RELATION BETWEEN BRAIN GLOBAL METASTABILITY AND IDENTIFIABILITY IN NATURALISTIC FMRI

Metastability is a measure of functional dynamics defined as the variation in partial synchrony between brain regions. Another type of measure involves the intra-individual stability of whole-brain functional connectivity, which promotes subject identifiability, i.e., the brain “fingerprinting” technique. Independently, studies involving both measures have recently focused their work on naturalistic stimuli (music, movies, narratives, etc.) in their data collection, which reduces motion artifacts; increases test-retest reliability; and provides a more complex signal that better approximates reality compared to traditional fMRI stimuli.This literature suggests that movies induce distinct brain states dynamics, leading to an increased level of global metastability of the fMRI signal. Moreover, narrative movies have been associated with higher levels of fMRI-based identifiability compared to non-narrative movies. Understanding the potential relation between metastability and identifiability of the fMRI signal might provide a mechanistic insight for mental states variations and foster the development of more individualized non-invasive interventions. However, to date, no study has proposed to investigate the potential relations between fMRI metastability and identifiability during a long-duration naturalistic stimulus.