Publication Type Academic Article
Authors Razlighi Q, Habeck C, Steffener J, Gazes Y, Zahodne L, Mackay-Brandt A, Stern Y
Journal Brain Behav
Volume 4
Issue 2
Pagination 143-57
Date Published 12/29/2013
ISSN 2162-3279
Keywords Aging, Cerebral Cortex, Magnetic Resonance Imaging, Nerve Net, Psychomotor Performance
Abstract BACKGROUND: Disruption of the default-mode network (DMN) in healthy elders has been reported in many studies. METHODS: In a group of 51 participants (25 young, 26 elder) we examined DMN connectivity in subjects' native space. In the native space method, subject-specific regional masks (obtained independently for each subject) are used to extract regional fMRI times series. This approach substitutes the spatial normalization and subsequent smoothing used in prevailing methods, affords more accurate spatial localization, and provides the power to examine connectivity separately in the two hemispheres instead of averaging regions across hemispheres. RESULTS: The native space method yielded new findings which were not detectable by the prevailing methods. The most reliable and robust disruption in elders' DMN connectivity were found between supramarginal gyrus and superior-frontal cortex in the right hemisphere only. The mean correlation between these two regions in young participants was about 0.5, and dropped significantly to 0.04 in elders (P = 2.1 × 10(-5)). In addition, the magnitude of functional connectivity between these regions in the right hemisphere correlated with memory (P = 0.05) and general fluid ability (P = 0.01) in elder participants and with speed of processing in young participants (P = 0.008). These relationships were not observed in the left hemisphere. CONCLUSION: These findings suggest that analysis of DMN connectivity in subjects' native space can improve localization and power and that it is important to examine connectivity separately in each hemisphere.
DOI 10.1002/brb3.202
PubMed ID 24683508
PubMed Central ID PMC3967531
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