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Memoria e inteligencia : interdependencia en función de los procesos y contenidos de las tareas; Memory and intelligence : Interdependence according to processes and content of tasks

Ferreira, Aristides Isidoro; Almeida, Leandro S.; Prieto, Gerardo; Guisande, M. Adelina
Fonte: Pontificia Universidad Javeriana Psychology Faculty Publicador: Pontificia Universidad Javeriana Psychology Faculty
Tipo: Artigo de Revista Científica
Publicado em //2012 Português
Relevância na Pesquisa
46.08%
Este trabajo procura analizar las características de los factores específicos de la memoria (procesos o contenidos) asociados a Gsm del modelo CHC. Para esto, a una muestra de estudiantes universitarios se le administraron tareas de memoria con diferentes contenidos, varios tests de aptitudes y una prueba de inteligencia general. Se evaluaron dos modelos que relacionan la aptitud general Gsm, bien con la memoria de trabajo y la amplitud de memoria, bien con aptitudes verbales-numéricas y viso-espaciales. Los resultados muestran, para ambos modelos, buenos índices de ajuste, sin embargo, se encontraron datos de regresión estandarizados con una regresión positiva superior entre Gsm y memoria de trabajo y entre Gsm y contenido viso-espacial. También se debe destacar que en ambos modelos se observaron valores de regresión estandarizados de 0.54 y 0.73 entre Gsm y el factor g. Teniendo en cuenta los resultados obtenidos, se discuten algunas implicaciones del estudio para comprender la relación entre inteligencia y memoria.; This study investigates the characteristics of the specific memory factors (processes and content) that are associated to the Gsm from the CHC model. Memory tasks with different content, including various aptitude tests and a general intelligence test...

Intelligence of adolescents is related to their parents’ educational level but not to family income

Lemos, Gina C.; Almeida, Leandro S.; Colom, Roberto
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.1%
Parental educational level and family income have been related to individual differences in intelligence. However, large and representative samples are hardly available. Here two samples of young and old adolescents totaling 3233 boys and girls completed an intelligence battery comprising abstract, numerical, verbal, mechanical, and spatial reasoning subtests. Parents’ educational levels, family incomes, and adolescents’ general intelligence (g) were simultaneously related using SEM (structural equation modeling) analyses. The main findings show that (1) parental education strongly predicts family differences in income, (2) family income is not related to adolescents’ intelligence, and (3) parents’ education predicts adolescents’ intelligence regardless of family income. Because it is widely acknowledged that personal intelligence is the best predictor of educational differences, the next causal chain is endorsed: brighter parents reach higher levels of education, which allows approaching better occupations, and, therefore, they can create families with higher incomes. Adolescents from more affluent families tend to be brighter because their parents are brighter, not because they enjoy better family environments.

Relação entre rede social, Inteligência geral, inteligência social e hormonas em humanos

Pestana, José Antonio Melo
Fonte: ISPA -Instituto Universitário Publicador: ISPA -Instituto Universitário
Tipo: info:eu-repo/semantics/masterthesis
Publicado em //2013 Português
Relevância na Pesquisa
46.17%
Dissertação de Mestrado em Psicobiologia, apresentada ao ISPA - Instituto Universitário; Segundo a Hipótese da Inteligência Maquiaveliana, o principal motor evolutivo responsável pelo desenvolvimento das capacidades cognitivas que muitas espécies exibem terá sido a exigência que o processamento de uma rede social numerosa e complexa pede. Um factor importante para o estabelecimento de relações sociais humanas é a Teoria da Mente, que é definida como a capacidade de inferir sobre os estados mentais dos outros. Existem também numerosas evidências relativas à influência de várias hormonas no comportamento social. De forma a investigar quais as variáveis cognitivas e fisiológicas relacionadas com o tamanho e complexidade da rede social em humanos, foram recolhidos dados sobre Inteligência Geral (medida através de “Matrizes Progressivas Avançadas de Raven”), Teoria da Mente (através de” Reading the Eyes in the Mind Test”, cuja versão portuguesa foi também aqui validada, num N = 130), rede social (através de “Social Network Index”), testosterona e cortisol. Não foram encontradas relações da rede social e hormonas com nenhuma das restantes variáveis em estudo. Foi, contudo, observada uma associação entre Inteligência Geral e Teoria da Mente...

Estudo exploratório da inteligência emocional em adolescentes

Oliveira, Elisabete Sofia Meelind de
Tipo: info:eu-repo/semantics/masterthesis
Publicado em //2008 Português
Relevância na Pesquisa
46.23%
Dissertação de Mestrado apresentada ao Instituto Superior de Psicologia Aplicada; O presente estudo teve como principal objectivo estudar a Inteligência Emocional numa amostra de adolescentes com idades compreendidas entre os 14 e os 18 anos. Pretendeu-se averiguar a existência de correlações entre a Inteligência Emocional, a idade, o género, o número de retenções vs nenhuma retenção escolar, a inteligência geral, o ser aluno dos Cursos Educação e Formação vs. alunos do Ensino Regular, o auto – conceito e o estatuto sócio económico. Para concretizar o objectivo, usou-se o Emotional Intelligence Scale (EIS), as Matrizes Progressivas de Raven (SPM), a Escala de Auto-Conceito de Song & Hattie e a Classificação Social Internacional de Graffar. As restantes variáveis foram obtidas mediante preenchimento de dados colocados no início dos instrumentos atrás mencionados. Como principais resultados obteve-se uma correlação não significativa entre a Inteligência Emocional e a idade e o género, grupo (ser aluno dos CEF vs do ensino regular), o número de retenções vs. nenhuma retenção a inteligência geral e o estatuto sócio económico (verificou-se no entanto que estas três últimas variáveis relacionam-se entre si). A Inteligência Emocional mostrou-se então correlacionada unicamente com a variável Auto-Conceito.; ABSTRACT: The main objective of this study is to analyse Emotional Intelligence within a sample of adolescents of ages ranging between 14 and 18 years old. It is aimed to examine the existence of the correlation between Emotional Intelligence...

Mild myotonic dystrophy is associated with memory impairment in the context of normal general intelligence.

Rubinsztein, J S; Rubinsztein, D C; McKenna, P J; Goodburn, S; Holland, A J
Tipo: text
Publicado em /03/1997 Português
Relevância na Pesquisa
46.18%
Previous investigations of cognitive function in myotonic dystrophy (DM) suggested that DM subjects have impairment of general intelligence and severe defects in executive function. These studies had to neglect patients with mild clinical disease, since they were generally performed before the availability of DNA testing for DM. We have investigated a group of milder DM cases (defined both by their degree of disability and CTG expansion size) and have not found any defect in general intelligence using the National Adult Reading Test, Standard Progressive Matrices, and Mini-Mental State examination. Three executive function tests were used. The cognitive estimates test and the Wisconsin Card Sorting Test showed tendencies towards impairment, which were of borderline significance, but the verbal fluency task was performed normally. However, in the face of normal general intelligence, mild DM subjects as a group show impairment of memory function. This suggests that memory function may be more sensitive to small CTG repeat expansions than general intelligence.

Distributed neural system for general intelligence revealed by lesion mapping

Gläscher, J.; Rudrauf, D.; Colom, R.; Paul, L. K.; Tranel, D.; Damasio, H.; Adolphs, R.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: text
Português
Relevância na Pesquisa
46.05%
General intelligence (g) captures the performance variance shared across cognitive tasks and correlates with real-world success. Yet it remains debated whether g reflects the combined performance of brain systems involved in these tasks or draws on specialized systems mediating their interactions. Here we investigated the neural substrates of g in 241 patients with focal brain damage using voxel-based lesion–symptom mapping. A hierarchical factor analysis across multiple cognitive tasks was used to derive a robust measure of g. Statistically significant associations were found between g and damage to a remarkably circumscribed albeit distributed network in frontal and parietal cortex, critically including white matter association tracts and frontopolar cortex. We suggest that general intelligence draws on connections between regions that integrate verbal, visuospatial, working memory, and executive processes.

Cerebral Blood Flow during Rest Associates with General Intelligence and Creativity

Takeuchi, Hikaru; Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Nagase, Tomomi; Nouchi, Rui; Kawashima, Ryuta
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: text
Publicado em 29/09/2011 Português
Relevância na Pesquisa
46.07%
Recently, much scientific attention has been focused on resting brain activity and its investigation through such methods as the analysis of functional connectivity during rest (the temporal correlation of brain activities in different regions). However, investigation of the magnitude of brain activity during rest has focused on the relative decrease of brain activity during a task, rather than on the absolute resting brain activity. It is thus necessary to investigate the association between cognitive factors and measures of absolute resting brain activity, such as cerebral blood flow (CBF), during rest (rest-CBF). In this study, we examined this association using multiple regression analyses. Rest-CBF was the dependent variable and the independent variables included two essential components of cognitive functions, psychometric general intelligence and creativity. CBF was measured using arterial spin labeling and there were three analyses for rest-CBF; namely mean gray matter rest-CBF, mean white matter rest-CBF, and regional rest-CBF. The results showed that mean gray and white matter rest-CBF were significantly and positively correlated with individual psychometric intelligence. Furthermore, mean white matter rest-CBF was significantly and positively correlated with creativity. After correcting the effect of mean gray matter rest-CBF the significant and positive correlation between regional rest-CBF in the perisylvian anatomical cluster that includes the left superior temporal gyrus and insula and individual psychometric intelligence was found. Also...

BDNF Polymorphism Predicts General Intelligence after Penetrating Traumatic Brain Injury

Rostami, Elham; Krueger, Frank; Zoubak, Serguei; Dal Monte, Olga; Raymont, Vanessa; Pardini, Matteo; Hodgkinson, Colin A.; Goldman, David; Risling, Mårten; Grafman, Jordan
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: text
Publicado em 08/11/2011 Português
Relevância na Pesquisa
46.17%
Neuronal plasticity is a fundamental factor in cognitive outcome following traumatic brain injury. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, plays an important role in this process. While there are many ways to measure cognitive outcome, general cognitive intelligence is a strong predictor of everyday decision-making, occupational attainment, social mobility and job performance. Thus it is an excellent measure of cognitive outcome following traumatic brain injury (TBI). Although the importance of the single-nucleotide polymorphisms polymorphism on cognitive function has been previously addressed, its role in recovery of general intelligence following TBI is unknown. We genotyped male Caucasian Vietnam combat veterans with focal penetrating TBI (pTBI) (n?=?109) and non-head injured controls (n?=?38) for 7 BDNF single-nucleotide polymorphisms. Subjects were administrated the Armed Forces Qualification Test (AFQT) at three different time periods: pre-injury on induction into the military, Phase II (10–15 years post-injury, and Phase III (30–35 years post-injury). Two single-nucleotide polymorphisms, rs7124442 and rs1519480, were significantly associated with post-injury recovery of general cognitive intelligence with the most pronounced effect at the Phase II time point...

An integrative architecture for general intelligence and executive function revealed by lesion mapping

Barbey, Aron K.; Colom, Roberto; Solomon, Jeffrey; Krueger, Frank; Forbes, Chad; Grafman, Jordan
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: text
Português
Relevância na Pesquisa
46.19%
Although cognitive neuroscience has made remarkable progress in understanding the involvement of the prefrontal cortex in executive control, the broader functional networks that support high-level cognition and give rise to general intelligence remain to be well characterized. Here, we investigated the neural substrates of the general factor of intelligence (g) and executive function in 182 patients with focal brain damage using voxel-based lesion–symptom mapping. The Wechsler Adult Intelligence Scale and Delis–Kaplan Executive Function System were used to derive measures of g and executive function, respectively. Impaired performance on these measures was associated with damage to a distributed network of left lateralized brain areas, including regions of frontal and parietal cortex and white matter association tracts, which bind these areas into a coordinated system. The observed findings support an integrative framework for understanding the architecture of general intelligence and executive function, supporting their reliance upon a shared fronto-parietal network for the integration and control of cognitive representations and making specific recommendations for the application of the Wechsler Adult Intelligence Scale and Delis–Kaplan Executive Function System to the study of high-level cognition in health and disease.

Dorsolateral Prefrontal Contributions to Human Intelligence

Barbey, Aron K.; Colom, Roberto; Grafman, Jordan
Tipo: text
Português
Relevância na Pesquisa
36.25%
Although cognitive neuroscience has made remarkable progress in understanding the involvement of the prefrontal cortex in executive control functions for human intelligence, the necessity of the dorsolateral prefrontal cortex (dlPFC) for key competencies of general intelligence and executive function remains to be well established. Here we studied human brain lesion patients with dlPFC lesions to investigate whether this region is computationally necessary for performance on neuropsychological tests of general intelligence and executive function, administering the Wechsler Adult Intelligence Scale (WAIS) and subtests of the Delis Kaplan Executive Function System (D-KEFS) to three groups: dlPFC lesions (n = 19), non-dlPFC lesions (n = 152), and no brain lesions (n = 55). The key results indicate that: (1) patients with focal dlPFC damage exhibit lower scores, at the latent variable level, than controls in general intelligence (g) and executive function; (2) dlPFC patients demonstrate lower scores than controls in several executive measures; and (3) these latter differences are no longer significant when the pervasive influence of the general factor of intelligence (g) is statistically removed. The observed findings support a central role for the dlPFC in general intelligence and make specific recommendations for the interpretation and application of the WAIS and D-KEFS to the study of high-level cognition in health and disease.

Most Reported Genetic Associations with General Intelligence Are Probably False Positives

Chabris, Christopher F.; Hebert, Benjamin M.; Benjamin, Daniel J.; Beauchamp, Jonathan P.; Cesarini, David; van der Loos, Matthijs J.H.M.; Johannesson, Magnus; Magnusson, Patrik K.E.; Lichtenstein, Paul; Atwood, Craig S.; Freese, Jeremy; Hauser, Taissa S.
Tipo: text
Português
Relevância na Pesquisa
45.91%
General intelligence (g) and virtually all other behavioral traits are heritable. Associations between g and specific single-nucleotide polymorphisms (SNPs) in several candidate genes involved in brain function have been reported. We sought to replicate published associations between 12 specific genetic variants and g using three independent, longitudinal datasets of 5571, 1759, and 2441 well-characterized individuals. Of 32 independent tests across all three datasets, only one was nominally significant at the p < .05 level. By contrast, power analyses showed that we should have expected 10–15 significant associations, given reasonable assumptions for genotype effect sizes. As positive controls, we confirmed accepted genetic associations for Alzheimer disease and body mass index, and we used SNP-based relatedness calculations to replicate estimates that about half of the variance in g is accounted for by common genetic variation among individuals. We conclude that different approaches than candidate genes are needed in the molecular genetics of psychology and social science.

Processing Speed Mediates the Development of General Intelligence (g) in Adolescence

Coyle, Thomas R.; Pillow, David R.; Snyder, Anissa C.; Kochunov, Peter
Tipo: text
Português
Relevância na Pesquisa
45.91%
In the research reported here, we examined whether processing speed mediates the development of general intelligence (g) in adolescence. Using the Armed Services Vocational Aptitude Battery, a battery of 12 diverse cognitive tests, we assessed processing speed and g in a large sample of 13- to 17-year-olds obtained from the National Longitudinal Survey of Youth (N = 6,969). The direct effect of age on g was small compared with the total effect of age on g, which was almost fully mediated through speed. The results suggest that increases in g in adolescence can be attributed to increases in mental speed.

Association of Structural Global Brain Network Properties with Intelligence in Normal Aging

Fischer, Florian U.; Wolf, Dominik; Scheurich, Armin; Fellgiebel, Andreas
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: text
Publicado em 22/01/2014 Português
Relevância na Pesquisa
36.27%
Higher general intelligence attenuates age-associated cognitive decline and the risk of dementia. Thus, intelligence has been associated with cognitive reserve or resilience in normal aging. Neurophysiologically, intelligence is considered as a complex capacity that is dependent on a global cognitive network rather than isolated brain areas. An association of structural as well as functional brain network characteristics with intelligence has already been reported in young adults. We investigated the relationship between global structural brain network properties, general intelligence and age in a group of 43 cognitively healthy elderly, age 60–85 years. Individuals were assessed cross-sectionally using Wechsler Adult Intelligence Scale-Revised (WAIS-R) and diffusion-tensor imaging. Structural brain networks were reconstructed individually using deterministic tractography, global network properties (global efficiency, mean shortest path length, and clustering coefficient) were determined by graph theory and correlated to intelligence scores within both age groups. Network properties were significantly correlated to age, whereas no significant correlation to WAIS-R was observed. However, in a subgroup of 15 individuals aged 75 and above...

Preservation of General Intelligence following Traumatic Brain Injury: Contributions of the Met66 Brain-Derived Neurotrophic Factor

Barbey, Aron K.; Colom, Roberto; Paul, Erick; Forbes, Chad; Krueger, Frank; Goldman, David; Grafman, Jordan
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: text
Publicado em 26/02/2014 Português
Relevância na Pesquisa
46.08%
Brain-derived neurotrophic factor (BDNF) promotes survival and synaptic plasticity in the human brain. The Val66Met polymorphism of the BDNF gene interferes with intracellular trafficking, packaging, and regulated secretion of this neurotrophin. The human prefrontal cortex (PFC) shows lifelong neuroplastic adaption implicating the Val66Met BDNF polymorphism in the recovery of higher-order executive functions after traumatic brain injury (TBI). In this study, we examined the effect of this BDNF polymorphism on the preservation of general intelligence following TBI. We genotyped a sample of male Vietnam combat veterans (n?=?156) consisting of a frontal lobe lesion group with focal penetrating head injuries for the Val66Met BDNF polymorphism. Val/Met did not differ from Val/Val genotypes in general cognitive ability before TBI. However, we found substantial average differences between these groups in general intelligence (? half a standard deviation or 8 IQ points), verbal comprehension (6 IQ points), perceptual organization (6 IQ points), working memory (8 IQ points), and processing speed (8 IQ points) after TBI. These results support the conclusion that Val/Met genotypes preserve general cognitive functioning, whereas Val/Val genotypes are largely susceptible to TBI.

Associations between cortical thickness and general intelligence in children, adolescents and young adults

Menary, Kyle; Collins, Paul F.; Porter, James N.; Muetzel, Ryan; Olson, Elizabeth A.; Kumar, Vipin; Steinbach, Michael; Lim, Kelvin O.; Luciana, Monica
Tipo: text
Publicado em //2013 Português
Relevância na Pesquisa
46.19%
Neuroimaging research indicates that human intellectual ability is related to brain structure including the thickness of the cerebral cortex. Most studies indicate that general intelligence is positively associated with cortical thickness in areas of association cortex distributed throughout both brain hemispheres. In this study, we performed a cortical thickness mapping analysis on data from 182 healthy typically developing males and females ages 9 to 24 years to identify correlates of general intelligence (g) scores. To determine if these correlates also mediate associations of specific cognitive abilities with cortical thickness, we regressed specific cognitive test scores on g scores and analyzed the residuals with respect to cortical thickness. The effect of age on the association between cortical thickness and intelligence was examined. We found a widely distributed pattern of positive associations between cortical thickness and g scores, as derived from the first unrotated principal factor of a factor analysis of Wechsler Abbreviated Scale of Intelligence (WASI) subtest scores. After WASI specific cognitive subtest scores were regressed on g factor scores, the residual score variances did not correlate significantly with cortical thickness in the full sample with age covaried. When participants were grouped at the age median...

Medial Frontal White and Gray Matter Contributions to General Intelligence

Ohtani, Toshiyuki; Nestor, Paul G.; Bouix, Sylvain; Saito, Yukiko; Hosokawa, Taiga; Kubicki, Marek
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: text
Publicado em 31/12/2014 Português
Relevância na Pesquisa
46.17%
The medial orbitofrontal cortex (mOFC) and rostral anterior cingulate cortex (rACC) are part of a wider neural network that plays an important role in general intelligence and executive function. We used structural brain imaging to quantify magnetic resonance gray matter volume and diffusion tensor white matter integrity of the mOFC-rACC network in 26 healthy participants who also completed neuropsychological tests of intellectual abilities and executive function. Stochastic tractography, the most effective Diffusion Tensor Imaging method for examining white matter connections between adjacent gray matter regions, was employed to assess the integrity of mOFC-rACC pathways. Fractional anisotropy (FA), which reflects the integrity of white matter connections, was calculated. Results indicated that higher intelligence correlated with greater gray matter volumes for both mOFC and rACC, as well as with increased FA for left posterior mOFC-rACC connectivity. Hierarchical regression analyses revealed that DTI-derived FA of left posterior mOFC-rACC uniquely accounted for 29%–34% of the variance in IQ, in comparison to 11%–16% uniquely explained by gray matter volume of the left rACC. Together, left rACC gray matter volume and white matter connectivity between left posterior mOFC and rACC accounted for up to 50% of the variance in general intelligence. This study is to our knowledge the first to examine white matter connectivity between OFC and ACC...

By their words ye shall know them: Evidence of genetic selection against general intelligence and concurrent environmental enrichment in vocabulary usage since the mid 19th century

Menie, Michael A. Woodley of; Fernandes, Heitor B. F.; José Figueredo, Aurelio; Meisenberg, Gerhard
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: text
Publicado em 21/04/2015 Português
Relevância na Pesquisa
46.01%
It has been theorized that declines in general intelligence (g) due to genetic selection stemming from the inverse association between completed fertility and IQ and the Flynn effect co-occur, with the effects of the latter being concentrated on less heritable non-g sources of intelligence variance. Evidence for this comes from the observation that 19th century populations were more intellectually productive, and also exhibited faster simple reaction times than modern ones, suggesting greater information-processing ability and therefore higher g. This co-occurrence model is tested via examination of historical changes in the utilization frequencies of words from the highly g-loaded WORDSUM test across 5.9 million texts spanning the period 1850–2005. Consistent with predictions, words with higher difficulties (? parameters from Item Response Theory) and stronger negative correlations between pass rates and completed fertility declined in use over time whereas less difficult and less strongly selected words, increased in use over time, consistent with a Flynn effect stemming in part from the vocabulary enriching effects of increases in population literacy. These findings persisted when explicitly controlled for word age, changing literacy rates and temporal autocorrelation. These trends constitute compelling evidence for the co-occurrence model.

General Intelligence in Another Primate: Individual Differences across Cognitive Task Performance in a New World Monkey (Saguinus Oedipus)

Tsao, Fritz; Banerjee, Konika; Chabris, Christopher F; Johnson, Valen E.; Lee, James J.; Tsao; Hauser, Marc David
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.07%
Background: Individual differences in human cognitive abilities show consistently positive correlations across diverse domains, providing the basis for the trait of “general intelligence” (g). At present, little is known about the evolution of g, in part because most comparative studies focus on rodents or on differences across higher-level taxa. What is needed, therefore, are experiments targeting nonhuman primates, focusing on individual differences within a single species, using a broad battery of tasks. To this end, we administered a large battery of tasks, representing a broad range of cognitive domains, to a population of captive cotton-top tamarin monkeys (Saguinus oedipus). Methodology and Results: Using a Bayesian latent variable model, we show that the pattern of correlations among tasks is consistent with the existence of a general factor accounting for a small but significant proportion of the variance in each task (the lower bounds of 95% Bayesian credibility intervals for correlations between g and task performance all exceed 0.12). Conclusion: Individual differences in cognitive abilities within at least one other primate species can be characterized by a general intelligence factor, supporting the hypothesis that important aspects of human cognitive function most likely evolved from ancient neural substrates.; Psychology

Most Reported Genetic Associations with General Intelligence Are Probably False Positives

Laibson, David I.; Chabris, Christopher F.; Hebert, Benjamin Michael; Benjamin, Daniel J.; Beauchamp, Jonathan P.; Cesarini, David; van der Loos, Matthijs J. H. M.; Johannesson, Magnus; Magnusson, Patrik K. E.; Lichtenstein, Paul; Atwood, Craig S.; Freese
Fonte: Sage Publicador: Sage
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
56.01%
General intelligence (g) and virtually all other behavioral traits are heritable. Associations between g and specific single-nucleotide polymorphisms (SNPs) in several candidate genes involved in brain function have been reported. We sought to replicate published associations between g and 12 specific genetic variants (in the genes DTNBP1, CTSD, DRD2, ANKK1, CHRM2, SSADH, COMT, BDNF, CHRNA4, DISC1, APOE, and SNAP25) using data sets from three independent, well-characterized longitudinal studies with samples of 5,571, 1,759, and 2,441 individuals. Of 32 independent tests across all three data sets, only 1 was nominally significant. By contrast, power analyses showed that we should have expected 10 to 15 significant associations, given reasonable assumptions for genotype effect sizes. For positive controls, we confirmed accepted genetic associations for Alzheimer’s disease and body mass index, and we used SNP-based calculations of genetic relatedness to replicate previous estimates that about half of the variance in g is accounted for by common genetic variation among individuals. We conclude that the molecular genetics of psychology and social science requires approaches that go beyond the examination of candidate genes.; Economics

Medial Frontal White and Gray Matter Contributions to General Intelligence

Ohtani, Toshiyuki; Nestor, Paul G.; Bouix, Sylvain; Saito, Yukiko; Hosokawa, Taiga; Kubicki, Marek
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.17%
The medial orbitofrontal cortex (mOFC) and rostral anterior cingulate cortex (rACC) are part of a wider neural network that plays an important role in general intelligence and executive function. We used structural brain imaging to quantify magnetic resonance gray matter volume and diffusion tensor white matter integrity of the mOFC-rACC network in 26 healthy participants who also completed neuropsychological tests of intellectual abilities and executive function. Stochastic tractography, the most effective Diffusion Tensor Imaging method for examining white matter connections between adjacent gray matter regions, was employed to assess the integrity of mOFC-rACC pathways. Fractional anisotropy (FA), which reflects the integrity of white matter connections, was calculated. Results indicated that higher intelligence correlated with greater gray matter volumes for both mOFC and rACC, as well as with increased FA for left posterior mOFC-rACC connectivity. Hierarchical regression analyses revealed that DTI-derived FA of left posterior mOFC-rACC uniquely accounted for 29%–34% of the variance in IQ, in comparison to 11%–16% uniquely explained by gray matter volume of the left rACC. Together, left rACC gray matter volume and white matter connectivity between left posterior mOFC and rACC accounted for up to 50% of the variance in general intelligence. This study is to our knowledge the first to examine white matter connectivity between OFC and ACC...