Lateralization of resting state networks and relationship to age and gender

Abstract

Brain lateralization is a widely studied topic, however there has been little work focused on lateralization of intrinsic networks (regions showing similar patterns of covariation among voxels) in the resting brain. In this study, we evaluate resting state network lateralization in an age and gender-balanced functional magnetic resonance imaging (fMRI) dataset comprising over 600 healthy subjects ranging in age from 12 to 71. After establishing sample-wide network lateralization properties, we continue with an investigation of age and gender effects on network lateralization. All data was gathered on the same scanner and preprocessed using an automated pipeline (Scott et al., 2011). Networks were extracted via group independent component analysis (gICA) (Calhoun, Adali, Pearlson, & Pekar, 2001). Twenty-eight resting state networks discussed in previous (Allen et al., 2011) work were re-analyzed with a focus on lateralization. We calculated homotopic voxelwise measures of laterality in addition to a global lateralization measure, called the laterality cofactor, for each network. As expected, many of the intrinsic brain networks were lateralized. For example, the visual network was strongly right lateralized, auditory network and default mode networks were mostly left lateralized. Attentional and frontal networks included nodes that were left lateralized and other nodes that were right lateralized. Age was strongly related to lateralization in multiple regions including sensorimotor network regions precentral gyrus, postcentral gyrus and supramarginal gyrus; and visual network regions lingual gyrus; attentional network regions inferior parietal lobule, superior parietal lobule and middle temporal gyrus; and frontal network regions including the inferior frontal gyrus. Gender showed significant effects mainly in two regions, including visual and frontal networks. For example, the inferior frontal gyrus was more right lateralized in males. Significant effects of age were found in sensorimotor and visual networks on the global measure. In summary, we report a large-sample of lateralization study that finds intrinsic functional brain networks to be highly lateralized, with regions that are strongly related to gender and age locally, and with age a strong factor in lateralization, and gender exhibiting a trend-level effect on global measures of laterality.

Differential patterns of age‐related cortical and subcortical functional connectivity in 6‐to‐10 year old children: A connectome‐wide association study

“…Our results suggest that activity is increasingly directed by cortical regions rather than subcortical regions. Asymmetry in brain connectivity has previously been observed in lateralization studies (Agcaoglu, Miller, Mayer, Hugdahl, & Calhoun, 2015; Di, Kim, Chen, & Biswal, 2014; Holland et al., 2007). Adolescent and adult brains are highly lateral across several resting state networks, with several brain regions showing a decrease in lateralization with age (Agcaoglu et al., 2015).…”

“…Asymmetry in brain connectivity has previously been observed in lateralization studies (Agcaoglu, Miller, Mayer, Hugdahl, & Calhoun, 2015; Di, Kim, Chen, & Biswal, 2014; Holland et al., 2007). Adolescent and adult brains are highly lateral across several resting state networks, with several brain regions showing a decrease in lateralization with age (Agcaoglu et al., 2015). In children, language networks become increasingly left‐lateralized throughout development (Groen, Whitehouse, Badcock, & Bishop, 2012; Holland et al., 2007), whereas visuospatial networks become right‐lateralized (Groen et al., 2012).…”

Lateralization of gene expression in human language cortex

“…One prominently lateralized functional network underlies the human ability to speak and understand language, and critically involves the Superior Temporal Gyrus (STG) and the auditory cortex of Heschl's Gyrus (HG), both of which show anatomical asymmetry (Agcaoglu, Miller, Mayer, Hugdahl, & Calhoun, 2014;Dikker, Silbert, Hasson, & Zevin, 2014;Lyttelton et al, 2009;Mazoyer et al, 2014;Menenti, Gierhan, Segaert, & Hagoort, 2011;Willems, Van der Haegen, Fisher, & Francks, 2014). These regions have also shown microanatomical (Hutsler, 2003) and neurophysiological (Morillon et al, 2010) lateralization; left-sided neural oscillatory frequencies reportedly correspond to syllabic speech rhythms (Morillon et al, 2010).…”

“…Functional lateralization of the language network is robust across this age range (Agcaoglu et al, 2014), and we excluded data from outside this range in order to reduce variance associated with neurodevelopment or advanced age. In order to further maximise sensitivity for the analysis, we then applied several approaches that have not previously been used in examining lateralization of gene expression in these datasets.…”

Enabling the effective application of spatial auditory displays in modern flight decks

“…This notion has received further support recently through MRI studies focusing on the effects of age and gender on asymmetric functioning. Agcaoglu et al (2015) conducted a large study of over 600 participants ranging in age from 12 to 71. Their findings support theories that the brain functioning becomes more asymmetric with age to compensate for neural decline.…”