Effects of scopolamine on anterograde and remote memory in humans

Previous research with laboratory animals indicates that anterograde-memory functions are more easily disrupted by anticholinergic drug treatment than are established reference memories. In studies with human subjects, some measures of established (remote) memory appear to be disrupted by anticholinergic agents, while other measures of remote memory have proven insensitive to anticholinergic treatments. To clarify the effects of anticholinergic treatment on remote memory in humans, we studied the effects of administering 0.5 or 0.8 mg scopolamine to middleaged men on a battery of tests of anterograde and remote memory. Dose-related impairments on measures of anterograde short-term memory and verbal and nonverbal learning were observed and, in addition, performance on a category-fluency task, which required retrieval of information from established semantic memory, was disrupted. In contrast, measures of remote memory that required identification of photographs of famous people, recall of past public events, and display of geographical knowledge were not affected by scopolamine treatment. Implications of the findings for drug models of memory failure in dementia are discussed.