Spiral brain dynamics track the temporal unfolding of subjective intensity during the N,N-dimethyltryptamine experience

This preprint reanalysed placebo-controlled DMT fMRI data from healthy volunteers (n=17 for the main analyses; n=14 for time-resolved analyses). DMT increased spiral vorticity and its spatial dispersion and reduced temporal irreversibility. The spiral measures tracked subjective intensity, with the strongest reorganisation during offset and recovery rather than peak intensity. These associations do not establish a causal explanation of the experience.