After taking LSD, the brain's dynamics become less stable and more diverse in response to perturbations. Using a whole-brain computational model fitted to fMRI data from individuals under LSD or placebo, researchers simulated external disruptions to different brain regions. They measured recovery time with the Perturbational Integration Latency Index (PILI). Globally, LSD caused consistently higher PILI values, indicating a shift further from stable equilibrium. Locally, the largest differences appeared in the limbic, visual, and default mode networks. LSD also increased variability of PILI across brain regions, suggesting greater response diversity. These findings reveal brain-wide dynamical changes underlying the psychedelic state and suggest potential clinical applications for psychiatric disorders.
LSD alters brain dynamics by shifting the brain's global working point further from a stable equilibrium, as shown by consistently higher Perturbational Integration Latency Index (PILI) values after intake. Using a whole-brain computational model perturbed in silico, the largest differences were found in the limbic, visual, and default mode networks. Greater variability of PILI values across brain regions under LSD indicates higher response diversity to external perturbations. These findings provide insights into the brain-wide dynamical changes underlying the psychedelic state and suggest possible clinical applications for psychiatric disorders.
Meditation shifts the brain's global dynamics toward a less complex, more stable state compared to resting. Experienced meditators scanned with fMRI while meditating (focused attention on breathing) showed lower dynamical complexity than during rest, a difference not seen in non-meditators. At rest, meditators' brains exhibited higher metastability—a wider range of dynamic activity over time—than controls. These findings suggest that the meditation state operates in a distinct dynamical regime from the resting state, helping clarify how meditation alters whole-brain communication.