TY - JOUR PY - 2005// TI - Impaired perception of self-motion (heading) in abstinent ecstasy and marijuana users JO - Psychopharmacology A1 - Rizzo, Matthew A1 - Lamers, Caroline T. J. A1 - Sauer, C. G. A1 - Ramaekers, Johannes Gerardus A1 - Bechara, A. A1 - Andersen, George J. SP - 559 EP - 566 VL - 179 IS - 3 N2 - RATIONALE: Illicit drug use can increase driver crash risk due to loss of control over vehicle trajectory. This study asks, does recreational use of +/-3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) and tetrahydrocannabinol (THC; marijuana) impair cognitive processes that help direct our safe movement through the world? OBJECTIVE: This study assesses the residual effects of combined MDMA/THC use, and of THC use alone, upon perceived trajectory of travel. METHODS: Perception of self-motion, or heading, from optical flow patterns was assessed using stimuli comprising random dot ground planes presented at three different densities and eight heading angles (1, 2, 4 and 8 degrees to the left or right). On each trial, subjects reported if direction of travel was to the left or the right. RESULTS: Results showed impairments in both drug groups, with the MDMA/THC group performing the worst. CONCLUSIONS: The finding that these psychoactive agents adversely affect heading perception, even in recently abstinent users, raises potential concerns about MDMA use and driving ability. Keywords: Cannabis impaired driving LA - en SN - 0033-3158 UR - http://dx.doi.org/10.1007/s00213-004-2100-7 ID - ref1 ER -