title: Differential electrophysiological response during rest, self-referential, and non-self-referential tasks in human posteromedial cortex.
abstract: The electrophysiological basis for higher brain activity during rest and internally directed cognition within the human default mode network (DMN) remains largely unknown. Here we use intracranial recordings in the human posteromedial cortex (PMC), a core node within the DMN, during conditions of cued rest, autobiographical judgments, and arithmetic processing. We found a heterogeneous profile of PMC responses in functional, spatial, and temporal domains. Although the majority of PMC sites showed increased broad gamma band activity (30-180 Hz) during rest, some PMC sites, proximal to the retrosplenial cortex, responded selectively to autobiographical stimuli. However, no site responded to both conditions, even though they were located within the boundaries of the DMN identified with resting-state functional imaging and similarly deactivated during arithmetic processing. These findings, which provide electrophysiological evidence for heterogeneity within the core of the DMN, will have important implications for neuroimaging studies of the DMN.
authors.affiliation: Laboratory of Behavioral and Cognitive Neurology, Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Dastjerdi
authors.forename: Brett L
authors.initials: BL
authors.lastname: Foster
authors.forename: Sharmin
authors.initials: S
authors.lastname: Nasrullah
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Rauschecker
authors.forename: Robert F
authors.initials: RF
authors.lastname: Dougherty
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Townsend
authors.forename: Catie
authors.initials: C
authors.lastname: Chang
authors.forename: Michael D
authors.initials: MD
authors.lastname: Greicius
authors.forename: Vinod
authors.initials: V
authors.lastname: Menon
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Kennedy
authors.forename: Josef
authors.initials: J
authors.lastname: Parvizi
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D011939:Mental Recall; D008959:Models, Neurological; D011597:Psychomotor Performance / Q000502:physiology*; D012146:Rest / Q000502:physiology; D012649:Self Concept