General Executive Control Research Articles

Inhibitory Control Partially Mediates the Relationship between Metalinguistic Awareness and Perspective-Taking.

Increased metalinguistic awareness (MLA) has been associated with improved performance in tasks of theory of mind; researchers have proposed that individuals with increased MLA, such as bilinguals, rely on metalinguistic skills when completing tasks that require taking other people's perspective into account compared to other individuals who mostly rely on general executive control to complete the same tasks. MLA would, therefore, act as a less effortful path to understanding other perspectives, especially when they differ from one's own. However, the evidence underlying this claim is scant and largely limited to children's theoretical frameworks. In this study, we investigated whether individual differences in MLA predict perspective-taking Theory of Mind above and beyond inhibitory control in a sample of diverse adults across a wide range of linguistic, socioeconomic, and cognitive factors. Bootstrapped mediation analyses revealed that inhibitory control partially, but not fully, mediated the relationship between MLA and perspective-taking. In addition, when differences in language, education and culture were controlled for, the effects of both MLA and inhibitory control were reduced. Overall, the findings emphasize the need to consider multivariate approaches towards understanding the mechanisms underlying theory of mind.

The link between executive skills and neural dynamics during encoding, inhibition, and retrieval of visual information in the elderly.

During aging the inter-individual variability in both the neural and behavioral functions is likely to be emphasized. Decreased competence particularly in working memory and general executive control compromises many aspects of the quality of life also within the nonclinical population. We aimed, first, to clarify the brain basis of visual working memory and inhibition during multi-stage natural-like task performance, and second, to identify associations between variation in task-related neural activity and relevant cognitive skills, namely inhibition and general working memory capacity. We recorded, using magnetoencephalography (MEG), the neural modulations associated with encoding, maintenance, and retrieval, as well as interference suppression during a visual working memory task in older adults. We quantified the neural correlates of these cognitive processes through two complementary approaches: evoked responses and oscillatory activity. Neural activity during memory retrieval and interference suppression were correlated with behavioral measures of task switching and general executive functions. Our results show that general inhibitory control induced frontocentral neural modulation across a broad range of frequencies whereas domain-specific inhibition was limited to right posterior areas. Our findings also suggest that modulations particularly in phase-locked evoked neural activity can be reliably associated with explicit measures of cognitive skills, with better inhibitory control linked with an early neural effect of distractor inhibition during retrieval. In general, we show that exploiting the inherent inter-individual variability in neural measures and behavioral markers of cognition in aging populations can help establish reliable links between specific brain functions and their behavioral manifestations.

The Difference between Monolingual and Bilingual Stutterers: A Systematic Review

The article is a comprehensive review regarding group differences of brain structures, cognitive process, and emotional responses between monolingual people who stutter (MWS) and bilingual people who stutter (BWS). Until now, researchers have been examining MWS and BWS separately, yet the compare between these two groups of people is lacking. In this work, the overview of MWS and BWS are introduced, different types and traits of stutter between MWS and BWS are compared, and the differences between brain structure, executive force, motor control, and cognitive reserve are investigated and synthesized based on previous studies. Both MWS and BWS have executive deficits in speech motor control, while BWS seem to be classified as having greater potential in language inhibitory and switching, thus transferring to general executive control. The conclusions are that BWS generally experience increased neural connectivity due to larger volume of grey and white matter than MWS, and thus gaining cognitive control abilities. Further research is warranted for the bilingual advantage and the exact etiology for stuttering.

Cognitive Dysfunction of Chikungunya Virus Infection in Older Adults.

BackgroundChikungunya fever is a disabling articular disease caused by chikungunya virus (CHIKV). In the past decade it has affected millions of people across America, Africa, Asia, and Europe, turning this infection into a public health concern. The acute phase of chikungunya infection is usually self-limiting, characterized by severe arthralgia, fever, chills, myalgia, headache, and rash. CHIKV neurovirulence is evident and seems to be higher among elders. Considering their susceptibility to cognitive decline and dementia, the aim of our study was to investigate whether CHIKV infection might cause long-term cognitive impairment in aged people.MethodsA cross-sectional study was conducted with volunteers aged from 60 to 90 who had been affected by chikungunya and also with healthy controls. A structured questionnaire was used to record demographic and clinical data, functional status, and depression. Global cognitive function was assessed through MoCA. A comprehensive neuropsychological battery was performed to assess specific cognitive functions.ResultsSubjective memory complaints were present in 70% of subjects with previous chikungunya. This group had a poorer performance in MoCA (p = 0.000) and specific cognitive tests: Semantic (p = 0.05) and Phonemic Verbal Fluency (p = 0.003), 5-Digit (choice, reading, counting and alternance, p = 0.003, p = 0.014, p = 0.021, and p = 0.021, respectively), Stroop test (time, errors and interference, p = 0.000, p = 0.027 and p = 0.015, respectively), and RAVLT (word total session p = 0.05). These tests reflect performance on general executive functions, cognitive flexibility, inhibitory control, processing speed, semantic memory and episodic memory.ConclusionOur data suggest that CHIKV infection may cause long-term cognitive decline in aged people and might be a risk factor for future dementia in this population.

Cognitive and Psychosocial Outcomes of Self-Guided Executive Function Training and Low-Intensity Aerobic Exercise in Healthy Older Adults.

ObjectivesPrior work has demonstrated that executive function training or physical exercise can improve older adults’ cognition. The current study takes an exploratory approach to compare the feasibility and efficacy of online executive function training and low-intensity aerobic exercise for improving cognitive and psychosocial functioning in healthy older adults.MethodFollowing a standard pretest-training-posttest protocol, 40 older adults (aged 65 and above) were randomly assigned to an executive function or a physical training group. A battery of cognitive and psychosocial outcome measures were administered before and after training. During the 10 weeks of self-guided training at home (25–30 min/day, 4 days/week), the executive function training group practiced a set of adaptive online executive function tasks designed by Lumos Labs, whereas the physical training group completed an adaptive Digital Video Disc (DVD)-based low-intensity aerobic exercise program.ResultsTraining transfer effects were limited. Relative to low-intensity aerobic exercise, executive function training yielded cognitive improvement on the 64-card Wisconsin Card Sorting Task (WCST-64), a general executive function measure. Depression and stress levels dropped following both training programs, but this could be driven by decreased stress or excitement in performing the tasks over time.DiscussionThe results revealed limited cognitive benefits of the online executive function training program, specifically to a near transfer test of general executive control. Importantly, the current study supports the feasibility of home-based self-guided executive function and low-intensity physical training with healthy older adults.

Differences between young and older adults in unity and diversity of executive functions

ABSTRACT Miyake and colleagues (2000) identified three independent but correlated components of executive function in young adults – set shifting, inhibition, and updating. The present study compared the factor structure in young adults to two groups of older adults (ages 60–73 and 74–98). A three-factor model of shifting, inhibition and updating was confirmed in young adults, but the factors were weakly or uncorrelated. In both older groups, a two-factor solution was indicated, updating/inhibition and shifting, which were moderately correlated in young-older adults, and strongly correlated in the old-older group. A nested factors model in the oldest group revealed a common factor, which loaded on all but one of the tests, and a shifting-specific factor. We concluded that in young adulthood, shifting, updating and inhibition may operate relatively independently. As people age and processing becomes less efficient, they may rely increasingly on general executive control processes, reallocating their limited resources to optimize performance.

Randomized, crossover, sham-controlled, double-blind study of transcranial direct current stimulation of left DLPFC on executive functions .

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique commonly used to modulate cognitive functions; so-called "anodal" stimulation is considered to increase cortical excitability while "cathodal" stimulation is presumed to have the opposite result. Yet, a growing number of recent studies question the robustness of this polarity-dependent effect, namely because of the important inter-individual variability with regards to tDCS modulatory effects. A plausible reason for this heterogenous response may lay in task impurity issues in the evaluation of cognitive functions. To address the question of task impurity the NIH-Examiner, a neuropsychological test battery that uses latent variables, which assess the common variance across multiple measures of a given concept, was administered to 24 healthy individuals following tDCS. This battery contains 11 tasks and provides latent variables for general executive functioning, fluency, cognitive control and working memory. Anodal, cathodal, and sham stimulation (20 minutes, 1.5 mA) was administered over left dorsolateral prefrontal cortex and right supra-orbital area in a randomized, crossover, sham-controlled, double blind protocol. Factorial scores and task performance indices of executive function were not modulated by tDCS. Offline tDCS has limited impact on executive functions at both the task and factorial levels. This suggests that reducing task impurity does not increase the effectiveness of tDCS in modulating cognitive functions.

Enhanced food-related responses in the ventral medial prefrontal cortex in narcolepsy type 1

Narcolepsy type 1 is a chronic sleep disorder caused by a deficiency of the orexin (hypocretin) neuropeptides. In addition to sleep regulation, orexin is important for motivated control processes. Weight gain and obesity are common in narcolepsy. However, the neurocognitive processes associated with food-related control and overeating in narcolepsy are unknown. We explored the neural correlates of general and food-related attentional control in narcolepsy-type-1 patients (n = 23) and healthy BMI-matched controls (n = 20). We measured attentional bias to food words with a Food Stroop task and general executive control with a Classic Stroop task during fMRI. Moreover, using multiple linear regression, we assessed the relative contribution of neural responses during Food Stroop and Classic Stroop to spontaneous snack intake. Relative to healthy controls, narcolepsy patients showed enhanced ventral medial prefrontal cortex responses and connectivity with motor cortex during the Food Stroop task, but attenuated dorsal medial prefrontal cortex responses during the Classic Stroop task. Moreover, the former activity but not the latter, was a significant predictor of spontaneous snack intake. These findings demonstrate that narcolepsy, characterized by orexin deficiency, is associated with decreased dorsal medial prefrontal cortex responses during general executive control and enhanced ventral medial prefrontal cortex responses during food-driven attention.

Dual roles of the hippocampus and intraparietal sulcus in network integration and segregation support scene recognition.

Effectively recognizing surroundings is a critical ability in human navigation. Previous neuroimaging studies have depicted distributed brain regions underpinning spatial navigation, but little is known about how these regions are formed into the navigation network (NN) supporting scene recognition. In this study, we addressed this issue by using a voxel-based global functional connectivity method to characterize the integration (i.e., within-network connectivity, WNC) of the NN and its segregation (i.e., between-network connectivity, BNC) from non-NN networks. We found that the majority of the voxels in the NN showed a stronger WNC than BNC, indicating the encapsulation of the NN. Importantly, individuals with stronger WNC and weaker BNC in the left hippocampus (Hipp) and intraparietal sulcus (IPS) performed better in scene recognition, suggesting that the left Hipp and IPS were involved in scene recognition by both integrating regions in the NN and separating the NN from non-NN networks. Further analyses showed that the integration of these two regions in the NN serves different functions, that is, while the WNC of the left Hipp was only related to scene recognition, the WNC of the left IPS was also related to the general executive control function of attention. In short, our study demonstrated the dual roles of the Hipp and IPS in integration and segregation of the NN to support scene recognition, suggesting that scene recognition involves not only regions specialized in spatial navigation, but also those with general functions.

The role of inhibition in moving beyond perceptually focused noun extensions

When young children interpret novel nouns, they tend to be very much affected by the perceptual features of the referent objects, especially shape. This article investigates whether children might inhibit a prepotent tendency to base novel nouns on the shape of referent objects in order to base them on conceptual features (i.e. taxonomic object categories). The study tested 3- to 5-year old children on a noun extension task, alongside a test of their inhibition and more general executive control ability. Noun extensions were related to inhibition ability, independent of age. Noun extensions were not related to individual differences in the general executive control task. This suggests a potential role for inhibition in extension which is independent of other aspects of cognitive development.

Bilingual Language Switching in the Laboratory versus in the Wild: The Spatiotemporal Dynamics of Adaptive Language Control.

For a bilingual human, every utterance requires a choice about which language to use. This choice is commonly regarded as part of general executive control, engaging prefrontal and anterior cingulate cortices similarly to many types of effortful task switching. However, although language control within artificial switching paradigms has been heavily studied, the neurobiology of natural switching within socially cued situations has not been characterized. Additionally, although theoretical models address how language control mechanisms adapt to the distinct demands of different interactional contexts, these predictions have not been empirically tested. We used MEG (RRID: NIFINV:nlx_inv_090918) to investigate language switching in multiple contexts ranging from completely artificial to the comprehension of a fully natural bilingual conversation recorded “in the wild.” Our results showed less anterior cingulate and prefrontal cortex involvement for more natural switching. In production, voluntary switching did not engage the prefrontal cortex or elicit behavioral switch costs. In comprehension, while laboratory switches recruited executive control areas, fully natural switching within a conversation only engaged auditory cortices. Multivariate pattern analyses revealed that, in production, interlocutor identity was represented in a sustained fashion throughout the different stages of language planning until speech onset. In comprehension, however, a biphasic pattern was observed: interlocutor identity was first represented at the presentation of the interlocutor and then again at the presentation of the auditory word. In all, our findings underscore the importance of ecologically valid experimental paradigms and offer the first neurophysiological characterization of language control in a range of situations simulating real life to various degrees.SIGNIFICANCE STATEMENT Bilingualism is an inherently social phenomenon, interactional context fully determining language choice. This research addresses the neural mechanisms underlying multilingual individuals' ability to successfully adapt to varying conversational contexts both while speaking and listening. Our results showed that interactional context critically determines language control networks' engagement: switching under external constraints heavily recruited prefrontal control regions, whereas natural, voluntary switching did not. These findings challenge conclusions derived from artificial switching paradigms, which suggested that language switching is intrinsically effortful. Further, our results predict that the so-called bilingual advantage should be limited to individuals who need to control their languages according to external cues and thus would not occur by virtue of an experience in which switching is fully free.

Is language control just a form of executive control? Evidence for overlapping processes in language switching and task switching

Whereas some models claim that language control is part of more general executive control, others have proposed that there is little overlap between these two processes. To shed light on this controversy, we compared switching effects observed in closely matched language switching and task switching tasks. The correlation analyses showed a positive moderate to strong correlation between the two switching variants in all three experiments. The results further showed that language- and task-switch costs differed although the cues, stimuli, response modality, and the number of response alternatives were identical across the two switching variants (Experiments 1), and when additionally the same linguistic tasks (picture naming/category naming) were used in both switching variants (Experiment 3), at least for the error rates. However, similar language- and task-switch costs were obtained when the same non-linguistic tasks (parity/magnitude) were used (Experiment 2). These results point towards overlapping mechanisms for language control and executive control.

Self-perspective inhibition deficits cannot be explained by general executive control difficulties

Understanding other people's point of view is crucial for successful social interaction but can be particularly challenging in situations where the other person's point view conflicts with our own view. Such situations require executive control processes that help us resist interference from our own perspective. In this study, we examined how domain-general these executive processes are. We report the performance of two pairs of brain-damaged patients who had sustained lesions in different areas of the prefrontal cortex and who showed deficits in classic executive function tasks. The patients were presented with desire reasoning tasks in which two sources of executive control were manipulated: the need to resist interference from one's own desire when inferring someone else's conflicting desire and the need to resist interference from the ascription of an approach motivation when inferring an avoidance-desire. The pattern of performance of the two pairs of patients conformed to a classic double dissociation with one pair of patients showing a deficit in resisting interference from their own perspective but not from the ascription of an approach motivation while the other pair of patients showed the opposite profile. The results are discussed in relation to the specificity of the processes recruited when we resist interference from our own perspective.

Among three different executive functions, general executive control ability is a key predictor of decision making under objective risk.

Executive functioning is supposed to have an important role in decision making under risk. Several studies reported that more advantageous decision-making behavior was accompanied by better performance in tests of executive functioning and that the decision-making process was accompanied by activations in prefrontal and subcortical brain regions associated with executive functioning. However, to what extent different components of executive functions contribute to decision making is still unclear. We tested direct and indirect effects of three executive functions on decision-making performance in a laboratory gambling task, the Game of Dice Task (GDT). Using Brand's model of decisions under risk (2006) we tested seven structural equation models with three latent variables that represent executive functions supposed to be involved in decision making. The latent variables were general control (represented by the general ability to exert attentional and behavioral self-control that is in accordance with task goals despite interfering information), concept formation (represented by categorization, rule detection, and set maintenance), and monitoring (represented by supervision of cognition and behavior). The seven models indicated that only the latent dimension general control had a direct effect on decision making under risk. Concept formation and monitoring only contributed in terms of indirect effects, when mediated by general control. Thus, several components of executive functioning seem to be involved in decision making under risk. However, general control functions seem to have a key role. They may be important for implementing the calculative and cognitively controlled processes involved in advantageous decision making under risk.

Episodic foresight deficits in long-term opiate users.

There is considerable literature showing that opiate use is associated with a range of neurocognitive deficits, including deficits in executive control and episodic memory. However, no study to date has assessed whether these neurocognitive difficulties extend to the ability to mentally time travel into one's personal future. This is a surprising omission given that executive control and episodic memory are considered to be critical for episodic foresight. In addition, opiate-related brain changes have been identified in the neural regions that underlie the capacity for episodic foresight. In the present study, we assessed how episodic foresight is affected in the context of chronic opiate use, as well as the degree to which any deficits are related to difficulties with executive control and episodic memory. Forty-eight long-term heroin users enrolled in an opiate substitution program and 48 controls were tested. The results showed that, relative to controls, the clinical group exhibited significant impairment in episodic foresight but not episodic memory (as indexed by an adapted version of the Autobiographical Interview). For executive function, the clinical group was impaired on only one of three measures (Inhibition). These data provide important preliminary evidence that episodic foresight might be particularly susceptible to the neurocognitive effects of opiate use, as the difficulties identified were not secondary to more general executive control or episodic memory impairment. Because a number of widely used relapse prevention protocols require the ability to mentally project into the future, these data have potentially important practical implications in relation to the treatment of substance dependence disorders.

FMRI of Simultaneous Interpretation Reveals the Neural Basis of Extreme Language Control.

We used functional magnetic resonance imaging (fMRI) to examine the neural basis of extreme multilingual language control in a group of 50 multilingual participants. Comparing brain responses arising during simultaneous interpretation (SI) with those arising during simultaneous repetition revealed activation of regions known to be involved in speech perception and production, alongside a network incorporating the caudate nucleus that is known to be implicated in domain-general cognitive control. The similarity between the networks underlying bilingual language control and general executive control supports the notion that the frequently reported bilingual advantage on executive tasks stems from the day-to-day demands of language control in the multilingual brain. We examined neural correlates of the management of simultaneity by correlating brain activity during interpretation with the duration of simultaneous speaking and hearing. This analysis showed significant modulation of the putamen by the duration of simultaneity. Our findings suggest that, during SI, the caudate nucleus is implicated in the overarching selection and control of the lexico-semantic system, while the putamen is implicated in ongoing control of language output. These findings provide the first clear dissociation of specific dorsal striatum structures in polyglot language control, roles that are consistent with previously described involvement of these regions in nonlinguistic executive control.

Unexpected novelty and familiarity orienting responses in lateral parietal cortex during recognition judgment

The role of lateral parietal cortex during recognition memory is heavily debated. We examined parietal activation during an Explicit Memory Cueing recognition paradigm that biases participants towards expecting novel or familiar stimuli on a trial-by-trial basis using anticipatory cues (“Likely Old”, “Likely New”), compared to trials with neutral cues (“????”). Three qualitatively distinct patterns were observed in the left lateral parietal cortex. An unexpected novelty response occurred in left anterior intraparietal cortex (IPS)/post-central gyrus (PoCG) in which greater activation was observed for new vs. old materials following the “Likely Old” cue, but not following the “Likely New” cue. In contrast, anterior angular gyrus demonstrated an unexpected familiarity response with greater activation for old vs. new materials following the “Likely New” cue, but not the “Likely Old” cue. Thus these two regions demonstrated increased responses that were selective for either new or old materials respectively, but only when they were unexpected. In contrast, a mid IPS area demonstrated greater response for whichever class of memoranda was unanticipated given the cue condition (an unexpected memory response). Analogous response patterns in regions outside of parietal cortex, and the results of a resting state connectivity analysis, suggested these three response patterns were associated with visuo-spatial orienting following unexpected novelty, source monitoring operations following unexpected familiarity, and general executive control processes following violated expectations. These findings support a Memory Orienting Model of the left lateral parietal cortex in which the region is linked to the investigation of unexpected novelty or familiarity in the environment.

Missed by an inch or a mile? Predicting the size of intention–behaviour gap from measures of executive control

Failing to achieve healthy intentions can have a direct impact on subsequent health. The extent of this impact is partially determined by the size of the discrepancy between intentions and behaviour, that is, on whether an unachieved behavioural target is missed by an inch or a mile. Over two studies, measures of ‘executive control’ ability were used to predict the size of the intention–behaviour gap for two dietary behaviours – eating fruits and vegetables and snacking. In Study 1, participants (n = 50) reported intended dietary intake, completed objective and self-report measures of executive control ability and recorded actual dietary intake over 3 days with computerised diaries. Using multiple regression, general executive control ability was found to account for 16–23% of the variance in the size of intention–behaviour gap for both the dietary behaviours. In Study 2 (n = 52), deviation from intentions about snacking was significantly related to individual differences in prepotent response inhibition. Overall, individuals with weak executive control ate less fruits and vegetables and more snacks than intended. Intention–behaviour ‘failures’ are not homogenous, but instead vary predictably with the availability of executive control resources. This suggests that individuals with large intention–behaviour shortfalls may benefit from interventions designed to reduce the demands on executive control.

How useful is executive control training? Age differences in near and far transfer of task‐switching training

Although executive functions can be improved by training, little is known about the extent to which these training-related benefits can be transferred to other tasks, or whether this transfer can be modulated by the type of training. This study investigated lifespan changes in near transfer of task-switching training to structurally similar tasks and its modulation by verbal self-instructions and variable training, as well as far transfer to structurally dissimilar 'executive' tasks and fluid intelligence. Three age groups (8-10; 18-26; 62-76 years of age) were examined in a pretest-training-posttest design. We found near transfer of task-switching training in all age groups, especially in children and older adults. Near transfer was enhanced in adults and impaired in children when training tasks were variable. We also found substantial far transfer to other executive tasks and fluid intelligence in all age groups, pointing to the transfer of relatively general executive control abilities after training.

Individual differences in childhood sleep problems predict later cognitive executive control.

To determine whether individual differences in developmental patterns of general sleep problems are associated with 3 executive function abilities-inhibiting, updating working memory, and task shifting-in late adolescence. 916 twins (465 female, 451 male) and parents from the Colorado Longitudinal Twin Study. Parents reported their children's sleep problems at ages 4 years, 5 y, 7 y, and 9-16 y based on a 7-item scale from the Child-Behavior Checklist; a subset of children (n = 568) completed laboratory assessments of executive functions at age 17. Latent variable growth curve analyses were used to model individual differences in longitudinal trajectories of childhood sleep problems. Sleep problems declined over time, with approximately 70% of children having > or = 1 problem at age 4 and approximately 33% of children at age 16. However, significant individual differences in both the initial levels of problems (intercept) and changes across time (slope) were observed. When executive function latent variables were added to the model, the intercept did not significantly correlate with the later executive function latent variables; however, the slope variable significantly (P < 0.05) negatively correlated with inhibiting (r = -0.27) and updating (r = -0.21), but not shifting (r = -0.10) abilities. Further analyses suggested that the slope variable predicted the variance common to the 3 executive functions (r = -0.29). Early levels of sleep problems do not seem to have appreciable implications for later executive functioning. However, individuals whose sleep problems decrease more across time show better general executive control in late adolescence.