Lorazepam-induced modifications of saccadic and smooth-pursuit eye movements in humans: Attentional and motor factors.

Measured the effects of low dose lorazepam on attentional and motor factors involved in saccadic and smooth pursuit eye movements. The authors manipulated the temporal interval between the extinction of the central fixation target and the appearance of a 2nd eccentric target (gap/overlap step paradigm). The 2nd target was either stationary (saccade trial) or moving in a direction opposite to the step (pursuit trail). In 14 healthy volunteers (mean age 26.3 yrs), the authors found that the temporal interval between fixation target offset and eccentric target onset modulates the latency of saccadic and smooth pursuit eye movements in a similar way. As compared to placebo, lorazepam significantly increased the latency of both types of eye movements, but did not modify the gap/overlap effect. Moreover, lorazepam significantly decreased the peak velocity of the 1st saccade towards the eccentric stationary target, as well as the gain of tracking towards the eccentric moving target. However, the overall accuracy of both behaviors was not significantly affected, indicating that systematic errors in foveating or tracking were detected and corrected by appropriate corrective or catch-up saccades, respectively. (PsycInfo Database Record (c) 2020 APA, all rights reserved)