Impaired perception of self-motion (heading) in abstinent ecstasy and marijuana users

M. Rizzo, C. T.J. Lamers, C. G. Sauer, J. G. Ramaekers, A. Bechara, G. J. Andersen

Research output: Contribution to journalArticlepeer-review

25 Scopus citations


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° 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.

Original languageEnglish (US)
Pages (from-to)559-566
Number of pages8
Issue number3
StatePublished - May 2005
Externally publishedYes


  • Driving
  • MDMA
  • Substance abuse
  • THC
  • Visual motion

ASJC Scopus subject areas

  • Pharmacology


Dive into the research topics of 'Impaired perception of self-motion (heading) in abstinent ecstasy and marijuana users'. Together they form a unique fingerprint.

Cite this