Dose effects of triazolam and scopolamine on metamemory.

Abstract

The present study compared the acute dose effects of the benzodiazepine triazolam and the anticholinergic scopolamine on metamemory (knowledge and awareness of one's own memory) in a two-phase paradigm designed to assess effects on both monitoring and control components of metamemory in both semantic (general knowledge) and episodic memory (cued recall) tasks. Placebo and two doses each of triazolam (0.125, 0.25 mg/70 kg, oral) and scopolamine (0.25, 0.50 mg/70 kg, subcutaneous) were administered to 80 healthy volunteers (16/group) in a double-blind, doubledummy, independent groups design. Both triazolam and scopolamine impaired episodic memory (quantity and accuracy) but not semantic memory. Results suggested that both drugs impaired monitoring as reflected in absolute accuracy measures (impaired calibration in the direction of overconfidence) and control sensitivity (the relationship between confidence and behavior). Overall, the results did not provide evidence for differences between triazolam and scopolamine in memory or metamemory. In addition to the clinical relevance of the observed effects, this study adds to the accumulating body of cognitive psychopharmacological research illustrating the usefulness of druginduced amnesia as a vehicle to explore memory and metamemory.Metamemory, which refers to an individual's knowledge and awareness of his/her own memory (Flavell, 1971;Metcalfe & Shimamura, 1994), plays an important role in memory performance in many everyday situations. Metamemory can be thought of as encompassing two components: Monitoring, which consists of processes involved in an individual's selfassessment of his/her memory, and control, which refers to ways in which an individual can regulate cognitive processing when given the opportunity to do so (Nelson & Narens, 1990. One can take as an example an eyewitness in a courtroom who swears to "tell the truth, the whole truth, and nothing but the truth." Given that memory is a reconstructive process, the witness presumably must first assess the features of his/her memory of the event being discussed (monitoring) and then determine which features of that memory to report in court (i.e., which features reach the subjective threshold of "truth") (control).It is well established that benzodiazepine (e.g., diazepam: Valium®, lorazepam: Ativan®; triazolam: Halcion®) and anticholinergic (e.g., scopolamine) drugs induce temporary amnesia when administered acutely to healthy volunteers (for reviews, see Curran, 1991Curran, , 2000Kopelman, 1986;Polster, 1993). The effects of memory-impairing drugs on metamemory have both clinical and theoretical significance. From a clinical perspective, if a drug produces memory impairment, it is essential to know the degree to which patients being prescribed that Publisher's Disclaimer:The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated vers...

Lactobacillus pentosusvar.plantarumC29 protects scopolamine-induced memory deficit in mice

“…Scopolamine has been shown to cause memory impairment (Mintzer et al . ). Many studies indicate that scopolamine is increasingly disruptive with increasing age and declining cognitive status (Araujo et al .…”

Cognitive effects of intramuscular ketamine and oral triazolam in healthy volunteers

“…Dependent measures were the proportion of old words correctly identified as old (collapsed across definitely old, probably old, and maybe old; this is the hit rate), the proportion of new words incorrectly identified as old (collapsed across definitely old, probably old, and maybe old; this is the false alarm rate), and signal detection measures of sensitivity in distinguishing between old and new words ( d ′) and response bias ( C ) (Snodgrass and Corwin 1988). Metamemory (participants’ awareness of the state of their memory) was assessed by the Goodman–Kruskal gamma correlation (a correlation between confidence and correctness in recognition; Goodman and Kruskal 1954) for the recognition memory task; this approach has been shown to be sensitive to detecting impairments in metamemory (Nelson 1984; Koriat and Goldsmith 1996; Mintzer et al 2010). …”

Cholinergic receptor subtypes and their role in cognition, emotion, and vigilance control: An overview of preclinical and clinical findings

“…category fluency) task (Tröster et al 1989), while several studies reported neither impairments nor improvements after scopolamine administration (e.g. Dunne 1990;Huff et al 1988;Mintzer et al 2010). Scopolamine, therefore, seems to spare semantic memory functions to some extent.…”

“…In healthy volunteers, the muscarinic antagonist scopolamine has been shown repeatedly to impair episodic memory performance on a number of verbal tasks (Bishop et al 1996;Ellis et al 2006;Huff et al 1988;Kamboj and Curran 2006a, b;Koller et al 2003;Kopelman and Corn 1988;Litvan et al 1995;Mintzer et al 2010;Terry and Buccafusco 2003;Vitiello et al 1997; see Table 2 for details) as well as in visual recognition memory tasks (Koller et al 2003;Sherman et al 2003).…”