Detection of Cannabis Impairment With an Eye Tracker

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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Cannabis Intoxication

Intervention / Treatment
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* Drug: Cannabis Sativa


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 26 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Screening
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cannabis sativa<br>a 750 mg cannabis cigarette with 12.5% THC | Drug: Cannabis Sativa<br>* 750 mg cannabis cigarette with 12.5% THC<br>* Other names: Marijuana;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in eye gaze | Measures of eye movement with an eye tracker | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in saccades | Measures of quick eye movements with an eye tracker | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in eye fixations | Measure of where the eye is looking with an eye tracker | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in blinking rate | The number of blinks, measured with an eye tracker | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in blinking duration | The length of time that blinks last, measured with a eye tracker | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in blinking speed | How fast the blinking is, measured with an eye tracker | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in pupil size | The diameter of pupils while driving, measured with an eye tracker | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in mean speed on the driving simulator | The speed, in km, while driving a driving simulator | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in standard deviation of speed on the driving simulator | The amount of variation in speed while driving the driving simulator | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in maximum speed on the driving simulator | The greatest speed obtained on the driving simulator | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in standard deviation of lateral position on the driving simulator | The amount of weaving while driving the driving simulator | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in minimum time to collision on the driving simulator | The time needed to collide with the car in front, while driving the simulator | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in number of collisions | The number of times a car impacts another car while driving the simulator | baseline, 15 minutes, 35 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in blood concentrations of delta-9-tetrahydrocannabinol | The levels of the psychoactive component of cannabis, THC, in blood | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in blood concentrations of carboxy-tetrahydrocannabinol | The levels of the inactive metabolite of THC in blood | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in blood concentrations of 11-hydroxy-tetrahydrocannabinol | The levels of the active metabolite of THC in blood | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in saliva THC detection | Detection of THC in saliva | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in systolic blood pressure | Vital signs | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in diastolic blood pressure | Vital signs | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in heart rate | Vital signs | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in temperature | Vital signs | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in number of respirations per minute | Vital signs | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours | 
| Change in Subjective cannabis effects with a visual analog scale | The amount of liking of cannabis from 0 to 100, with 100 being the greatest value | baseline, 5 minutes, 25 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours |