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.
|Number of pages||11|
|State||Published - May 1 2015|
Bibliographical noteFunding Information:
This study was supported by the National Institute on Aging of the National Institutes of Health under award number R01AG033036 and the National Science Foundation under award number BCS 0814302 . The content is solely the responsibility of the authors and does not necessarily represent the official views of these granting agencies. We thank Sara Cilles for her assistance in recruiting, and testing some of the participants and Dr. David Powell for aiding with MRI sequence selection.
© 2015 Elsevier Ltd.
- Diffusion tensor imaging
ASJC Scopus subject areas
- Experimental and Cognitive Psychology
- Cognitive Neuroscience
- Behavioral Neuroscience