Impairment of saccadic eye movements by scopolamine treatment

The effects of Scopolamine on the dynamics of saccadic eye movements, stimulated over a random time interval, have been investigated in humans. A 0.5-mg dose of the drug (intramuscular injection) had various influences on the basic saccadic parameters. For all subjects duration increased and peak velocity decreased, while for 50% of the subjects saccades became hypometric and latency increased. Standard deviation increased consistently too. Moreover, the Scopolamine treatment affected postsaccadic fixation; at the end of many saccades, the eye drifted considerably, but stability was recovered after a few seconds.