title: Intrinsic and task-dependent coupling of neuronal population activity in human parietal cortex.
abstract: Human neuroimaging studies have suggested that subregions of the medial and lateral parietal cortex form key nodes of a larger brain network supporting episodic memory retrieval. To explore the electrophysiological correlates of functional connectivity between these subregions, we recorded simultaneously from medial and lateral parietal cortex using intracranial electrodes in three human subjects. We observed electrophysiological co-activation of retrosplenial/posterior cingulate cortex (RSC/PCC) and angular gyrus (AG) in the high-frequency broadband (HFB, or high-gamma) range, for conditions that required episodic retrieval. During resting and sleeping states, slow fluctuations (<1 Hz) of HFB activity were highly correlated between these task-co-activated neuronal populations. Furthermore, intrinsic electrophysiological connectivity patterns matched those obtained with resting-state fMRI from the same subjects. Our findings quantify the spatiotemporal dynamics of parietal cortex during episodic memory retrieval and provide clear neurophysiological correlates of intrinsic and task-dependent functional connectivity in the human brain.
authors: Laboratory of Behavioral & Cognitive Neurology, Stanford Human Intracranial Cognitive Electrophysiology Program (SHICEP), Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA 94305, USA. Electronic address: blfoster@stanford.edu.
authors: Brett L
authors: BL
authors: Foster
authors: Laboratory of Behavioral & Cognitive Neurology, Stanford Human Intracranial Cognitive Electrophysiology Program (SHICEP), Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA 94305, USA.
authors: Vinitha
authors: V
authors: Rangarajan
authors: Laboratory of Behavioral & Cognitive Neurology, Stanford Human Intracranial Cognitive Electrophysiology Program (SHICEP), Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA 94305, USA.
authors: William R
authors: WR
authors: Shirer
authors: Laboratory of Behavioral & Cognitive Neurology, Stanford Human Intracranial Cognitive Electrophysiology Program (SHICEP), Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA 94305, USA.
authors: Josef
authors: J
authors: Parvizi
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004569:Electroencephalography; D005260:Female; D006802:Human Activities; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D061212:Memory, Episodic; D009474:Neurons / Q000502:physiology*; D010296:Parietal Lobe / Q000166:cytology / Q000502:physiology*; D012146:Rest / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D013647:Task Performance and Analysis; D055815:Young Adult