Examine the Feasibility of a Standardized Field Test for Marijuana Impairment: Laboratory Evaluations

This responds to NHTSA's request with a proposal to increase our understanding of smoked cannabis' (CNB's) acute effects on cognition and simulated driving performance, the persistence of these deficits over the hours after use, and the influence of prior experience with CNB on these effects. The project also will link an extensive literature on CNB's effects on laboratory cognitive tests to simulated driving performance for the first time, providing a crucial validation of CNB's neurofunctional effects identifying maximally relevant candidate measures for field sobriety tests. To this goal, the proposed study was based upon a careful and thorough review of the scientific literature describing CNB effects on cognitive test performance and driving, as well as current state-of-knowledge on the sensitivity of biological assays for identifying recent CNB use. The study will carefully characterize the persistence of CNB's acute effects on cognitive test performance and driving over a several-hour time span. This will allow us to identify the point at which any effects of CNB intoxication on cognitive tests and driving performance cannot be distinguished from normal, i.e., the first step towards establishing standards for legal and social policy. The data obtained from simulated driving, cognitive tests, and biological assays of THC will be used in analyses aimed at identifying what tests or combination of tests predict both recent use and driving impairment risk. Participants