Role of the Global Signal in Mental State Characterization

COEX 

The fMRI global signal (GS) as the average BOLD signal across the brain, is a controversial aspect of the brain’s functional data analysis. While some argue that the GS reflects non-neural physiological noise, others contend it contains valuable information about the brain’s functional organization. We recently showed that the GS amplitude varies across different mental states, from mind blanking (Mortaheb et al 2022; Boulakis et al, 2023) to psychedelic experiences (Mortaheb et al, 2023). Here, I will present how the GS amplitude complements the dynamic functional connectivity analysis to better interpret the neural substrate of different mental states.