Paper Info
Title
Age-related differences in memory-encoding fMRI responses after accounting for decline in vascular reactivity.
Abstract
BOLD fMRI has provided a wealth of information about the aging brain. A common finding is that posterior regions of the brain manifest an age-related decrease in activation while the anterior regions show an age-related increase. Several neurocognitive models have been proposed to interpret these findings. However, one issue that has not been sufficiently considered to date is that the BOLD signal is based on vascular responses secondary to neural activity. Thus the above findings could be in part due to a vascular change, especially in view of the expected decline of vascular health with age. In the present study, we aim to examine age-related differences in memory-encoding fMRI response in the context of vascular aging. One hundred and thirty healthy subjects ranging from 20 to 89years old underwent a scene-viewing fMRI task and, in the same session, cerebrovascular reactivity (CVR) was measured in each subject using a CO2-inhalation task. Without accounting for the influence of vascular changes, the task-activated fMRI signal showed the typical age-related decrease in visual cortex and medial temporal lobe (MTL), but manifested an increase in the right inferior frontal gyrus (IFG). In the same individuals, an age-related CVR reduction was observed in all of these regions. We then used a previously proposed normalization approach to calculate a CVR-corrected fMRI signal, which was defined as the uncorrected signal divided by CVR. Based on the CVR-corrected fMRI signal, an age-related increase is now seen in both the left and right sides of IFG; and no brain regions showed a signal decrease with age. We additionally used a model-based approach to examine the fMRI data in the context of CVR, which again suggested an age-related change in the two frontal regions, but not in the visual and MTL regions.
Year
DOI
Venue
2013
10.1016/j.neuroimage.2013.04.053
NeuroImage
Keywords
Field
DocType
Cognitive aging,Age-related increase,Age-related decrease,Cerebral vascular reactivity (CVR),Functional magnetic resonance imaging (fMRI),fMRI normalization
Accounting,Brain mapping,Developmental psychology,Neuroscience,Visual cortex,Psychology,Neural activity,Young adult,Aging brain,Neurocognitive,Magnetic resonance imaging,Temporal lobe
Journal
Volume
ISSN
Citations 
78
1053-8119
9
PageRank 
References 
Authors
0.57
8
7
Name
Order
Citations
PageRank
Peiying Liu1242.16
Andrew Hebrank2222.25
Karen M Rodrigue3738.49
Kristen M Kennedy4566.64
Jarren Section590.57
Denise C. Park613212.85
Hanzhang Lu714317.86