Detection of Cannabis Impairment With an Eye Tracker

Effects of Cannabis on Driver Performance and Eye Movements and Characteristics During Simulated Driving: Feasibility Study

Cannabis is one of the widely used psychoactive substances in the world. With increasing legalization, the prevalence of driving under the influence of cannabis will undoubtedly rise. At present, roadside detection of cannabis intoxication is largely dependent on drug recognition experts who rely on changes in eye movements when impaired. In this regard, use of eye trackers can help to detect impairment in drivers. The purpose of the present study is to determine the feasibility of the use of eye trackers in detecting impairment in participants who smoked a cannabis cigarette.

Participants will attend one study session after determination of eligibility. During this session, they will smoke a cannabis cigarette with 12.5% THC prior to driving a simulator. Driving will be assessed prior to smoking cannabis and at 7 time points after smoking cannabis. Eye tracking measures will also be taken while driving after smoking cannabis. Blood will be drawn for determination of levels of the psychoactive substance THC and its metabolites. Saliva tests, urine tests and subjective tests will also be performed at various times points after smoking cannabis.

Inclusion Criteria:

• Weekly use of cannabis (1 to 4 days per week) confirmed by urine point-of-care testing;
• 19-26 years of age;
• holds a class G or G2 Ontario driver's licence (or equivalent from another jurisdiction) for at least 12 months;
• Willing to abstain from using alcohol for 48 hours and cannabis for 72 hours prior to the study session;
• Willing to abstain from all other drugs not prescribed for medical purposes for the duration of the study;
• Provides written and informed consent.

Exclusion Criteria:

• Urine toxicology screens negative for cannabis upon eligibility assessment;
• Diagnosis of severe medical or psychiatric conditions;
• Females: Pregnancy or breastfeeding;
• Meets criteria for Alcohol or Substance Dependence (current or lifetime) (DSM-IV);
• Is a regular user of medications that affect brain function (i.e., antidepressants, benzodiazepines, stimulants);
• First-degree relative diagnosed with schizophrenia.