Longer chronic cannabis use in humans is associated with impaired implicit motor learning and supranormal resting state cortical activity
bioRxiv (Cold Spring Harbor Laboratory) April 21, 2025 Shikha Prashad, Andrew Paek, Lisa R. Fournier 1 citation preprint
Chronic cannabis use is linked to cognitive impairment, but its effect on implicit motor learning—the unconscious acquisition of movement sequences—was unclear. In a study of 30 regular cannabis users and 32 non-users, implicit motor learning occurred in both groups, but longer cannabis use was associated with a smaller learning index and increased beta and gamma EEG activity during rest. Cannabis users also showed reduced visuospatial short-term and working memory on the Corsi block-tapping test. The authors suggest chronic cannabis use may disrupt corticostriatal pathways, impairing implicit motor learning through increased cortical noise.