Effect of Diazepam upon Verbal Recall Associated with SimplÉ Picture Recognition 1

Abstract

30 normal, young adults of superior intellectual ability were administered either 0.2 mg/kg diazepam (p.o.) or a lactose placebo to assess the effects of diazepam upon short- and long-term verbal recall of pictorially depicted common objects. A recognition task was used to determine the presence of differences between groups and between visual recognition and verbal recall. The memory tasks employed were a combination of three of Randt's Memory Test Picture Recognition subtests in which black line-drawings are used to depict common objects. Diazepam did not reduce verbal recall significantly immediately following stimulus presentation. It did adversely affect long-term verbal recall. Diazepam also resulted in a small but significant reduction in immediate picture-recognition performance, which remained unchanged 24 hr. later. The results, consistent with previous research, suggest that the amnestic effect frequently observed with benzodiazepines reflects a disruption in the acquisition and/or consolidation phase of memory formation. The absence of a recency effect in delayed free verbal recall together with no significant change in delayed recognition by the diazepam group suggests that diazepam may also disrupt retrieval mechanisms 24 hr. following drug administration.