In a double-blind, placebo-controlled experiment that used midazolam, a benzodiazepine that creates temporary amnesia, we compared acquisition and retention of paired associates of different types. Some word pairs were studied before the injection of saline or midazolam, and two lists of word pairs were studied after the injection. Critical comparisons involved retention of pairs that were practiced on all three lists, pairs studied on only one list, and pairs that involved recombining cue and response terms from one list to the next, as a function of drug condition. Previous research with benzodiazepines had found retrograde facilitation for material acquired prior to injection, compared with the control condition. One explanation for this facilitation is that the anterograde amnesia produced by the benzodiazepine frees up the hippocampus to better consolidate previously learned material (Wixted, 2004(Wixted, , 2005. We accounted for a rich data set using a simple computational model that incorporated interference effects (cue overload) at retrieval for both general (experimental context) interference and specific (stimulus term) interference without the need to postulate a role for consolidation. The computational model as an Excel spreadsheet may be downloaded from www.psychonomic.org/archive.Psychologists have long investigated the class of mechanisms that affect retention of past experience. Wixted (2004Wixted ( , 2005 notes that psychologists have ignored the role of consolidation while debating the role of interference and decay as mechanisms of forgetting. He reviews evidence from psychology, psychopharmacology, and neuroscience to argue that the traditional psychological theories of forgetting "may not be relevant to the kind of interference that induces most forgetting in everyday life" (p.6). Wixted reviews evidence from Correspondence concerning this article should be addressed to L. M. Reder, Psychology Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (e-mail: reder@cmu.edu).
Archived MaterialsThe following materials [and links] associated with this article may be accessed through the Psychonomic Society's Norms, Stimuli, and Data archive, www.psychonomic.org/archive. To access these files [or links], search the archive for this article using the journal name (Psychonomic Bulletin & Review), the first author's name (Reder), and the publication year (2007 psychopharmacology to support the claim that general interference or "mental exertion" is a major determinant in whether information is forgotten. In particular he notes that benzodiazepines, which produce amnesia for material learned after the drug, create retrograde facilitation for material learned before the drug. He argues that this results from the absence of mental exertion. This article reports a new study designed to understand the mechanisms that underlie the retrograde facilitation observed under the influence of benzodiazepines.Studies using benzodiazepines, such as diazepam (Valium) and alprazolam...