Regional and cannabis-related differences in prefrontal multiscale entropy of resting-state EEG.
Clinical neurophysiology practice January 1, 2026 William T Creel, Colleen A Brenner, Richard E Hartman
Frequent cannabis use is associated with reduced neural signal complexity in the prefrontal cortex, as measured by multiscale entropy (MSE) of resting-state EEG. In 57 adults—non-users, low-frequency users (≤1x/week), and frequent users (≥2x/week)—MSE increased with coarser temporal scales in all groups, but the slope was significantly flatter in frequent users. From medium to very-coarse scales, their prefrontal entropy slope was 0.12 to 0.16 bits lower than non-users. Across all participants, the prefrontal cortex showed lower MSE than parietal, occipital, and temporal lobes, with larger differences at coarser scales. MSE detects cannabis-related reductions in prefrontal signal complexity at longer temporal scales.