title: Mapping the self in the brain's default mode network.
abstract: The brain's default mode network (DMN) has become closely associated with self-referential mental activity, particularly in the resting-state. While the DMN is important for such processes, it has functions other than self-reference, and self-referential processes are supported by regions outside of the DMN. In our study of 88 participants, we examined self-referential and resting-state processes to clarify the extent to which DMN activity was common and distinct between the conditions. Within areas commonly activated by self-reference and rest we sought to identify those that showed additional functional specialization for self-referential processes: these being not only activated by self-reference and rest but also showing increased activity in self-reference versus rest. We examined the neural network properties of the identified 'core-self' DMN regions-in medial prefrontal cortex (MPFC), posterior cingulate cortex (PCC), and inferior parietal lobule-using dynamic causal modeling. The optimal model identified was one in which self-related processes were driven via PCC activity and moderated by the regulatory influences of MPFC. We thus confirm the significance of these regions for self-related processes and extend our understanding of their functionally specialized roles.
authors.affiliation: Orygen, The National Centre of Excellence in Youth Mental Health, Parkville, Australia; Centre for Youth Mental Health, The University of Melbourne, Parkville, Australia; Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Australia. Electronic address: c.davey@unimelb.edu.au.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Davey
authors.affiliation: MRI Research Unit, CRC Mar, Hospital del Mar, CIBERSAM G21, Barcelona, Spain.
authors.forename: Jesus
authors.initials: J
authors.lastname: Pujol
authors.affiliation: Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Australia.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Harrison
mesh_terms: D000293:Adolescent; D000328:Adult; D001828:Body Image; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009434:Neural Pathways / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology; D012649:Self Concept; D055815:Young Adult
keywords: Default mode network; Dynamic causal modeling; Self; fMRI