Open AccessUnilateral disruptions in the default network with aging in native space
Author(s) -
Razlighi Qolamreza R.,
Habeck Christian,
Steffener Jason,
Gazes Yunglin,
Zahodne Laura B.,
MacKayBrandt Anna,
Stern Yaakov
Publication year - 2014
Publication title -
brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 41
ISSN - 2162-3279
DOI - 10.1002/brb3.202
Subject(s) - supramarginal gyrus , default mode network , spatial normalization , lateralization of brain function , right hemisphere , functional connectivity , psychology , normalization (sociology) , smoothing , space (punctuation) , neuroscience , voxel , cognitive psychology , computer science , mathematics , functional magnetic resonance imaging , artificial intelligence , statistics , sociology , anthropology , operating system
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 f MRI 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.