An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging
Open Access
- 14 August 2013
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 8 (8), e71275
- https://doi.org/10.1371/journal.pone.0071275
Abstract
Lateralized brain regions subserve functions such as language and visuospatial processing. It has been conjectured that individuals may be left-brain dominant or right-brain dominant based on personality and cognitive style, but neuroimaging data has not provided clear evidence whether such phenotypic differences in the strength of left-dominant or right-dominant networks exist. We evaluated whether strongly lateralized connections covaried within the same individuals. Data were analyzed from publicly available resting state scans for 1011 individuals between the ages of 7 and 29. For each subject, functional lateralization was measured for each pair of 7266 regions covering the gray matter at 5-mm resolution as a difference in correlation before and after inverting images across the midsagittal plane. The difference in gray matter density between homotopic coordinates was used as a regressor to reduce the effect of structural asymmetries on functional lateralization. Nine left- and 11 right-lateralized hubs were identified as peaks in the degree map from the graph of significantly lateralized connections. The left-lateralized hubs included regions from the default mode network (medial prefrontal cortex, posterior cingulate cortex, and temporoparietal junction) and language regions (e.g., Broca Area and Wernicke Area), whereas the right-lateralized hubs included regions from the attention control network (e.g., lateral intraparietal sulcus, anterior insula, area MT, and frontal eye fields). Left- and right-lateralized hubs formed two separable networks of mutually lateralized regions. Connections involving only left- or only right-lateralized hubs showed positive correlation across subjects, but only for connections sharing a node. Lateralization of brain connections appears to be a local rather than global property of brain networks, and our data are not consistent with a whole-brain phenotype of greater “left-brained” or greater “right-brained” network strength across individuals. Small increases in lateralization with age were seen, but no differences in gender were observed.Keywords
This publication has 57 references indexed in Scilit:
- Spatial Neglect and Attention NetworksAnnual Review of Neuroscience, 2011
- Cerebral Asymmetry in SchizophreniaThe Neuroscientist, 2011
- Hemisphere- and gender-related differences in small-world brain networks: A resting-state functional MRI studyNeuroImage, 2011
- Atypical diffusion tensor hemispheric asymmetry in autismAutism Research, 2010
- Evidence for the Default Network's Role in Spontaneous CognitionJournal of Neurophysiology, 2010
- Brain Hemispheric Structural Efficiency and Interconnectivity Rightward Asymmetry in Human and Nonhuman PrimatesCerebral Cortex, 2010
- Toward discovery science of human brain functionProceedings of the National Academy of Sciences of the United States of America, 2010
- Language lateralization in left-handed and ambidextrous peopleNeurology, 2002
- Searching for a baseline: Functional imaging and the resting human brainNature Reviews Neuroscience, 2001
- How Can We Learn About Developmental Processes From Cross-Sectional Studies, or Can We?American Journal of Psychiatry, 2000