Assessment of Executive and Cognitive Functions in Children with Restless Sleep Disorder: A Pilot Study.

Restless sleep disorder affects children and is characterized by frequent nocturnal movements, iron deficiency, and daytime symptoms such as poor school performance or behavioral problems. Although sleep parameters have been thoroughly studied and daytime sleepiness has been previously assessed, neurocognitive and executive functions have not. In this study, we evaluated neurocognitive functions in a group of 13 children diagnosed with restless sleep disorder using the National Institute of Health Toolbox (NIH toolbox). The mean age was 10.62 (S.D. 2.785). Among them, seven were male and six were female. The fully corrected T-scores (adjusted for demographic variables: age, ethnicity, and education level) showed the lowest values for the Flanker test (selective attention) and dimensional change card sorting test (cognitive flexibility and inhibitory control), with a very large effect size vs. the corresponding expected frequencies. For all the other tests, the average scores were 50; however, individual children scored low on pattern recognition and two composite scores (fluid and total). In conclusion, these data support the fact that cognitive functions are affected in children with restless sleep disorder, especially selective attention. Clinicians must recognize sleep disorders and daytime impairment in order to promptly intervene and prevent cognitive impairments.

Correction: One Size Does Not Fit All: Assuming the Same Normal Body Temperature for Everyone is Not Justified.

[This corrects the article DOI: 10.1371/journal.pone.0245257.].

One size does not fit all: Assuming the same normal body temperature for everyone is not justified.

Despite the increasing personalization of medicine, surprisingly ~37.0°C (98.6°F) continues as the estimate of normal temperature. We investigated between-subject and within-subject thermal variability, whether a significant percentage of individuals have a low mean oral temperature, and whether these differ by sex, age, time of day, ethnicity, body mass index (BMI), or menstrual phase. Oral temperature was measured by Life Brand® Fast-Read Digital Oral Thermometers and sampled 14 times over two weeks, seven morning and seven evening readings. The volunteer sample consisted of 96 adults (42 men, 54 women; 27 couples, 42 singletons), ages 18-67 years. We found sizeable individual differences in body temperature and that the normal temperature of many individuals is considerably lower than 37.0°C (98.6°F). Mean temperatures ranged from 35.2°C (95.4°F) to 37.4°C (99.3°F). The mean temperature across all participants was 36.1°C (97.0°F)-lower than most studies have reported, consistent with recent evidence of temperature declining over decades. 77% had mean temperatures at least 0.55°C (1°F) lower than 37.0°C (98.6°F). Mean temperature did not differ by age, but women had higher temperatures than men, even within a couple with room temperature and warmth of clothing equated. Although oral temperature varied widely across individuals, it showed marked stability within individuals over days. Variability of temperature over days did not differ by sex, but was larger among younger adults. Using 37.0°C (98.6°F) as the assumed normal temperature for everyone can result in healthcare professionals failing to detect a serious fever in individuals with a low normal temperature or obtaining false negatives for those individuals when using temperature to screen for COVID-19, mistaking their elevated temperature as normal. Some have called for lowering the estimate of normal temperature slightly (e.g., 0.2°C [0.36°F]). That still seems an overly high estimate. More important, using any standardized "normal" temperature will lead to errors for many people. Individual differences are simply too great. Personalizing body temperature is needed. Temperature could be measured at yearly doctor visits, as blood pressure is now. That would be simple to implement. Since our results show marked thermal stability within an individual, sampling temperature only once yearly could provide an accurate indication of a person's normal temperature at that time of day. Such records over time would also provide a more accurate understanding of how temperature changes over the lifespan.

First Demonstration of Double Dissociation between COMT-Met158 and COMT-Val158 Cognitive Performance When Stressed and When Calmer.

We present here the first evidence of the much-predicted double dissociation between the effect of stress on cognitive skills [executive functions (EFs)] dependent on prefrontal cortex (PFC) by catechol-O-methyltransferase (COMT) genotype. The COMT gene polymorphism with methionine (Met) at codon 158 results in more dopamine (DA) in PFC and generally better EFs, while with valine (Val) at codon 158 the result is less PFC DA and generally poorer EFs. Many have predicted that mild stress, by raising PFC DA levels should aid EFs of COMT-Vals (bringing their PFC DA levels up, closer to optimal) and impair EFs of COMT-Mets (raising their PFC DA levels past optimal). We tested 140 men and women in a within-subject crossover design using extremely mild social evaluative stress. On trials requiring EFs (incongruent trials) of the Flanker/Reverse Flanker task, COMT-Val158 homozygotes performed better when mildly stressed than when calmer, while COMT-Met158 carriers performed worse when mildly stressed. Two other teams previously tried to obtain this, but only found stress impairing EFs of COMT-Mets, not improving EFs of COMT-Vals. Perhaps we found both because we used a much milder stressor. Evidently, the bandwidth for stress having a facilitative effect on EFs is exceedingly narrow.

Executive functions.

First, executive functions are defined. Then the development of executive functions in children, from infancy to 10-11 years of age, is briefly described. The relation between the speed of processing and the development of executive functions is addressed. Finally, tools and pointers for evaluating executive functioning in younger and older children are discussed. A cautionary note is sounded, in that almost no executive function measure requires only one executive function. A child might fail a working memory task because of problems with inhibitory control (not working memory), fail an inhibitory control task because of working memory problems, or fail a cognitive flexibility, planning, or reasoning task because of problems with inhibitory control or working memory.

Children Only 3 Years Old Can Succeed at Conditional "If, Then" Reasoning, Much Earlier Than Anyone Had Thought Possible.

That conditional, if-then reasoning does not emerge until 4-5 years has long been accepted. Here we show that children barely 3 years old can do conditional reasoning. All that was needed was a superficial change to the stimuli: When color was a property of the shapes (line drawings of a star and truck) rather than of the background (as in all past conditional discrimination [CD] testing), 3-year-olds could succeed. Three-year-olds do not seem to use color to inform them which shape is correct unless color is a property of the shapes themselves. While CD requires integrating color and shape information, the dimensional change card sort (DCCS) task requires keeping those dimension cognitively separate - inhibiting attention to one (e.g., shape) when sorting by the other (e.g., color). For DCCS, a superficial change to the stimuli that is the inverse of what helps on CD enables 3-year-olds to succeed when normally they do not until ∼ 4 ⁤ 1 2 years. As we and others have previously shown, 3-year-olds can succeed at DCCS when color is a property of the background (e.g., a white truck on a red background), instead of a property of the stimulus (e.g., a red truck on a white background, as in standard DCCS). Our findings on CD and DCCS suggest that scaffolding preschoolers' emerging conceptual skills by changing the way stimuli look (perceptual bootstrapping) enables 3-year-olds to demonstrate reasoning abilities long thought beyond their grasp. Evidently, children of 3 years have difficulty mentally separating dimensions (e.g., color and shape) of the same object and difficulty mentally integrating dimensions not part of the same object. Our present CD findings plus our earlier DCCS findings provide strong evidence against prominent cognitive complexity, conditional reasoning, and graded memory theories for why 3-year-olds fail these two tasks. The ways we have traditionally queried children may have obscured the budding reasoning competencies present at 3 years of age.

Randomized control trial of Tools of the Mind: Marked benefits to kindergarten children and their teachers.

The kindergarten program, Tools of the Mind (Tools), has been shown to improve executive functions (as assessed by laboratory measures) and academic performance. The objective here was to see if Tools can improve executive functions in the real world (in the classroom), academic outcomes not previously investigated, reduce bullying and peer ostracism, and increase teachers' and students' joy in being in the classroom. This first randomized controlled trial of Tools in Canada included 351 kindergarten children (mean age 5.2 years at entry; 51% female) in 18 public schools. Stratified randomization resulted in teachers and students in both groups being closely matched. Teachers in both groups received the same number of training hours and same funds for new materials. Outcome measures were pre and post standardized academic skill assessments and teacher online survey responses. This study replicated that Tools improves reading and shows for the first time that it improves writing (far exceeding levels the school districts had seen before), self-control and attention-regulation in the real world (e.g., time on task without supervision), reduces teacher burnout and children being ostracized or excluded, and increases the joy students and teachers experience in school. By Spring, Tools teachers were still enthusiastic about teaching; control teachers were exhausted. These results were not only better than the control group but also better than Tools teachers experienced the year before Tools. Thus, children in a kindergarten curriculum that emphasized play, improving self-regulation, working together and helping one another, and hands-on learning performed better academically, showed less bullying and peer ostracism and more kindness and helping behavior than students in more traditional classes, and teacher enthusiasm for teaching soared. Tools reduced initial disparities separating children, schools, and teachers.

Maturational Changes in Human Dorsal and Ventral Visual Networks.

Developmental neuroimaging studies report the emergence of increasingly diverse cognitive functions as closely entangled with a rise-fall modulation of cortical thickness (CTh), structural cortical and white-matter connectivity, and a time-course for the experience-dependent selective elimination of the overproduced synapses. We examine which of two visual processing networks, the dorsal (DVN; prefrontal, parietal nodes) or ventral (VVN; frontal-temporal, fusiform nodes) matures first, thus leading the neuro-cognitive developmental trajectory. Three age-dependent measures are reported: (i) the CTh at network nodes; (ii) the matrix of intra-network structural connectivity (edges); and (iii) the proficiency in network-related neuropsychological tests. Typically developing children (age ~6 years), adolescents (~11 years), and adults (~21 years) were tested using multiple-acquisition structural T1-weighted magnetic resonance imaging (MRI) and neuropsychology. MRI images reconstructed into a gray/white/pial matter boundary model were used for CTh evaluation. No significant group differences in CTh and in the matrix of edges were found for DVN (except for the left prefrontal), but a significantly thicker cortex in children for VVN with reduced prefrontal ventral-fusiform connectivity and with an abundance of connections in adolescents. The higher performance in children on tests related to DVN corroborates the age-dependent MRI structural connectivity findings. The current findings are consistent with an earlier maturational course of DVN.

Effects of physical activity interventions on cognitive and academic performance in children and adolescents: a novel combination of a systematic review and recommendations from an expert panel.

OBJECTIVE: To summarise the current evidence on the effects of physical activity (PA) interventions on cognitive and academic performance in children, and formulate research priorities and recommendations. DESIGN: Systematic review (following PRISMA guidelines) with a methodological quality assessment and an international expert panel. We based the evaluation of the consistency of the scientific evidence on the findings reported in studies rated as of high methodological quality. DATA SOURCES: PubMed, PsycINFO, Cochrane Central, Web of Science, ERIC, and SPORTDiscus. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: PA-intervention studies in children with at least one cognitive or academic performance assessment. RESULTS: Eleven (19%) of 58 included intervention studies received a high-quality rating for methodological quality: four assessed effects of PA interventions on cognitive performance, six assessed effects on academic performance, and one on both. All high-quality studies contrasted the effects of additional/adapted PA activities with regular curriculum activities. For cognitive performance 10 of 21 (48%) constructs analysed showed statistically significant beneficial intervention effects of PA, while for academic performance, 15 of 25 (60%) analyses found a significant beneficial effect of PA. Across all five studies assessing PA effects on mathematics, beneficial effects were reported in six out of seven (86%) outcomes. Experts put forward 46 research questions. The most pressing research priority cluster concerned the causality of the relationship between PA and cognitive/academic performance. The remaining clusters pertained to PA characteristics, moderators and mechanisms governing the 'PA-performance' relationship and miscellaneous topics. CONCLUSION: There is currently inconclusive evidence for the beneficial effects of PA interventions on cognitive and overall academic performance in children. We conclude that there is strong evidence for beneficial effects of PA on maths performance.The expert panel confirmed that more 'high-quality' research is warranted. By prioritising the most important research questions and formulating recommendations we aim to guide researchers in generating high-quality evidence. Our recommendations focus on adequate control groups and sample size, the use of valid and reliable measurement instruments for physical activity and cognitive performance, measurement of compliance and data analysis. PROSPERO REGISTRATION NUMBER: CRD42017082505.

Children's stress regulation mediates the association between prenatal maternal mood and child executive functions for boys, but not girls.

Prenatal exposure to maternal mood disturbances shapes children's cognitive development reflected in the critical construct of executive functions (EFs). Little is known, however, about underlying mechanisms. By examining cortisol responses in both everyday and lab challenge settings, we tested whether the child/offspring hypothalamic-pituitary-adrenal axis mediates effects of prenatal maternal mood on child EFs at age 6. In 107 Canadian children born to women with a wide range of anxious and depressive symptoms during pregnancy, we found that in boys but not girls, depressed and/or anxious prenatal maternal mood is associated with heightened diurnal cortisol levels in everyday settings, as well as heightened cortisol reactivity to a lab challenge and that this heightened reactivity was associated with poorer EFs. Among boys we also observed that cortisol reactivity but not diurnal cortisol mediated the association between depressed and/or anxious prenatal maternal mood and EFs. Depressed and/or anxious prenatal maternal mood was related to child EFs for both girls and boys. To our knowledge, this is the first study to demonstrate a mediating role for child stress regulation in the association between prenatal maternal stress-related mood disturbances and child EFs, providing evidence of a mechanism contributing to fetal programming of cognition.

Maternal depression trajectories from pregnancy to 3 years postpartum are associated with children's behavior and executive functions at 3 and 6 years.

The objective of this study was to investigate how patterns of maternal depressive symptoms from mid-pregnancy to 3 years postpartum are associated with children's behavior at age 3 years and executive functions. Maternal depressive symptoms were measured from mid-pregnancy to 3 years postpartum. Growth mixture modeling was used on standardized maternal depression scores (n = 147) to identify trajectories. Children's behavioral problems and mental health symptomatology (internalizing, externalizing, and attention deficit hyperactivity disorder) were obtained at 3 and 6 years. EFs were assessed by a laboratory-based computerized task and maternal-report at 6 years. Multivariable linear regressions of children's outcomes against maternal depressive symptom trajectories were conducted (n = 103). Three distinct patterns of maternal depressive symptom trajectories were identified: low (n = 105), increasing (n = 27), and decreasing (n = 15). Children of mothers whose depressive symptoms increased reported more problem behaviors at 3 years and poorer EFs at 6 years as assessed by both instruments, but no significant differences in mental health symptomatology at 6 years, relative to those whose mothers had consistently low depressive symptoms. Children whose mothers became less depressed over time had comparable levels of behavioral problems at age 3, executive functions, and internalizing and externalizing scores at age 6; and fewer reported ADHD behaviors at age 6, than those whose mothers remained less depressed over time. If mothers' depressive symptoms improve over the first 3 years postpartum, their children's outlook may be comparable to those whose mothers had consistently low depressive symptoms.

Do children need reminders on the Day-Night task, or simply some way to prevent them from responding too quickly?

We previously reported better performance on the Day-Night task when a ditty was chanted between stimulus presentation and when children could respond (Diamond, Kirkham, & Amso, 2002). Here we investigated competing hypotheses about why the ditty helps. Does it help because it imposes a brief waiting time (the child waits while the ditty is chanted before responding)? Or, does the ditty help because of its content, providing information helpful to performing the task? One-third of the 72 children (age 4) were tested with the ditty previously used which reminds them: "Think about the answer; don't tell me." Another 24 children were tested with a ditty with no task-relevant content: "I hope you have a nice time; I like you." One-third received the standard condition. Performance in both ditty conditions was comparable and better than in the standard condition. That indicates that a factor common to both ditties (that chanting them took time, allowing the prepotent response to subside and the more-considered answer to reach response threshold) likely accounts for their benefit. Whether a ditty reminded children what to do or not did not affect the results. The challenge of the Day-Night task for preschoolers is not its working memory demands but the need to inhibit a dominant response, making a different response instead.

Conclusions about interventions, programs, and approaches for improving executive functions that appear justified and those that, despite much hype, do not.

The 'Executive Functions' (EFs) of inhibitory control, working memory, and cognitive flexibility enable us to think before we act, resist temptations or impulsive reactions, stay focused, reason, problem-solve, flexibly adjust to changed demands or priorities, and see things from new and different perspectives. These skills are critical for success in all life's aspects and are sometimes more predictive than even IQ or socioeconomic status. Understandably, there is great interest in improving EFs. It's now clear they can be improved at any age through training and practice, much as physical exercise hones physical fitness. However, despite claims to the contrary, wide transfer does not seem to occur and 'mindless' aerobic exercise does little to improve EFs. Important questions remain: How much can EFs be improved (are benefits only superficial) and how long can benefits be sustained? What are the best methods for improving EFs? What about an approach accounts for its success? Do the answers to these differ by individual characteristics such as age or gender? Since stress, sadness, loneliness, or poor health impair EFs, and the reverse enhances EFs, we predict that besides directly train EFs, the most successful approaches for improving EFs will also address emotional, social, and physical needs.

Research that Helps Move Us Closer to a World where Each Child Thrives.

Schools are curtailing programs in arts, physical exercise, and play so more time and resources can be devoted to academic instruction. Yet indications are that the arts (e.g., music, dance, or theatre) and physical activity (e.g., sports, martial arts, or youth circus) are crucial for all aspects of children's development - including success in school. Thus in cutting those activities, schools may be impeding academic success, not aiding it. Correlational and retrospective studies have laid the groundwork, as have moving personal accounts, case studies, and theoretical arguments. The time is ripe for rigorous studies to investigate causality (Do arts and physical activities actually produce academic benefits or would kids in those activities have succeeded anyway?) and what characteristics of programs account for the benefits. Instead of simply claiming that the arts and/or physical activities can transform kids' lives, that needs to be demonstrated, and granting agencies need to be more open to funding rigorous research of real-world arts and physical-activity programs.

Effects of Physical Exercise on Executive Functions: Going beyond Simply Moving to Moving with Thought.

Studies of the cognitive benefits of physical activity need to move beyond simple aerobic activities that require little thought (treadmill running, riding a stationary bicycle, or rapid walking) and resistance training. Many studies have looked at this in older adults, and the evidence points strongly to those activities having little or no cognitive benefit, certainly little or no improvement to the executive functions that depend on prefrontal cortex. There is encouraging evidence for other types of physical activity improving executive functions; however they have received far less study.

Enhancing cognitive and social-emotional development through a simple-to-administer mindfulness-based school program for elementary school children: a randomized controlled trial.

The authors hypothesized that a social and emotional learning (SEL) program involving mindfulness and caring for others, designed for elementary school students, would enhance cognitive control, reduce stress, promote well-being and prosociality, and produce positive school outcomes. To test this hypothesis, 4 classes of combined 4th and 5th graders (N = 99) were randomly assigned to receive the SEL with mindfulness program versus a regular social responsibility program. Measures assessed executive functions (EFs), stress physiology via salivary cortisol, well-being (self-reports), prosociality and peer acceptance (peer reports), and math grades. Relative to children in the social responsibility program, children who received the SEL program with mindfulness (a) improved more in their cognitive control and stress physiology; (b) reported greater empathy, perspective-taking, emotional control, optimism, school self-concept, and mindfulness, (c) showed greater decreases in self-reported symptoms of depression and peer-rated aggression, (d) were rated by peers as more prosocial, and (e) increased in peer acceptance (or sociometric popularity). The results of this investigation suggest the promise of this SEL intervention and address a lacuna in the scientific literature-identifying strategies not only to ameliorate children's problems but also to cultivate their well-being and thriving. Directions for future research are discussed.

An effect of inhibitory load in children while keeping working memory load constant.

Children are slower and more error-prone when the correct response is counter to their initial inclination (incongruent trials) than when they just need to do what comes naturally (congruent trials). Children are almost always tested on a congruent-trial block and then on an incongruent-trial block. That order of testing makes it impossible to determine whether worse performance on incongruent trials is due to the need to inhibit a pre-potent response, the need to clear the rule for Block 1 from working memory, some other demand of task-switching, or some combination of these. However, if the congruent block and incongruent blocks each have only one rule (e.g., "press on the same side as the stimulus" for congruent trials and "press on the side opposite the stimulus" for incongruent trials, as on the hearts and flowers task) and children's performance when the incongruent block is presented first is fully comparable to their performance when it is presented second, the only possible explanation for their worse performance on incongruent versus congruent trials would seem to be the added inhibitory demand on incongruent trials. Certainly, worse performance on Block 1 would not be due to inefficient clearing of working memory or task-switching demands. We tested 96 children (49 girls) 6-10 years of age on the hearts and flowers test with order of congruent and incongruent blocks counterbalanced across children. Children were slower and made more errors on incongruent trials regardless of task order. We expected task-switching demands to account for some of the variance, but to our surprise, performance was fully comparable on the incongruent block whether it came first or second. These results indicate that increasing inhibitory demands alone is sufficient to impair children's performance in the face of no change in working memory demands, suggesting that inhibition is a separate mental function from working memory.