Gray matter correlates of cognitive ability tests used for vocational guidance

<p>Abstract</p> <p>Background</p> <p>Individual differences in cognitive abilities provide information that is valuable for vocational guidance, but there is an ongoing debate about the role of ability factors, including general intelligence (<it>g</it>), compared to individual tests. Neuroimaging can help identify brain parameters that may account for individual differences in both factors and tests. Here we investigate how eight tests used in vocational guidance correlate to regional gray matter. We compare brain networks identified by using scores for ability factors (general and specific) to those identified by using individual tests to determine whether these relatively broad and narrow approaches yield similar results.</p> <p>Findings</p> <p>Using MRI and voxel-based morphometry (VBM), we correlated gray matter with independent ability factors (general intelligence, speed of reasoning, numerical, spatial, memory) and individual test scores from a battery of cognitive tests completed by 40 individuals seeking vocational guidance. Patterns of gray matter correlations differed between group ability factors and individual tests. Moreover, tests within the same factor showed qualitatively different brain correlates to some degree.</p> <p>Conclusions</p> <p>The psychometric factor structure of cognitive tests can help identify brain networks related to cognitive abilities beyond a general intelligence factor (<it>g</it>). Correlates of individual ability tests with gray matter, however, appear to have some differences from the correlates for group factors.</p

Sex differences in the relationship between white matter connectivity and creativity

Creative cognition emerges from a complex network of interacting brain regions. This study investigated the relationship between the structural organization of the human brain and aspects of creative cognition quantified by divergent thinking tasks. Diffusion weighted imaging (DWI) was used to obtain fiber tracts from 83 segmented cortical regions. This information was represented as a network and metrics of connectivity organization, including connectivity strength, clustering and efficiency were computed, and their relationship to personal levels of creativity was examined. Permutation testing identified significant sex differences in the relationship between global connectivity and creativity as measured by divergent thinking tests. Females demonstrated significant inverse relationships between global connectivity and creative cognition; there were no significant relationships observed in males. Node specific analyses found inverse relationships across measures of Connectivity, Efficiency, Clustering and creative cognition in widespread regions in females. Our findings suggest that females involve more regions of the brain in processing to produce novel ideas to solutions, perhaps at the expense of efficiency (greater path lengths). Males, in contrast, exhibited few, relatively weak positive relationships across these measures. Extending recent observations of sex differences in connectome structure, our findings of sexually dimorphic relationships suggest a unique topological organization of connectivity underlying the generation of novel ideas in males and females

Sex differences in white matter development during adolescence: A DTI study

Adolescence is a complex transitional period in human development, composing physical maturation, cognitive and social behavioral changes. The objective of this study is to investigate sex differences in white matter development and the associations between intelligence and white matter microstructure in the adolescent brain using diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS). In a cohort of 16 typically-developing adolescents aged 13 to 17 years, longitudinal DTI data were recorded from each subject at two time points that were one year apart. We used TBSS to analyze the diffusion indices including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). Our results suggest that boys (13–18 years) continued to demonstrate white matter maturation, whereas girls appeared to reach mature levels earlier. In addition, we identified significant positive correlations between FA and full-scale intelligence quotient (IQ) in the right inferior fronto-occipital fasciculus when both sexes were looked at together. Only girls showed significant positive correlations between FA and verbal IQ in the left cortico-spinal tract and superior longitudinal fasciculus. The preliminary evidence presented in this study supports that boys and girls have different developmental trajectories in white matter microstructure

Sukupuolittunut lukeminen ja vanhempien tuki Suomessa

Ensimmäisestä PISA-tutkimuksesta alkaen poikien lukutaidon tulokset ovat Suomessa olleet tyttöjä heikompia. Poikien heikompia tuloksia on selitetty aiemmissa tutkimuksissa neurologisilla kehityseroilla, ADHD-diagnoosien yleisyydellä ja maskuliinisella kulttuurilla, missä lukeminen koetaan tyttöjen juttuna. Aiemmissa tutkimuksissa on tuotu esiin kodin sosioekonomisen aseman ja lukutaidon välinen yhteys. Tätä yhteyttä ei ole kuitenkaan tarkasteltu Suomessa sukupuolten välillä. Tässä pro gradu -tutkielmassa selvitetään kodin sosioekonomisen aseman yhteyttä lapsen tukemiseen sekä tuen yhteyttä lukutaitoon sukupuolten välillä. Tutkielmassa hyödynnetään sekä sosiaali- että käyttäytymistieteellisiä selitysmalleja. Analyysit perustuvat Suomessa vuonna 2015 kerättyyn PISA-kyselyyn, johon osallistui 5882 oppilasta. Tutkimusmenetelmänä käytetään lineaarista regressioanalyysiä. Tuen sukupuolittuneisuutta tutkitaan interaktio- eli yhdysvaikutusten tarkastelulla, missä analysoidaan vanhempien resurssien ja tukemisen yhteyttä sukupuolten välillä sekä tuen ja lukutaidon yhteyttä. Koulun merkitys lukutaitoon huomioidaan analyysissä kiinteiden vaikutusten monitasomallina. Tulosten mukaan kotitausta selittää lapselle annettua tukea ja vanhempien korkeammalla sosioekonomisella asemalla on positiivinen yhteys tukemiseen. Sosioekonominen asema ei kuitenkaan ole yhteydessä tuen sukupuolittuneisuuteen. Vanhempien tuen lisääntyminen on yhteydessä lukutaidon korkeampaan pistemäärään. Vanhempien tuen ja lukutaidon tulosten välinen yhteys on suhteellisesti positiivisempi pojilla verrattuna tyttöihin. Vanhempien tuki kompensoi poikien heikkoa lukemisen lähtötasoa ja kaventaa lukutaidon pisteiden eroja sukupuolten välillä. Sukupuolten välisten lukutaitoerojen tasoittamisessa tulisi huomioida vanhempien tuen merkitys poikien lukutaidon parantamisessa ja purkaa maskuliinisen kulttuuriin perustava käsitys lukemisesta tyttöjen juttuna. Vanhempien tuen vahvistaminen sosioekonomisesti heikommassa asemassa olevissa perheissä kaventaisi tuen puutteesta johtuvia lukutaidon eroja erilaisista perhetaustoista tulevien oppilaiden välillä

Characterizing Developmental Growth and Individual Differences in Brain Systems Supporting Inhibitory Control: A Longitudinal fMRI Study

Inhibitory control, the ability to voluntarily suppress responses to task-irrelevant stimuli, enables goal-directed behaviors and continues to develop through adolescence. Neuroimaging studies indicate that developmental improvements in inhibitory performance are supported by the maturation of brain systems, but these studies have not used longitudinal designs and continuous metrics of age to characterize the process of growth or individual differences in trajectories. This study used longitudinal fMRI data from over 312 visits from 129 participants aged 8 to 28 years to characterize growth curves of brain function. Mean growth curves revealed developmental increases in activity within an error monitoring region, the dorsal anterior cingulate cortex (dACC). DACC activity was uniquely associated with task performance, suggesting that late-maturing dACC activity may be a primary process underlying the maturation of inhibitory control. Activity in the right dorsolateral prefrontal cortex (dlPFC) declined from childhood to adolescence, and may function as a scaffold to support immature networks. Growth curves across remaining areas of the inhibitory control circuitry did not show developmental changes, suggesting that the foundational inhibitory control system is available early in development. Investigating individual differences in trajectories revealed patterns of variability segregated according to function. Error monitoring evidenced the least variability, and executive control regions showed parallel trajectories, indicating a preservation of rank-order stability over development. Some motor response control regions showed a decline in variability with age,v indicating individuals follow different paths to the same end point of maturity. Sex predicted slope variability in a set of motor response control regions and an executive control region, with females but not males showing developmental declines in reactivity. Taken together, these findings extend prior cross-sectional studies to indicate that primary to the development of inhibitory control is enhanced error monitoring and less reliance on supportive dlPFC control. Further, results highlight important variability in developmental pathways, including notable sex differences

A Life Course Study of Early Childhood Height Growth and Adult Working Memory and Depression Outcomes

Evidence has been mounting that exposures during fetal development and early postnatal life are important determinants of many adult health outcomes including. diabetes, obesity and cardiovascular disease. Critical periods of early development have been identified for certain outcomes. Early life factors are suspected as having a role in cognitive and psychiatric outcomes, but research to date is limited. Birth weight, considered a marker for fetal development, has been positively associated with cognitive abilities. A few postnatal studies provide evidence that early childhood height growth, an indicator of overall development, is also positively associated with cognitive abilities in adults under age 25 years. There has been no research on early childhood height growth and cognitive outcomes in middle age adults. Low birth weight has also been associated with a spectrum of neuropsychiatric disorders, including, in one study, affective disorders. There are no known studies of early childhood height growth and neuropsychiatric disorders. With this background, I made two hypotheses. First, I hypothesized that early childhood height growth is positively associated with working memory ability in middle age adults. Second, I hypothesized that early childhood height growth is inversely associated with lifetime major depressive disorder in middle age adults. I also explored effect modification by sex and by small for gestational age status. I tested these hypotheses using data from the Early Determinants of Adult Health (EDAH) study and its sister study Fetal Antecedents of Major Depression and Cardiovascular Disease (MDCVD). These studies were adult follow-up studies of two birth cohorts recruited in the 1960’s: the Child Health and Development Studies (CHDS) and the New England Family Study (NEFS); both followed subjects from birth through childhood. Birth length and successive early childhood height measures were available enabling a study of three height growth periods, birth to 4 months, 4 months to 1 year and 1 to 4 years. The adult follow up study included 4 measures of different aspects of working memory ability as well as a structured interview that assessed neuropsychiatric outcomes including lifetime major depressive disorder. We found some evidence that early childhood height growth was positively associated with adult working memory ability in specific growth periods. Results of the analysis of early childhood height growth and adult lifetime MDD do not support the association between early childhood height growth and lifetime MDD

Neuroimagen en adolescentes con talento matemático

Un talento representa una forma especial de inteligencia que muestra un alto cociente intelectual y funcionamiento ejecutivo, una creatividad excepcional y una mayor motivación en ciertos rasgos específicos. Cuando uno de estos rasgos es el pensamiento matemático, a estos sujetos se les conoce como talentos matemáticos. Por esto, el hecho de definir a un talento únicamente por su mayor cociente intelectual podría dar lugar a confusión en la identificación de estos sujetos. Los talentos matemáticos muestran mayor capacidad de razonamiento fluido, memoria de trabajo y en imaginería mental. Estas capacidades se consideran fundamentales en el razonamiento matemático. Las técnicas de neuroimagen están contribuyendo a una mejor comprensión del sustrato neurobiológico de los talentos matemáticos. Estudios previos describieron que estos talentos muestran unas funciones cerebrales atípicas. En particular, los talentos matemáticos presentan mayor desarrollo y activación del hemisferio derecho, que es importante para el procesamiento de la información visoespacial. Los sujetos con talento matemático muestran una gran conectividad funcional entre los hemisferios izquierdo y derecho. Esta gran conectividad funcional interhemisférica junto con la mayor participación del hemisferio derecho podría causar una forma especial de bilateralidad funcional en la red fronto-parietal. Algunos estudios de neuroimagen describen asociaciones significativas entre las activaciones neuronales, o bien la microestructura de la sustancia blanca o bien morfometría cortical, y las habilidades cognitivas de los sujetos, tales como la inteligencia o la creatividad. Sin embargo, hasta donde hoy sabemos, no hay estudios sobre el estado de la sustancia blanca que confirmen la mayor conectividad estructural entre diferentes regiones cerebrales en talentos matemáticos. Así mismo, a día de hoy no existen estudios sobre morfometría cortical en talentos matemáticos..

Exploring the ventral language pathways of the brain through bilingualism: a Tractography study

The focus of the present PhD thesis is to compare the brain correlates associated to bimodal bilingualism with respect to unimodal bilingualism. The overarching aim is to identify which are the common neuronal substrates between signed and spoken languages, with respect to the neural substrates that are specific for each linguistic modality, i.e., signed versus spoken. This is a relevant issue as it allows to better explore (i) to what extent and for which function the two language modalities might interact; (ii) for which function they might interfere, and (iii) whether the two language modalities are supported by independent neuronal systems. In addition, this project explores the organization of the bilingual brain in a broader view, assessing whether the neural structures underlying the first language (L1) can be separated from structures mainly devoted at handling the second language (L2). Measures of diffusion magnetic resonance imaging tractography will be assessed in a group of unimodal bilinguals of Italian (L1) and English (L2) and in a group of bimodal bilinguals of Italian (L1) and Italian Sign Language (L2), with variable level of proficiency in the second language. Together with the tract-specific measures, both demographical and behavioral data will be collected in order to assess the level of performance for both L1 and L2. Tract-specific data will be correlated with behavioral data, revealing how the degree of expertise with signed or spoken language and the relative modality are capable of shaping the neural circuitry at the service of specific linguistic functions