The effects of alcohol and marijuana (tetrahhydrocannabinol THC) on saccades smooth pursuit, and optokinetic nystagmus were quantitatively evaluated in 24 normal subjects using electrooculographic recordings. Each subject was given an initial trial run and then tested three times (at weekly intervals) with either 0.0 THC or 100THC/kg bodyweight while at three different blood alcohol concentrations (0.0,0.05 and 0.1%). A 2x3 factorial design was used. Saccades and smooth pursuit were induced by a dot of light moving in steps and ramps on a modified television set. Optokinetic nystagmus was induced by a cloth drum completely surrounding the subject and moving at a constant velocity. The addittion of THC caused performance to further deteriorate at each blood alcohol level but, in all but one instance, the added effect was not statistically significant (p>0.05) at the THC and alcohol concentrations used in this study, the eye movement effects of alcohol overshadowed those of marijuana. (A)
Samenvatting