. The current fMRI study examined contributions of two common modifiable cardiovascular risk factors (arterial stiffness and physical fitness) on DMN activations involved during random n-back, a task of executive functioning and working memory, in older adults. The results show that high cardiovascular risk of either increased arterial stiffness or decreased fitness independently contributed to worse task performance and reduced deactivations in two DMN regions: the anterior and posterior cingulate cortices. We then examined not only the potential interaction between the two risk factors, but also their additive (i.e., combined) effect on performance and DMN deactivations. A significant interaction between the two cardiovascular risk factors was observed on performance, with arterial stiffness moderating the relationship between physical fitness and random n-back accuracy. The additive effect of the two factors on task performance was driven by arterial stiffness. Arterial stiffness was also found to be the driving factor when the additive effect of the two risk factors was examined on DMN deactivations. However, in posterior cingulate cortex, a hub region of the DMN, the additive effect on its deactivation was significantly higher than the effect of each risk factor alone. These results suggest that the effects of cardiovascular risks on the aging brain are complicated and multi-dimensional, with arterial stiffness moderating or driving the combined effects on performance and anterior DMN deactivations, but physical fitness contributing additional effect to posterior DMN deactivation during executive functioning.

Comparing the Effects of Two Cardiovascular Health Factors on Working Memory Capacity in Healthy Aging: Separate and Combined Effects of Arterial Elasticity and Physical Fitness.

OBJECTIVES: Arterial elasticity and physical fitness are 2 important cardiovascular health factors that influence cognition in older adults. Working memory capacity (WMC), a core component underlying cognitive aging across many cognitive domains, may be affected by individual differences in cardiovascular health in older adults. This study aims to identify in older adults: (a) separate and combined effects of these 2 cardiovascular health factors on WMC and (b) which of the 2 factors is more critical in influencing WMC. METHODS: WMC in 89 healthy older adults was assessed by 2 complex span tasks. Arterial elasticity was assessed by pulse pressure (PsP). Physical fitness was measured by an established proxy of VO2 max (MET). Effects of PsP and MET on WMC were evaluated via step-wise regressions. RESULTS: After controlling for age, sex, and education, PsP and MET were separately predictive of WMC in older adults. Together, the combined effect of PsP and MET was more predictive of WMC than fitness alone, but not more than PsP alone. Mediation analysis indicates that the relationship between MET and WMC was completely mediated by PsP. DISCUSSION: This study innovatively demonstrates that though arterial elasticity and physical fitness separately predict WMC, the former completely mediates the relationship between fitness and WMC. This suggests that biologically based cardiovascular health factors like arterial elasticity are crucial individual difference variables that should be measured and monitored in cognitive aging studies as well as in physical interventions that are designed to improve cognition in healthy aging.

Are the advantages of chess expertise on visuo-spatial working-memory capacity domain specific or domain general?

Chess experts have repeatedly demonstrated exceptional recall of chessboards, which is weakened by disruption of the chessboard. However, chess experts still perform better than novices when recalling such disrupted chessboards, suggesting a somewhat generalized expertise effect. In the current study, we examined the extent of this generalized expertise effect on early processing of visuo-spatial working memory (VSWM), by comparing 14 chess experts (Elo rating > 2000) and 15 novices on a change-detection paradigm using disrupted chessboards, where attention had to be selectively deployed to either visual or spatial features, or divided across both features. The paradigm differed in the stimuli used (domain-specific chess pieces vs. novel visual shapes) to evaluate domain-general effects of chess expertise. Both experts and novices had greater memory discriminability for chess stimuli than for the unfamiliar stimuli, suggesting a salience advantage for familiar stimuli. Experts, however, demonstrated better memory discriminability than novices not only for chess stimuli presented on these disrupted chessboards, but also for novel, domain-general stimuli, particularly when detecting spatial changes. This expertise advantage was greater for chessboards with supra-capacity set sizes. For set sizes within the working-memory capacity, the expertise advantage was driven by enhanced selective attention to spatial features by chess experts when compared to visual features. However, any expertise-related VSWM advantage disappeared in the absence of the 8 × 8 chessboard display, which implicates the chessboard display as an essential perceptual aspect facilitating the "expert memory effect" in chess, albeit one that might generalize beyond strictly domain-relevant stimuli.

Corrigendum: Past Gaming Experience and Cognition as Selective Predictors of Novel Game Learning Across Different Gaming Genres.

[This corrects the article DOI: 10.3389/fpsyg.2020.00786.].

Tracking Changes in Frontal Lobe Hemodynamic Response in Individual Adults With Developmental Language Disorder Following HD tDCS Enhanced Phonological Working Memory Training: An fNIRS Feasibility Study.

Background: Current research suggests a neurobiological marker of developmental language disorder (DLD) in adolescents and young adults may be an atypical neural profile coupled with behavioral performance that overlaps with that of normal controls. Although many imaging techniques are not suitable for the study of speech and language processing in DLD populations, fNIRS may be a viable option. In this study we asked if fNIRS can be used to identify atypical cortical activation patterns in individual adults with DLD and track potential changes in cortical activation patterns following a phonological working memory training protocol enhanced with anodal HD tDCS stimulation to the presupplementary motor area (preSMA). Objective/Hypothesis: The purpose of this study was two-fold: (1) to determine if fNIRS can be used to identify atypical hemodynamic responses in individual young adults with DLD during active spoken word processing and, (2) to determine if fNIRS can detect changes in hemodynamic response in these same adults with DLD following anodal HD tDCS enhanced phonological working memory training. Methods: Two adult subjects with DLD (female, age 25) completed a total of two sessions of fNIRs working memory task prior to and following one session of a non-word repetition task paired with anodal HD tDCS (1.0 mA tDCS; 20 min) to the preSMA. Standardized z-scores of behavioral measures (accuracy and reaction time) and changes in hemodynamic response during an n-back working memory task for the two participants with DLD was compared to that of a normative sample of 21 age- and gender- matched normal controls (ages 18 to 25) prior to and following phonological working memory training. Results: Individual standardized z-scores for each participant with DLD indicated that prior to training, hemoglobin response in the prefrontal lobe for both participants was markedly different from each other and normal controls. Following training, standard scores showed that the hemodynamic response for both participants moved within normal limits for ROIs. Conclusion: These findings highlight the feasibility of fNIRS to establish individual differences in the link between behavior and neural patterns in single subjects with DLD, as well as track individual differences in changes in brain activity following working memory training.

Influence of Multiple Cardiovascular Risk Factors on Task-Switching in Older Adults: An fMRI Study.

Not only are the effects of cardiovascular risk factors such as high blood pressure and low fitness on executive functions and brain activations in older adults scarcely investigated, no fMRI study has investigated the combined effects of multiple risk factors on brain activations in older adults. This fMRI study examined the independent and combined effects of two cardiovascular risk factors, arterial plasticity, and physical fitness, on brain activations during task-switching in older adults. The effects of these two risk factors on age-related differences in activation between older and younger adults were also examined. Independently, low physical fitness and low arterial plasticity were related to reduced suppressions of occipital brain regions. The combined effects of these two risks on occipital regions were greater than the independent effects of either risk factor. Age-related overactivations in frontal cortex were observed in low fitness older adults. Brain-behavior correlation indicates that these frontal overactivations are maladaptive to older adults' task performance. It is possible that the resulting effects of cardiovascular risks on the aging brain, especially the maladaptive overactivations of frontal brain regions by high risk older adults, contribute to often found posterior-anterior shift in aging (PASA) brain activations. Furthermore, observed age-related differences in brain activations during task-switching can be partially attributed to individual differences in cardiovascular risks among older adults.

Past Gaming Experience and Cognition as Selective Predictors of Novel Game Learning Across Different Gaming Genres.

Past experience with video games and cognitive abilities have been hypothesized to independently facilitate a greater ability to learn new video games and other complex tasks. The present study was conducted to examine this "learning to learn" hypothesis. We examined the predictive effects of gaming habits (e.g., self-identification as a "gamer," hours spent gaming per week, weekly gaming frequency, relative preference for strategy over action games) and cognitive abilities (short-term memory, working memory, and processing speed) on learning of two novel video games in 107 participants (aged 18-77 years). One video game was from the action genre, and the other was from the strategy genre. Hours spent gaming per week and working memory were found to specifically predict learning of the novel strategy video game, after controlling for the effects of age, gender, and action game learning. In contrast, self-identification as a "gamer" was the only specific significant predictor of action game learning, after controlling for the effects of age, gender, and strategy game learning. Age of the participant negatively impacted learning of both games; however, the pattern of the predictive relationships on both action and strategy game learning was not moderated by age. Importantly, a preference for the action versus the strategy game genre had no differential effects on learning of the two novel games, nor were there any gender differences in identification as a gamer or genre preference. Findings from this study suggest that while past gaming experience and cognition do appear to influence the learning of novel video games, these effects are selective to the game genre studied and are not as broad as the "learning to learn" model suggests.

Differential effects of cognitive training modules in healthy aging and mild cognitive impairment: A comprehensive meta-analysis of randomized controlled trials.

This meta-analysis was designed to compare the effectiveness of 2 cognitive training modules, single-component training, which targets 1 specific cognitive ability, versus multicomponent training, which trains multiple cognitive abilities, on both trained abilities (near transfer) and untrained abilities (far transfer) in older adults. The meta-analysis also assessed whether individual differences in mental status interacted with the extent of transfer. Eligible randomized controlled trials (215 training studies) examined the immediate effects of cognitive training in either healthy aging (HA) or mild cognitive impairment (MCI). Results yielded an overall net-gain effect size (g) for the cognitive training of 0.28 (p < .001). These effects were similar across mental status and training modules, and were significant for both near (g = 0.37) and far (g = 0.22) transfer. Although all training modules yielded significant near transfer, only a few yielded significant far transfer. Single-component training of executive functions was most effective on near and far transfer, with processing speed training improving everyday functioning. All modules of multicomponent training (specific and nonspecific) yielded significant near and far transfer, including everyday functioning. Training effects on cognition were moderated by educational attainment and number of cognitive outcomes, but only in HA. These findings suggest that, in older adults, all modules of multicomponent training are more effective in engendering near and far transfer, including everyday functioning, when compared with single-component training modules. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Age-related differences in brain activation during working memory updating: An fMRI study.

Recent neuroimaging studies have reported an age-related reduction in brain activations in response to working memory load in task-sensitive brain regions. The current fMRI study investigated the age-related differences in brain activations of the updating mechanism in working memory, which was not investigated in previous studies. With a hybrid block/event-related design, this study was able to examine changes in BOLD signals (i.e., neuromodulation) to increase in updating, a type of cognitive control that is understudied. Older adults were separated into young-old and old-old cohorts to examine whether, within healthy aging, the neuromodulation to cognitive control decreases with age. Our results show that younger adults activate left precentral gyrus and right cerebellum more during trials that require updating than trials that do not require updating. Although older adults showed reduced neuromodulation in these two regions, the old-old cohort failed to show any significant neuromodulation in response to updating. Moreover, older adults not only showed reduced suppressions of the default mode network (DMN) regions during the task, they also overactivated some of the DMN regions, esp. the old-old, when compared to the younger adults. Older adults also showed overactivations in a region (right precentral gyrus) that is contralateral to a task-sensitive region that was activated in the younger adults during updating. Brain-behavior correlations suggest that age-related overactivations of these DMN regions and the right precentral gyrus are maladaptive to their performance. Our results suggest that not only the neuromodulation in response to updating demands is diminished in healthy aging, older adults also show maladaptive increases in activations of task-irrelevant regions and reduced hemispheric specificity during updating. These effects are most pronounced in old-old cohort, compared to young-old, suggesting that age-related declines in neuromodulation during cognitive control is more pronounced in older cohorts within healthy aging.

Functional magnetic neuroimaging data on age-related differences in task switching accuracy and reverse brain-behavior relationships.

The data presented in this article is related to the research article entitled "Age-related Differences in BOLD Modulation to Cognitive Control Costs in a Multitasking Paradigm: Global Switch, Local Switch, and Compatibility-Switch Costs" (Nashiro et al., 2018) [1]. This article describes age-related differences in accuracies for various cognitive costs incurred during task switching across three different age-cohorts: younger (18-35 years), younger-old (50-64 years) and older-old (65-80 years). The cognitive costs evaluated were global switch costs (GSC), local switch costs (LSC) and compatibility switch costs (CSC). Whole brain analyses were conducted to determine the brain regions sensitive to these cognitive costs, irrespective of age. Furthermore, age-related differences in brain-behavior relationships were evaluated by correlating activations from these regions with global switch costs, indexed by both response times and accuracies, for younger and older adults separately. Activations of age-sensitive regions during the task, where younger adults activated more than the combined groups of older adults, were also correlated with response times and accuracies to determine age-related differences in brain-behavior relationships of these under-recruited brain regions by older adults.

Effects of task complexity and age-differences on task-related functional connectivity of attentional networks.

Studies investigating the strength and membership of regions within multiple functional networks primarily focus on either resting state or single cognitive tasks. The goals of the current study were to investigate whether task-related functional connectivity changes with task complexity, and whether this connectivity-complexity relationship is age-sensitive. We assessed seed-to-voxel functional connectivity for the default mode network (DMN) and two attentional networks [cingulo-opercular (CO), fronto-parietal (FP)] in three cognitive control tasks of increasing complexity (Single task, Dual task, and Memory Updating), across younger and older adults (N = 52; NYoung = 23; NOld = 29). The three tasks systematically varied in cognitive control demands due to differing maintenance, switching, and updating requirements. Functional connectivity for all networks, resulting from task > rest contrasts, increased with greater task complexity, irrespective of age and gray matter volume. Moreover, between-network connectivity for DMN, CO, and FP regions was greatest for working memory updating, the most complex task. Regarding age-related differences in accuracy, none were observed for Single or Dual tasks, but older adults had poorer accuracy in Memory Updating. More anterior frontal clusters of functional connectivity were observed for older, compared to younger, adults; these were limited to seeds of the two attentional networks. Importantly, increased connectivity in these additional frontal regions in older adults were non-compensatory, because they were associated with detrimental task performance, especially Memory Updating. For the Memory Updating > Rest, the younger > older contrast resulted in greater DMN seed connectivity to regions in the other two attentional networks, implicating increased reliance on between-network connectivity for the DMN seeds during complex cognitive tasks. Our results also implicate functional connectivity between attentional networks and the cerebellum during cognitive control. Reliability of multiple seeds in the seed-to-voxel connectivity is also discussed.

Age-related differences in BOLD modulation to cognitive control costs in a multitasking paradigm: Global switch, local switch, and compatibility-switch costs.

It is well documented that older adults recruit additional brain regions compared to those recruited by younger adults while performing a wide variety of cognitive tasks. However, it is unclear how such age-related over-recruitment interacts with different types of cognitive control, and whether this over-recruitment is compensatory. To test this, we used a multitasking paradigm, which allowed us to examine age-related over-activation associated with three types of cognitive costs (i.e., global switch, local switch, compatibility-switch costs). We found age-related impairments in global switch cost (GSC), evidenced by slower response times for maintaining and coordinating two tasks vs. performing only one task. However, no age-related declines were observed in either local switch cost (LSC), a cognitive cost associated with switching between the two tasks while maintaining two task loads, or compatibility-switch cost (CSC), a cognitive cost associated with incompatible vs. compatible stimulus-response mappings across the two tasks. The fMRI analyses allowed for identification of distinct cognitive cost-sensitive brain regions associated with GSC and LSC. In fronto-parietal GSC and LSC regions, older adults' increased activations were associated with poorer performance (greater costs), whereas a reverse relationship was observed in younger adults. Older adults also recruited additional fronto-parietal brain regions outside the cognitive cost-sensitive areas, which was associated with poorer performance or no behavioral benefits. Our results suggest that older adults exhibit a combination of inefficient activation within cognitive cost-sensitive regions, specifically the GSC and LSC regions, and non-compensatory over-recruitment in age-sensitive regions. Age-related declines in global switching, compared to local switching, was observed earlier in old age at both neural and behavioral levels.

Evaluating the relationship between white matter integrity, cognition, and varieties of video game learning.

BACKGROUND: Many studies are currently researching the effects of video games, particularly in the domain of cognitive training. Great variability exists among video games however, and few studies have attempted to compare different types of video games. Little is known, for instance, about the cognitive processes or brain structures that underlie learning of different genres of video games. OBJECTIVE: To examine the cognitive and neural underpinnings of two different types of game learning in order to evaluate their common and separate correlates, with the hopes of informing future intervention research. METHODS: Participants (31 younger adults and 31 older adults) completed an extensive cognitive battery and played two different genres of video games, one action game and one strategy game, for 1.5 hours each. DTI scans were acquired for each participant, and regional fractional anisotropy (FA) values were extracted using the JHU atlas. RESULTS: Behavioral results indicated that better performance on tasks of working memory and perceptual discrimination was related to enhanced learning in both games, even after controlling for age, whereas better performance on a perceptual speed task was uniquely related with enhanced learning of the strategy game. DTI results indicated that white matter FA in the right fornix/stria terminalis was correlated with action game learning, whereas white matter FA in the left cingulum/hippocampus was correlated with strategy game learning, even after controlling for age. CONCLUSION: Although cognition, to a large extent, was a common predictor of both types of game learning, regional white matter FA could separately predict action and strategy game learning. Given the neural and cognitive correlates of strategy game learning, strategy games may provide a more beneficial training tool for adults suffering from memory-related disorders or declines in processing speed, particularly older adults.

Illusory conjunctions in visual short-term memory: Individual differences in corpus callosum connectivity and splitting attention between the two hemifields.

Overloading the capacity of visual attention can result in mistakenly combining the various features of an object, that is, illusory conjunctions. We hypothesize that if the two hemispheres separately process visual information by splitting attention, connectivity of corpus callosum-a brain structure integrating the two hemispheres-would predict the degree of illusory conjunctions. In the current study, we assessed two types of illusory conjunctions using a memory-scanning paradigm; the features were either presented across the two opposite hemifields or within the same hemifield. Four objects, each with two visual features, were briefly presented together followed by a probe-recognition and a confidence rating for the recognition accuracy. MRI scans were also obtained. Results indicated that successful recollection during probe recognition was better for across hemifields conjunctions compared to within hemifield conjunctions, lending support to the bilateral advantage of the two hemispheres in visual short-term memory. Age-related differences regarding the underlying mechanisms of the bilateral advantage indicated greater reliance on recollection-based processing in young and on familiarity-based processing in old. Moreover, the integrity of the posterior corpus callosum was more predictive of opposite hemifield illusory conjunctions compared to within hemifield illusory conjunctions, even after controlling for age. That is, individuals with lesser posterior corpus callosum connectivity had better recognition for objects when their features were recombined from the opposite hemifields than from the same hemifield. This study is the first to investigate the role of the corpus callosum in splitting attention between versus within hemifields.