Aging, cognition, and the brain: effects of age-related variation in white matter integrity on neuropsychological function

Abstract

Alterations in brain structure are viewed as neurobiological indicators which are closely tied to cognitive changes in healthy human aging. The current study used diffusion tensor imaging (DTI) tractography to investigate the relationship between age, brain variation in white matter (WM) integrity, and cognitive function. Sixteen younger adults (aged 20-28 years) and 18 healthy older adults (aged 60-75 years) underwent DTI scanning and a standardized battery of neuropsychological measures. Behaviorally, older adults exhibited poorer performance on multiple cognitive measures compared to younger adults. At the neural level, the effects of aging on theWM integrity were evident within interhemispheric (the anterior portion of corpus callosum) and transverse (the right uncinate fasciculus) fibers of the frontal regions, and the cingulum-angular fibers. Our correlation results showed that age-related WM differentially influenced cognitive function, with increased fractional anisotropy values in both the anterior corpus callosum and the right cingulum/angular fibers positively correlated with performance on the visuospatial task in older adults. Moreover, mediation analysis further revealed that the WM tract integrity of the frontal interhemspheric fibers was a significant mediator of age-visuospatial performance relation in older adults, but not in younger adults. These findings support the vulnerability of the frontal WM fibers to normal aging and push forward our understanding of cognitive aging by providing a more integrative view of the neural basis of linkages among aging, cognition, and brain.

Plasma Tau and Amyloid Are Not Reliably Related to Injury Characteristics, Neuropsychological Performance, or White Matter Integrity in Service Members with a History of Traumatic Brain Injury

“…Plasma tau and Ab42 levels were the independent variables, and DTI measures (i.e., FA, MD, RD, and AD across the 18 ROIs and whole brain) were the dependent variables. Given the known influence of age on DTI measures, 56 age was included in the first step in each regression model as a covariate. Tau and amyloid were each entered separately in the second step of the model.…”

Culture-Related and Individual Differences in Regional Brain Volumes: A Cross-Cultural Voxel-Based Morphometry Study

“…The composite score of the SCS was computed and used as a continuous variable to conduct regression analyses to investigate the associations between cultural values and regional brain volume. Moreover, given that post hoc mediation analysis provides a theoretical way of investigating the role of intermediate variables which may play a role in the relationship between two other variables (Na et al, 2017; Fan et al, 2018), we applied this approach to examine whether cultural orientation play a role in explaining culture-related and individual differences in regional gray-matter volume. Based on prior neuroimaging works showing that individuals with a more independent focus are associated with increased brain volume in prefrontal cortex (PFC; Kitayama et al, 2017; Wang et al, 2017) and that Westerners had greater brain volume in fronto-parietal regions (Zilles et al, 2001; Kochunov et al, 2003; Green et al, 2007; Chee et al, 2011; Tang et al, 2018), we hypothesized that two cultural groups would show culture-related volumetric differences in fronto-parietal networks.…”

Ativação cortical do lobo frontal em adultos jovens e idosos: uma análise eletroencefalográfica durante um exergame para equilíbrio postural

“…Indivíduos mais velhos tendem a ativar regiões frontais adicionais para recuperação de memória quando a carga de tarefa apresenta uma alta demanda desta competência. Ao que parece, atuando como uma resposta compensatória (Cook et al, 2007), pois o cérebro envelhecido consegue contrabalancear a alterações estruturais, alterando os padrões funcionais de recrutamento para manter as funções cognitivas (Eggenberg et al, 2016;Fan et al, 2019).…”

“…A região frontal do cérebro, está diretamente relacionada ao processamento motor, gerando a percepção e interpretação das informações provenientes dos jogos por meio de feedback visual; e com as funções executivas, permitindo a captação dos estímulos do ambiente e uma resposta adequada a eles (Luft et al, 2006). A redução da substância branca e cinzenta são os principais marcadores das modificações oriundas do envelhecimento, a nível cortical, levando a redução da velocidade de processamento dos sinais neurais, da cognição e memória (Luft et al, 2006;Cook et al, 2007;Fan et al, 2019). O volume do tecido cerebral Research, Society andDevelopment, v. 9, n. 8, e225985726, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i8.5726 das regiões pré-frontais tende a ser afetado de maneira mais pronunciada (Eggenberg et al, 2016) Na especialização hemisférica, o lado direito é mais ativado ao ser submetido a novas experiências, sendo responsável pelo processamento de novos estímulos e aquisição de novas habilidades (Schaefer et al, 2012;Bradcock et al, 2013;Oliveira et al, 2018).…”

“…As variedades de estímulos existentes em ambientes terapêuticos levam a adaptações neuroplásticas que se relacionam intimamente com as funções do lobo frontal, como a captação de informações, planejamento, organização e formação da resposta para a execução de uma determinada atividade (Andrade, Luft & Rolim 2004;Long et al, 2012;Oliveira et al, 2018). Nesse sentido, diversos fatores, desde alterações senis a lesões cerebrais, podem comprometer a função do lobo frontal, influenciando a aprendizagem e comprometendo a aquisição de habilidades motoras (Fan et al, 2019).…”