Midazolam-induced amnesia: implications for the implicit/explicit memory distinction.

In order to examine how the distinction between implicit and explicit memory might relate to theories regarding the organization of memory, two types of memory tests were administered in conjunction with the amnesia-inducing benzodiazepine midazolam. Performance on an implicit task (perceptual facilitation in identifying degraded pictures and words) was relatively unimpaired by midazolam, whereas performance on an explicit task (recognition memory) was severely impaired. Interpreting the results in both the implicit/explicit framework and an independent stage analysis suggests that the terms implicit and explicit may reflect something about the nature of the memory representation and need not be reserved solely to describe classes of memory tasks.