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Motion and form perception in healthy individuals with adolescent cannabis use

Balázs Barko, Szabolcs Kéri

Frontiers in Psychiatry August 17, 2026 DOI: 10.3389/fpsyt.2026.1902131 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Cross-sectional study Longitudinal Peer reviewed
Sample size 130
Population Abstinent adults in sustained remission from cannabis-related problems for at least 12 months, free of current psychoactive substance use and DSM-5 psychiatric disorders: cannabis-naïve controls (n=50), non-heavy adolescent users (n=38), and heavy adolescent users (daily use before age 15; n=42)
Measures Motion coherence (random-dot display) thresholds, form coherence (orientation-defined circles) thresholds, Cannabis Exposure Inventory (CEI)
Topics Cannabis
Key findings Heavy cannabis use beginning before age 15 was associated with a selective deficit in global motion perception, while global form perception was spared; non-heavy adolescent users performed like controls, and Cannabis Exposure Inventory scores predicted motion coherence thresholds. The authors argue this pattern is consistent with increased vulnerability of the dorsal visual stream and say longitudinal studies are needed to confirm it.

Abstract

Introduction: Neuronal mechanisms of motion perception are susceptible to developmental anomalies. We tested whether heavy adolescent cannabis use is associated with enduring deficits in global motion perception, with relative sparing of global form perception, in abstinent adults.

Methods: In a cross-sectional study, 130 adults were enrolled: cannabis-naïve controls (n=50), non-heavy adolescent users (n=38), and heavy adolescent users (daily use before age 15; n=42). Participants reported no current psychoactive substance use and were in sustained remission from cannabis-related problems for ≥12 months. DSM-5 psychiatric disorders were excluded. Motion coherence (random-dot display) and form coherence (orientation-defined circles) thresholds were measured. Cannabis exposure was quantified with the Cannabis Exposure Inventory (CEI).

Results: > 10, strong Bayesian evidence). Form coherence thresholds did not differ between groups. Non-heavy users did not differ from controls on either task. The CEI scores predicted motion coherence thresholds.

Conclusions: Heavy cannabis exposure starting in early adolescence is associated with a selective deficit in global motion integration, consistent with the hypothesis of increased vulnerability of the dorsal visual stream. This hypothesis should be confirmed by longitudinal studies.