The psychosocial relevance of longitudinal structural brain development in the transition from childhood to adulthood
Appears in the following Collection
- Psykologisk institutt 
AbstractAdolescence is a transitional period, recognized in virtually all human societies, that marks the transition from childhood to adulthood. Adolescents undergo substantial changes in psychological traits and behavior, and these changes are paralleled by considerable changes in brain structure and function. Most importantly, it is a period of both opportunities and risk, whereby substantial neural plasticity facilitates both learning and vulnerability to environmental factors. Many mental disorders start in adolescence and affect developmental trajectories throughout the lifespan. It is therefore of the uttermost importance to understand the developmental origins of brain-mind relations. Most existing knowledge, however, is derived from cross-sectional studies, which are not well suited to study developmental change. Using data from a unique dataset where children and adolescents were repeatedly assessed over a 7-year-period, this thesis aimed to investigate how psychosocial traits and behavior relate to longitudinal changes in brain structure, as derived from magnetic resonance imaging (MRI). Personality traits, prosocial behavior and emotion regulation strategies (cognitive reappraisal and expressive suppression) were examined because they are related to mental health, or even conceptualized as lying on a continuum with mental disorders, where psychopathology is lying at the extreme end of the continuum. Understanding how more and less healthy traits and behavior differentially relate to structural brain development may thus provide clues about the ontology of mental health and disorders. The first paper used data from the two initial assessments in the research project and demonstrated that more adaptive personality profiles, i.e. high emotional stability, imagination and conscientiousness, were related to greater regionally specific cortical thinning. Associations were also found between levels of extraversion, benevolence and conscientiousness and cortical surface area development. The second paper used up to three observations per individual and the results suggested that in regions previously linked to social cognition, value-based decision-making and behavioral control, higher prosociality is associated with greater cortical thinning during early-to-middle adolescence, followed by attenuation of this process during the transition to young adulthood. This implies that both rate and possibly timing of cortical thinning in these regions is related to prosocial behavior. The third paper, which also included up to three time points per individual, demonstrated that habitual use of cognitive reappraisal and expressive suppression were associated with cortical developmental patterns in distributed regions, but not with development of subcortical volumes. Together, the three papers suggest that examining change in macrostructural measures of brain structure by means of MRI is of relevance for the study of psychosocial traits and behavior across adolescence and understanding these brain-body relations may inform developmental theories.
List of papers
|Paper I. Ferschmann, L., Fjell, A.M., Vollrath, M.E., Grydeland, H., Walhovd, K.B., and Tamnes, C.K. (2018). Personality traits are associated with cortical development across adolescence: A longitudinal structural MRI study. Child Development, 89(3), 811-822. DOI: 10.1111/cdev.13016. The article is not available in the thesis due to publisher restrictions. The published version is available at: https://doi.org/10.1111/cdev.13016|
|Paper II. Ferschmann, L., Vijayakumar, N., Grydeland, H., Overbye, K., Sederevicius, D., Due-Tønnessen, P., Fjell, A.M., Walhovd, K.B., Pfeifer, J.H., and Tamnes, C.K. (2019). Prosocial behavior relates to the rate and timing of cortical thinning from adolescence to young adulthood. Developmental Cognitive Neuroscience, 40, 100734. DOI: 10.1016/j.dcn.2019.100734. The article is included in the thesis. Also available at: https://doi.org/10.1016/j.dcn.2019.100734|
|Paper III. Ferschmann, L., Vijayakumar, N., Grydeland, H., Overbye, K., Mills, K.L., Fjell, A.M., Walhovd, K.B., Pfeifer, J.H., and Tamnes, C.K. (submitted). Cognitive reappraisal and expressive suppression differentially relate to longitudinal structural brain development across adolescence. To be published. The paper is not available in DUO awaiting publishing.|