Age-related increases in right frontal activation during task switching are mediated by reaction time and white matter microstructure

Z. Zhu, J. G. Hakun, N. F. Johnson, B. T. Gold

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

Age-related increases in right frontal cortex activation are a common finding in the neuroimaging literature. However, neurocognitive factors contributing to right frontal over-recruitment remain poorly understood. Here we investigated the influence of age-related reaction time (RT) slowing and white matter (WM) microstructure reductions as potential explanatory factors for age-related increases in right frontal activation during task switching. Groups of younger (N=. 32) and older (N=. 33) participants completed a task switching paradigm while functional magnetic resonance imaging (fMRI) was performed, and rested while diffusion tensor imaging (DTI) was performed. Two right frontal regions of interest (ROIs), the dorsolateral prefrontal cortex (DLPFC) and insula, were selected for further analyses from a common network of regions recruited by both age groups during task switching. Results demonstrated age-related activation increases in both ROIs. In addition, the older adult group showed longer RT and decreased fractional anisotropy in regions of the corpus callosum with direct connections to the fMRI ROIs. Subsequent mediation analyses indicated that age-related increases in right insula activation were mediated by RT slowing and age-related increases in right DLPFC activation were mediated by WM microstructure. Our results suggest that age-related RT slowing and WM microstructure declines contribute to age-related increases in right frontal activation during cognitive task performance.

Original languageEnglish (US)
Pages (from-to)51-61
Number of pages11
JournalNeuroscience
Volume278
Issue number1
DOIs
StatePublished - 2014

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Age-related increases in right frontal activation during task switching are mediated by reaction time and white matter microstructure'. Together they form a unique fingerprint.

Cite this