The time-dependent effects of benzodiazepines on implicit and explicit memory.
Date
2000
Authors
Buffett-Jerrott, Susan Elizabeth.
Journal Title
Journal ISSN
Volume Title
Publisher
Dalhousie University
Abstract
Description
Three studies examined the time-dependent effects of benzodiazepines (BZs) on implicit and explicit memory. Study 1 investigated the hypothesis that BZs would impair implicit memory if participants encoded the to-be-remembered stimuli around the time of the peak blood concentration of the drug. The effects of 2 mg lorazepam, 30 mg oxazepam, and placebo were examined by comparing the effects of each drug on implicit and explicit memory at 170 minutes post-drug. This time point is close to the peak blood concentration time for oxazepam and past the peak concentration time for lorazepam. Results indicated that both BZs impaired explicit and implicit task performance. Study 2 was designed to examine the time-dependent memory impairment curve of a single BZ, oxazepam. The effects of 30 mg oxazepam and placebo on implicit and explicit memory tasks were studied at 100 minutes (pre-peak), 170 minutes (peak) and 240 minutes (post-peak) after drug administration in a between-subjects design. Results indicated that at "pre-peak", only explicit memory was impaired by oxazepam. However, in the "peak" condition, oxazepam impaired performance on both memory tasks. In the "post-peak" condition, explicit memory was impaired, but priming impairments were beginning to wane. Study 3 was designed to replicate and extend the findings of Studies 1 and 2 to an applied setting. Study 3 used a placebo-controlled design to examine the effects of 0.50 mg/kg oral midazolam at two encoding times (pre-peak and peak) in children who were undergoing myringotomy surgery. The results indicated that explicit memory was impaired by midazolam at both encoding times. However, in contrast to findings with pilot participants, the priming task did not adequately assess implicit memory in the hospital situation. Results are discussed in terms of their implications for theories of memory organization and their clinical applications.
Thesis (Ph.D.)--Dalhousie University (Canada), 2000.
Thesis (Ph.D.)--Dalhousie University (Canada), 2000.
Keywords
Health Sciences, Pharmacology., Psychology, Clinical., Psychology, Cognitive.