Marijuana is one of the most widely used substances. However, marijuana intoxication is not fully understood in relation to driving. This study will help the investigators learn more about the potential impairments related to marijuana intoxicated driving. A combination of MRI and neuropsychological tests (which are computer and paper/pencil tasks) will be used to measure intoxication and impairment. This study will also assess levels of marijuana in blood and saliva samples. This study takes place in Hartford, Connecticut.