Skip to content

Effects of marijuana on equilibrium, psychomotor performance, and simulated driving.

A Liguori, C P Gatto, J H Robinson

Behavioural Pharmacology November 1998 DOI: 10.1097/00008877-199811000-00015 (opens in new tab)

Read Full Text
Relevant Not relevant

Study at a glance

AI-extracted from the abstract
Characteristics Within-subject experimental study Peer reviewed
Sample size 10
Population Marijuana users (seven men, three women)
Interventions 1.77 or 3.95% THC)
Dose 0, 1.77, or 3.95% THC
Duration 60-min test battery beginning 2 min after smoking
Measures subjective effects scales, computerized test of body sway, rapid judgment task, brake latency measurement in a driving simulator, critical flicker fusion (CFF), choice reaction time task (CRT)
Topics Cannabis
Key findings Smoking marijuana with 3.95% THC increased body sway and marginally increased brake latency by a mean of 55 ms, equivalent to nearly 5 feet more stopping distance at 60 mph, while 1.77% THC did not significantly affect body sway. Judgment, critical flicker fusion, and choice reaction time were unaffected by either dose. The authors state these equilibrium and brake latency effects resemble prior results at breath alcohol concentrations near 0.05%.

Abstract

Delta-9-tetrahydrocannabinol (THC) is frequently found in the blood of drivers involved in automobile accidents, and marijuana use has been associated with impaired field sobriety test performance. The present study used a within-subject design to compare the effects of marijuana (0, 1.77, or 3.95% THC) on equilibrium and simulated driving. Ten marijuana users (seven men, three women) smoked one marijuana cigarette at the beginning of each session. Then 2 min later, they began a 60-min test battery that included subjective effects scales, a computerized test of body sway, a rapid judgment task and brake latency measurement in a driving simulator, critical flicker fusion (CFF), and a choice reaction time task (CRT). Self-report ratings of 'high' and 'drug potency' increased comparably following both active doses. The high, but not the low, dose significantly increased body sway. The high dose also marginally increased brake latency by a mean of 55 ms (P < 0.10), which is comparable to an increase in stopping distance of nearly 5 feet at 60 mph Judgment, CFF, and CRT scores did not differ across dose conditions. The equilibrium and brake latency data with 3.95% THC are similar to prior results in our laboratory in participants with breath alcohol concentrations near 0.05%.

Comparable studies

Other experimental studies on cannabis, most cited first.

Study Year Design Participants
Smoked Cannabis' Psychomotor and Neurocognitive Effects in Occasional and Frequent Smokers Occasional (<2x/week) and frequent (≥4x/week) cannabis smokers 2015 Controlled within-subjects study n = 25
Dissociable effects of cannabis with and without cannabidiol on the human brain’s resting-state functional connectivity Healthy volunteers experienced with cannabis but not regular users 2019 Within-subjects experimental design n = 17
Which biological and self-report measures of cannabis use predict cannabis dependency and acute psychotic-like effects? Young cannabis users 2018 Observational study (naturalistic, within-subject counterbalanced design) n = 410
Cannabis Essential Oil: A Preliminary Study for the Evaluation of the Brain Effects Healthy volunteers 2018 Experimental study n = 5
Coming off cannabis: a cognitive and magnetic resonance imaging study in patients with multiple sclerosis Patients with multiple sclerosis who began using cannabis after disease onset, used it... 2019 Quasi-experimental study with odd-even allocation n = 40

Citations in the library

Cited by 7

and 2 more in the library

Related reading

Explore topics

Cannabis