A preliminary neuroimaging investigation of the effects of mindfulness training on attention reorienting and amygdala reactivity to emotional faces in adolescent and adult females.

INTRODUCTION: Adolescence is a time of increased emotional reactivity and improving cognitive control. Mindfulness meditation training may foster adolescents' cognitive control and emotional regulation skills; however little is known about the impact of mindfulness training in adolescents compared to adults. We examined the effect of mindfulness meditation versus a closely matched active control condition (relaxation training) on behavioral and neural measures of cognitive control and emotional reactivity in a small group of adolescents and adults. METHODS: Structural and functional magnetic resonance imaging data were collected before and after 8 weeks of training in 26 adolescent (12-14 years) and 17 adult (23-33 years) female participants in the United Kingdom while they completed an n-back task with emotional face distractors and an attentional control task. Participants of each group chose a class date/time and the classes were then randomly allocated to mindfulness or relaxation conditions. RESULTS: Compared to relaxation training, mindfulness training led to an increase in the speed of reorienting attention across age groups. In addition, there was preliminary evidence for reduced amygdala response to emotional face distractors in adolescents after mindfulness training. CONCLUSIONS: An 8-week mindfulness program showed similar facilitative effects in adolescent and adult females on the reorienting of attention, a skill that is repeatedly practiced during mindfulness meditation. Mindfulness also reduced left amygdala reactivity to emotional face distractors in adolescents only. Mindfulness meditation practice can therefore have a facilitative effect on female adolescents' attentional control, and possibly attenuate their emotional reactivity.

Neural and Cognitive Underpinnings of Counterintuitive Science and Math Reasoning in Adolescence.

Reasoning about counterintuitive concepts in science and math is thought to require suppressing naive theories, prior knowledge, or misleading perceptual cues through inhibitory control. Neuroimaging research has shown recruitment of pFC regions during counterintuitive reasoning, which has been interpreted as evidence of inhibitory control processes. However, the results are inconsistent across studies and have not been directly compared with behavior or brain activity during inhibitory control tasks. In this fMRI study, 34 adolescents (aged 11-15 years) answered science and math problems and completed response inhibition tasks (simple and complex go/no-go) and an interference control task (numerical Stroop). Increased BOLD signal was observed in parietal (Brodmann's area 40) and prefrontal (Brodmann's area 8, 45/47) cortex regions in counterintuitive problems compared with control problems, where no counterintuitive reasoning was required, and in two parietal clusters when comparing correct counterintuitive reasoning to giving the incorrect intuitive response. There was partial overlap between increases in BOLD signal in the complex response inhibition and interference control tasks and the science and math contrasts. However, multivariate analyses suggested overlapping neural substrates in the parietal cortex only, in regions typically associated with working memory and visuospatial attentional demands rather than specific to inhibitory control. These results highlight the importance of using localizer tasks and a range of analytic approach to investigate to what extent common neural networks underlie performance of different cognitive tasks and suggests visuospatial attentional skills may support counterintuitive reasoning in science and math.

Post-error slowing: Large scale study in an online learning environment for practising mathematics and language.

The ability to monitor and adjust our performance is crucial for adaptive behaviour, a key component of human cognitive control. One widely studied metric of this behaviour is post-error slowing (PES), the finding that humans tend to slow down their performance after making an error. This study is a first attempt at generalizing the effect of PES to an online adaptive learning environment where children practise mathematics and language skills. This population was of particular interest since the major development of error processing occurs during childhood. Eight million response patterns were collected from 150,000 users aged 5 to 13 years old for 6 months, across 23 different learning activities. PES could be observed in most learning activities and greater PES was associated with greater post-error accuracy. PES also varied as a function of several variables. At the task level, PES was greater when there was less time pressure, when errors were slower, and in learning activities focusing on mathematical rather than language skills. At the individual level, students who chose the most difficult level to practise and had higher skill ability also showed greater PES. Finally, non-linear developmental differences in error processing were found, where the PES magnitude increased from 6 to 9-years-old and decreased from 9 to 13. This study shows that PES underlies adaptive behaviour in an educational context for primary school students.

Modulatory effects of SES and multilinguistic experience on cognitive development: a longitudinal data analysis of multilingual and monolingual adolescents from the SCAMP cohort.

Previous research has shown that cognitive development is sensitive to socio-economic status (SES) and multilinguistic experiences. However, these effects are difficult to disentangle and SES may modulate the effects of multilingualism. The present study used data from a large cohort of pupils who took part in the Study of Cognition, Adolescents and Mobile Phones (SCAMP) at ages 11-12 (T1) and 13-15 years old (T2). Cognitive measures were derived from tasks of cognitive flexibility, verbal, spatial and visuo-spatial working memory, speech processing and non-verbal reasoning. Using SES information collected through questionnaires (school type, level of deprivation, parental education and occupation), the sample was clustered into high/medium/low SES groups. Comparisons focused on 517 monolingual and 329 multilingual pupils in the high/low SES groups. Having controlled for multiple comparisons, the results indicated a significant beneficial effect of bilingualism in measures of working memory, visuo-spatial processing and non-verbal reasoning. These effects were present in both high and low SES individuals and sustained at both times of development, with a particularly significant improvement of working memory abilities in low SES bilinguals at T2 as compared to monolingual peers. Theoretical and practical implications of these findings are considered and guidance for educators is discussed.

Digital Technology Use and BMI: Evidence From a Cross-sectional Analysis of an Adolescent Cohort Study.

BACKGROUND: The use of digital technology such as mobile phones is ubiquitous in adolescents. However, excessive use may have adverse health effects, possibly partially mediated by disruptions to sleep. OBJECTIVE: This study aims to assess the social predictors of digital technology use and their cross-sectional association with BMI z scores and being overweight in a large sample of adolescents. METHODS: We used baseline data from a subset of a large adolescent cohort from 39 schools across Greater London who participated in the Study of Cognition, Adolescents and Mobile Phones (n=1473). Digital technology use included phone calls, internet use on mobile phones, and video gaming on any device. Multilevel regression was used to assess the associations between digital technology use and age-specific and sex-specific BMI z scores and being overweight (including obesity). Measurements were derived from height and weight, obtained by the Tanita BC-418 Body Composition Analyzer. We examined whether these associations were mediated by insufficient sleep. RESULTS: Generally, participants with lower socioeconomic status reported more use of digital technology. Controlling for socioeconomic status, internet use on mobile phones for more than 3 hours per day was associated with higher BMI z scores (adjusted ß=.30, 95% CI 0.11-0.48) and greater odds of being overweight (adjusted odds ratio 1.60, 95% CI 1.09-2.34), compared with low use (≤30 minutes). Similar associations were found between video gaming and BMI z scores and being overweight. The BMI z score was more strongly related to weekday digital technology use (internet use on mobile phones and video gaming) than weekend use. Insufficient sleep partly mediated the associations between digital technology use and BMI z scores (proportion of mediation from 8.6% to 17.8%) by an indirect effect. CONCLUSIONS: We found an association between digital technology use and BMI in adolescents, partly mediated by insufficient sleep, suggesting that the underlying mechanisms may be multifactorial. Further research with longitudinal data is essential to explore the direction of the relationships.

Internalising and externalising in early adolescence predict later executive function, not the other way around: a cross-lagged panel analysis.

Developmental changes in the brain networks involved in emotion regulation are thought to contribute to vulnerability to mental health problems during adolescence. Executive control is often viewed as allowing top-down regulation of emotional responses. However, while associations between executive control and mental health are commonly observed in both clinical and non-clinical populations, the direction of these associations remains unclear. Low, or immature, cognitive control could limit emotion regulation. Reversely, high emotionality could impede cognitive functioning. The scarcity of longitudinal studies testing for bi-directional effects, particularly in adolescence, has made it difficult to draw conclusions. This study analysed data from 1,445 participants of a longitudinal cohort in a cross-lagged panel design to understand bi-directional longitudinal associations between executive function and emotional behaviours across adolescence. Executive function was assessed using experimental working memory and inhibitory control tasks, emotional behaviours through parental report of internalising and externalising behaviours. Cross-sectional associations were replicated. Controlling for cross-sectional associations, early executive functions were not found to predict later emotional behaviours. Instead, early emotional behaviours predicted later executive function, with the strongest link observed between early externalising and later working memory. These results suggest that emotional well-being may affect the maturation of executive function during adolescence.

Sustained and Transient Processes in Event-based Prospective Memory in Adolescence and Adulthood.

Prospective memory (PM) refers to the cognitive processes associated with remembering to perform an intended action after a delay. Varying the salience of PM cues while keeping the intended response constant, we investigated the extent to which participants relied on strategic monitoring, through sustained, top-down control, or on spontaneous retrieval via transient bottom-up processes. There is mixed evidence regarding developmental improvements in event-based PM performance after the age of 13 years. We compared PM performance and associated sustained and transient neural correlates in 28 typically developing adolescents (12-17 years old) and 19 adults (23-30 years old). Lower PM cue salience associated with slower ongoing task (OT) RTs, reflected by increased µ ex-Gaussian parameter, and sustained increases in frontoparietal activation during OT blocks, both thought to reflect greater proactive control supporting cue monitoring. Behavioral and neural correlates of PM trials were not specifically modulated by cue salience, revealing little difference in reactive control between conditions. The effect of cue salience was similar across age groups, suggesting that adolescents are able to adapt proactive control engagement to PM task demands. Exploratory analyses showed that younger, but not older, adolescents were less accurate and slower in PM trials relative to OT trials than adults and showed greater transient activation in PM trials in an occipito-temporal cluster. These results provide evidence of both mature and still maturing aspects of cognitive processes associated with implementation of an intention after a delay during early adolescence.

Development of dopaminergic genetic associations with visuospatial, verbal and social working memory.

Dopamine transmission in the prefrontal cortex (PFC) supports working memory (WM), the temporary holding, processing and manipulation of information in one's mind. The gene coding the catechol-O-methyltransferase (COMT) enzyme, which degrades dopamine, in particular in the PFC, has a common single nucleotide polymorphism leading to two versions of the COMT enzyme which vary in their enzymatic activity. The methionine (Met) allele has been associated with higher WM performance and lower activation of the PFC in executive function tasks than the valine (Val) allele. In a previous study, COMT genotype was associated with performance on verbal and visuospatial WM tasks in adults, as well as with performance on a novel social WM paradigm that requires participants to maintain and manipulate information about the traits of their friends or family over a delay. Here, data collected in children and adolescents (N = 202) were compared to data from the adult sample (N = 131) to investigate possible age differences in genetic associations. Our results replicate and extend previous work showing that the pattern of superior WM performance observed in Met/Met adults emerges during development. These findings are consistent with a decrease in prefrontal dopamine levels during adolescence. Developmentally moderated genetic effects were observed for both visuospatial and social WM, even when controlling for non-social WM performance, suggesting that the maintenance and manipulation of social information may also recruit the dopamine neurotransmitter system. These findings show that development should be considered when trying to understand the impact of genetic polymorphisms on cognitive function.

Should online math learning environments be tailored to individuals' cognitive profiles?

Online learning environments are well-suited for tailoring the learning experience of children individually and on a large scale. An environment such as Math Garden allows children to practice exercises adapted to their specific mathematical ability; this is thought to maximize their mathematical skills. In the current experiment, we investigated whether learning environments should also consider the differential impact of cognitive load on children's math performance depending on their individual verbal working memory (WM) and inhibitory control (IC) capacity. A total of 39 children (8-11 years old) performed a multiple-choice computerized arithmetic game. Participants were randomly assigned to two conditions where the visibility of time pressure, a key feature in most gamified learning environments, was manipulated. Results showed that verbal WM was positively associated with arithmetic performance in general but that higher IC predicted better performance only when the time pressure was not visible. This effect was mostly driven by the younger children. Exploratory analyses of eye-tracking data (N = 36) showed that when time pressure was visible, children attended more often to the question (e.g., 6 × 8). In addition, when time pressure was visible, children with lower IC, in particular younger children, attended more often to answer options representing operant confusion (e.g., 9 × 4 = 13) and visited more answer options before responding. These findings suggest that tailoring the visibility of time pressure, based on a child's individual cognitive profile, could improve arithmetic performance and may in turn improve learning in online learning environments.

Total recall in the SCAMP cohort: Validation of self-reported mobile phone use in the smartphone era.

Mobile phone use, predominantly smartphones, is almost ubiquitous amongst both adults and children. However adults and children have different usage patterns. A major challenge with research on mobile phone use is the reliability of self-reported phone activity for accurate exposure assessment. We investigated the agreement between self-reported mobile phone use data and objective mobile operator traffic data in a subset of adolescents aged 11-12 years participating in the Study of Cognition, Adolescents and Mobile Phones (SCAMP) cohort. We examined self-reported mobile phone use, including call frequency, cumulative call time duration and text messages sent among adolescents from SCAMP and matched these data with records provided by mobile network operators (n = 350). The extent of agreement between self-reported mobile phone use and mobile operator traffic data use was evaluated using Cohen's weighted Kappa (ĸ) statistics. Sensitivity and specificity of self-reported low (< 1 call/day, ≤ 5min of call/day or ≤ 5 text messages sent/day) and high (≥ 11 calls/day, > 30min of call/day or ≥ 11 text messages sent /day) use were estimated. Agreement between self-reported mobile phone use and mobile operator traffic data was highest for the duration spent talking on mobile phones per day on weekdays (38.9%) and weekends (29.4%) compared to frequency of calls and number of text messages sent. Adolescents overestimated their mobile phone use during weekends compared to weekdays. Analysis of agreement showed little difference overall between the sexes and socio-economic groups. Weighted kappa between self-reported and mobile operator traffic data for call frequency during weekdays was κ = 0.12, 95% CI 0.06-0.18. Of the three modes of mobile phone use measured in the questionnaire, call frequency was the most sensitive for low mobile phone users on weekdays and weekends (77.1, 95% CI: 69.3-83.7 and 72.0, 95% CI: 65.0-78.4, respectively). Specificity was moderate to high for high users with the highest for call frequency during weekdays (98.4, 95% CI: 96.4-99.5). Despite differential agreement between adolescents' self-reported mobile phone use and mobile operator traffic data, our findings demonstrate that self-reported usage adequately distinguishes between high and low use. The greater use of mobile smartphones over Wi-Fi networks by adolescents, as opposed to mobile phone networks, means operator data are not the gold standard for exposure assessment in this age group. This has important implications for epidemiologic research on the health effects of mobile phone use in adolescents.

Social and Nonsocial Relational Reasoning in Adolescence and Adulthood.

Reasoning during social interactions requires the individual manipulation of mental representations of one's own traits and those of other people as well as their joint consideration (relational integration). Research using nonsocial paradigms has linked relational integration to activity in the rostrolateral PFC. Here, we investigated whether social reasoning is supported by the same general system or whether it additionally relies on regions of the social brain network, such as the medial PFC. We further assessed the development of social reasoning. In the social task, participants evaluated themselves or a friend, or compared themselves with their friend, on a series of traits. In the nonsocial task, participants evaluated their hometown or another town or compared the two. In a behavioral study involving 325 participants (11-39 years old), we found that integrating relations, compared with performing single relational judgments, improves during adolescence, both for social and nonsocial information. Thirty-nine female participants (10-31 years old) took part in a neuroimaging study using a similar task. Activation of the relational integration network, including the rostrolateral PFC, was observed in the comparison condition of both the social and nonsocial tasks, whereas the medial PFC showed greater activation when participants processed social as opposed to nonsocial information across conditions. Developmentally, the right anterior insula showed greater activity in adolescents compared with adults during the comparison of nonsocial versus social information. This study shows parallel recruitment of the social brain and the relational reasoning network during the relational integration of social information in adolescence and adulthood.

Development of online use of theory of mind during adolescence: An eye-tracking study.

We investigated the development of theory of mind use through eye-tracking in children (9-13years old, n=14), adolescents (14-17.9years old, n=28), and adults (19-29years old, n=23). Participants performed a computerized task in which a director instructed them to move objects placed on a set of shelves. Some of the objects were blocked off from the director's point of view; therefore, participants needed to take into consideration the director's ignorance of these objects when following the director's instructions. In a control condition, participants performed the same task in the absence of the director and were told that the instructions would refer only to items in slots without a back panel, controlling for general cognitive demands of the task. Participants also performed two inhibitory control tasks. We replicated previous findings, namely that in the director-present condition, but not in the control condition, children and adolescents made more errors than adults, suggesting that theory of mind use improves between adolescence and adulthood. Inhibitory control partly accounted for errors on the director task, indicating that it is a factor of developmental change in perspective taking. Eye-tracking data revealed early eye gaze differences between trials where the director's perspective was taken into account and those where it was not. Once differences in accuracy rates were considered, all age groups engaged in the same kind of online processing during perspective taking but differed in how often they engaged in perspective taking. When perspective is correctly taken, all age groups' gaze data point to an early influence of perspective information.

The audience effect in adolescence depends on who's looking over your shoulder.

Adolescents have been shown to be particularly sensitive to peer influence. However, the data supporting these findings have been mostly limited to the impact of peers on risk-taking behaviours. Here, we investigated the influence of peers on performance of a high-level cognitive task (relational reasoning) during adolescence. We further assessed whether this effect on performance was dependent on the identity of the audience, either a friend (peer) or the experimenter (non-peer). We tested 24 younger adolescent (10.6-14.2 years), 20 older adolescent (14.9-17.8 years) and 20 adult (21.8-34.9 years) female participants. The presence of an audience affected adolescent, but not adult, relational reasoning performance. This audience effect on adolescent performance was influenced by the participants' age, task difficulty and the identity of the audience. These findings may have implications for education, where adolescents often do classwork or homework in the presence of others.

Developmental changes in effective connectivity associated with relational reasoning.

Rostrolateral prefrontal cortex (RLPFC) is part of a frontoparietal network of regions involved in relational reasoning, the mental process of working with relationships between multiple mental representations. RLPFC has shown functional and structural changes with age, with increasing specificity of left RLPFC activation for relational integration during development. Here, we used dynamic causal modeling (DCM) to investigate changes in effective connectivity during a relational reasoning task through the transition from adolescence into adulthood. We examined fMRI data of 37 healthy female participants (11­30 years old) performing a relational reasoning paradigm. Comparing relational integration to the manipulation of single relations revealed activation in five regions: the RLPFC, anterior insula, dorsolateral PFC, inferior parietal lobe, and medial superior frontal gyrus. We used a new exhaustive search approach and identified a full DCM model, which included all reciprocal connections between the five clusters in the left hemisphere, as the optimal model. In line with previous resting state fMRI results, we showed distinct developmental effects on the strength of long-range frontoparietal versus frontoinsular short-range fixed connections. The modulatory connections associated with relational integration increased with age. Gray matter volume in left RLPFC, which decreased with age, partly accounted for changes in fixed PFC connectivity. Finally, improvements in relational integration performance were associated with greater modulatory and weaker fixed PFC connectivity. This pattern provides further evidence of increasing specificity of left PFC function for relational integration compared to the manipulation of single relations, and demonstrates an association between effective connectivity and performance during development.

Developmental inter-relations between early maternal depression, contextual risks, and interpersonal stress, and their effect on later child cognitive functioning.

BACKGROUND: Maternal depression and contextual risks (e.g. poverty) are known to impact children's cognitive and social functioning. However, few published studies have examined how stress in the social environment (i.e. interpersonal stress) might developmentally inter-relate with maternal depression and contextual risks to negatively affect a child in these domains. This was the purpose of the current study. METHOD: Mother-child pairs (n = 6979) from the Avon Longitudinal Study of Parents were the study participants. Mothers reported on depression, contextual risks, and interpersonal stress between pregnancy and 33 months child age. At age 8, the children underwent cognitive assessments and the mothers reported on the children's social cognitive skills. RESULTS: Maternal depression, contextual risks, and interpersonal stress showed strong continuity and developmental inter-relatedness. Maternal depression and contextual risks directly predicted a range of child outcomes, including executive functions and social cognitive skills. Interpersonal stress worked indirectly via maternal depression and contextual risks to negatively affect child outcomes. CONCLUSION: Maternal depression and contextual risks each increased interpersonal stress in the household, which, in turn, contributed to reduced child cognitive and social functioning.

Trust and social reciprocity in adolescence--a matter of perspective-taking.

Changes in social behaviour from childhood to adulthood have been suggested to be driven by an increased sensitivity to others' perspectives. Yet, the link between perspective-taking and social processes, such as trust and reciprocity, has rarely been investigated during adolescence. Using two trust games with a cooperative and an unfair counterpart and an online perspective-taking task with 50 adolescents, we show that those with a higher perspective-taking tendency demonstrate greater trust towards others and higher levels of trust during cooperative interactions. Both low and high perspective-takers adapted their levels of trust in response to unfair behaviour. However, high perspective-takers reduced their trust more drastically and showed more malevolent and less benevolent tit-for-tat when they were treated unfairly by their counterpart. The findings suggest that a higher perspective-taking tendency in adolescence is associated with specific mechanisms of trust and reciprocity, as opposed to undifferentiated increases in positive social behaviour towards others.

Dynamic causal modelling of effective connectivity during perspective taking in a communicative task.

Previous studies have shown that taking into account another person's perspective to guide decisions is more difficult when their perspective is incongruent from one's own compared to when it is congruent. Here we used dynamic causal modelling (DCM) for functional magnetic resonance imaging (fMRI) to investigate effective connectivity between prefrontal and posterior brain regions in a task that requires participants to take into account another person's perspective in order to guide the selection of an action. Using a new procedure to score model evidence without computationally costly estimation, we conducted an exhaustive search for the best of all possible models. The results elucidate how the activity in the areas from our previously reported analysis (Dumontheil et al., 2010) are causally linked and how the connections are modulated by both the social as well as executive task demands of the task. We find that the social demands modulate the backward connections from the medial prefrontal cortex (MPFC) more strongly than the forward connections from the superior occipital gyrus (SOG) and the medial temporal gyrus (MTG) to the MPFC. This was also the case for the backward connection from the MTG to the SOG. Conversely, the executive task demands modulated the forward connections of the SOG and the MTG to the MPFC more strongly than the backward connections. We interpret the results in terms of hierarchical predictive coding.

Brain activity during a visuospatial working memory task predicts arithmetical performance 2 years later.

Visuospatial working memory (WM) capacity is highly correlated with mathematical reasoning abilities and can predict future development of arithmetical performance. Activity in the intraparietal sulcus (IPS) during visuospatial WM tasks correlates with interindividual differences in WM capacity. This region has also been implicated in numerical representation, and its structure and activity reflect arithmetical performance impairments (e.g., dyscalculia). We collected behavioral (N = 246) and neuroimaging data (N = 46) in a longitudinal sample to test whether IPS activity during a visuospatial WM task could provide more information than psychological testing alone and predict arithmetical performance 2 years later in healthy participants aged 6-16 years. Nonverbal reasoning and verbal and visuospatial WM measures were found to be independent predictors of arithmetical outcome. In addition, WM activation in the left IPS predicted arithmetical outcome independently of behavioral measures. A logistic model including both behavioral and imaging data showed improved sensitivity by correctly classifying more than twice as many children as poor arithmetical performers after 2 years than a model with behavioral measures only. These results demonstrate that neuroimaging data can provide useful information in addition to behavioral assessments and be used to improve the identification of individuals at risk of future low academic performance.

The development of metacognitive ability in adolescence.

Introspection, or metacognition, is the capacity to reflect on our own thoughts and behaviours. Here, we investigated how one specific metacognitive ability (the relationship between task performance and confidence) develops in adolescence, a period of life associated with the emergence of self-concept and enhanced self-awareness. We employed a task that dissociates objective performance on a visual task from metacognitive ability in a group of 56 participants aged between 11 and 41 years. Metacognitive ability improved significantly with age during adolescence, was highest in late adolescence and plateaued going into adulthood. Our results suggest that awareness of one's own perceptual decisions shows a prolonged developmental trajectory during adolescence.

Multi-level meta-analysis of whether fostering creativity during physical activity interventions increases their impact on cognitive and academic outcomes during childhood.

Neuroplasticity research supports the idea that varied practice and new environments promote cognitive engagement and enhance learning. Expanding on a meta-analysis of the effect of physical activity interventions on cognition and academic outcomes, we reviewed and quantified the impact of task and environmental factors that foster creative physical activity. Interventions were considered as fostering creative physical activity to a greater extent if (1) they were varied, (2) relied less on technical acquisition, instruction or demonstration, (3) involved open spaces, props, or open-ended instructions, and (4) involved interactions with peers. A wide range of physical activities were considered, from dance to aerobic exercise across 92 studies in 5-12-year-old children. Creativity ratings of physical activity interventions were varied but did not associate with greater beneficial effects on executive functions (k = 45), academic achievement (k = 47), or fluid intelligence (k = 8). Studies assessing on-task behaviour (k = 5) tended not to foster creativity, while reversely studies assessing creativity tended to foster creative physical activities (k = 5). As a group, three studies that fostered more creative PA showed a small significant negative summary effect on cognitive flexibility. Considering qualitative differences in the physical activities performed in schools will improve our understanding of their mechanisms of impact. Future research should consider using more varied measures, including more proximal outcomes that involve body movements (e.g., a Simon Says task to measure inhibitory control).