Relations between large-scale brain connectivity and effects of regional stimulation depend on collective dynamical state
Fig 6
Effects of local excitations on power spectra are more restricted at the high background drive working point (WP3).
(A) Schematic of a brain network depicting the stimulated site i in brightest red. The black arrows point to two other regions j and k that lie at progressively further topological distances from the perturbed area in the structural network. In this figure, regions i, j, and k correspond to brain areas 1 (R–Lateral Orbitofrontal), 4 (R–Medial Orbitofrontal), and 10 (R–Precentral), respectively. (B) Left: A segment of region i’s activity time-course in the baseline condition. Right: A segment of region i’s activity time-course when it is stimulated. (C) Power spectra of area i and two other downstream regions j and k. In all three panels, the lighter curves correspond to the baseline condition, and the darker curves correspond to the state in which i is driven with additional input. The gray vertical lines indicate the peak frequency of region i in the excited condition. (D) Histogram of the shift in peak frequency
induced by exciting unit i, plotted over all choices of the perturbed area. (E) The average shift in the peak frequency of the stimulated region
for WP1, WP2, and WP3 (error bars indicate the standard deviation over all choices of the excited unit). (F) Distribution of peak frequencies of all units in the baseline condition
(light gray) and distribution of the peak frequency units acquire when directly excited
(dark gray). (G) Average power spectra 〈psd〉j≠i over all units j ≠ i at baseline (light gray) and when unit i is perturbed with additional input (dark gray). Because stimulation does not induce a well-separated excited frequency band, we only assess perturbation-induced changes in the PLV between brain areas for a single baseline frequency band (purple area).