Lorazepam impairs both visual and auditory perceptual priming

Rationale: Lorazepam has been repeatedly shown to impair both explicit memo ry and perceptual priming, a form of implicit memory, in the visual domain. However, the effects of this benzodiazepine on priming in other perceptual domains, such as auditory priming, have never been explored. Objective: Th e present study investigated whether the deleterious effects of lorazepam o n perceptual priming are restricted to the visual domain, or if they could be extended to the auditory domain. Methods: Thirty-two healthy volunteers were randomly assigned to two parallel groups, placebo and lorazepam 0.038 mg/kg. The drug was administered orally, following a double-blind procedure . In the same subjects, perceptual priming was assessed in the auditory and visual domains using similar word-stem completion tasks, and explicit memo ry was explored using a free-recall task. Results: Lorazepam markedly reduc ed free-recall performance for visually and auditorily presented words. Lor azepam equally impaired visual and auditory priming. In the auditory word-s tem completion task, prior presentation of a word facilitated perception of its stem in the placebo group. This facilitation effect was not observed i n the lorazepam group. The lorazepam-induced impairment of priming was not due to sedation or explicit contamination. Conclusion: These results indica te that the deleterious effects of lorazepam on priming are not restricted to the visual modality, but extend to the auditory modality.