Retrograde facilitation under midazolam: The role of general and specific interference

Abstract

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...

Why It’s Easier to Remember Seeing a Face We Already Know Than One We Don’t

“…A novel stimulus can be re-coded in terms of known constituents (e.g., “attractive, blond female”) but that encoded representation may not facilitate discrimination of targets from foils. Our view, that labels facilitate encoding because there is less of a burden on working memory resources (Reder et al, 2007), is consistent with an argument put forward by Lupyan (e.g., Lupyan, Rakison & McClelland, 2007). When contextual information is unavailable for recognition, judgments are based on a familiarity process.…”

“…In Experiment 2, subjects in the midazolam condition exhibited markedly impaired recognition memory, a finding established many times before (Hirshman et al, 1999; Hirshman, et al, 2001; Park et al, 2004; Reder et al, 2006; Reder et al, 2007). As expected, subjects in the midazolam condition had fewer “Remember” hits, indicating that they were unable to make context-dependent recollection judgments, but instead relied on familiarity to make more general “Know” responses.…”

“…In our view (e.g. Park, Quinlan, Thornton, & Reder, 2004; Reder et al, 2007) midazolam affects the ability to form new associations (i.e., bind stimuli to context). We concluded that the differential effect of midazolam on these three classes of stimuli (abstract images, unknown faces/places, and words) is due to their ability to be bound to context when no drug is present.…”

“…Midazolam is a benzodiazepine that creates temporary anterograde amnesia by blocking the formation of new memories (Hirshman, Passanante, Arndt, 1999; Hirshman, Passanante, Arndt, 2001; Hirshman, Passanante, & Henzler, 1999; Park, Quinlan, Thornton, Reder, 2004; Reder et al, 2006; Reder et al, 2007). 4 Hirshman, Fisher, Henthorn, Arndt and Passannante (2002) showed that under the influence of the drug, subjects were unable to bind studied information to associated context, resulting in a reduced ability to make successful recollection-based judgments and an increased reliance on familiarity.…”

The effects of word frequency and context variability in cued recall

“…There are three types of nodes in SAC: the concept node represents the pre-experimental familiarity of an item and the level of familiarity is derived from word frequency; context nodes represent contexts in which items have occurred including one for the experiment itself; the episode node is the binding between the context and concept nodes. The episode node is where recollection and recall take place (i.e., remembering the concept in the experimental context; Reder et al, 2000Reder et al, , 2007 and the activation of that node is partially determined by the total number of contexts bound to the concept. More activation spreads to episode nodes from concepts with a smaller number of prior contexts.…”