Personality and local brain structure: their shared genetic basis and reproducibility

Abstract

33Personality traits are key indices of inter-individual variation. Personality is heritable and 34 associated with brain structure and function. To date, it is unknown whether the relation 35 between personality and brain macrostructure can be explained by shared genetic factors. In a 36 large-scale twin sample, we show that key personality traits, e.g. agreeableness and 37 extraversion, were genetically associated with thickness of specific brain regions. Second, we 38 observed that spatial patterns of phenotypic and genetic correlations between personality and 39 cortical thickness were significantly positive, suggesting a genetic basis for phenotypic 40 associations. However, these findings did not replicate in two large-scale datasets of unrelated 41 individuals. We were able to reconcile this discrepancy by probing the latent relation between 42 personality and cortical thickness using a multivariate approach. Here we could uncover a 43 latent association between personality traits and cortical thickness. This component accounted 44 for 30% of the variance shared between personality traits and cortical thickness. The results of 45 our multivariate analysis indicate that personality is associated with regions supporting lower-46 order sensory as well as integrative cognitive processes. Our study provides first evidence of a 47 "Personality" is an individuals' characteristic set of cognitive, emotional and behavioral 52

Linking interindividual variability in brain structure to behaviour

“…In particular, current neuroimaging techniques readily provide estimates of local grey matter volume and cortical thickness across the brain (see Box 1). As reviewed by Kanai and Rees in 2011 3 , reports of structural brain-behaviour (SBB) associations quickly ranged from common cognitive functions, such as working memory 4 , to social and affective traits measured with standard questionnaires, such as personality traits 2,5 or impulsivity 6 but also extended to a variety of aspects evaluated with specific instruments pertaining to dedicated theories or research aims. As illustrated in Fig.…”

“…In the last two decades, advances in structural imaging opened the door to a broad range of reports of associations between specific aspects of human behaviour and local brain morphological features in healthy populations. This literature, in turn, served as an empirical background on which further investigations and conceptual theories about interindividual variability are still building, such as the interpretation of local brain morphological differences between men and women 1 or the genetic bases of interindividual variability in psychological measures 2 . However, this empirical pillar of cognitive neuroscience has recently been shaken by a replication crisis.…”

Asymmetric Signaling Across the Hierarchy of Cytoarchitecture within the Human Connectome

“…To achieve this, we assembled the upper triangle of each subject’s T E Δ matrix into a 793 × 190 feature table, X . To ensure normality, columns of X were normalized using an inverse normal transformation 105,106 . Then, we used a cross-validated ridge regression model implemented in scikit-learn 107 with default parameters ( α = 1) to predict participants’ ages ( y ).…”

Can neuroscience help to understand narcissism? A systematic review of an emerging field

“…Quasi-experimental studies using measures of brain structure or baseline functions could contribute most effectively to acquiring a robust base of knowledge by using data analysis methods corresponding exactly to those of previous studies (at least complemental to new methods) in large datasets. While such studies have recently been carried out for the Five-Factor Model dimensions and yield a rather pessimistic picture regarding the consistency of personality neuroscience findings (Avinun et al, 2020;Valk et al, 2019), it might be that narcissism, as a more specific personality construct, might still display consistent correlates. (6) Finally, it needs to be stated that many neuroscience studies of narcissism used small or very small samples to investigate genuinely subtle associations between personality and physiological or biological indicators, which sometimes include complex relationships such as moderation.…”