Fig. 3. 7 T imaging shows two primary activity modes at behavioral arousal, largely segregated into thalamic activation and cortical deactivation.

a Schematic of the thalamic nuclei of interest that were resolved with this imaging protocol. This image was created by the authors and was inspired by the Allen Brain Atlas¹³¹. b In one subject scanned with simultaneous EEG (n = 6 arousals), mean alpha power significantly increases during behavioral arousal (dashed line), consistent with Experiment 1. Shading is a standard error. c Experiment 2 replicates the result that the thalamus activates (20% latency indicated by red arrow) prior to behavioral arousal, while cortical deactivation (blue arrow) follows (n = 13 subjects, 99 arousals). Shading is standard error. d A principal component analysis of all nine thalamic regions and 30 cortical regions reveals two primary modes of activity in the thalamus and cortex: one which increases before arousal and one which decreases after arousal. e The first principal component is more heavily influenced by cortical regions, and the second is influenced primarily by thalamic regions, demonstrating segregation of thalamic and cortical activity during arousal. Source data are provided in the “Fig. 3 Source Data” file.