Title
Low frequency fluctuations reveal integrated and segregated processing among the cerebral hemispheres
Abstract
Resting-state functional magnetic resonance imaging (fMRI) has provided a novel approach for examining interhemispheric interaction, demonstrating a high degree of functional connectivity between homotopic regions in opposite hemispheres. However, heterotopic resting-state functional connectivity (RSFC) remains relatively uncharacterized. In the present study, we examine non-homotopic regions, characterizing heterotopic RSFC and comparing it to intrahemispheric RSFC, to examine the impact of hemispheric separation on the integration and segregation of processing in the brain. Resting-state fMRI scans were acquired from 59 healthy participants to examine inter-regional correlations in spontaneous low frequency fluctuations in BOLD signal. Using a probabilistic atlas, we correlated probability-weighted time series from 112 regions (56 per hemisphere) distributed throughout the entire cerebrum. We compared RSFC for pairings of non-homologous regions located in different hemispheres (heterotopic connectivity) to RSFC for the same pairings when located within hemisphere (intrahemispheric connectivity). For positive connections, connectivity strength was greater within each hemisphere, consistent with integrated intrahemispheric processing. However, for negative connections, RSFC strength was greater between the hemispheres, consistent with segregated interhemispheric processing. These patterns were particularly notable for connections involving frontal and heteromodal regions. The distribution of positive and negative connectivity was nearly identical within and between the hemispheres, though we demonstrated detailed regional variation in distribution. We discuss implications for leading models of interhemispheric interaction. The future application of our analyses may provide important insight into impaired interhemispheric processing in clinical and aging populations.
Year
DOI
Venue
2011
10.1016/j.neuroimage.2010.05.073
NeuroImage
Keywords
Field
DocType
limbic system,low frequency,young adult,time series,cerebrum,brain mapping,magnetic resonance imaging,resting state
Brain mapping,Reference values,Developmental psychology,Cerebrum,Probabilistic atlas,Neuroscience,Functional magnetic resonance imaging,Psychology,Entire cerebrum,Limbic system
Journal
Volume
Issue
ISSN
54
1
1053-8119
Citations 
PageRank 
References 
7
0.78
12
Authors
11
Name
Order
Citations
PageRank
Dylan G Gee11237.69
Bharat B Biswal250336.32
Clare Kelly361934.17
david e stark471.45
Daniel S Margulies526219.14
Zarrar Shehzad6805.20
Lucina Q Uddin735226.92
Donald F Klein822012.12
Marie T Banich9799.48
F Xavier Castellanos1083444.64
Michael P Milham1188448.19