Poster B76, Sunday, March 25, 8:00-10:00 am, Exhibit Hall C
Frequency-dependent temporal fluctuations of functional connectivity within intrinsic networks in human cortex
Aaron Kucyi1, Josef Parvizi1; 1Stanford University
Intrinsic brain networks are comprised of remote regions that have correlated spontaneous activity seen in functional imaging, known as intrinsic functional connectivity (FC), that is remarkably persistent across distinct consciousness states. Given the limited temporal resolution of imaging methods, little is known about fluctuations of FC on the scale of tens of seconds (known as “dynamic FC”), and controversy remains over the potential behavioral and neural relevance of dynamic FC. Here we aimed to identify electrophysiological correlates of intrinsic BOLD FC in canonical cortical networks and to clarify how electrophysiological FC within those networks fluctuates across frequencies on short time scales. We studied neurosurgical patients with intracranial electrodes directly implanted simultaneously within individually-localized nodes of the default, dorsal attention and frontoparietal control networks. Within these networks in both wakeful rest and sleep states, we found that electrophysiological functional connectivity of both high-frequency broadband (HFB, or high gamma; 70-170 Hz) and alpha (8-12 Hz) power amplitudes were reproducibly correlated spatially with functional connectivity in separately recorded resting-state fMRI within the same subjects. Although there were modest negative correlations between HFB and alpha local activity within each network, spatial connectivity patterns showed similarities between these frequency ranges. In contrast, within-network HFB and alpha coupling often diverged from one another temporally across short windows (on the order of seconds). These results suggest that temporal fluctuations of functional connectivity within widely studied human brain networks are shaped by multiple, dissociable neurophysiological processes that potentially have distinct behavioral relevance.
Topic Area: METHODS: Electrophysiology