► Exercise was related to translational virtual Morris Water Task (vWMT) behavior. ► Aerobic fitness relates to learning on the vWMT in adolescents. ► Fitness also relates to hippocampal, but not ...total gray matter, volume in youth. ► These findings suggest some specificity of exercise's effect on the adolescent brain.
In rodents, exercise increases hippocampal neurogenesis and allows for better learning and memory performance on water maze tasks. While exercise has also been shown to be beneficial for the brain and behavior in humans, no study has examined how exercise impacts spatial learning using a directly translational water maze task, or if these relationships exist during adolescence – a developmental period which the animal literature has shown to be especially vulnerable to exercise effects. In this study, we investigated the influence of aerobic fitness on hippocampal size and subsequent learning and memory, including visuospatial memory using a human analogue of the Morris Water Task, in 34 adolescents. Results showed that higher aerobic fitness predicted better learning on the virtual Morris Water Task and larger hippocampal volumes. No relationship between virtual Morris Water Task memory recall and aerobic fitness was detected. Aerobic fitness, however, did not relate to global brain volume or verbal learning, which might suggest some specificity of the influence of aerobic fitness on the adolescent brain. This study provides a direct translational approach to the existing animal literature on exercise, as well as adds to the sparse research that exists on how aerobic exercise impacts the developing human brain and memory.
Head motion represents one of the greatest technical obstacles in magnetic resonance imaging (MRI) of the human brain. Accurate detection of artifacts induced by head motion requires precise ...estimation of movement. However, head motion estimates may be corrupted by artifacts due to magnetic main field fluctuations generated by body motion. In the current report, we examine head motion estimation in multiband resting state functional connectivity MRI (rs-fcMRI) data from the Adolescent Brain and Cognitive Development (ABCD) Study and comparison ‘single-shot’ datasets. We show that respirations contaminate movement estimates in functional MRI and that respiration generates apparent head motion not associated with functional MRI quality reductions. We have developed a novel approach using a band-stop filter that accurately removes these respiratory effects from motion estimates. Subsequently, we demonstrate that utilizing a band-stop filter improves post-processing fMRI data quality. Lastly, we demonstrate the real-time implementation of motion estimate filtering in our FIRMM (Framewise Integrated Real-Time MRI Monitoring) software package.
•Respiratory perturbations of the main field inflate fMRI head motion estimates.•Breathing-related head motion artifacts compromise functional connectivity quality.•Notch filtering motion estimates (respiratory frequency band) improves data quality.•Motion estimate filtering can be achieved in real-time with FIRMM software.
Background: Adolescents with a family history of alcoholism (FHP) are at risk for developing an alcohol use disorder (AUD), and some studies indicate that FHP individuals show deficits in executive ...functioning. The ability to make adaptive decisions is one aspect of successful executive functioning that is often measured during risk‐taking tasks; however, this behavior has not been examined in FHP youth. As impaired decision‐making could predispose FHP youth to make poor choices related to alcohol use, the current study examined the neural substrates of risk‐taking in FHP adolescents and their family history negative (FHN) peers.
Methods: Thirty‐one (18 FHP, 13 FHN) youth between 13 and 15 years old were included in this study. All youth had used little to no alcohol prior to study involvement. Functional magnetic resonance imaging was used to examine the neural substrates of risk‐taking during the Wheel of Fortune (WOF) decision‐making task (Ernst et al., 2004) in FHP and FHN youth.
Results: FHP youth did not differ from FHN youth in risk‐taking behavior, but showed less brain response during risky decision‐making in right dorsolateral prefrontal cortex and right cerebellar regions compared with FHN peers.
Conclusions: Despite no behavioral differences on the WOF decision‐making task, FHP youth exhibited atypical neural response during risk‐taking compared with FHN peers. Atypical brain activity, in regions implicated in executive functioning could lead to reduced cognitive control, which may result in risky choices regarding alcohol use. This could help explain the higher rates of AUDs seen in FHP adolescents. Further examination of risky behavior and associated brain response over the course of adolescence is necessary to characterize the vulnerabilities of FHP youth in the absence of alcohol abuse.
► Adolescent working memory improves as a function of age and pubertal status. ► Adolescents show lateralized brain activity during spatial and verbal working memory. ► Adolescents show age-related ...changes in brain activation during working memory. ► Adolescents do not show developmental change in brain activity lateralization.
Adult functional magnetic resonance imaging (fMRI) literature suggests that a left–right hemispheric dissociation may exist between verbal and spatial working memory (WM), respectively. However, investigation of this type has been obscured by incomparable verbal and spatial WM tasks and/or visual inspection at arbitrary thresholds as means to assess lateralization. Furthermore, it is unclear whether this hemispheric lateralization is present during adolescence, a time in which WM skills are improving, and whether there is a developmental association with laterality of brain functioning. This study used comparable verbal and spatial WM n-back tasks during fMRI and a bootstrap analysis approach to calculate lateralization indices (LIs) across several thresholds to examine the potential of a left–right WM hemispheric dissociation in healthy adolescents. We found significant left hemispheric lateralization for verbal WM, most notably in the frontal and parietal lobes, as well as right hemisphere lateralization for spatial WM, seen in frontal and temporal cortices. Although no significant relationships were observed between LI and age or LI and performance, significant age-related patterns of brain activity were demonstrated during both verbal and spatial WM. Specifically, increased adolescent age was associated with less activity in the default mode brain network during verbal WM. In contrast, increased adolescent age was associated with greater activity in task-positive posterior parietal cortex during spatial working memory. Our findings highlight the importance of utilizing non-biased statistical methods and comparable tasks for determining patterns of functional lateralization. Our findings also suggest that, while a left–right hemispheric dissociation of verbal and spatial WM is apparent by early adolescence, age-related changes in functional activation during WM are also present.
The Adolescent Brain Cognitive Development (ABCD) study is poised to be the largest single-cohort long-term longitudinal study of neurodevelopment and child health in the United States. Baseline data ...on N= 4521 children aged 9–10 were released for public access on November 2, 2018. In this paper we performed principal component analyses of the neurocognitive assessments administered to the baseline sample. The neurocognitive battery included seven measures from the NIH Toolbox as well as five other tasks. We implemented a Bayesian Probabilistic Principal Components Analysis (BPPCA) model that incorporated nesting of subjects within families and within data collection sites. We extracted varimax-rotated component scores from a three-component model and associated these scores with parent-rated Child Behavior Checklist (CBCL) internalizing, externalizing, and stress reactivity. We found evidence for three broad components that encompass general cognitive ability, executive function, and learning/memory. These were significantly associated with CBCL scores in a differential manner but with small effect sizes. These findings set the stage for longitudinal analysis of neurocognitive and psychopathological data from the ABCD cohort as they age into the period of maximal adolescent risk-taking.
Physical exercise during adolescence, a critical developmental window, can facilitate neurogenesis in the dentate gyrus and astrogliogenesis in Cornu Ammonis (CA) hippocampal subfields of rats, and ...which have been associated with improved hippocampal dependent memory performance. Recent translational studies in humans also suggest that aerobic fitness is associated with hippocampal volume and better spatial memory during adolescence. However, associations between fitness, hippocampal subfield morphology, and learning capabilities in human adolescents remain largely unknown. Employing a translational study design in 34 adolescent males, we explored the relationship between aerobic fitness, hippocampal subfield volumes, and both spatial and verbal memory. Aerobic fitness, assessed by peak oxygen utilization on a high-intensity exercise test (VO
peak), was positively associated with the volumetric enlargement of the hippocampal head, and the CA1 head region specifically. Larger CA1 volumes were also associated with spatial learning on a Virtual Morris Water Maze task and verbal learning on the Rey Auditory Verbal Learning Test, but not recall memory. In line with previous animal work, the current findings lend support for the long-axis specialization of the hippocampus in the areas of exercise and learning during adolescence.
Adolescence is a time of significant neurobiological development, including changes in white matter microstructure. Familial alcoholism and adolescent binge-drinking have both been associated with ...altered white matter microstructure; however, the temporal nature of these effects, and their interaction, is unclear. Using diffusion-weighted imaging and voxel-wise multilevel modeling, the effects of familial alcoholism and future binge-drinking on white matter microstructural development were assessed in 45 adolescents, who went on to binge-drink (but were alcohol-naive at baseline), and 68 adolescents, who remained largely alcohol-naive, all with varying degrees of familial alcoholism. Both future binge-drinking and familial alcoholism were associated with altered frontostriatal white matter microstructure early in adolescence, prior to alcohol use. While several binge-drinking-related effects persisted throughout adolescence (in the posterior limb of the internal capsule, superior corona radiata, and cerebellar peduncles), the association between familial alcoholism and altered white matter microstructure dissipated across adolescence in all regions. There were no white matter regions identified where future binge-drinking or familial alcoholism were significantly associated with emergent or exacerbated alterations in white matter microstructure. Altogether, these findings suggest that alterations in frontostiatal white matter microstructure, some of which are associated with familial alcoholism, may be used to predict which adolescents are more likely to go on and engage in alcohol use. Meanwhile, a reduction in family history-related associations with altered white matter microstructure by late-adolescence is encouraging for future prevention work targeted at at-risk youth.
Identification of biomarkers is a priority for attention-deficit/hyperactivity disorder (ADHD). Studies have documented macrostructural brain alterations in ADHD, but few have examined white matter ...microstructure, particularly in preadolescent children. Given dramatic white matter maturation across childhood, microstructural differences seen in adolescents and adults with ADHD may reflect compensatory restructuring, rather than early neurophenotypic markers of the disorder.
Using tract-based spatial statistics, mean fractional anisotropy (FA) maps were created using diffusion tensor imaging. FA, mean diffusivity (MD), and associated axial and radial diffusivities were compared between 16 children with ADHD and 20 healthy children (age 7-9 years).
Youth with ADHD showed decreased FA in frontoparietal, frontolimbic, cerebellar, corona radiata, and temporo-occipital white matter compared with controls. In addition, ADHD was associated with lower MD in the posterior limb of the internal capsule and frontoparietal white matter and greater MD in frontolimbic white matter. Lower axial diffusion and/or higher radial diffusion were differentially observed for youth with ADHD in earlier versus later maturing areas of group FA/MD difference.
This study suggests that, even prior to adolescence, ADHD represents a disorder of altered structural connectivity of the brain, characterized by distributed atypical white matter microstructure. In addition, later maturing frontolimbic pathways were abnormal in children with ADHD, likely due to delayed or decreased myelination, a finding not previously demonstrated in the adolescent or adult stages of the disorder. These results suggest that disruptions in white matter microstructure may play a key role in the early pathophysiology of ADHD.
The objective of the current study was to build predictive models for suicidal ideation in a sample of children aged 9-10 using features previously implicated in risk among older adolescent and adult ...populations. This case-control analysis utilized baseline data from the Adolescent Brain and Cognitive Development (ABCD) Study, collected from 21 research sites across the United States (N = 11,369). Several regression and ensemble learning models were compared on their ability to classify individuals with suicidal ideation and/or attempt from healthy controls, as assessed by the Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version. When comparing control participants (mean age: 9.92±0.62 years; 4944 girls 49%) to participants with suicidal ideation (mean age: 9.89±0.63 years; 451 girls 40%), both logistic regression with feature selection and elastic net without feature selection predicted suicidal ideation with an AUC of 0.70 (CI 95%: 0.70-0.71). The random forest with feature selection trained to predict suicidal ideation predicted a holdout set of children with a history of suicidal ideation and attempt (mean age: 9.96±0.62 years; 79 girls 41%) from controls with an AUC of 0.77 (CI 95%: 0.76-0.77). Important features from these models included feelings of loneliness and worthlessness, impulsivity, prodromal psychosis symptoms, and behavioral problems. This investigation provided an unprecedented opportunity to identify suicide risk in youth. The use of machine learning to examine a large number of predictors spanning a variety of domains provides novel insight into transdiagnostic factors important for risk classification.
Abstract Adolescents with a family history of alcoholism (FHP) are at heightened risk for developing alcohol use disorders (AUDs). The nucleus accumbens (NAcc), a key brain region for reward ...processing, is implicated in the development of AUDs. Thus, functional connectivity of the NAcc may be an important marker of risk in FHP youth. Resting state functional magnetic resonance imaging (rs-fcMRI) was used to examine the intrinsic connectivity of the NAcc in 47 FHP and 50 family history negative (FHN) youth, ages 10–16 years old. FHP and FHN adolescents showed significant group differences in resting state synchrony between the left NAcc and bilateral inferior frontal gyri and the left postcentral gyrus (PG). Additionally, FHP youth differed from FHN youth in right NAcc functional connectivity with the left orbitofrontal cortex (OFC), left superior temporal gyrus, right cerebellum, left PG, and right occipital cortex. These results indicate that FHP youth have less segregation between the NAcc and executive functioning brain regions, and less integration with reward-related brain areas, such as the OFC. The findings of the current study highlight that premorbid atypical connectivity of appetitive systems, in the absence of heavy alcohol use, may be a risk marker in FHP adolescents.
PDF
