Because of enduring experience of managing two languages, bilinguals have been argued to develop superior executive functioning compared with monolinguals. Despite extensive investigation, there is, ...however, no consensus regarding the existence of such a bilingual advantage. Here we synthesized comparisons of bilinguals' and monolinguals' performance in six executive domains using 891 effect sizes from 152 studies on adults. We also included unpublished data, and considered the potential influence of a number of study-, task-, and participant-related variables. Before correcting estimates for observed publication bias, our analyses revealed a very small bilingual advantage for inhibition, shifting, and working memory, but not for monitoring or attention. No evidence for a bilingual advantage remained after correcting for bias. For verbal fluency, our analyses indicated a small bilingual disadvantage, possibly reflecting less exposure for each individual language when using two languages in a balanced manner. Moreover, moderator analyses did not support theoretical presuppositions concerning the bilingual advantage. We conclude that the available evidence does not provide systematic support for the widely held notion that bilingualism is associated with benefits in cognitive control functions in adults.
Public Significance Statement
The idea that bilinguals outperform monolinguals in cognitive control functions seems to have already been accepted by the popular media and educators, because of a number of influential studies reporting a bilingual advantage. Our thorough meta-analysis, however, suggests that healthy bilingual adults do not have such a cognitive control advantage. The synthesis of 152 studies and 891 comparisons and several moderator variables does not show systematic advantages across the analyzed cognitive domains, tasks, or bilingual populations.
Recent findings suggest that executive function (EF) plays a critical role in the regulation of gait in older adults, especially under complex and challenging conditions, and that EF deficits may, ...therefore, contribute to fall risk. The objective of this study was to evaluate if reduced EF is a risk factor for future falls over the course of 5 years of follow-up. Secondary objectives were to assess whether single and dual task walking abilities, an alternative window into EF, were associated with fall risk.
We longitudinally followed 256 community-living older adults (age: 76.4±4.5 yrs; 61% women) who were dementia free and had good mobility upon entrance into the study. At baseline, a computerized cognitive battery generated an index of EF, attention, a closely related construct, and other cognitive domains. Gait was assessed during single and dual task conditions. Falls data were collected prospectively using monthly calendars. Negative binomial regression quantified risk ratios (RR). After adjusting for age, gender and the number of falls in the year prior to the study, only the EF index (RR: .85; CI: .74-.98, p = .021), the attention index (RR: .84; CI: .75-.94, p = .002) and dual tasking gait variability (RR: 1.11; CI: 1.01-1.23; p = .027) were associated with future fall risk. Other cognitive function measures were not related to falls. Survival analyses indicated that subjects with the lowest EF scores were more likely to fall sooner and more likely to experience multiple falls during the 66 months of follow-up (p<0.02).
These findings demonstrate that among community-living older adults, the risk of future falls was predicted by performance on EF and attention tests conducted 5 years earlier. The present results link falls among older adults to cognition, indicating that screening EF will likely enhance fall risk assessment, and that treatment of EF may reduce fall risk.
In the present meta-analysis all available evidence regarding the efficacy of different behavioral interventions for children's executive function skills were synthesized. After a systematic search ...we included experimental studies aiming to enhance children's (up to 12 years of age) executive functioning with neurodevelopmental tests as outcome measures. The results of 100 independent effect sizes in 90 studies including data of 8,925 children confirmed that it is possible to foster these skills in childhood (Diamond & Lee, 2011). We did not find convincing evidence, however, for the benefits to remain on follow-up assessment. Different approaches were effective for typically and nontypically developing samples. For nontypically developing children (including children with neurodevelopmental disorders or behavior problems) acquiring new strategies of self-regulation including biofeedback-enhanced relaxation and strategy teaching programs were the most effective. For typically developing children we found evidence for the moderate beneficial effects of mindfulness practices. Although small to moderate effects of explicit training with tasks loading on executive function skills in the form of computerized and noncomputer training were found, these effects were consistently weaker for nontypically developing children who might actually be more in need of such training. Thus, atypically developing children seem to profit more from acquiring new strategies of self-regulation as compared with practice with executive function tasks. We propose that explicit training does not seem to be meaningful as the approaches that implicitly foster executive functions are similarly or more effective, and these activities are more enjoyable and can be more easily embedded in children's everyday activities.
Public Significance Statement
The present meta-analysis evidences the efficacy of implicit approaches to fostering children's executive function skills over explicit training, highlighting specifically the benefits of interventions that provide children with strategies of self-regulation. More specifically, the evidence points to the potential of mindfulness practices for typically developing samples and that of biofeedback-enhanced relaxation and strategy teaching programs for atypically developing children.
Background: Habit formation is theorized to be a critical component for behavioral weight loss (BWL). That is, as core weight loss behaviors become increasingly automatic, they are more likely to ...persist, even in the absence of motivational or conscious processes. Previous studies have shown that physical activity (PA) and self-weighing (SW) are key behaviors for achieving clinically meaningful weight loss. However, it remains unclear how habits for PA and SW are established over the course of online BWL intervention. Also, while executive function (EF) is linked to overweight/obesity and BWL intervention outcomes, it is not known whether EF impacts the development of habits. This study established habit automaticity for PA and SW at pre- and post-treatment in an online BWL intervention, examined the associations between changes in habit automaticity for PA and SW and weight loss, and explored the role EF plays in habit formation. Methods: Participants (N=754, 83% female, age 50.65±12.02 years, BMI 34.70±5.61 kg/m2) enrolled in a 4-month online BWL intervention. The Self-Report Behavioral Automaticity Index (SRBAI) and the Behavior Rating Inventory of Executive Function for Adults Self Report Form (BRIEF-A) measured habit automaticity for PA and SW and EF, respectively. Weight was objectively assessed. Results: Automaticity for PA and SW habits increased during the intervention (ps <.001) and these increases were associated with greater percent weight loss for both PA (p =.045) and SW (p <.001). EF did not predict changes in habit automaticity for either PA or SW, but was associated with baseline and 4-month PA habit automaticity (ps <.001). Conclusions: Establishing habits for PA and SW was associated with better weight loss outcomes among individuals in an online BWL program. EF was associated with habit automaticity for PA but not SW, perhaps because forming PA habits requires greater executive control compared to SW. Additional research is needed to understand if, and how, habits are sustained during weight loss maintenance.
Children and adolescents with critical cyanotic congenital heart disease (CHD) are at risk for deficits in aspects of executive function (EF). The primary aim of this investigation was to compare EF ...outcomes in three groups of children/adolescents with severe CHD and controls (ages 10-19 years). Participants included 463 children/adolescents with CHD dextro-transposition of the great arteries (TGA), n=139; tetralogy of Fallot (TOF), n=68; and, single-ventricle anatomy requiring Fontan procedure (SVF), n=145 and 111 controls, who underwent laboratory and informant-based evaluation of EF skills. Rates of EF impairment on D-KEFS measures were nearly twice as high for CHD groups (75-81%) than controls (43%). Distinct EF profiles were documented between CHD groups on D-KEFS tasks. Deficits in flexibility/problem-solving and verbally mediated EF skills were documented in all three CHD groups; visuo-spatially mediated EF abilities were impaired in TOF and SVF groups, but preserved in TGA. Parent, teacher, and self-report ratings on the BRIEF highlighted unique patterns of metacognitive and self-regulatory concerns across informants. CHD poses a serious threat to EF development. Greater severity of CHD is associated with worse EF outcomes. With increased understanding of the cognitive and self-regulatory vulnerabilities experienced by children and adolescents with CHD, it may be possible to identify risks early and provide individualized supports to promote optimal neurodevelopment.
•Cold EF rely on Central-Executive Network, specifically left DLPFC activation.•Hot EF rely on Default Mode Network and central-executive network, benefitting from both left DLPFC and right OFC ...activation.•Inhibitory control and risk taking are the coldest and hottest EF domains respectively.•EF are on a continuum with cold and hot domains related to lateral and mesial prefrontal areas.•None of EF domains are purely cold or purely hot.
An organizing principle which has recently emerged proposes that executive functions (EF) can be divided into cognitive (cold) and affective/reward-related (hot) processes related to the dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) respectively. A controversial question is whether cold and hot EF are functionally and structurally independent or not. This study investigated how the left DLPFC (l-DLPFC) and right OFC (r-OFC) interact in hot and cold EF using transcranial direct current stimulation (tDCS). Twenty-four healthy male subjects received anodal, cathodal and sham tDCS (20 min, 1.5 mA) over the l-DLPFC (F3) and r-OFC (Fp2) with a 72-h interval between each stimulation condition. After five minutes of stimulation, participants underwent a series of cold and hot EF tasks including the Go/No-Go and Tower of Hanoi (TOH) as measures of cold EF and the BART and temporal discounting tasks as measures of hot EF. Inhibitory control mostly benefited from anodal l-DLPFC/cathodal r-OFC tDCS. Planning and problem solving were more prominently affected by anodal l-DLPFC/cathodal r-OFC stimulation, although the reversed electrode position with the anode positioned over the r-OFC also affected some aspects of task performance. Risk-taking behavior and risky decision-making decreased under both anodal l-DLPFC/cathodal r-OFC and anodal r-OFC/cathodal l-DLPFC tDCS. Cold EF rely on DLPFC activation while hot EF rely on both, DLPFC and OFC activation. Results suggest that EF are placed on continuum with lateral and mesial prefrontal areas contributing to cold and hot aspects respectively.
A theoretical distinction exists between the cool and hot aspects of executive function (EF). At the neural level, cool EF may be associated with activation in the lateral prefrontal cortex and the ...anterior cingulate cortex, whereas the orbitofrontal cortex may play a key role in hot EF. However, some recent studies have shown that young children show activity in the lateral prefrontal regions during hot EF tasks, suggesting that the distinction between hot and cool EF may not be as marked. Nevertheless, few neuroimaging studies have directly examined the relationship between cool and hot EF. In this study, preschool children (N = 46, mean age = 66.1 months) were given both cool (Dimensional Change Card Sort (DCCS) and Stroop‐like tasks) and hot (delay of gratification) EF tasks, and neural activation during these tasks was measured using functional near‐infrared spectroscopy (fNIRS). Correlational analyses and analysis of variance (ANOVA) were conducted to assess the relationship between cool and hot EF. At the behavioral level, a moderate correlation was found between DCCS and Stroop‐like tasks, but no correlation emerged between cool and hot EF tasks. At the neural level, prefrontal activations during the cool EF tasks did not correlate with those during the hot EF task. Further, children showed stronger prefrontal activations during the DCCS tasks compared to the delay of gratification tasks. The results suggest that the neural basis of hot and cool EF may differ during early childhood.
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.
Background: Impulsivity has been implicated in refractory obesity. The dorsolateral prefrontal cortex (DLPFC) may counterbalance overactive brain reward by enhancing executive function (EF), ...including impulse control, mitigating loss-of-control eating. Galioto found that EF predicted weight-1 oss in structured medical weightloss programs (Galioto 2016). Cognitive training (CT) monotherapy for EF improvement has not shown sufficient therapeutic promise nor has DLPFC-directed transcranial direct current stimulation (tDCS), but coupled, they may enhance EF. The aim of this study was to determine if tDCS coupled with computerized CT decreased impulsivity in individuals with obesity. Methods: In this pilot randomized double-blind study of sham vs. active tDCS (five days, 25 minutes, 2mA); 17 participants completed stimulation initially and NIH Examiner tasks (flanker, set shifting, dot counting and unstructured planning) four times during the 4-month study. Results: The active group (8 men/1 woman) had age (mean +/- standard deviation SD) of 56.5 years (+/-13.2); sham (6 men/3 women) was 58.8 (+/-12.4). The NIH Flanker measures the inhibitory control domain of EF, related to impulsivity. Flanker total mean reaction time, (p = .057, t-test, and p = .006, median difference test from quantile regression), was higher with treatment, indicating less impulsivity. Stratified by baseline weight, set shifting score, especially with higher weight, was greater with treatment compared to sham (p = 0.043) at end-study, reflective of greater treatment-related cognitive flexibility. In this pandemic-shortened pilot, we did not see treatment effects on weight, dot counting or unstructured planning. Conclusions: DLPFC-directed-tDCS coupled with CT may decrease impulsivity and enhance cognitive flexibility in individuals with obesity. Our preliminary impulsivity and brain reward-related work has transdiagnostic application; it may inform understanding and management of other addictive, impulsive behaviors.
Concepts of cognitive control (CC) and executive function (EF) are defined in terms of their relationships with goal-directed behavior versus habits and controlled versus automatic processing, and ...related to the functions of the prefrontal cortex (PFC) and related regions and networks. A psychometric approach shows unity and diversity in CC constructs, with 3 components in the most commonly studied constructs: general or common CC and components specific to mental set shifting and working memory updating. These constructs are considered against the cellular and systems neurobiology of PFC and what is known of its functional neuroanatomical or network organization based on lesioning, neurochemical, and neuroimaging approaches across species. CC is also considered in the context of motivation, as "cool" and "hot" forms. Its Common CC component is shown to be distinct from general intelligence (g) and closely related to response inhibition. Impairments in CC are considered as possible causes of psychiatric symptoms and consequences of disorders. The relationships of CC with the general factor of psychopathology (p) and dimensional constructs such as impulsivity in large scale developmental and adult populations are considered, as well as implications for genetic studies and RDoC approaches to psychiatric classification.
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