Executive functions and their disorders

Dissociating the role of dACC and dlPFC for emotion appraisal and mood regulation using cathodal tDCS

Several neuroimaging studies have shown that a distributed network of brain regions is involved in our ability to appraise the emotions we experience in daily life. In particular, scholars suggested that the dorsal anterior cingulate cortex (dACC) may play a role in the appraisal of emotional stimuli together with subcortical regions, especially when stimuli are negatively valenced, and the dorsolateral prefrontal cortex (dlPFC) may play a role in regulating emotions. However, proofs of the causal role of these regions are lacking. In the present study, we aim at testing this model by stimulating both the dACC and the left dlPFC via cathodal tDCS. Twenty-four participants were asked to attend and rate the arousal and valence of negative and neutral emotional stimuli (pictures and words) in three different experimental sessions: cathodal stimulation of dACC, left dlPFC, or sham. In addition to the experimental task, the baseline affective state was measured before and after the stimulation to further assess the effect of stimulation over the baseline affective state after the experimental session. Results showed that cathodal stimulation of dACC, but not the left dlPFC, was associated with reduced arousal ratings of emotional stimuli, both compared with the sham condition. Moreover, cathodal stimulation of left dlPFC decreased participant's positive affective state after the session. These findings suggest for the first time, a dissociation between the dACC and dlPFC, with the former more involved in emotion appraisal, and the latter more involved in mood modulation.

An Item Response Theory Analysis of the Wisconsin Card Sorting Test in Normal Aging, Alzheimer's Disease and Parkinson's Disease: Neurophysiological Approach

The Wisconsin Card Sorting Test (WCST) is widely used to assess executive function, specifically mental flexibility. Item Response Theory (IRT) has several advantages over classical test theory, including the invariance of the measure. This study aimed to apply IRT to study the psychometric properties of WCST in control subjects and patients with idiopathic Parkinson's disease (PD) and Alzheimer's disease (AD). The sample consisted of 86 controls, 77 Parkinson's disease subjects, and 155 AD subjects. The Rasch model was applied to binary data from the conversion to percentiles adjusted for age and schooling. The R program was used to calibrate the difficulty parameter. The characteristic curves of the items and the estimation of the difficulty parameter for each diagnostic group were obtained. WCST makes it possible to separate between different skill levels among the three diagnostic entities and its application may be useful for other neuropsychological tests. In conclusion, WCST has good clinical sensitivity and excellent discriminant validity in the groups under study, making it possible to separate them between different levels of ability or latent trait. Its application may be useful for other neuropsychological tests.

The Frontal and Cerebellar Metabolism Related to Cognitive Dysfunction in Multiple System Atrophy

Background

Cognitive dysfunctions have been reported in multiple system atrophy (MSA). However the underlying mechanisms remain to be elucidated. This study aimed to explore the possible cerebral metabolism associated with domain-specific cognitive performances in MSA.

Methods

A total of 84 patients were diagnosed as probable or possible MSA, comprised of 27 patients as MSA with predominant parkinsonism (MSA-P) and 57 patients as MSA with predominant cerebellar ataxia (MSA-C). The comprehensive neuropsychological tests and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) imaging were performed. Z-score was calculated to non-dimensionalize and unify indicators of different tests in the domains of executive function, attention, language, memory, and visuospatial function. Correlations between specific Z-score and cerebral ¹⁸F-FDG uptake were analyzed using statistical parametric mapping. The cognition-related metabolic differences between patients with MSA-P and MSA-C were analyzed using the post-hoc test.

Results

Z-scores of the domains including attention, executive function, and language correlated positively with the metabolism in the superior/inferior frontal gyrus and cerebellum, but negatively with that in the insula and fusiform gyrus (p < 0.001). No significant differences in neuropsychological performances and frontal metabolism were found between patients with MSA-P and MSA-C. Only lower metabolism in the cerebellum was observed in MSA-C.

Conclusion

Metabolic changes in the frontal lobe and cerebellum may participate in the cognitive impairments of patients with MSA. Nevertheless, cognitive and corresponding metabolic differences between the two subtypes of MSA still need more exploration.

Opioid use disorder and the brain: a clinical perspective

Opioid use disorder (OUD) has gained increasing publicity and interest during recent years, with many countries describing problems of epidemic proportions with regard to opioid use and deaths related to opioids. While opioids are not themselves acutely neurotoxic, the chronic relapsing and remitting nature of this disorder means that individuals are often exposed to exogenous opioids for lengthy periods of time (either illicit or prescribed as treatment). We are increasingly characterizing the effect of such long-term opioid exposure on the brain. This narrative review aims to summarize the literature regarding OUD and the brain from a clinical perspective. Alterations of brain structure and function are discussed, as well as neurological and psychiatric disorders in OUD. Finally, we review current and new directions for assessment and treatment.

Alterations in pain processing circuitries in episodic migraine

Background

The precise underlying mechanisms of migraine remain unknown. Although we have previously shown acute orofacial pain evoked changes within the brainstem of individuals with migraine, we do not know if these brainstem alterations are driven by changes in higher cortical regions. The aim of this investigation is to extend our previous investigation to determine if higher brain centers display altered activation patterns and connectivity in migraineurs during acute orofacial noxious stimuli.

Methods

Functional magnetic resonance imaging was performed in 29 healthy controls and 25 migraineurs during the interictal and immediately (within 24-h) prior to migraine phases. We assessed activation of higher cortical areas during noxious orofacial heat stimulation using a thermode device and assessed whole scan and pain-related changes in connectivity.

Results

Despite similar overall pain intensity ratings between all three groups, migraineurs in the group immediately prior to migraine displayed greater activation of the ipsilateral nucleus accumbens, the contralateral ventrolateral prefrontal cortex and two clusters in the dorsolateral prefrontal cortex (dlPFC). Reduced whole scan dlPFC [Z + 44] connectivity with cortical/subcortical and brainstem regions involved in pain modulation such as the putamen and primary motor cortex was demonstrated in migraineurs. Pain-related changes in connectivity of the dlPFC and the hypothalamus immediately prior to migraine was also found to be reduced with brainstem pain modulatory areas such as the rostral ventromedial medulla and dorsolateral pons.

Conclusions

These data reveal that the modulation of brainstem pain modulatory areas by higher cortical regions may be aberrant during pain and these alterations in this descending pain modulatory pathway manifests exclusively prior to the development of a migraine attack.

A Comparison Between the Performances of Verbal and Nonverbal Fluency Tests in Discriminating Between Mild Cognitive Impairments and Alzheimer’s Disease Patients and Their Brain Morphological Correlates

Background and Purpose

Methods

Results

Conclusions

The impact of anxiety on the cognitive function of informal Parkinson's disease caregiver: Evidence from task-based and resting-state fNIRS

Informal Parkinson's disease (PD) caregivers are considered to experience high levels of caregiver burden, negatively affecting the health of caregivers. However, few studies explored the relationship between anxiety in caregiver burden and cognitive function in informal PD caregivers. Although, no study has even investigated the neural mechanisms underlying this connection. This study aimed to conduct comprehensive cognitive and clinical assessments and evaluate brain activity from task-based state and resting-state using functional near-infrared spectroscopy (fNIRS). A total of ten informal PD caregivers and 15 matched, healthy, non-caregivers were recruited. Comprehensive cognitive and clinical assessments were conducted to evaluate five cognitive domains and mental states. Neural activity induced by verbal fluency task (VFT) and brain connectivity during resting state were monitored, and their correlations with the neuropsychological and clinical tests were explored. Our results showed that compared to non-caregiver, an informal PD caregiver exhibited no difference in most cognitive domains of function but performed better in attentional function, along with higher levels of anxiety. Decreased activation over prefrontal regions during VFT and hypo-connectivity within the frontoparietal network (FPN) and between default mode network (DMN) and FPN in the resting state were confirmed in this study as a result of the negative effects of anxiety on the brain. Furthermore, Spearman's correlation found that neural activity in FPN during task-based state and resting state was negatively correlated with the severity of anxiety. These findings indicate that despite normal or even better cognitive function, informal PD caregivers have impaired brain function, and this deficit in neural activity was related to anxiety.

The relationship between theory of mind and executive functions in major depressive disorders: A review

Patients suffering from major depressive disorder (MDD) experience difficulties in multiple cognitive and affective abilities. A large body of literature has argued that MDD patients show impaired executive functions (EFs) and deficits in theory of mind (ToM), the ability to infer the mental states of others. However, the relationship between ToM and EFs has been poorly investigated. The aim of this review is to provide an overview of studies that evaluated the association between ToM and EFs in patients with MDD diagnosis. A literature review was conducted to identify all published studies in which ToM and EFs measures were administered to individuals with MDD and in which the relationship between these two domains was investigated. Eleven studies were included, and for each study, we discussed the findings related to ToM, EFs, and the nature of the link between these two aspects. Most of the studies reported that patients with MDD, compared with healthy controls, showed significant impairments in both ToM and EFs abilities. Moreover, this review indicates the presence of a significant association between these two domains in MDD patients, supporting the evidences that executive functioning is important to perform ToM tasks. Although the results that emerged are interesting, the relationship between ToM and EFs in MDD needs further investigation.

OUP accepted manuscript

One of the great frontiers of consciousness science is understanding how early consciousness arises in the development of the human infant. The reciprocal relationship between the default mode network and fronto-parietal networks—the dorsal attention and executive control network—is thought to facilitate integration of information across the brain and its availability for a wide set of conscious mental operations. It remains unknown whether the brain mechanism of conscious awareness is instantiated in infants from birth. To address this gap, we investigated the development of the default mode and fronto-parietal networks and of their reciprocal relationship in neonates. To understand the effect of early neonate age on these networks, we also assessed neonates born prematurely or before term-equivalent age. We used the Developing Human Connectome Project, a unique Open Science dataset which provides a large sample of neonatal functional MRI data with high temporal and spatial resolution. Resting state functional MRI data for full-term neonates (n = 282, age 41.2 weeks ± 12 days) and preterm neonates scanned at term-equivalent age (n = 73, 40.9 weeks ± 14.5 days), or before term-equivalent age (n = 73, 34.6 weeks ± 13.4 days), were obtained from the Developing Human Connectome Project, and for a reference adult group (n = 176, 22–36 years), from the Human Connectome Project. For the first time, we show that the reciprocal relationship between the default mode and dorsal attention network was present at full-term birth or term-equivalent age. Although different from the adult networks, the default mode, dorsal attention and executive control networks were present as distinct networks at full-term birth or term-equivalent age, but premature birth was associated with network disruption. By contrast, neonates before term-equivalent age showed dramatic underdevelopment of high-order networks. Only the dorsal attention network was present as a distinct network and the reciprocal network relationship was not yet formed. Our results suggest that, at full-term birth or by term-equivalent age, infants possess key features of the neural circuitry that enables integration of information across diverse sensory and high-order functional modules, giving rise to conscious awareness. Conversely, they suggest that this brain infrastructure is not present before infants reach term-equivalent age. These findings improve understanding of the ontogeny of high-order network dynamics that support conscious awareness and of their disruption by premature birth.

Lateralized Contributions of Medial Prefrontal Cortex Network to Episodic Memory Deficits in Subjects With Amnestic Mild Cognitive Impairment

Both episodic memory and executive function are impaired in amnestic mild cognitive impairment (aMCI) subjects, but it is unclear if these impairments are independent or interactive. The present study aimed to explore the relationship between episodic memory deficits and executive function deficits, and the underlying functional mechanisms in aMCI subjects. Thirty-one aMCI subjects and 27 healthy subjects underwent neuropsychological tests and multimodal magnetic resonance imaging (MRI) scans. Hippocampal networks and medial prefrontal cortex (MPFC) networks were identified based on resting-sate functional MRI (fMRI) data. AMCI subjects displayed lower episodic memory scores and executive function scores than control subjects, and the episodic memory scores were positively correlated with the executive function scores in aMCI subjects. Brain network analyses showed an interaction between the hippocampal networks and the MPFC networks, and the interaction was significantly associated with the episodic memory scores and the executive function scores. Notably, aMCI subjects displayed higher functional connectivity (FC) of the right hippocampal network with the right prefrontal cortex than did control subjects, but this difference disappeared when controlling for the MPFC networks. Furthermore, the effects of the MPFC networks on the hippocampal networks were significantly associated with the episodic memory scores in aMCI subjects. The present findings suggested that the episodic memory deficits in aMCI subjects could be partially underpinned by the modulation of the MPFC networks on the hippocampal networks.

Effects of activities of daily living-based dual-task training on upper extremity function, cognitive function, and quality of life in stroke patients

Objectives

The aim of this study was to investigate the effect of daily living dual-task training focused on improving attention and executive function of the upper extremities, cognitive function, and quality of life in stroke patients.

Methods

We included 30 stroke patients who were hospitalized between July 2020 and October 2020. They were divided into experimental and control groups through randomization. The experimental group performed 20 minutes of dual-task training and received 10 minutes of conventional occupational therapy, while the control group performed 20 minutes of single-task training and received 10 minutes of conventional occupational therapy. Both groups underwent their respective rehabilitation for 30 minutes per session, 5 times per week for 5 weeks.

Results

Both groups showed significant improvements in upper extremity function, cognitive function, and quality of life; the experimental group showed higher results for all items. A significant between-group difference was observed in the magnitude of the changes.

Conclusion

In stroke patients, dual-task training that combined attention and executive function with daily living activities was found to be meaningful, as it encouraged active participation and motivation. This study is expected to be used as a foundation for future interventions for stroke patients.

Impaired Perception of Unintentional Transgression of Social Norms after Prefrontal Cortex Damage: Relationship to Decision Making, Emotion Recognition, and Executive Functions

OBJECTIVE

Patients with prefrontal cortex damage often transgress social rules and show lower accuracy in identifying and explaining inappropriate social behavior. The objective of this study was to examine the relationship between the ability to perceive other unintentional transgressions of social norms and both decision making and emotion recognition as these abilities are critical for appropriate social behavior.

METHOD

We examined a group of patients with focal prefrontal cortex damage (N = 28) and a group of matched control participants (N = 28) for their abilities to detect unintentional transgression of social norms using the "Faux-Pas" task of theory of mind, to make advantageous decisions on the Iowa gambling task, and to recognize basic emotions on the Ekman facial affect test.

RESULTS

The group of patients with frontal lobe damage was impaired in all of these tasks compared with control participants. Moreover, all the "Faux-Pas", Iowa gambling, and emotion recognition tasks were significantly associated and predicted by executive measures of inhibition, flexibility, or planning. However, only measures from the Iowa gambling task were associated and predicted performance on the "Faux-Pas" task. These tasks were not associated with performance in recognition of basic emotions. These findings suggest that theory of mind, executive functions, and decision-making abilities act in an interdependent way for appropriate social behavior. However, theory of mind and emotion recognition seem to have distinct but additive effects upon social behavior. Results from VLSM analysis also corroborate these data by showing a partially overlapped prefrontal circuitry underlying these cognitive domains.

Decreased gray matter volume and increased white matter volume in patients with neovascular age-related macular degeneration: a voxel-based morphometry study

OBJECTIVE

To measure white and gray matter volume (WMV, GMV) in patients with neovascular age-related macular degeneration (nAMD) using voxel-based morphometry (VBM).

MATERIAL

Eighteen patients (9 men, 9 women) with nAMD and 18 (9 men, 9 women) healthy controls (HCs) aligned were recruited. Functional magnetic resonance imaging (fMRI) and VBM of three-dimensional T1 brain images were analyzed. And we also apply t-tests to look for GMV and WMV differences between groups. Correlation analysis was utilized to probe the connection between observational GMV and WMV values of diverse brain areas and the severity of HADS (hospital anxiety and depression scale). Also, distinctions between nAMD and HCs in GMV can be presented with the help of a ROC (receiver operating characteristic) curve.

RESULTS

Compared with HCs, GMV values were significantly lower in patients with neovascular age-related macular degeneration in the right inferior frontal gyrus, temporal pole of left superior temporal gyrus, left superior temporal gyrus, left middle frontal gyrus, left anterior cingulate and para cingulate gyrus. While WMV was slightly increased in these areas. HADS (hospital anxiety and depression scale) scores portrayed a non-linear correlation with the GMV value of the right inferior frontal gyrus, left middle frontal gyrus, left anterior cingulate and paracingulate gyrus of the nAMD group (r=-0.6629, P=0.0027)(r=-0.9451, P<0.0001)(r=-0.6183, P=0.0062). Moreover, the ROC curve analysis of the mean VBM values for altered brain regions indicated high diagnostic accuracy.

CONCLUSION

These results indicated that patients with nAMD have abnormal GMV and WMV and formed a basis for future research on pathological mechanisms in this disease. Moreover, decreased gray matter volume in particular brain regions might be associated with choroidal neovascularization and abnormal HADS score. It might help to explain the pathological mechanism of anxiety and depression in patients with nAMD.

To learn or to gain: neural signatures of exploration in human decision-making

Individuals not only take actions to obtain immediate rewards but also to gain more information to guide future choices. An ideal exploration-exploitation balance is crucial for maximizing reward over the long run. However, the neural signatures of exploration in humans remain unclear. Using quantitative meta-analyses of functional magnetic resonance imaging experiments on exploratory behaviors, we sought to identify the concordant activity pertaining to exploration over a range of experiments. The results revealed that exploration activates concordant brain activity associated with risk (e.g., dorsal medial prefrontal cortex and anterior insula), cognitive control (e.g., dorsolateral prefrontal cortex and inferior frontal gyrus), and motor processing (e.g., premotor cortex). These stereotaxic maps of exploration may indicate that exploration is highly linked to risk processing, but is also specifically associated with regions involved in executive control processes. Although this explanation should be treated as exploratory, these findings support theories positing an important role for the prefrontal-insular-motor cortical network in exploration.

Movement System Diagnoses for Balance Dysfunction: Recommendations From the Academy of Neurologic Physical Therapy's Movement System Task Force

The movement system was identified as the focus of our expertise as physical therapists in the revised vision statement for the profession adopted by the American Physical Therapy Association in 2013. Attaining success with the profession's vision requires the development of movement system diagnoses that will be useful in clinical practice, research, and education. To date, only a few movement system diagnoses have been identified and described, and none of these specifically address balance dysfunction. Over the past 2 years, a Balance Diagnosis Task Force, a subgroup of the Movement System Task Force of the Academy of Neurologic Physical Therapy, focused on developing diagnostic labels (or diagnoses) for individuals with balance problems. This paper presents the work of the task force that followed a systematic process to review available diagnostic frameworks related to balance, identify 10 distinct movement system diagnoses that reflect balance dysfunction, and develop complete descriptions of examination findings associated with each balance diagnosis. A standardized approach to movement analysis of core tasks, the Framework for Movement Analysis developed by the Academy of Neurologic Physical Therapy Movement Analysis Task Force, was integrated into the examination and diagnostic processes. The aims of this perspective paper are to (1) summarize the process followed by the Balance Diagnosis Task Force to develop an initial set of movement system (balance) diagnoses; (2) report the recommended diagnostic labels and associated descriptions; (3) demonstrate the clinical decision-making process used to determine a balance diagnosis and develop a plan of care; and (4) identify next steps to validate and implement the diagnoses into physical therapist practice, education, and research.

IMPACT

The development and use of diagnostic labels to classify distinct movement system problems is needed in physical therapy. The 10 balance diagnosis proposed can aid in clinical decision making regarding intervention.

Pediatric concussion working memory outcomes: a scoping review

Objective: Characterize the working memory (WM) profile of children and youth who have experienced concussion by systematically synthesizing existing literature on the neuropsychological outcomes of these injuries.Methods: Implemented a peer-reviewed search strategy combining key concepts of concussion/mild traumatic brain injury (mTBI), WM, and pediatrics across MedLine, Embase, PsycINFO, and CINAHL. Included studies written in English with extractable results on a WM outcome measure in individuals aged 21 and under who experienced concussion. Applied narrative synthesis to identify trends in the literature. Assessed risk of bias and quality using the NHLBI's Quality Assessment of Observational Cohort and Cross-Sectional Studies.Results: 40 articles met inclusion criteria. 34/40 studies compared WM performance in children or youth with concussion to healthy controls, pre-injury performance, or normative values, of which 15 reported significantly lower WM performance in the concussion sample. Visual/spatial WM was more consistently impacted than verbal WM. Cognitive demanding dual-task conditions were also reliably impacted.Conclusion: Literature indicated that WM is vulnerable to negative outcomes following pediatric concussion, yet the nature of outcomes is variable. Clinicians and researchers should implement comprehensive and theoretically motivated WM assessments to better understand the WM components impacted by injury.

A machine learning approach for the factorization of psychometric data with application to the Delis Kaplan Executive Function System

While a replicability crisis has shaken psychological sciences, the replicability of multivariate approaches for psychometric data factorization has received little attention. In particular, Exploratory Factor Analysis (EFA) is frequently promoted as the gold standard in psychological sciences. However, the application of EFA to executive functioning, a core concept in psychology and cognitive neuroscience, has led to divergent conceptual models. This heterogeneity severely limits the generalizability and replicability of findings. To tackle this issue, in this study, we propose to capitalize on a machine learning approach, OPNMF (Orthonormal Projective Non-Negative Factorization), and leverage internal cross-validation to promote generalizability to an independent dataset. We examined its application on the scores of 334 adults at the Delis-Kaplan Executive Function System (D-KEFS), while comparing to standard EFA and Principal Component Analysis (PCA). We further evaluated the replicability of the derived factorization across specific gender and age subsamples. Overall, OPNMF and PCA both converge towards a two-factor model as the best data-fit model. The derived factorization suggests a division between low-level and high-level executive functioning measures, a model further supported in subsamples. In contrast, EFA, highlighted a five-factor model which reflects the segregation of the D-KEFS battery into its main tasks while still clustering higher-level tasks together. However, this model was poorly supported in the subsamples. Thus, the parsimonious two-factors model revealed by OPNMF encompasses the more complex factorization yielded by EFA while enjoying higher generalizability. Hence, OPNMF provides a conceptually meaningful, technically robust, and generalizable factorization for psychometric tools.

Multiscale neural modeling of resting-state fMRI reveals executive-limbic malfunction as a core mechanism in major depressive disorder

Major depressive disorder (MDD) represents a grand challenge to human health and society, but the underlying pathophysiological mechanisms remain elusive. Previous neuroimaging studies have suggested that MDD is associated with abnormal interactions and dynamics in two major neural systems including the default mode - salience (DMN-SAL) network and the executive - limbic (EXE-LIM) network, but it is not clear which network plays a central role and which network plays a subordinate role in MDD pathophysiology. To address this question, we refined a newly developed Multiscale Neural Model Inversion (MNMI) framework and applied it to test whether MDD is more affected by impaired circuit interactions in the DMN-SAL network or the EXE-LIM network. The model estimates the directed connection strengths between different neural populations both within and between brain regions based on resting-state fMRI data collected from normal healthy subjects and patients with MDD. Results show that MDD is primarily characterized by abnormal circuit interactions in the EXE-LIM network rather than the DMN-SAL network. Specifically, we observe reduced frontoparietal effective connectivity that potentially contributes to hypoactivity in the dorsolateral prefrontal cortex (dlPFC), and decreased intrinsic inhibition combined with increased excitation from the superior parietal cortex (SPC) that potentially lead to amygdala hyperactivity, together resulting in activation imbalance in the PFC-amygdala circuit that pervades in MDD. Moreover, the model reveals reduced PFC-to-hippocampus excitation but decreased SPC-to-thalamus inhibition in MDD population that potentially lead to hypoactivity in the hippocampus and hyperactivity in the thalamus, consistent with previous experimental data. Overall, our findings provide strong support for the long-standing limbic-cortical dysregulation model in major depression but also offer novel insights into the multiscale pathophysiology of this debilitating disease.

The relationship between autistic characteristics, social engagement and executive function in a typical sample

Purpose

This study aims to represent a first attempt to examine in a non-clinical population the interplay between social engagement, executive function (EF) and theory of mind (ToM) within a social motivation theory framework.

Design/methodology/approach

A total of 170 participants (135 female; mean age = 19.01 and standard deviation = 1.27) completed measures of ToM (Faux Pas task), autistic traits (Autism Spectrum Quotient), social engagement (reward dependence subscale of the Temperament and Character Inventory), sociability and EF (both subscales of the Adult Temperament Questionnaire).

Findings

Path analyses found that EF, sociability and social engagement were negatively associated with autistic traits both directly and indirectly. Results indicate that EF may impact sociability and social engagement and their interaction may relate to the degree of autistic traits shown in a typical sample. However, ToM (as measured by the Faux Pas test) was not related to any of the other variables.

Originality/value

Sociability, social engagement and effortful control deficits may be linked to higher levels of autistic traits. These factors appear to form a hierarchy of factors underpinning autism spectrum disorder, with EF contributing to all aspects, followed by sociability and social engagement at a higher level. Future research examining in clinical populations the utility of a more integrated model of social motivation that incorporates EF appears warranted.

The interplay between early social interaction, language and executive function development in deaf and hearing infants

In this article, we review the influence of early social interaction on the development of executive function and language in infants. We first define social interaction, executive function and language and show how they are related in infant development. Studies of children born deaf are used to illustrate this connection because they represent cases where there has been a disruption to early social interaction and the development of intersubjectivity. Unlike other groups, the disturbance to development is known to be largely environmental rather than neuro-biological. This enables us to more accurately tease apart those impacts on EF that are associated with social interaction and language, since the potential confounds of disordered cognitive development are largely controlled for. The review offers a unifying model for how social, cognitive and linguistic development work together in early human development.

Interacting effects of frontal lobe neuroanatomy and working memory capacity to older listeners' speech recognition in noise

Many older adults are struggling with understanding spoken language, particularly when background noise interferes with comprehension. In the present study, we investigated a potential interaction between two well-known factors associated with greater speech-in-noise (SiN) reception thresholds in older adults, namely a) lower working memory capacity and b) age-related structural decline of frontal lobe regions. In a sample of older adults (N = 25) and younger controls (N = 13) with normal pure-tone thresholds, SiN reception thresholds and working memory capacity were assessed. Furthermore, T1-weighted structural MR-images were recorded to analyze neuroanatomical traits (i.e., cortical thickness (CT) and cortical surface area (CSA)) of the cortex. As expected, the older group showed greater SiN reception thresholds compared to the younger group. We also found consistent age-related atrophy (i.e., lower CT) in brain regions associated with SiN recognition, namely the superior temporal lobe bilaterally, the right inferior frontal and precentral gyrus, as well as the left superior frontal gyrus. Those older participants with greater atrophy in these brain regions showed greater SiN reception thresholds. Interestingly, the association between CT in the left superior frontal gyrus and SiN reception thresholds was moderated by individual working memory capacity. Older adults with greater working memory capacity benefitted more strongly from thicker frontal lobe regions leading to better SiN recognition. Overall, our results fit well into the literature showing that age-related structural decline in auditory- and cognition-related brain areas is associated with greater SiN reception thresholds in older adults. However, we highlight that this association changes as a function of individual working memory capacity. We therefore believe that future interventions to improve SiN recognition in older adults should take into account the role of the frontal lobe as well as individual working memory capacity.

Neural Biomarkers Distinguish Severe From Mild Autism Spectrum Disorder Among High-Functioning Individuals

Several previous studies have reported atypicality in resting-state functional connectivity (FC) in autism spectrum disorder (ASD), yet the relatively small effect sizes prevent us from using these characteristics for diagnostic purposes. Here, canonical correlation analysis (CCA) and hierarchical clustering were used to partition the high-functioning ASD group (i.e., the ASD discovery group) into subgroups. A support vector machine (SVM) model was trained through the 10-fold strategy to predict Autism Diagnostic Observation Schedule (ADOS) scores within the ASD discovery group (r = 0.30, P < 0.001, n = 260), which was further validated in an independent sample (i.e., the ASD validation group) (r = 0.35, P = 0.031, n = 29). The neuroimage-based partition derived two subgroups representing severe versus mild autistic patients. We identified FCs that show graded changes in strength from ASD-severe, through ASD-mild, to controls, while the same pattern cannot be observed in partitions based on ADOS score. We also identified FCs that are specific for ASD-mild, similar to a partition based on ADOS score. The current study provided multiple pieces of evidence with replication to show that resting-state functional magnetic resonance imaging (rsfMRI) FCs could serve as neural biomarkers in partitioning high-functioning autistic individuals based on their symptom severity and showing advantages over traditional partition based on ADOS score. Our results also indicate a compensatory role for a frontocortical network in patients with mild ASD, indicating potential targets for future clinical treatments.

Neonatal brain abnormalities and brain volumes associated with goal setting outcomes in very preterm 13-year-olds

Executive dysfunction including impaired goal setting (i.e., planning, organization skills, strategic reasoning) is documented in children born very preterm (VP; <30 weeks/<1250 g), however the neurological basis for this impairment is unknown. This study sought to examine the relationship between brain abnormalities and brain volumes on neonatal magnetic resonance imaging (MRI) and goal setting abilities of VP 13-year-olds. Participants were 159 children born VP in a prospective longitudinal study. Qualitative brain abnormality scores and quantitative brain volumes were derived from neonatal MRI brain scans (40 weeks' gestational age ± 2 weeks). Goal setting at 13 years was assessed using the Delis-Kaplan Executive Function Systems Tower Test, the Rey Complex Figure, and the Behavioural Assessment of the Dysexecutive System for Children Zoo Map and Six Part Test. A composite score was generated denoting overall performance on these goal setting measures. Separate regression models examined the association of neonatal brain abnormality scores and brain volumes with goal setting performance. There was evidence that higher neonatal white matter, deep grey matter and cerebellum abnormality scores were associated with poorer goal setting scores at 13 years. There was also evidence of positive associations between total brain volume, cerebellum, thalamic and cortical grey matter volumes and goal setting performance. Evidence for the associations largely persisted after controlling for potential confounders. Neonatal brain abnormality and brain volumes are associated with goal setting outcome in VP 13-year-olds. Used in conjunction with other clinical indicators, neonatal MRI may help to identify VP children at risk for later executive dysfunction.

Neurocognitive heterogeneity in patients with bipolar disorder and their unaffected relatives: associations with emotional cognition

BACKGROUND

Recent evidence suggests that neurocognitive impairments in remitted patients with bipolar disorder (BD) are heterogeneous. Our study aims to replicate recent findings of neurocognitive subgroups, and further explore whether these are related to impairments in affective cognition, in a large sample of remitted patients recently diagnosed with BD and their unaffected relatives compared to healthy controls (HCs).

METHODS

Hierarchal cluster analysis was conducted using neurocognitive data from remitted patients with BD (n = 158). Relatives of patients with BD (n = 52) were categorised into groups consistent with their affected relative's cluster assignment. The neurocognitive clusters of patients with BD and relatives, respectively, were compared with HCs (n = 110) in neurocognition and affective cognition (i.e. emotion processing and regulation).

RESULTS

Three discrete neurocognitive clusters were identified in patients with BD: a globally impaired (23.4%), a selectively impaired (31.0%) and a cognitively intact cluster (45.6%). The neurocognitive subgroups differed in affective cognition, with patients categorised as globally impaired exhibited most impairments in facial expression recognition and emotion regulation in social scenarios. First-degree relatives of cognitively impaired patients displayed impaired facial expression recognition but no impairments in non-emotional cognition.

CONCLUSIONS

In a clinical sample of remitted patients recently diagnosed with BD 54.4% had either global or selective cognitive impairment, replicating results of previous studies in patients with longer illness duration. The results suggest that patterns of neurocognition are associated with differential impairments in affective cognition. Aberrant affective cognition in relatives of patients categorised as neurocognitively impaired indicates an inherited risk for BD.

Alcohol exposure in utero disrupts cortico-striatal coordination required for behavioral flexibility

Deficits in behavioral flexibility are a hallmark of multiple psychiatric, neurological, and substance use disorders. These deficits are often marked by decreased function of the prefrontal cortex (PFC); however, the genesis of such executive deficits remains understudied. Here we report how the most preventable cause of developmental disability, in utero exposure to alcohol, alters cortico-striatal circuit activity leading to impairments in behavioral flexibility in adulthood. We utilized a translational touch-screen task coupled with in vivo electrophysiology in adult mice to examine single unit and coordinated activity of the lateral orbital frontal cortex (OFC) and dorsolateral striatum (DS) during flexible behavior. Prenatal alcohol exposure (PAE) decreased OFC, and increased DS, single unit activity during reversal learning and altered the number of choice responsive neurons in both regions. PAE also decreased coordinated activity within the OFC and DS as measured by oscillatory field activity and altered spike-field coupling. Furthermore, PAE led to sustained connectivity between regions past what was seen in control animals. These findings suggest that PAE causes altered coordination within and between the OFC and DS, promoting maladaptive perseveration. Our model suggests that in optimally functioning mice OFC disengages the DS and updates the newly changed reward contingency, whereas in PAE animals, aberrant and persistent OFC to DS signaling drives behavioral inflexibility during early reversal sessions. Together, these findings demonstrate how developmental exposure alters circuit-level activity leading to behavioral deficits and suggest a critical role for coordination of neural timing during behaviors requiring executive function.

Effects of β-Lactolin on Regional Cerebral Blood Flow within the Dorsolateral Prefrontal Cortex during Working Memory Task in Healthy Adults: A Randomized Controlled Trial

Epidemiological studies have reported that consumption of dairy products rich in β-lactolin is beneficial for cognitive decline among elderly individuals. Although previous studies have shown that β-lactolin supplementation improves memory function and attention in healthy adults, the mechanism through which β-lactolin affects human brain function has yet to be elucidated. This placebo-controlled randomized double-blind study therefore examined the effects of β-lactolin on human regional cerebral blood flow (rCBF) using near-infrared spectroscopy (NIRS) according to the Consolidated Standards of Reporting Trials guidelines. A total of 114 healthy participants aged between 50 and 75 years with relatively low cognition were randomly allocated into the β-lactolin or placebo groups (n = 57 for both groups) and received supplementation for 6 weeks. After the 6 weeks of supplementation, total hemoglobin during cognitive tasks (Kraepelin and 2-back tasks) was measured using two-channel NIRS to determine rCBF. Accordingly, the β-lactolin group had significantly higher changes in total hemoglobin at the left dorsolateral prefrontal cortex (DLPFC) area measured using the left-side channel during the 2-back tasks (p = 0.027) compared to the placebo group. The present study suggests that β-lactolin supplementation increases rCBF and DLPFC activity during working memory tasks.

The effect of non-invasive brain stimulation on executive functioning in healthy controls: A systematic review and meta-analysis

In recent years, there has been a heightened interest in the effect of non-invasive brain stimulation on executive functioning. However, there is no comprehensive overview of its effects on different executive functioning domains in healthy individuals. Here, we assessed the state of the field by conducting a systematic review and meta-analysis on the effectiveness of non-invasive brain stimulation (i.e. repetitive transcranial magnetic stimulation and transcranial direct current stimulation) over prefrontal regions on tasks assessing working memory, inhibition, flexibility, planning and initiation performance. Our search yielded 63 studies (n = 1537), and the effectiveness of excitatory and inhibitory non-invasive brain stimulation were assessed per executive functioning task. Our analyses showed that excitatory non-invasive brain stimulation had a small but positive effect on Stop Signal Task and Go/No-Go Task performance, and that inhibitory stimulation had a small negative effect on Flanker Task performance. Non-invasive brain stimulation did not affect performance on working memory and flexibility tasks, and effects on planning tasks were inconclusive.

REACT study protocol: resilience after the COVID-19 threat (REACT) in adolescents

INTRODUCTION

COVID-19-related social isolation and stress may have significant mental health effects, including post-traumatic stress, anxiety and depression. These factors are thought to disproportionately affect populations at risk of psychopathology, such as adolescents with a history of childhood adversity (CA). Therefore, examining which factors may buffer the impact of COVID-19-related stress and isolation in vulnerable adolescents is critical. The Resilience After the COVID-19 Threat (REACT) study assesses whether emotion regulation capacity, inflammation and neuroimmune responses to stress induced in the laboratory prior to the pandemic predict responses to COVID-19-related social isolation and stress in adolescents with CA. We aim to elucidate the mechanisms that enable vulnerable adolescents to maintain or regain good mental health when confronted with COVID-19.

METHODS AND ANALYSIS

We recruited 79 adolescents aged 16-26 with CA experiences from the Resilience After Individual Stress Exposure study in which we assessed emotion regulation, neural and immune stress responses to an acute stress task. Our sample completed questionnaires at the start of the UK lockdown ('baseline'; April 2020) and three (July 2020) and 6 months later (October 2020) providing crucial longitudinal information across phases of the pandemic progression and government response. The questionnaires assess (1) mental health, (2) number and severity of life events, (3) physical health, (4) stress perception and (5) loneliness and friendship support. We will use multilevel modelling to examine whether individual differences at baseline are associated with responses to COVID-19-related social isolation and stress.

ETHICS AND DISSEMINATION

This study has been approved by the Cambridge Psychology Research Ethics Committee (PRE.2020.037). Results of the REACT study will be disseminated in publications in scientific peer-reviewed journals, presentations at scientific conferences and meetings, publications and presentations for the general public, and through social media.

Comparing objective cognitive impairments in patients with peripheral neuropathic pain or fibromyalgia

Existing studies on cognitive impairments in chronic pain do not investigate peripheral neuropathic pain (PNP) or compare pain conditions in a satisfactory manner. Here we aimed to compare executive dysfunctions in PNP patients with fibromyalgia (FM) and healthy controls (HC). Patients who self-reported cognitive impairments were assessed according to criteria for PNP or FM. Seventy-three patients met criteria and completed testing on executive functioning and IQ measures. We also included twenty matched healthy controls. Regression models controlling for age, sex and IQ, tested associations between group category (PNP, FM or HC) and outcomes. If a substantial association was detected, we followed up with head-to-head comparisons between PNP and FM. Multivariate regression models then tested associations between executive functioning and pain type, controlling for significant confounders. Results from head-to-head comparison between pain conditions showed significant differences on years lived with pain (FM > PNP), the use of anticonvulsants (PNP > FM) and use of analgesics (PNP > FM). When controlled for all significant differences, PNP patients had significantly lower scores on an attention-demanding cued-recall task compared to FM. Poor performance on attention-demanding cued-recall task was associated with PNP, which translate into problems with retaining fast-pace or advanced information.

N2b Reflects the Cognitive Changes in Executive Functioning After Concussion: A Scoping Review

Objectives: The N2b is an event-related potential (ERP) component thought to index higher-order executive function. While the impact of concussion on executive functioning is frequently discussed in the literature, limited research has been done on the role of N2b in evaluating executive functioning in patients with concussion. The aims of this review are to consolidate an understanding of the cognitive functions reflected by the N2b and to account for discrepancies in literature findings regarding the N2b and concussion.

Methods: A scoping review was conducted on studies that used the N2b to measure cognitive functioning in healthy control populations, as well as in people with concussions.

Results: Sixty-six articles that met inclusion criteria demonstrated that the N2b effectively represents stimulus-response conflict management, response selection, and response inhibition. However, the 19 included articles investigating head injury (using terms such as concussion, mild head injury, and mild traumatic brain injury) found widely varied results: some studies found the amplitude of the N2b to be increased in the concussion group, while others found it to be decreased or unchanged.

Conclusion: Based on the available evidence, differences in the amplitude of the N2b have been linked to response selection, conflict, and inhibition deficits in concussion. However, due to large variations in methodology across studies, findings about the directionality of this effect remain inconclusive. The results of this review suggest that future research should be conducted with greater standardization and consistency.

Changes in Regional Homogeneity of Medication-Free Major Depressive Disorder Patients With Different Onset Ages

Background: Neurobiological mechanisms underlying the development of major depressive disorder (MDD) may differ depending on onset ages. Our aim was to determine whether regional homogeneity (ReHo) changes in early-onset depression (EOD) and late-onset depression (LOD) are different, which could also delineate EOD and LOD. Methods: Ninety-one MDD patients and 115 healthy controls (HCs) were recruited, and resting-state functional magnetic resonance imaging data were collected. The ReHo comparison was conducted using analysis of variance. Results: Compared with HCs, MDD patients showed decreased ReHo in the left precentral gyrus and the left middle cingulum area, and increased ReHo in the left middle orbital frontal gyrus and superior temporal gyrus. Compared with LOD patients, young HC separately, EOD patients had significantly increased ReHo in the right inferior frontal triangular gyrus and the left postcentral gyrus. However, compared with young HC, EOD patients showed decreased ReHo in the right superior frontal gyrus/supplementary motor area and the right medial frontal gyrus. ReHo in the right inferior frontal triangular gyrus was negatively correlated with the severity of cognitive disturbance in LOD patients (r = -0.47, p = 0.002), but not in EOD patients (r = 0.21, p = 0.178). Conclusion: MDD patients with different onset ages may have different pathophysiological mechanisms; the EOD patients had more abnormal ReHo than LOD patients in the prefrontal lobe, especially the right inferior frontal triangular gyrus.

Hot and cold executive functions in the brain: A prefrontal-cingular network

Executive functions, or cognitive control, are higher-order cognitive functions needed for adaptive goal-directed behaviours and are significantly impaired in majority of neuropsychiatric disorders. Different models and approaches are proposed for describing how executive functions are functionally organised in the brain. One popular and recently proposed organising principle of executive functions is the distinction between hot (i.e. reward or affective-related) versus cold (i.e. purely cognitive) domains of executive functions. The prefrontal cortex is traditionally linked to executive functions, but on the other hand, anterior and posterior cingulate cortices are hugely involved in executive functions as well. In this review, we first define executive functions, their domains, and the appropriate methods for studying them. Second, we discuss how hot and cold executive functions are linked to different areas of the prefrontal cortex. Next, we discuss the association of hot versus cold executive functions with the cingulate cortex, focusing on the anterior and posterior compartments. Finally, we propose a functional model for hot and cold executive function organisation in the brain with a specific focus on the fronto-cingular network. We also discuss clinical implications of hot versus cold cognition in major neuropsychiatric disorders (depression, schizophrenia, anxiety disorders, substance use disorder, attention-deficit hyperactivity disorder, and autism) and attempt to characterise their profile according to the functional dominance or manifest of hot-cold cognition. Our model proposes that the lateral prefrontal cortex along with the dorsal anterior cingulate cortex are more relevant for cold executive functions, while the medial-orbital prefrontal cortex along with the ventral anterior cingulate cortex, and the posterior cingulate cortex are more closely involved in hot executive functions. This functional distinction, however, is not absolute and depends on several factors including task features, context, and the extent to which the measured function relies on cognition and emotion or both.

Effects of long-term cocaine self-administration on brain resting-state functional connectivity in nonhuman primates

Long-term cocaine use is associated with a variety of neural and behavioral deficits that impact daily function. This study was conducted to examine the effects of chronic cocaine self-administration on resting-state functional connectivity of the dorsal anterior cingulate (dACC) and putamen-two brain regions involved in cognitive function and motoric behavior-identified in a whole brain analysis. Six adult male squirrel monkeys self-administered cocaine (0.32 mg/kg/inj) over 140 sessions. Six additional monkeys that had not received any drug treatment for ~1.5 years served as drug-free controls. Resting-state fMRI imaging sessions at 9.4 Tesla were conducted under isoflurane anesthesia. Functional connectivity maps were derived using seed regions placed in the left dACC or putamen. Results show that cocaine maintained robust self-administration with an average total intake of 367 mg/kg (range: 299-424 mg/kg). In the cocaine group, functional connectivity between the dACC seed and regions primarily involved in motoric behavior was weaker, whereas connectivity between the dACC seed and areas implicated in reward and cognitive processing was stronger. In the putamen seed, weaker widespread connectivity was found between the putamen and other motor regions as well as with prefrontal areas that regulate higher-order executive function; stronger connectivity was found with reward-related regions. dACC connectivity was associated with total cocaine intake. These data indicate that functional connectivity between regions involved in motor, reward, and cognitive processing differed between subjects with recent histories of cocaine self-administration and controls; in dACC, connectivity appears to be related to cumulative cocaine dosage during chronic exposure.

A Possible Association Between Executive Dysfunction and Frailty in Patients With Neurocognitive Disorders

Frailty is an age-related dynamic status, characterized by a reduced resistance to stressors due to the cumulative decline of multiple physiological systems. Several researches have highlighted a relationship between physical frailty and cognitive decline; however, the role of specific cognitive domains has not been deeply clarified yet. Current studies have hypothesized that physical frailty and neuropsychological deficits may share systemic inflammation and increased oxidative stress in different neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease. However, the role of the executive dysfunction should be investigated in a more detailed way using a multidimensional approach. With this aim, we conducted a review of the literature on the few experimental articles published to discuss the existence of a relationship between frailty and cognitive impairment in neurocognitive disorders, particularly focusing on the domain of executive dysfunction. The data suggest that physical frailty and cognitive decline, especially executive dysfunction, are two aspects strongly linked in mild and major neurocognitive disorders due to Alzheimer’s and Parkinson’s disease. In light of this, a new framework linking aging, cognitive decline, and neurodegenerative diseases is needed. In order to analyze the effects that aging processes have on neural decline and neurocognitive disease, and to identify relevant groups of users and patients, future longitudinal studies should adopt a multidimensional approach, in the field of primary prevention and in the continuum from mild to major neurocognitive disorder.

Transcranial Direct Current Stimulation Improves Executive Dysfunctions in ADHD: Implications for Inhibitory Control, Interference Control, Working Memory, and Cognitive Flexibility

Objective: This study examined effects of transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) on major executive functions (EFs), including response inhibition, executive control, working memory (WM), and cognitive flexibility/task switching in ADHD. Method: ADHD children received (a) left anodal/right cathodal DLPFC tDCS and (b) sham stimulation in Experiment 1 and (a) left anodal DLPFC/right cathodal OFC tDCS, (b) left cathodal DLPFC/right anodal OFC tDCS, and (c) sham stimulation in Experiment 2. The current intensity was 1 mA for 15 min with a 72-hr interval between sessions. Participants underwent Go/No-Go task, N-back test, Wisconsin Card Sorting Test (WCST), and Stroop task after each tDCS condition. Results: Anodal left DLPFC tDCS most clearly affected executive control functions (e.g., WM, interference inhibition), while cathodal left DLPFC tDCS improved inhibitory control. Cognitive flexibility/task switching benefited from combined DLPFC-OFC, but not DLPFC stimulation alone. Conclusion: Task-specific stimulation protocols can improve EFs in ADHD.

Associations between stuttering, comorbid conditions and executive function in children: a population-based study

Background

The aim of this study was to investigate the relationship between executive function (EF), stuttering, and comorbidity by examining children who stutter (CWS) and children who do not stutter (CWNS) with and without comorbid conditions. Data from the National Health Interview Survey were used to examine behavioral manifestations of EF, such as inattention and self-regulation, in CWS and CWNS.

Methods

The sample included 2258 CWS (girls = 638, boys = 1620), and 117,725 CWNS (girls = 57,512; boys = 60,213). EF, and the presence of stuttering and comorbid conditions were based on parent report. Descriptive statistics were used to describe the distribution of stuttering and comorbidity across group and sex. Regression analyses were to determine the effects of stuttering and comorbidity on EF, and the relationship between EF and socioemotional competence.

Results

Results point to weaker EF in CWS compared to CWNS. Also, having comorbid conditions was also associated with weaker EF. CWS with comorbidity showed the weakest EF compared to CWNS with and without comorbidity, and CWS without comorbidity. Children with stronger EF showed higher socioemotional competence. A majority (60.32%) of CWS had at least one other comorbid condition in addition to stuttering. Boys who stutter were more likely to have comorbid conditions compared to girls who stutter.

Conclusion

Present findings suggest that comorbidity is a common feature in CWS. Stuttering and comorbid conditions negatively impact EF.

Cool Executive Function and Verbal Comprehension Mediate the Relation of Hot Executive Function and Theory of Mind in Children with Autism Spectrum Disorder

Impaired executive function (EF), verbal comprehension, and theory of mind (ToM) may contribute to social difficulties in children with autism spectrum disorder (ASD). The linkage between cool (cognitive) EF and ToM has been widely investigated, but the relations between hot (affective) EF and ToM remain largely unknown. The roles of cool EF and verbal comprehension have not been previously explored together to address hot EF-ToM relations. This study applied mediation analysis to investigate the mediating effects of cool EF and verbal comprehension to further elaborate the link between hot EF and ToM in children with ASD and average intellectual abilities. A total of 97 children with ASD aged from 6 to 12 years participated in this study. Children's cool EF, hot EF, and verbal comprehension were, respectively, measured with the computerized Dimensional Change Card Sort task, Children's Gambling Task, and the verbal comprehension index of the Wechsler Intelligence Scale for Children-fourth edition. Children's ToM was assessed with the Theory of Mind Task Battery. Partial correlation coefficients indicated that hot EF was significantly related with ToM with age controlled for. The results of the mediation analysis showed that cool EF and verbal comprehension mediated the linkage between hot EF and ToM. These findings highlight not only the connections between hot EF and ToM but also the importance of cool EF and verbal comprehension on hot EF-ToM relations in clinical assessments and interventions for school-aged children with ASD and average intellectual abilities. LAY SUMMARY: Relatively few studies have investigated the hot (affective) executive function (EF)-theory of mind (ToM) relations in children with autism spectrum disorder (ASD). This study discovered that hot EF was significantly related to ToM, while cool (cognitive) EF and verbal comprehension mediated the relationship between hot EF and ToM. Therefore, the influence of cool EF and verbal comprehension on hot EF-ToM relations should be considered in studies involving children with ASD. Autism Res 2021, 14: 921-931. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

β-lactolin increases cerebral blood flow in dorsolateral prefrontal cortex in healthy adults: a randomized controlled trial

The number of elderly individuals with age-related cognitive decline or dementia is rapidly increasing. Dairy product consumption, including β-lactolin, is beneficial for their cognitive function. The underlying mechanism of β-lactolin's effects on human brain activity is yet to be investigated. We examined the β-lactolin effects on human cerebral blood flow (CBF) using near-infrared spectroscopy (NIRS) in a placebo-controlled randomized double-blind study, which reported according to the CONSORT guidelines. Fifty healthy participants (aged 45-60 years) were randomly allocated into the β-lactolin or the placebo group (n = 25 each) and supplemented for 6 weeks. During the 6^th week, oxy-hemoglobin during the working memory tasks was measured using 34-channels (CHs) NIRS. The changes of oxy-hemoglobin, which represents the CBF, in CH 23 located at the left dorsolateral prefrontal cortex (DLPFC) during the spatial working memory task showed higher statistical significance (false discovery rate (q) = 0.045) in the β-lactolin than in the placebo group. The oxy-Hb changes in CH23 have a co-relationship with the working memory task reaction time. This clinical trial showed an increase in the CBF in the left DLPFC area during the 6-week β-lactolin supplementation. This study contributes to elucidating the underlying mechanisms of β-lactolin on cognitive performance.

Two Case Reports of Neuropsychological Functioning in Congenital Insensitivity to Pain with Anhidrosis (CIPA)

Individuals with congenital insensitivity to pain with anhidrosis (CIPA) are reported to have intellectual disability but to our knowledge, no detailed study about neuropsychological functioning of this condition has ever been published. The present study assessed neuropsychological outcomes of two children with CIPA using standardized neuropsychological tests. The neuropsychological assessment revealed difficulties in a wide range of cognitive, executive, and integrative functions, such as a behavioral and adaptive level. Both children with CIPA functioned in the intellectual disability range with symptoms related to an executive dysfunction and negative-oriented personal emotional processing, and limitations in academic and self-care skills.

The Effects of Mobile Texting and Walking Speed on Gait Characteristics of Normal Weight and Obese Adults

The aim of this study was to examine how usage of mobile devices while simultaneously walking affects walking characteristics and texting performance of normal weight (NW) and obese (OB) individuals. Thirty-two OB (body mass index [BMI] = 34.4) and NW (BMI = 22.7) adults performed two 60-s walking trials at three-step frequencies along a rectangular walkway in two conditions (No Texting and Texting). Dual-task cost as well as unadjusted spatial and temporal gait characteristics were measured. Dual-task costs for the gait parameters as well as texting performance were not different between the groups, except for the lateral step variability showing a larger variability at the preferred frequency in OB individuals. For the unadjusted variables, OB exhibited longer double support, longer stance time, and lower turn velocity compared with NW. Overall, the results highlight a similar dual-task cost for the OB individuals compared with the NW individuals, in spite of underlying differences in gait mechanics.

Repeated transcranial direct current stimulation of dorsolateral-prefrontal cortex improves executive functions, cognitive reappraisal emotion regulation, and control over emotional processing in borderline personality disorder: A randomized, sham-controlled, parallel-group study

BACKGROUND

Borderline personality disorder (BPD) is primarily characterized by deficient emotion regulation. Impaired cognitive control over negative emotions is central to emotion dysregulation in BPD. Respective executive dysfunctions are associated with hypoactivation of prefrontal regions, and consecutive alterations of fronto-limbic network functionality. Here, we investigated the effect of increasing activity of the dorsolateral prefrontal cortex (DLPFC) with repeated transcranial direct current stimulation (tDCS) on (1) executive dysfunctions and (2) whether improving cognitive control affects emotion dysregulation and emotional processing in BPD.

METHODS

Thirty-two patients diagnosed with BPD were randomly assigned to active stimulation (N = 16) or sham stimulation (N = 16) group in a randomized, sham-controlled, parallel-group design. They received 10 sessions of active (2 mA, 20 min, anodal left- cathodal right DLPFC) or sham tDCS over 10 days. Major executive functions, emotion regulation strategies, and emotional processing of the patients were assessed before and immediately after the intervention.

RESULTS

The active stimulation group showed a significant improvement in major executive function domains. Importantly, cognitive reappraisal strategy of emotion regulation and several factors of emotional processing involved in the control of emotion significantly improved in the active stimulation group after the intervention. Factors related to emotional expression were, however, not affected.

LIMITATIONS

The single-blind design, absence of follow-up measures, and the intrinsically limited focality of tDCS are limitations of this study.

CONCLUSIONS

Increasing activity of the DLPFC improves executive functioning in BPD and improves ´cognitive control over negative emotions. Cognitive control interventions could be a potential, symptom-driven therapeutic approach in BPD.

Neuroanatomical Differences Among Sexual Offenders: A Targeted Review with Limitations and Implications for Future Directions

As sexual assault and child sexual abuse continue to be worldwide public health concerns, research has continued to explore factors associated with sexual offending. Structural and functional neuroanatomical brain differences have been examined in an effort to differentiate sexual offenders and their behavior. This targeted review searched PubMed and Google Scholar for empirical studies using brain imaging techniques to examine possible structural or functional differences among control groups compared with at least one group of sexual offenders with contact offenses. This targeted review summarizes the structural and functional findings of 15 brain imaging studies (i.e., computed tomography, diffusion tensor imaging, magnetic resonance imaging, positron emission tomography, and functional magnetic resonance imaging), which suggest possible differences in brain size and gray matter volume, cortical thickness, white matter connectivity, and specific structural and functional differences among brain regions (fronto-temporal region, amygdala, prefrontal cortex, etc.). The methodological limitations of brain imaging studies and the associated findings with regard to sexual offenders are highlighted, as research indicates that many of the proposed differences in brain structure and function are not unique to this population. We further highlight several limitations to using neuroimaging studies to examine this population of interest, including publication bias, small sample size, underpowered studies, and all-male samples. As these results are mixed and findings are not seemingly unique to sexual offenders, we suggest future sexual offender research may benefit from focusing on more financially feasible options, such as neuropsychological assessment approaches, to assess for and attend to offenders' criminogenic and rehabilitative/therapeutic needs in alignment with the risk-need-responsivity model.

The Demands of Performance Generating Systems on Executive Functions: Effects and Mediating Processes

Performance generating systems (PGS) are rule- and task-based approaches to improvisation on stage in theater, dance, and music. These systems require performers to draw on predefined source materials (texts, scores, memories) while working on complex tasks within limiting rules. An interdisciplinary research team at a large Western Canadian University hypothesized that learning to sustain this praxis over the duration of a performance places high demands on executive functions; demands that may improve the performers' executive abilities. These performers need to continuously shift attention while remaining responsive to embodied and environmental stimuli in the present, they are required to inhibit automated responses and impulses using the rules of the system, and they strive toward addressing multitasking challenges with fluidity and flexibility. This study set out to test the mentioned hypothesis deductively and identify mediating processes inductively, using mixed empirical methods. In a small sample experiment with a control group (28 participants; 15 in intervention group, 13 in control group), standardized quantitative tests of executive functions (D-KEFS) were administered before and after an 8-week intervention. Participant-reported qualitative observations from the praxis were also collected throughout the intervention for grounded analysis. Within the limitations of small sample data, we found both statistically significant and trending effects on inhibition, problem-solving initiation, fluidity, and cognitive flexibility. Examining the mediating process, we found that participants experienced significant challenges sustaining the practice halfway through the intervention. The participant-reported solutions to these challenges, which emerged as the strongest behavioral patterns when coding the qualitative data to saturation, were strategies of problem-solving and of re-directing attention. These strategies support and advance our understanding of the effects measured in the standardized tests. In terms of application, our results identify characteristics of PGS that could potentially maintain and strengthen executive functions over and above less demanding performing arts interventions. The results also deliver new insight into how PGS works, which may contribute to the development and teaching of this artistic practice.

Subcortical neural tracks play an important role in executive function in schizophrenia: An experimental study among patients with schizophrenia and healthy comparisons

The literature has long emphasized the involvement of cortical and subcortical networks in executive function impairments among patients with schizophrenia. However, previous studies have not examined the relative involvement of monocular (mostly subcortical) versus binocular (mostly cortical) neural tracks in patients' EF deficits.

Patients with schizophrenia and healthy comparisons were administered a dichotic version of the Stroop task, in which eye-of-origin manipulation was employed to isolate the involvement of monocular (mostly subcortical; thalamic regions) versus binocular (mostly cortical; extrastriate cortex) visual pathways. The eye-of-origin manipulation, in which a color patch (e.g., a green patch) was presented to one eye, and a word (e.g., “RED”) to the other eye, enabled a split of the conflicting information between the two monocular channels. This results in the presentation of conflicting information to the higher cortical regions, but not to the lower subcortical structures. In the Stroop color task, when the monocular neural channels were not exposed to the conflicting information, the differences in task performance between the patients and the HCs significantly increased, and only the patients exhibited larger task conflict. When monocular neural channels were not exposed to the conflicting information, a robust dysfunction of the patients' group was observed. This abnormality might result from impairments in cortical regions or reduced computational power available for solving the conflict. However, additional studies that take into account the resolution of monocular and binocular neural channels are needed to enrich our understanding of the interplay between cortical and subcortical mechanisms in patients' EF deficits.

An examination of reciprocal associations between substance use and effortful control across adolescence using a bifactor model of externalizing symptoms

Early adolescence is thought to represent a window of vulnerability when exposure to substances is particularly harmful, partly because the neurotoxic effects of adolescent substance use may derail self-regulation development. However, previous studies fail to account for externalizing symptoms, such as aggression and delinquency, that accompany adolescent substance use and may also derail the development of self-regulation. The current study aims to clarify whether the neurotoxic effects of adolescent substance use are associated with deficits in effortful control (EC) after accounting for externalizing symptoms and to examine reciprocal relationships between EC, externalizing symptoms, and substance use. A longitudinal sample of adolescents (N = 387) was used to estimate bifactor models of externalizing symptoms across five assessments (Mage = 11.6 to 19.9). The broad general externalizing factors were prospectively associated with declines in EC across adolescence and emerging adulthood. However, the narrow substance use specific factors were not prospectively associated with EC. Findings suggest that the broader externalizing context, but not the specific neurotoxic effects of substance use, may hamper self-regulation development. It is critical to account for the hierarchical structure of psychopathology, namely externalizing symptoms, when considering development of EC.

Neurocognitive Correlates of Internet Search Skills for eHealth Fact and Symptom Information in a Young Adult Sample

As the Covid 19 crisis has revealed, the internet is a first-line tool for learning critical health-related information. However, internet searches are a complex and dynamic process that can be fraught with subtleties and potential error. The mechanics of searching for and using electronic health (eHealth) information is ostensibly cognitively demanding; yet we know little about the role of neurocognitive abilities in this regard. Fifty-six young adults completed two naturalistic eHealth search tasks: fact-finding (eHealth Fact) and symptom-diagnosis (eHealth Search). Participants also completed neurocognitive tests of attention, psychomotor speed, learning/memory, and executive functions. Shorter eHealth symptom-diagnosis search time was related to better executive functions, while better eHealth symptom-diagnosis search accuracy was related to better episodic and prospective memory. In contrast, neither eHealth Fact search time nor its accuracy were related to any of the neurocognitive measures. Our findings suggest a differential relationship between neurocognitive abilities and eHealth search behaviors among young adults such that higher-order abilities may be implicated in eHealth searches requiring greater synthesis of information. Future work should examine the cognitive architecture of eHealth search in persons with neurocognitive disorders, as well as that of other aspects of eHealth search behaviors (e.g., search term generation, website reliability, and decision-making).

Assessing executive functions in Brazilian children: A critical review of available tools

The goal of this review is to perform a critical analysis of the instruments used to assess executive functions (EFs) in preschool and school-age children in Brazil. We identified 37 assessment measures through a systematic review. Some performance-based tests for assessing working memory and inhibition were identified. However, there is a lack of rating measures and instruments to assess flexibility and planning in clinical practice. We observed regional differences in the performance of EFs measures. One possible explanation may be the use of normative samples from more highly-developed regions to characterize performance in less-developed regions. However, there may be alternative explanations, such as variations in the exposure to testing and the adequacy of test materials in different regions. Joint efforts among research groups should be encouraged in order to obtain normative references that are more representative of the socio-cultural diversity of the country. This improvement is essential to better understand the typical and atypical development of EFs and how the peculiarities of each country's context and culture can impact its trajectory.

Executive function in XXY: Comparison of performance-based measures and rating scales

Few studies have systematically assessed executive functioning (EF) skills in boys with XXY, and these are limited by small samples and restricted EF assessment. This study used a broader battery of performance-based measures as well as parent-rating scales of EF in 77 boys and adolescents with XXY (mean age = 12.5 years), recruited from a clinical trial and an outpatient clinic. Exploratory factor analyses were used to create EF domains from performance-based measures, and similar domains were measured using the Behavior Rating Inventory of Executive Function and Conners Parent-Rating Scales. The boys with XXY showed a distinct EF profile, with the greatest deficit in attention and more moderate deficits in working memory, switching, and planning/problem solving. Parent ratings showed similar challenges, as well as impaired inhibition. Independent sample t-tests showed no difference on performance measures between boys diagnosed or not diagnosed with attention-deficit/hyperactivity disorder (ADHD), although parents of boys diagnosed with ADHD reported more difficulties. There were no differences on performance-based tests between those diagnosed pre- and postnatally, although parents of postnatally diagnosed boys reported more metacognitive problems. Language deficits, cognition, and socio-economic status did not account for EF deficits.