Yameng Gu1 and Xiao Liu1
1Pennsylvania State University, State College, PA, United States
1Pennsylvania State University, State College, PA, United States
Infra-slow propagations along an axis of cortical hierarchy were found in both human resting-state fMRI (rsfMRI ) and monkey electrophysiology data, adding a new piece of direct evidence for the neural origin of rsfMRI propagations.
Figure 1: The infra-slow rsfMRI propagations are primarily along a hierarchical axis. (A) Illustration of the procedures for deriving the major propagating direction. (B) Decomposing delay profiles of a synthesized fMRI data (left) recovered the directions of simulated propagating structures (right). (C) The principal direction of infra-slow rsfMRI propagations was produced. (D) The averaged patterns of these two types of propagations in both the time-position graph and brain surface.
Figure 2: Cross-hierarchy propagations in the monkey gamma-band ECoG signals. (A) The principal delay profile shows a clear contrast between the SM areas and the higher-order (HO) brain regions. (B) Single exemplary instances of the bottom-up (SM-to-HO) and top-down (HO-to-SM) propagations as shown in the time-position graph and brain surface. (C) The time-position correlations along the principal propagating and control directions. (D) The averaged patterns of the two types of propagations.