title: The development of the intrinsic functional connectivity of default network subsystems from age 3 to 5.
abstract: In recent years, research on human functional brain imaging using resting-state fMRI techniques has been increasingly prevalent. The term "default mode" was proposed to describe a baseline or default state of the brain during rest. Recent studies suggested that the default mode network (DMN) is comprised of two functionally distinct subsystems: a dorsal-medial prefrontal cortex (DMPFC) subsystem involved in self-oriented cognition (i.e., theory of mind) and a medial temporal lobe (MTL) subsystem engaged in memory and scene construction; both subsystems interact with the anterior medial prefrontal cortex (aMPFC) and posterior cingulate (PCC) as the core regions of DMN. The present study explored the development of DMN core regions and these two subsystems in both hemispheres from 3- to 5-year-old children. The analysis of the intrinsic activity showed strong developmental changes in both subsystems, and significant changes were specifically found in MTL subsystem, but not in DMPFC subsystem, implying distinct developmental trajectories for DMN subsystems. We found stronger interactions between the DMPFC and MTL subsystems in 5-year-olds, particularly in the left subsystems that support the development of environmental adaptation and relatively complex mental activities. These results also indicate that there is stronger right hemispheric lateralization at age 3, which then changes as bilateral development gradually increases through to age 5, suggesting in turn the hemispheric dominance in DMN subsystems changing with age. The present results provide primary evidence for the development of DMN subsystems in early life, which might be closely related to the development of social cognition in childhood.
authors.affiliation: College of Education, Guangzhou University, No. 230 Waihuan West Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, China.|Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Yaqiong
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: College of Education, Guangzhou University, No. 230 Waihuan West Road, Higher Education Mega Center, Panyu District, Guangzhou, 510006, China. zhaihongchang@126.com.
authors.forename: Hongchang
authors.initials: H
authors.lastname: Zhai
authors.affiliation: Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Angela D
authors.initials: AD
authors.lastname: Friederici
authors.affiliation: Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, No. 1068, Xueyuan Avenue, Xili University Town, Shenzhen, 518055, China. fc.jia@siat.ac.cn.
authors.forename: Fucang
authors.initials: F
authors.lastname: Jia
mesh_terms: D001921:Brain / Q000254:growth & development* / Q000502:physiology*; D001931:Brain Mapping; D002675:Child, Preschool; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000254:growth & development / Q000502:physiology; D012146:Rest; D056345:Theory of Mind / Q000502:physiology
keywords: Default network; Functional connectivity; Preschool children; Resting-state fMRI; Theory of mind