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Objective: To examine the relationship between carotid atherosclerosis and cerebral cortical thickness and investigate whether cortical thickness mediates the association between carotid atheroma and relative cognitive decline.Methods: We assessed 554 community-dwelling subjects (male/female: 296/258) from the Lothian Birth Cohort 1936 who underwent brain magnetic resonance imaging and carotid Doppler ultrasound studies at age 73 years. The relationship between carotid atherosclerosis markers (internal carotid artery stenosis, intima-media thickness, velocity, pulsatility, and resistivity indexes) and vertex-wide cerebral cortical thickness was examined cross-sectionally, controlling for gender, extensive vascular risk factors (VRFs), and intelligence quotient at age 11 (IQ-11). We also determined the association between carotid stenosis and a composite measure of fluid intelligence at age 73 years. A mediation model was applied to examine whether cortical thickness mediated the relationship between carotid stenosis and cognitive function.Results: A widespread negative association was identified between carotid stenosis (median = 15%) and cerebral cortical thickness at age 73 years, independent of the side of carotid stenosis, other carotid measures, VRFs, and IQ-11. This association increased in an almost dose-response relationship from mild to severe degrees of carotid stenosis, across the anterior and posterior circulation territories. A negative association was also noted between carotid stenosis and fluid intelligence (standardized beta coefficient = -0.151, p = 0.001), which appeared partly (approximately 22%) mediated by carotid stenosis-related thinning of the cerebral cortex.Interpretation: The findings suggest that carotid stenosis represents a marker of processes that accelerate aging of the cerebral cortex and cognition that is in part independent of measurable VRFs. Cortical thinning within the anterior and posterior circulation territories partially mediated the relationship between carotid atheroma and fluid intelligence. Ann Neurol 2018;84:576-587. [ABSTRACT FROM AUTHOR]

Hampshire and colleagues used factor analyses and simulations to conclude that the g -factor is not a valid construct for general intelligence because it could be accounted for by at least two independent components defined by distinct brain networks. In our view, their results depend on a number of assumptions and subjective decisions that, at best, allow for different interpretations. We also had a unique role in the review process of their paper prior to its publication when we were invited to write a Preview. We detail that role here and describe how non-transparent editorial decision-making rejected our Preview and allowed publication despite our major concerns. The main purpose of this report is to invite Hampshire and colleagues to respond to our specific scientific concerns that aim to clarify their work and contribute a constructive discussion about the meaning of their findings. [ABSTRACT FROM AUTHOR]

While the limbic system theory continues to be part of common scientific parlance, its validity has been questioned on multiple grounds. Nonetheless, the issue of whether or not there exists a set of brain areas preferentially dedicated to emotional processing remains central within affective neuroscience. Recently, a widespread neural reference space for emotion which includes limbic as well as other regions was characterized in a large meta-analysis. As methodologically heterogeneous studies go into such meta-analyses, showing in an individual study in which all parameters are kept constant, the involvement of overlapping areas for various emotion conditions in keeping with the neural reference space for emotion, would serve as valuable confirmatory evidence. Here, using fMRI, 20 young adult men were scanned while viewing validated neutral and effective emotion-eliciting short film excerpts shown to quickly and specifically elicit disgust, amusement, or sexual arousal. Each emotion-specific run included, in random order, multiple neutral and emotion condition blocks. A stringent conjunction analysis revealed a large overlap across emotion conditions that fit remarkably well with the neural reference space for emotion. This overlap included symmetrical bilateral activation of the medial prefrontal cortex, the anterior cingulate, the temporo-occipital junction, the basal ganglia, the brainstem, the amygdala, the hippocampus, the thalamus, the subthalamic nucleus, the posterior hypothalamus, the cerebellum, as well as the frontal operculum extending towards the anterior insula. This study clearly confirms for the visual modality, that processing emotional stimuli leads to widespread increases in activation that cluster within relatively confined areas, regardless of valence. [ABSTRACT FROM AUTHOR]

Abstract: Prevailing psychometric theories of intelligence posit that individual differences in cognitive performance are attributable to three main sources of variance: the general factor of intelligence (g), cognitive ability domains, and specific test requirements and idiosyncrasies. Cortical thickness has been previously associated with g. In the present study, we systematically analyzed associations between cortical thickness and cognitive performance with and without adjusting for the effects of g in a representative sample of children and adolescents (N=207, Mean age=11.8; SD=3.5; Range=6 to 18.3years). Seven cognitive tests were included in a measurement model that identified three first-order factors (representing cognitive ability domains) and one second-order factor representing g. Residuals of the cognitive ability domain scores were computed to represent g-independent variance for the three domains and seven tests. Cognitive domain and individual test scores as well as residualized scores were regressed against cortical thickness, adjusting for age, gender and a proxy measure of brain volume. g and cognitive domain scores were positively correlated with cortical thickness in very similar areas across the brain. Adjusting for the effects of g eliminated associations of domain and test scores with cortical thickness. Within a psychometric framework, cortical thickness correlates of cognitive performance on complex tasks are well captured by g in this demographically representative sample. [Copyright &y& Elsevier]

Abstract: Previous studies of cortical asymmetry have relied mainly on voxel-based morphometry (VBM), or manual segmentation of regions of interest. This study uses fully automated, surface-based techniques to analyse position and surface area asymmetry for the mid-surfaces of 112 right-handed subjects'' cortical hemispheres from a cohort of young adults. Native space measurements of local surface area asymmetry and vertex position asymmetry were calculated from surfaces registered to a previously validated hemisphere-unbiased surface-based template. Our analysis confirms previously identified hemispheric asymmetries (Yakovlevian torque, frontal and occipital petalia) in enhanced detail. It does not support previous findings of gender/asymmetry interactions or rightward planum parietale areal increase. It reveals several new findings, including a striking leftward increase in surface area of the supramarginal gyrus (peak effect 18%), compared with a smaller areal increase in the left Heschl''s gyrus and planum temporale region (peak effect 8%). A second finding was rightward increase in surface area (peak effect 10%) in a band around the medial junction between the occipital lobe, and parietal and temporal lobes. By clearly separating out the effects of structural translocation and surface area change from those of thickness and curvature, this study resolves the confound of these variables inherent in VBM studies. [Copyright &y& Elsevier]

Background: Attention-Deficit/Hyperactivity Disorder (ADHD) is a heterogeneous disorder from both clinical and pathogenic viewpoints. Executive function deficits are considered among the most important pathogenic pathways leading to ADHD and may index part of the heterogeneity in this disorder. Methods: To investigate the relationship between the dopamine transporter gene (SLC6A3) 3'- UTR VNTR genotypes and executive function in children with ADHD, 196 children diagnosed with ADHD were sequentially recruited, genotyped, and tested using a battery of three neuropsychological tests aimed at assessing the different aspects of executive functioning. Results: Taking into account a correction for multiple comparisons, the main finding of this study is a significant genotype effect on performances on the Tower of London (F = 6.902, p = 0.009) and on the Wechsler Intelligence Scale for Children, Third Edition (WISC-III) Freedom From Distractibility Index (F = 7.125, p = 0.008), as well as strong trends on Self Ordered Pointing Task error scores (F = 4,996 p = 0.026) and WISC-III Digit Span performance (F = 6.28, p = 0.023). Children with the 9/10 genotype exhibited, on average, a poorer performance on all four measures compared to children with the 10/10 genotype. No effect of genotype on Wisconsin Card Sorting Test measures of performance was detected. Conclusion: Results are compatible with the view that SLC6A3 genotype may modulate components of executive function performance in children with ADHD. [ABSTRACT FROM AUTHOR]

Throughout childhood and adolescence, humans experience marked changes in cortical structure and cognitive ability. Cortical thickness and surface area, in particular, have been associated with cognitive ability. Here we ask the question: What are the time-related associations between cognitive changes and cortical structure maturation. Identifying a developmental sequence requires multiple measurements of these variables from the same individuals across time. This allows capturing relations among the variables and, thus, finding whether (a) developmental cognitive changes follow cortical structure maturation, (b) cortical structure maturation follows cognitive changes, or (c) both processes influence each other over time. Four hundred and thiry children and adolescents (age range = 6.01-22.28 years) completed the Wechsler Abbreviated Scale of Intelligence battery and were MRI scanned at 3 time points separated by ≈ 2 years (Mage T1 = 10.60, SD = 3.58; Mage T2 = 12.63, SD = 3.62; Mage T3 = 14.49, SD = 3.55). Latent change score models were applied to quantify age-related relationships among the variables of interest. Our results indicate that cortical and cognitive changes related to each other reciprocally. Specifically, the magnitude or rate of the change in each variable at any occasion--and not the previous level--was predictive of later changes. These results were replicated for brain regions selected according to the coordinates identified in the Basten et al.'s (2015) meta-analysis, to the parieto-frontal integration theory (Jung & Haier, 2007) and to the whole cortex. Potential implications regarding brain plasticity and cognitive enhancement are discussed. [ABSTRACT FROM AUTHOR]

Abstract: A patient with a treatment-refractory bipolar disorder with ultradian cycling responded to adjunctive topiramate. Response was maintained during 3-year follow-up. [Copyright &y& Elsevier]

There are multiple recent reports of an association between anxious/depressed (A/D) symptomatology and the rate of cerebral cortical thickness maturation in typically developing youths. We investigated the degree to which anxious/depressed symptoms are tied to age-related microstructural changes in cerebral fiber pathways. The participants were part of the NIH MRI Study of Normal Brain Development. Child Behavior Checklist A/D scores and diffusion imaging were available for 175 youths (84 males, 91 females; 241 magnetic resonance imagings) at up to three visits. The participants ranged from 5.7 to 18.4 years of age at the time of the scan. Alignment of fractional anisotropy data was implemented using FSL/Tract-Based Spatial Statistics, and linear mixed model regression was carried out using SPSS. Child Behavior Checklist A/D was associated with the rate of microstructural development in several white matter pathways, including the bilateral anterior thalamic radiation, bilateral inferior longitudinal fasciculus, left superior longitudinal fasciculus, and right cingulum. Across these pathways, greater age-related fractional anisotropy increases were observed at lower levels of A/D. The results suggest that subclinical A/D symptoms are associated with the rate of microstructural development within several white matter pathways that have been implicated in affect regulation, as well as mood and anxiety psychopathology. [ABSTRACT FROM AUTHOR]

• While maternal smoking during pregnancy (MSDP) is established as a risk factor for ADHD, the mechanisms underlying this association are not well understood. • We investigated the effect of MSDP on cortical brain structures in children with ADHD. • A significant effect of MSDP on structural MRI parameters was detected when using an epigenetic signature instead of maternal recall. Maternal smoking during pregnancy (MSDP) is considered a risk factor for ADHD. While the mechanisms underlying this association are not well understood, MSDP may impact the developing brain in ways that lead to ADHD. Here, we investigated the effect of prenatal smoking exposure on cortical brain structures in children with ADHD using two methods of assessing prenatal exposure: maternal recall and epigenetic typing. Exposure groups were defined according to: (1) maternal recall (+MSDP: n = 24; −MSDP: n = 85) and (2) epigenetic markers (EM) (+EM: n = 14 −EM: n = 21). CIVET-1.1.12 and RMINC were used to acquire cortical brain measurements and perform statistical analyses, respectively. The vertex with highest significance was tested for association with Continuous Performance Test (CPT) dimensions. While no differences of brain structures were identified between +MSDP and –MSDP, +EM children (n = 10) had significantly smaller surface area in the right orbitofrontal cortex (ROFc), middle temporal cortex (RTc) and parahippocampal gyrus (RPHg) (15% FDR) compared to -EM children (n = 20). Cortical surface area in the RPHg significantly correlated with CPT commission errors T-scores. This study suggests that molecular markers may better define exposure to environmental risks, as compared to human recall. [ABSTRACT FROM AUTHOR]

Abstract: Idiopathic Parkinson''s disease (PD) is a neurodegenerative disorder diagnosed on the basis of motor symptoms, but that also includes cognitive and visuo-spatial deficits. Though PD is known to initially affect subcortical regions, the cortex also exhibits neuronal loss in the course of the disease as post mortem studies have shown. So far, PD-related pattern of cortical damage remains unclear, because of disease-caused heterogeneity, and also in part because of methodological issues such as the limitations of Voxel Based Morphometry. Here corticometry was used, a technique that decouples local surface from thickness, to obtain a better picture of PD corticomorphometric patterns. We acquired MRI volumes for 33 healthy controls (HC) and 49 PD patients, extracted local cortical thickness and surface area and modeled both of them as a function of group and age for each participant. Cortical thickness averaged on the whole cortex did not differ between the two groups while mean surface area was significantly larger in the PD group. The bilateral parietal lobule, the right superior frontal gyrus, the left cingulate cortex and the left insular cortex exhibited larger local surface area in the PD group. The right precuneus exhibited cortical thinning associated with age in the PD group and not in the HC group. Furthermore, cortical thinning was observed in the PD group compared with the control group in the left medial supplementary motor area (SMA) and in the right dorsal pre-SMA. Finally, we found the left temporal pole thickness to correlate with disease duration, as well as the bilateral occipital cortex and Broca''s area. These results suggest that PD etiology is associated with specific cortical alterations, which could account for cognitive deficits that arise as the disease evolves. Finally, our results observed in the occipital cortex as a function of disease duration may indicate the increase in PD-related visuo-spatial deficits, which can sometimes result in hallucinations later on in the disease. In the future, MRI-generated corticometry, combined with additional behavioral markers, may prove to be a useful diagnosis tool to characterize the evolution of motor and cognitive deficits in PD. [Copyright &y& Elsevier]

There is evidence that men experience more sexual arousal than women but also that women in mid-luteal phase experience more sexual arousal than women outside this phase. Recently, a few functional brain imaging studies have tackled the issue of gender differences as pertaining to reactions to erotica. The question of whether or not gender differences in reactions to erotica are maintained with women in different phases has not yet been answered from a functional brain imaging perspective. In order to examine this issue, functional MRI was performed in 22 male and 22 female volunteers. Subjects viewed erotic film excerpts alternating with emotionally neutral excerpts in a standard block-design paradigm. Arousal to erotic stimuli was evaluated using standard rating scales after scanning. Two-sample t-test with uncorrected P<0.001 values for a priori determined region of interests involved in processing of erotic stimuli and with corrected P<0.05 revealed gender differences: Comparing women in mid-luteal phase and during their menses, superior activation was revealed for women in mid-luteal phase in the anterior cingulate, left insula, and orbitofrontal cortex. A superior activation for men was found in the left thalamus, the bilateral amygdala, the anterior cingulate, the bilateral orbitofrontal, bilateral parahippocampal, and insular regions, which were maintained at a corrected P in the amygdala, the insula, and thalamus. There were no areas of significant superior activation for women neither in mid-luteal phase nor during their menses. Our results indicate that there are differences between women in the two cycle times in cerebral activity during viewing of erotic stimuli. Furthermore, gender differences with women in mid-luteal phases are similar to those in females outside the mid-luteal phase. [ABSTRACT FROM AUTHOR]

Maternal antenatal depression strongly influences child mental health but with considerable inter-individual variation that is, in part, linked to genotype. The challenge is to effectively capture the genotypic influence. We outline a novel approach to describe genomic susceptibility to maternal antenatal depression focusing on child emotional/behavioral difficulties. Two cohorts provided measures of maternal depression, child genetic variation, and child mental health symptoms. We constructed a conventional polygenic risk score (PRS) for attention-deficit/hyperactivity disorder (ADHD) (PRSADHD) that significantly moderated the association between maternal antenatal depression and internalizing problems at 60 months (p = 2.94 × 10−4, R2 =.18). We then constructed an interaction PRS (xPRS) based on a subset of those single nucleotide polymorphisms from the PRSADHD that most accounted for the moderation of the association between maternal antenatal depression and child outcome. The interaction between maternal antenatal depression and this xPRS accounted for a larger proportion of the variance in child emotional/behavioral problems than models based on any PRSADHD (p = 5.50 × 10−9, R2 =.27), with similar findings in the replication cohort. The xPRS was significantly enriched for genes involved in neuronal development and synaptic function. Our study illustrates a novel approach to the study of genotypic moderation on the impact of maternal antenatal depression on child mental health and highlights the utility of the xPRS approach. These findings advance our understanding of individual differences in the developmental origins of mental health. [ABSTRACT FROM AUTHOR]

Background: Are cognitive and biological variables useful for predicting future behavioral outcomes? Method: In two independent groups, we measured a set of cognitive (fluid and crystallized intelligence, working memory, and attention control) and biological (cortical thickness and cortical surface area) variables on two occasions separated by six months, to predict behavioral outcomes of interest (performance on an adaptive version of the n-back task) measured twelve and eighteen months later. We followed three stages: discovery, validation, and generalization. In the discovery stage, cognitive/biological variables and the behavioral outcome of interest were assessed in a group of individuals (in-sample). In the validation stage, the cognitive and biological variables were related with a parallel version of the behavioral outcome assessed several months later. In the generalization stage, the validation findings were tested in an independent group of individuals (out-of-sample). Results: The key finding revealed that cortical surface area variations within the right dorsolateral prefrontal cortex predict the behavioral outcome of interest in both groups, whereas the cognitive variables failed to show reliable predictive validity. Conclusions: Individual differences in biological variables might predict future behavioral outcomes better than cognitive variables concurrently correlated with these behavioral outcomes. [ABSTRACT FROM AUTHOR]

Highlights • Prefrontal-amygdalar covariance varies as a function of DHEA-cortisol ratio. • DHEA decreases prefrontal-amygdalar covariance, cortisol increases this covariance. • DHEA-cortisol ratio impacts working memory through prefrontal-amygdalar covariance. • Higher DHEA improves working memory, higher cortisol worsens working memory. • DHEA and cortisol may play antagonistic roles during brain development in humans. Abstract There is accumulating evidence that both dehydroepiandrosterone (DHEA) and cortisol play an important role in regulating physical maturation and brain development. High DHEA levels tend to be associated with neuroprotective and indirect anabolic effects, while high cortisol levels tend to be associated with catabolic and neurotoxic properties. Previous literature has linked the ratio between DHEA and cortisol levels (DC ratio) to disorders of attention, emotional regulation and conduct, but little is known as to the relationship between this ratio and brain development. Due to the extensive links between the amygdala and the cortex as well as the known amygdalar involvement in emotional regulation, we examined associations between DC ratio, structural covariance of the amygdala with whole-brain cortical thickness, and validated report-based measures of attention, working memory, internalizing and externalizing symptoms, in a longitudinal sample of typically developing children and adolescents 6–22 years of age. We found that DC ratio predicted covariance between amygdalar volume and the medial anterior cingulate cortex, particularly in the right hemisphere. DC ratio had a significant indirect effect on working memory through its impact on prefrontal-amygdalar covariance, with higher DC ratios associated with a prefrontal-amygdalar covariance pattern predictive of higher scores on a measure of working memory. Taken together, these findings support the notion, as suggested by animal and in vitro studies, that there are opposing effects of DHEA and cortisol on brain development in humans, and that these effects may especially target prefrontal-amygdalar development and working memory, in a lateralized fashion. [ABSTRACT FROM AUTHOR]

Highlights • There is evidence that neurodevelopmental disorders overlap. Yet it is unclear how etiological pathways intersect. • SNPs identified in non-ADHD GWAS showed association with multiple dimensions related to ADHD. • Here we attempt to tease apart the heterogeneity in the phenotype, and understand its genetic underpinnings. • Results are presented as preliminary findings as they provide insight into cross-disorder associations. Abstract Several epidemiological and genetic studies have provided evidence of an overlap between neurodevelopmental disorders. However, the details of the etiological pathways remain to be elucidated. In this study, we garnered the findings of previous GWAS, conducted with schizophrenia and bipolar disorder. We conducted an exploratory study to examine the association between these SNPs and quantitative clinical/ behavioural/ cognitive/ structural brain parameters, as well as response to treatment with a fixed dose of methylphenidate, in a relatively large sample of children with ADHD. Family-based association tests were conducted with nine tag SNPs with 602 nuclear families. In addition, structural magnetic resonance imaging (sMRI) was conducted in a subset of children with ADHD (n = 76). Of the 9 tag SNPs examined, rs1602565 showed a significant association with ADHD, several dimensional measures and response to treatment. An association was also observed between rs1006737 (CACNA1C) and performance IQ. In addition, significant reductions in cortical thickness measurements were observed with the risk allele in rs1006737. These results provide preliminary evidence for putative shared genetic vulnerability between childhood ADHD and other neurodevelopmental disorders. [ABSTRACT FROM AUTHOR]

The neural correlates of human personality have been of longstanding interest; however, most studies in the field have relied on modest sample sizes and few replicable results have been reported to date. We investigated relationships between personality and brain gray matter in a sample of generally healthy, older (mean age 73 years) adults from Scotland drawn from the Lothian Birth Cohort 1936. Participants (N = 578) completed a brain MRI scan and self-reported Big Five personality trait measures. Conscientiousness trait scores were positively related to brain cortical thickness in a range of regions, including bilateral parahippocampal gyrus, bilateral fusiform gyrus, left cingulate gyrus, right medial orbitofrontal cortex, and left dorsomedial prefrontal cortex. These associations – most notably in frontal regions – were modestly-to-moderately attenuated by the inclusion of biomarker variables assessing allostatic load and smoking status. None of the other personality traits showed robust associations with brain cortical thickness, nor did we observe any personality trait associations with cortical surface area and gray matter volume. These findings indicate that brain cortical thickness is associated with conscientiousness, perhaps partly accounted for by allostatic load and smoking status. [ABSTRACT FROM AUTHOR]

The analysis of the relationships between cortical and intellectual development is a complex matter. Greater brain plasticity in brighter individuals has been suggested, but the associations between developmental cortical changes and variations in the general factor of intelligence ( g ) across time at the latent level have not been addressed. For filling this gap, here we relate longitudinal changes in g with developmental changes in cortical thickness and cortical surface area. One hundred and thirty-two children and adolescents representative of the population from the Pediatric MRI Data Repository completed the Wechsler Abbreviated Scale of Intelligence in three time points and MRI scans were also obtained (mean inter-registration interval ≈ 2 years, age range = 6.1 to 21.3 years). Longitudinal latent variable analyses revealed an increase in g scores amounting to a full standard deviation on average. Intelligence differences estimated at the latent level were significantly correlated related with cortical changes. Older individuals showed greater decrease in cortical values along with smaller increase in intelligence. Furthermore, thickness preservation in brighter individuals was observed at early adolescence (10–14 years). [ABSTRACT FROM AUTHOR]

Fully characterizing age differences in the brain is a key task for combating aging-related cognitive decline. Using propensity score matching on 2 independent, narrow-age cohorts, we used data on childhood cognitive ability, socioeconomic background, and intracranial volume to match participants at mean age of 92 years ( n = 42) to very similar participants at mean age of 73 years ( n = 126). Examining a variety of global and regional structural neuroimaging variables, there were large differences in gray and white matter volumes, cortical surface area, cortical thickness, and white matter hyperintensity volume and spatial extent. In a mediation analysis, the total volume of white matter hyperintensities and total cortical surface area jointly mediated 24.9% of the relation between age and general cognitive ability (tissue volumes and cortical thickness were not significant mediators in this analysis). These findings provide an unusual and valuable perspective on neurostructural aging, in which brains from the 8th and 10th decades of life differ widely despite the same cognitive, socioeconomic, and brain-volumetric starting points. [ABSTRACT FROM AUTHOR]

The structural connectome provides relevant information about experience and training-related changes in the brain. Here, we used network-based statistics (NBS) and graph theoretical analyses to study structural changes in the brain as a function of cognitive training. Fifty-six young women were divided in two groups (experimental and control). We assessed their cognitive function before and after completing a working memory intervention using a comprehensive battery that included fluid and crystallized abilities, working memory and attention control, and we also obtained structural MRI images. We acquired and analyzed diffusion-weighted images to reconstruct the anatomical connectome and we computed standardized changes in connectivity as well as group differences across time using NBS. We also compared group differences relying on a variety of graph-theory indices (clustering, characteristic path length, global and local efficiency and strength) for the whole network as well as for the sub-network derived from NBS analyses. Finally, we calculated correlations between these graph indices and training performance as well as the behavioral changes in cognitive function. Our results revealed enhanced connectivity for the training group within one specific network comprised of nodes/regions supporting cognitive processes required by the training (working memory, interference resolution, inhibition, and task engagement). Significant group differences were also observed for strength and global efficiency indices in the sub-network detected by NBS. Therefore, the connectome approach is a valuable method for tracking the effects of cognitive training interventions across specific sub-networks. Moreover, this approach allows for the computation of graph theoretical network metrics to quantify the topological architecture of the brain network detected. The observed structural brain changes support the behavioral results reported earlier (see Colom, Román, et al., 2013) [ABSTRACT FROM AUTHOR]

Objective To investigate the extent to which subclinical variation in anxious/depressed psychopathology is associated with volume and age-related volumetric change of limbic structures in a longitudinal sample of healthy youths. Methods Linear mixed-effects models were used to analyze longitudinal behavioral and neuroimaging data (up to 3 data points per subject, collected at 2 year-intervals) in 371 typically developing youths, from 4 to 18 years of age (196 females; 723 MRIs). Volumetric measures were obtained using a validated segmentation method. The best-fit model (cubic, quadratic, or first-order linear) was determined for the effect of age on amygdalar and hippocampal volume (adjusted for total brain volume). Next, amygdalar and hippocampal volumes were regressed against Child Behavior Checklist Anxious/Depressed (A/D) scores. Age-by-A/D and sex-by-A/D interactions were tested. Results Analyses revealed age-related linear and quadratic volumetric change in the amygdalae and hippocampi, respectively. A/D was positively associated with total amygdalar volume ( p = 0.045), independent of age and sex. Age-by-A/D and sex-by-A/D interactions were not associated with amygdalar or hippocampal volume. Conclusions Results suggest that amygdalar structure is tied to A/D among typically developing youths, independent of age and sex. Developmental trajectories of amygdalar and hippocampal volume were not associated with subclinical anxiety. Taken together, increased amygdalar volume may serve as a significant marker of anxiety, regardless of developmental phase. [ABSTRACT FROM AUTHOR]

Verbal and non-verbal intelligence in children is highly correlated, and thus, it has been difficult to differentiate their neural substrates. Nevertheless, recent studies have shown that verbal and non-verbal intelligence can be dissociated and focal cortical regions corresponding to each have been demonstrated. However, the pattern of structural covariance corresponding to verbal and non-verbal intelligence remains unexplored. In this study, we used 586 longitudinal anatomical MRI scans of subjects aged 6–18 years, who had concurrent intelligence quotient (IQ) testing on the Wechsler Abbreviated Scale of Intelligence. Structural covariance networks (SCNs) were constructed using interregional correlations in cortical thickness for low-IQ (Performance IQ=100±8, Verbal IQ=100±7) and high-IQ (PIQ=121±8, VIQ=120±9) groups. From low- to high-VIQ group, we observed constrained patterns of anatomical coupling among cortical regions, complemented by observations of higher global efficiency and modularity, and lower local efficiency in high-VIQ group, suggesting a shift towards a more optimal topological organization. Analysis of nodal topological properties (regional efficiency and participation coefficient) revealed greater involvement of left-hemispheric language related regions including inferior frontal and superior temporal gyri for high-VIQ group. From low- to high-PIQ group, we did not observe significant differences in anatomical coupling patterns, global and nodal topological properties. Our findings indicate that people with higher verbal intelligence have structural brain differences from people with lower verbal intelligence – not only in localized cortical regions, but also in the patterns of anatomical coupling among widely distributed cortical regions, possibly resulting to a system-level reorganization that might lead to a more efficient organization in high-VIQ group. [ABSTRACT FROM AUTHOR]

Here we analyze gray matter indices before and after completing a challenging adaptive cognitive training program based on the n-back task. The considered gray matter indices were cortical thickness (CT) and cortical surface area (CSA). Twenty-eight young women (age range 17-22 years) completed 24 training sessions over the course of 3 months (12 weeks, 24 sessions), showing expected performance improvements. CT and CSA values for the training group were compared with those of a matched control group. Statistical analyses were computed using a ROI framework defined by brain areas distinguished by their genetic underpinning. The interaction between group and time was analyzed. Middle temporal, ventral frontal, inferior parietal cortices, and pars opercularis were the regions where the training group showed conservation of gray matter with respect to the control group. These regions support working memory, resistance to interference, and inhibition. Furthermore, an interaction with baseline intelligence differences showed that the expected decreasing trend at the biological level for individuals showing relatively low intelligence levels at baseline was attenuated by the completed training. [ABSTRACT FROM AUTHOR]

Several reports have described cortical thickness (CTh) developmental trajectories, with conflicting results. Some studies have reported inverted-U shape curves with peaks of CTh in late childhood to adolescence, while others suggested predominant monotonic decline after age 6. In this study, we reviewed CTh developmental trajectories in the NIH MRI Study of Normal Brain Development, and in a second step, evaluated the impact of post-processing quality control (QC) procedures on identified trajectories. The quality-controlled sample included 384 individual subjects with repeated scanning (1–3 per subject, total scans n = 753) from 4.9 to 22.3 years of age. The best-fit model (cubic, quadratic, or first-order linear) was identified at each vertex using mixed-effects models. The majority of brain regions showed linear monotonic decline of CTh. There were few areas of cubic trajectories, mostly in bilateral temporo-parietal areas and the right prefrontal cortex, in which CTh peaks were at, or prior to, age 8. When controlling for total brain volume, CTh trajectories were even more uniformly linear. The only sex difference was faster thinning of occipital areas in boys compared to girls. The best-fit model for whole brain mean thickness was a monotonic decline of 0.027 mm per year. QC procedures had a significant impact on identified trajectories, with a clear shift toward more complex trajectories (i.e., quadratic or cubic) when including all scans without QC (n = 954). Trajectories were almost exclusively linear when using only scans that passed the most stringent QC (n = 598). The impact of QC probably relates to decreasing the inclusion of scans with CTh underestimation secondary to movement artifacts, which are more common in younger subjects. In summary, our results suggest that CTh follows a simple linear decline in most cortical areas by age 5, and all areas by age 8. This study further supports the crucial importance of implementing post-processing QC in CTh studies of development, aging, and neuropsychiatric disorders. [ABSTRACT FROM AUTHOR]

Functional neuroimaging studies have revealed abnormal brain dynamics of male sexual arousal (SA) in psychogenic erectile dysfunction (pED). However, the neuroanatomical correlates of pED are still unclear. In this work, we obtained cortical thickness (CTh) measurements from structural magnetic resonance images of 40 pED patients and 39 healthy control subjects. Abnormalities in CTh related to pED were explored using a scale space search based brain morphometric analysis. Organizations of brain structural covariance networks were analyzed as well. Compared with healthy men, pED patients showed significantly decreased CTh in widespread cortical regions, most of which were previously reported to show abnormal dynamics of male SA in pED, such as the medial prefrontal, orbitofrontal, cingulate, inferotemporal, and insular cortices. CTh reductions in these areas were found to be significantly correlated with male sexual functioning degradation. Moreover, pED patients showed decreased interregional CTh correlations from the right lateral orbitofrontal cortex to the right supramarginal gyrus and the left angular cortex, implying disassociations between the cognitive, motivational, and inhibitory networks of male SA in pED. This work provides structural insights on the complex phenomenon of psychogenic sexual dysfunction in men, and suggests a specific vulnerability factor, possibly as an extra 'organic' factor, that may play an important role in pED. Hum Brain Mapp 36:4469-4482, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The etiology and maintenance of insomnia are proposed to be associated with increased cognitive and physiological arousal caused by acute stressors and associated cognitive rumination. A core feature of such hyperarousal theory of insomnia involves increased sensory processing that interferes with the onset and maintenance of sleep. In this work, we collected structural magnetic resonance imaging data from 35 patients with primary insomnia and 35 normal sleepers and applied structural covariance analysis to investigate whether insomnia is associated with disruptions in structural brain networks centered at the sensory regions (primary visual, primary auditory, and olfactory cortex). As expected, insomnia patients showed increased structural covariance in cortical thickness between sensory and motor regions. We also observed trends of increased covariance between sensory regions and the default-mode network, and the salience network regions, and trends of decreased covariance between sensory regions and the frontoparietal working memory network regions, in insomnia patients. The observed changes in structural covariance tended to correlated with poor sleep quality. Our findings support previous functional neuroimaging studies and provide novel insights into variations in brain network configuration that may be involved in the pathophysiology of insomnia. [ABSTRACT FROM AUTHOR]

People differ in their cognitive functioning. This variability has been exhaustively examined at the behavioral, neural and genetic level to uncover the mechanisms by which some individuals are more cognitively efficient than others. Studies investigating the neural underpinnings of interindividual differences in cognition aim to establish a reliable nexus between functional/structural properties of a given brain network and higher order cognitive performance. However, these studies have produced inconsistent results, which might be partly attributed to methodological variations. In the current study, 82 healthy young participants underwent MRI scanning and completed a comprehensive cognitive battery including measurements of fluid, crystallized, and spatial intelligence, along with working memory capacity/executive updating, controlled attention, and processing speed. The cognitive scores were obtained by confirmatory factor analyses. T1-weighted images were processed using three different surface-based morphometry (SBM) pipelines, varying in their degree of user intervention, for obtaining measures of cortical thickness (CT) across the brain surface. Distribution and variability of CT and CT-cognition relationships were systematically compared across pipelines and between two cognitively/demographically matched samples to overcome potential sources of variability affecting the reproducibility of findings. We demonstrated that estimation of CT was not consistent across methods. In addition, among SBM methods, there was considerable variation in the spatial pattern of CT-cognition relationships. Finally, within each SBM method, results did not replicate in matched subsamples. Hum Brain Mapp 36:3227-3245, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

People with larger brains tend to score higher on tests of general intelligence ( g ). It is unclear, however, how much variance in intelligence other brain measurements would account for if included together with brain volume in a multivariable model. We examined a large sample of individuals in their seventies ( n = 672) who were administered a comprehensive cognitive test battery. Using structural equation modelling, we related six common magnetic resonance imaging-derived brain variables that represent normal and abnormal features—brain volume, cortical thickness, white matter structure, white matter hyperintensity load, iron deposits, and microbleeds—to g and to fluid intelligence. As expected, brain volume accounted for the largest portion of variance (~ 12%, depending on modelling choices). Adding the additional variables, especially cortical thickness (+~ 5%) and white matter hyperintensity load (+~ 2%), increased the predictive value of the model. Depending on modelling choices, all neuroimaging variables together accounted for 18–21% of the variance in intelligence. These results reveal which structural brain imaging measures relate to g over and above the largest contributor, total brain volume. They raise questions regarding which other neuroimaging measures might account for even more of the variance in intelligence. [ABSTRACT FROM AUTHOR]

Most of the studies conducted on the development of the corpus callosum ( CC) have been limited to a relatively simple assessment of callosal area, providing an estimation of the size of the CC in two dimensions rather than its actual measurement. The goal of this study was to revisit callosal development in childhood and adolescence by using a three-dimensional (3D) magnetic resonance imaging template of the CC that considers the horizontal width of the CC and compares this with the two-dimensional (2D) callosal area. We mapped callosal growth in a large sample of youths followed longitudinally ( N = 370 at T1; N = 304 at T2; and N = 246 at T3). Both techniques were based on a five-section subdivision of the CC. The results obtained with the 3D method revealed that the rate of CC growth over a 4-year period in the rostrum, the genu, the anterior body and the splenium was significantly higher in the youngest age group (< 7 years) than in older groups, indicating an intense period of development in early childhood for the anterior and posterior parts of the CC. Similar results were obtained when 2D callosal area was used for the anterior and posterior parts of the CC. However, divergent results were found in the mid-body and the caudal body of the CC. As shown by differences between 2D estimations and actual 3D measurements of callosal growth, our study highlights the importance of considering the horizontal width in measuring developmental changes in the CC. [ABSTRACT FROM AUTHOR]

On average, men show larger brain volumes than women. Regional differences have been also observed, although most of the available studies apply voxel-based morphometry (VBM). Reports applying surface-based morphometry (SBM) have been focused mainly on cortical thickness (CT). Here we apply SBM for obtaining global and regional indices of CT, cortical surface area (CSA), and cortical gray matter volume (CGMV) from samples of men (N = 40) and women (N = 40) matched for their performance on four cognitive factors varying in their complexity: processing speed, attention control, working memory capacity, and fluid intelligence. These were the main findings: 1) CT and CSA produced very weak correlations in both sexes, 2) men showed larger values in CT, CSA, and CGMV, and 3) cognitive performance was unrelated to brain structural variation within sexes. Therefore, we found substantial group differences in brain structure, but there was no relationship with cognitive performance both between and within-sexes. [ABSTRACT FROM AUTHOR]

Objective: To assess the extent to which playing a musical instrument is associated with cortical thickness development among healthy youths. Method: Participants were part of the National Institutes of Health (NIH) Magnetic Resonance Imaging (MRI) Study of Normal Brain Development. This study followed a longitudinal design such that participants underwent MRI scanning and behavioral testing on up to 3 separate visits, occurring at 2-year intervals. MRI, IQ, and music training data were available for 232 youths (334 scans), ranging from 6 to 18 years of age. Cortical thickness was regressed against the number of years that each youth had played a musical instrument. Next, thickness was regressed against an "Age x Years of Playing" interaction term. Age, gender, total brain volume, and scanner were controlled for in analyses. Participant ID was entered as a random effect to account for within-person dependence. False discovery rate correction was applied (p < .05). Results: There was no association between thickness and years playing a musical instrument. The "Age x Years of Playing" interaction was associated with thickness in motor, premotor, and supplementary motor cortices, as well as prefrontal and parietal cortices. Follow-up analysis revealed that music training was associated with an increased rate of thickness maturation. Results were largely unchanged when IQ and handedness were included as covariates. Conclusion: Playing a musical instrument was associated with more rapid cortical thickness maturation within areas implicated in motor planning and coordination, visuospatial ability, and emotion and impulse regulation. However, given the quasi-experimental nature of this study, we cannot rule out the influence of confounding variables. [ABSTRACT FROM AUTHOR]

Objective: To describe the theory and methodology of the multi-wave, prospective Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) study. The goal of MAVAN is to examine the pre- and postnatal influences, and their interaction, in determining individual differences in mental health. Method: MAVAN is a community-based, birth cohort study of pregnant Canadian mothers and their offspring. Dyads are assessed longitudinally, with multiple assessments of both mother and child in home and laboratory across the child’s development. Study measures, including assessments of cognitive and emotional function, are described. The study uses a candidate gene approach to examine gene-environment interdependence in specific developmental outcomes. Finally, the study includes measures of both brain-based phenotypes and metabolism to explore comorbidities associated with child obesity. One of the unique features of the MAVAN protocol is the extensive measures of the mother-child interaction. The relation between these measures will be discussed. Results: Evidence from the MAVAN project shows interesting results about maternal care, families, and child outcomes. In our review, preliminary analyses showing the correlations between measures of maternal care are reported. As predicted, early evidence suggests that maternal care measures are positively correlated, overtime. Conclusions: This review provides evidence for the feasibility and value of laboratory-based measures embedded within a longitudinal birth cohort study. Though retention of the samples has been a challenge of MAVAN, they are within a comparable range to other studies of this nature. Indeed, the trade-off of somewhat greater participant burden has allowed for a rich database. The results yielded from the MAVAN project will not only describe typical development but also possible targets for intervention. Understanding certain endophenotypes will shed light on the pathogenesis of various mental and physical disorders, as well as their interrelation. [ABSTRACT FROM AUTHOR]

Intelligence is composed of a set of cognitive abilities hierarchically organized. General and specific abilities capture distinguishable, but related, facets of the intelligence construct. Here, we analyze gray matter with three morphometric indices (volume, cortical surface area, and cortical thickness) at three levels of the intelligence hierarchy (tests, first-order factors, and a higher-order general factor, g). A group of one hundred and four healthy young adults completed a cognitive battery and underwent high-resolution structural MRI. Latent scores were computed for the intelligence factors and tests were also analyzed. The key finding reveals substantial variability in gray matter correlates at the test level, which is substantially reduced for the first-order and the higher-order factors. This supports a reversed hierarchy in the brain with respect to cognitive abilities at different psychometric levels: the greater the generality, the smaller the number of relevant gray matter clusters accounting for individual differences in intelligent performance. Hum Brain Mapp 35:3805-3818, 2014. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Individual differences in general cognitive ability have been associated with various brain structure metrics. A relatively novel metric referred to as pericortical Gray-White Contrast (GWC) describes the sharpness of the pericortical gray-white boundary. GWC, which is hypothesized to be at least partly influenced by the degree to which myelinated axons invade the lower layers of cortex, is believed to be significantly associated with the dynamics of signal transmission across the brain and hence, with cognitive ability. The current work explores the association between GWC and IQ across the surface of the cortex. Subject data were retrieved from the NIH MRI Study of Normal Brain Development (Evans & Brain Development Cooperative, 2006). 376 subjects with a total of 742 scans were included in the longitudinal analyses. Mixed-effects regression analyses were used to map the relation between cortical contrast and each of full-scale, performance, and verbal IQ derived from the Wechsler Abbreviated Scale of Intelligence, while covarying for scanner, sex, and age effects. Significant associations were shown with FSIQ, PIQ, but not VIQ. We discuss the interpretation of these results and how they may relate to previously published results on structural cortical associations. • Gray-white contrast (GWC) was positively associated with FSIQ and PIQ, but not VIQ. • Significant associations reflected the same regionality as the Parieto-Frontal Integration Theory of intelligence. • Cognitive ability showed broader significant associations with GWC than with cortical thickness. [ABSTRACT FROM AUTHOR]

Neuroimaging studies have revealed associations between intelligence and brain morphology. However, researchers have focused primarily on the anatomical features of the cerebral cortex, whereas subcortical structures, such as the basal ganglia (BG), have often been neglected despite extensive functional evidence on their relation with higher-order cognition. Here we performed shape analyses to understand how individual differences in BG local morphology account for variability in cognitive performance. Structural MRI was acquired in 104 young adults (45 men, 59 women, mean age = 19.83, SD = 1.64), and the outer surface of striatal structures (caudate, nucleus accumbens, and putamen), globus pallidus, and thalamus was estimated for each subject and hemisphere. Further, nine cognitive tests were used to measure fluid (Gf), crystallized (Gc), and spatial intelligence (Gv). Latent scores for these factors were computed by means of confirmatory factor analysis and regressed vertex-wise against subcortical shape (local displacements of vertex position), controlling for age, sex, and adjusted for brain size. Significant results (FDR < 5%) were found for Gf and Gv, but not Gc, for the right striatal structures and thalamus. The main results show a relative enlargement of the rostral putamen, which is functionally connected to the right dorsolateral prefrontal cortex and other intelligence-related prefrontal areas. Hum Brain Mapp 35:1957-1968, 2014. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background: Fronto-amygdalar networks are implicated in childhood psychiatric disorders characterized by high rates of externalizing (aggressive, noncompliant, oppositional) behavior. Although externalizing behaviors are distributed continuously across clinical and nonclinical samples, little is known about how brain variations may confer risk for problematic behavior. Here, we studied cortical thickness, amygdala volume, and cortico-amygdalar network correlates of externalizing behavior in a large sample of healthy children. Methods: Two hundred ninety-seven healthy children (6–18 years; mean = 12 ± 3 years), with 517 magnetic resonance imaging scans, from the National Institutes of Health Magnetic Resonance Imaging Study of Normal Brain Development, were studied. Relationships between externalizing behaviors (measured with the Child Behavior Checklist) and cortical thickness, amygdala volume, and cortico-amygdalar structural networks were examined using first-order linear mixed-effects models, after controlling for age, sex, scanner, and total brain volume. Results significant at p ≤ .05, following multiple comparison correction, are reported. Results: Left orbitofrontal, right retrosplenial cingulate, and medial temporal cortex thickness were negatively correlated with externalizing behaviors. Although amygdala volume alone was not correlated with externalizing behaviors, an orbitofrontal cortex-amygdala network predicted rates of externalizing behavior. Children with lower levels of externalizing behaviors exhibited positive correlations between orbitofrontal cortex and amygdala structure, while these regions were not correlated in children with higher levels of externalizing behavior. Conclusions: Our findings identify key cortical nodes in frontal, cingulate, and temporal cortex associated with externalizing behaviors in children; and indicate that orbitofrontal-amygdala network properties may influence externalizing behaviors, along a continuum and across healthy and clinical samples. [ABSTRACT FROM AUTHOR]

Abstract: Intelligence quotient (IQ) scores tend to remain stable across the lifespan. Nevertheless, in some healthy individuals, significant decreases or increases in IQ have been observed over time. It is unclear whether such changes reflect true functional change or merely measurement error. Here, we applied surface-based corticometry to investigate vertex-wise cortical surface area and thickness correlates of changes in Full Scale IQ (FSIQ), Performance IQ (PIQ) and Verbal IQ (VIQ) in a representative sample of children and adolescents (n=188, mean age=11.59years) assessed two years apart as part of the NIH Study of Normal Brain Development. No significant associations between changes in IQ measures and changes in cortical surface area were observed, whereas changes in FSIQ, PIQ, and VIQ were related to rates of cortical thinning, mainly in left frontal areas. Participants who showed reliable gains in FSIQ showed no significant changes in cortical thickness on average, whereas those who exhibited no significant FSIQ change showed moderate declines in cortical thickness. Importantly, individuals who showed large decreases in FSIQ displayed the steepest and most significant reductions in cortical thickness. Results support the view that there can be meaningful cognitive ability changes that impact IQ within relatively short developmental periods and show that such changes are associated with the dynamics of cortical thickness development. [Copyright &y& Elsevier]

Neuroimaging studies provide evidence for organized intrinsic activity under task-free conditions. This activity serves functionally relevant brain systems supporting cognition. Here, we analyze changes in resting-state functional connectivity after videogame practice applying a test-retest design. Twenty young females were selected from a group of 100 participants tested on four standardized cognitive ability tests. The practice and control groups were carefully matched on their ability scores. The practice group played during two sessions per week across 4 weeks (16 h total) under strict supervision in the laboratory, showing systematic performance improvements in the game. A group independent component analysis (GICA) applying multisession temporal concatenation on test-retest resting-state fMRI, jointly with a dual-regression approach, was computed. Supporting the main hypothesis, the key finding reveals an increased correlated activity during rest in certain predefined resting state networks (albeit using uncorrected statistics) attributable to practice with the cognitively demanding tasks of the videogame. Observed changes were mainly concentrated on parietofrontal networks involved in heterogeneous cognitive functions. Hum Brain Mapp 34:3143-3157, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Short-term adaptive cognitive training based on the n-back task is reported to increase scores on individual ability tests, but the key question of whether such increases generalize to the intelligence construct is not clear. Here we evaluate fluid/abstract intelligence (Gf), crystallized/verbal intelligence (Gc), working memory capacity (WMC), and attention control (ATT) using diverse measures, with equivalent versions, for estimating any changes at the construct level after training. Beginning with a sample of 169 participants, two groups of twenty-eight women each were selected and matched for their general cognitive ability scores and demographic variables. Under strict supervision in the laboratory, the training group completed an intensive adaptive training program based on the n-back task (visual, auditory, and dual versions) across twenty-four sessions distributed over twelve weeks. Results showed that this group had the expected systematic improvements in n-back performance over time; this performance systematically correlated across sessions with Gf, Gc, and WMC, but not with ATT. However, the main finding showed no significant changes in the assessed psychological constructs for the training group as compared with the control group. Nevertheless, post-hoc analyses suggested that specific tests and tasks tapping visuospatial processing might be sensitive to training. [Copyright &y& Elsevier]

Humans and the great apes are the only species demonstrated to exhibit adrenarche, a key endocrine event associated with prepubertal increases in the adrenal production of androgens, most significantly dehydroepiandrosterone (DHEA) and to a certain degree testoster-one. Adrenarche also coincides with the emergence of the prosocial and neurobehavioral skills of middle childhood and may therefore represent a human-specific stage of development. Both DHEA and testosterone have been reported in animal and in vitro studies to enhance neuronal survival and programmed cell death depending on the timing, dose, and hormonal context involved, and to potentially compete for the same signaling pathways. Yet no extant brain-hormone studies have examined the interaction between DHEA- and testosterone-related cortical maturation in humans. Here, we used linear mixed models to examine changes in cortical thickness asso-ciated with salivary DHEA and testosterone levels in a longitudinal sample of developmentally healthy children and adolescents 4-22 years old. DHEA levels were associated with increases in cortical thickness of the left dorsolateral prefrontal cortex, right temporoparietal junction, right premotor and right entorhinal cortex between the ages of 4-13 years, a period marked by the androgenic changes of adrenarche. There was also an interaction between DHEA and testosterone on cortical thickness of the right cingulate cortex and occipital pole that was most significant in prepubertal subjects. DHEA and testosterone appear to interact and modulate the complex process of cortical maturation during middle childhood, consistent with evidence at the molecular level of fast/nongenomic and slow/genomic or conversion-based mechanisms underlying androgen-related brain development. [ABSTRACT FROM AUTHOR]

Abstract: Evidence from neuroimaging studies suggests that intelligence differences may be supported by a parieto-frontal network. Research shows that this network is also relevant for cognitive functions such as working memory and attention. However, previous studies have not explicitly analyzed the commonality of brain areas between a broad array of intelligence factors and cognitive functions tested in the same sample. Here fluid, crystallized, and spatial intelligence, along with working memory, executive updating, attention, and processing speed were each measured by three diverse tests or tasks. These twenty-one measures were completed by a group of one hundred and four healthy young adults. Three cortical measures (cortical gray matter volume, cortical surface area, and cortical thickness) were regressed against psychological latent scores obtained from a confirmatory factor analysis for removing test and task specific variance. For cortical gray matter volume and cortical surface area, the main overlapping clusters were observed in the middle frontal gyrus and involved fluid intelligence and working memory. Crystallized intelligence showed an overlapping cluster with fluid intelligence and working memory in the middle frontal gyrus. The inferior frontal gyrus showed overlap for crystallized intelligence, spatial intelligence, attention, and processing speed. The fusiform gyrus in temporal cortex showed overlap for spatial intelligence and attention. Parietal and occipital areas did not show any overlap across intelligence and cognitive factors. Taken together, these findings underscore that structural features of gray matter in the frontal lobes support those aspects of intelligence related to basic cognitive processes. [Copyright &y& Elsevier]

Abstract: Recent functional connectivity studies have demonstrated that, in resting humans, activity in a dorsally-situated neocortical network is inversely associated with activity in the amygdalae. Similarly, in human neuroimaging studies, aspects of emotion regulation have been associated with increased activity in dorsolateral, dorsomedial, orbital and ventromedial prefrontal regions, as well as concomitant decreases in amygdalar activity. These findings indicate the presence of two countervailing systems in the human brain that are reciprocally related: a dorsally-situated cognitive control network, and a ventrally-situated limbic network. We investigated the extent to which this functional reciprocity between limbic and dorsal neocortical regions is recapitulated from a purely structural standpoint. Specifically, we hypothesized that amygdalar volume would be related to cerebral cortical thickness in cortical regions implicated in aspects of emotion regulation. In 297 typically developing youths (162 females, 135 males; 572 MRIs), the relationship between cortical thickness and amygdalar volume was characterized. Amygdalar volume was found to be inversely associated with thickness in bilateral dorsolateral and dorsomedial prefrontal, inferior parietal, as well as bilateral orbital and ventromedial prefrontal cortices. Our findings are in line with previous work demonstrating that a predominantly dorsally-centered neocortical network is reciprocally related to core limbic structures such as the amygdalae. Future research may benefit from investigating the extent to which such cortical-limbic morphometric relations are qualified by the presence of mood and anxiety psychopathology. [Copyright &y& Elsevier]

Abstract: Here gray and white matter changes after four weeks of videogame practice were analyzed using optimized voxel-based morphometry (VBM), cortical surface and cortical thickness indices, and white matter integrity computed from several projection, commissural, and association tracts relevant to cognition. Beginning with a sample of one hundred young females, twenty right handed participants were recruited for the study and assigned to a practice or a control group carefully matched by their general cognitive ability scores. After the first scan, the practice group played ‘Professor Layton and The Pandora''s Box’ 4h per week during four weeks. A second scan was obtained at the end of practice and intelligence was measured again. Image analyses revealed gray and white matter changes in the practice group. Gray matter changes theoretically relevant for intelligence were observed for the practice group mainly in frontal clusters (Brodmann areas 9 and 10) and also in smaller parietal and temporal regions. White matter findings were focused in the hippocampal cingulum and the inferior longitudinal fasciculus. These gray and white matter changes presumably induced by practice did not interact with intelligence tests'' scores. [Copyright &y& Elsevier]

The article presents a case study examination into the cortical thickness correlates of symptoms of inattention in healthy children in order to highlight the relationship between cortical maturation and the damages of attention-deficit/hyperactivity disorder in children. A cross-sectional analysis of children's attentive behaviors and cortical thickness is presented. Conclusions are offered highlighting associations between attention problem symptoms and cortical thinness.

Background: The anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and basal ganglia have been implicated in pathological aggression. This study aimed at identifying neuroanatomical correlates of impulsive aggression in healthy children. Methods: Data from 193 representative 6- to 18-year-old healthy children were obtained from the National Institutes of Health Magnetic Resonance Imaging Study of Normal Brain Development after a blinded quality control. Cortical thickness and subcortical volumes were obtained with automated software. Aggression levels were measured with the Aggressive Behavior scale (AGG) of the Child Behavior Checklist. AGG scores were regressed against cortical thickness and basal ganglia volumes using first- and second-order linear models while controlling for age, gender, scanner site, and total brain volume. Gender by AGG interactions were analyzed. Results: There were positive associations between bilateral striatal volumes and AGG scores (right: r = .238, p = .001; left: r = .188, p = .01). A significant association was found with right ACC and subgenual ACC cortical thickness in a second-order linear model (p < .05, corrected). High AGG scores were associated with a relatively thin right ACC cortex. An AGG by gender interaction trend was found in bilateral OFC and ACC associations with AGG scores. Conclusions: This study shows the existence of relationships between impulsive aggression in healthy children and the structure of the striatum and right ACC. It also suggests the existence of gender-specific patterns of association in OFC/ACC gray matter. These results may guide research on oppositional-defiant and conduct disorders. [ABSTRACT FROM AUTHOR]

Documented associations between corpus callosum size and cognitive ability have heretofore been inconsistent potentially owing to differences in sample characteristics, differing methodologies in measuring CC size, or the use of absolute versus relative measures. We investigated the relationship between CC size and intelligence quotient (IQ) in the NIH MRI Study of Normal Brain Development sample, a large cohort of healthy children and adolescents (aged six to 18, n =198) recruited to be representative of the US population. CC midsagittal area was measured using an automated system that partitioned the CC into 25 subregions. IQ was measured using the Wechsler Abbreviated Scale of Intelligence (WASI). After correcting for total brain volume and age, a significant negative correlation was found between total CC midsagittal area and IQ (r=20.147; p= 0.040). Post hoc analyses revealed a significant negative correlation in children (age<12) (r=20.279; p= 0.004) but not in adolescents (age≥12) (r=20.005; p= 0.962). Partitioning the subjects by gender revealed a negative correlation in males (r=20.231; p =0.034) but not in females (r=0.083; p =0.389). Results suggest that the association between CC and intelligence is mostly driven by male children. In children, a significant gender difference was observed for FSIQ and PIQ, and in males, a significant age-group difference was observed for FSIQ and PIQ. These findings suggest that the correlation between CC midsagittal area and IQ may be related to age and gender. [ABSTRACT FROM AUTHOR]