Longitudinal alterations to brain function, structure, and cognitive performance in healthy older adults: A fMRI-DTI study. (May 2015)

• Record Type: Journal Article
• Authors: Hakun, Jonathan G.; Zhu, Zude; Brown, Christopher A.; Johnson, Nathan F.; Gold, Brian T.
• Is Part Of: Neuropsychologia. Volume 71(2015)
• Page Start: 225
• Page End: 235
• Publication Date: 2015-05
• Subjects: Aging -- Longitudinal -- Diffusion tensor imaging -- fMRI; Neuropsychology -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Neuropsychologie -- Périodiques; Neuropsychology; Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.neuropsychologia.2015.04.008
• Languages: English
• ISSNs: 0028-3932

Abstract

Abstract: Cross-sectional research has shown that older adults tend to have different frontal cortex activation patterns, poorer brain structure, and lower task performance than younger adults. However, relationships between longitudinal changes in brain function, brain structure, and cognitive performance in older adults are less well understood. Here we present the results of a longitudinal, combined fMRI-DTI study in cognitive normal (CN) older adults. A two time-point study was conducted in which participants completed a task switching paradigm while fMRI data was collected and underwent the identical scanning protocol an average of 3.3 years later (SD=2 months). We observed longitudinal fMRI activation increases in bilateral regions of lateral frontal cortex at time point 2. These fMRI activation increases were associated with longitudinal declines in WM microstructure in a portion of the corpus callosum connecting the increasingly recruited frontal regions. In addition, the fMRI activation increase in the left VLPFC was associated with longitudinal increases in response latencies. Taken together, our results suggest that local frontal activation increases in CN older adults may in part reflect a response to reduced inter-hemispheric signaling mechanisms. Highlights: Longitudinal increases in frontal activation were observed in healthy older adults. Declines in white matter microstructure and cognitive performance were observed. Correlated change was observed between frontal function, structure, and performance. Regions showing correlated structure-function change were connected anatomically.