Midazolam does not inhibit association formation, just its storage and strengthening
- First Online:
- 75 Downloads
Although there have been many studies examining the effects of benzodiazepines on memory performance, their effects on working memory are equivocal and little is known about whether they affect the efficacy of practice of already learned material.
The objectives in two experiments were to examine (a) whether midazolam impairs performance on a working memory task designed to minimize mnemonic strategies such as rehearsal or chunking of information to be recalled and (b) the effect of midazolam on repeated practice of paired associates that were learned before drug administration.
Materials and methods
Both experiments involved subcutaneous administration of 0.03 mg of saline or midazolam per kilogram of bodyweight in within-subject, placebo-controlled designs, involving 23 subjects in (a) and 31 in (b).
The drug had no effect on the ability to recall the digits in serial order even though the encoding task prevented the digits from being rehearsed or maintained in an articulatory buffer. Paired associates that were learned before the injection showed a benefit of subsequent practice under saline but not under midazolam.
The results suggest that (a) midazolam does not affect the formation of new associations in short-term memory provided that the presentation rate is not too fast to form these associations when sedated, despite the evidence that the drug blocks long-term memory (LTM) retention of associations; and (b) the potential for over-learning with practice of learned associations in LTM is adversely affected by midazolam such that repeated exposures do not strengthen new learning.
KeywordsBenzodiazepine Working memory Memory Binding Paired associate learning Practice MODS task Midazolam Over-learning Digit span
- Baddeley AD (1986) Working memory. Oxford University Press, Oxford, EnglandGoogle Scholar
- Caplan D, Rochon E, Waters GS (1992) Articulatory and phonological determinants of word length effects in span tasks. Q J Exp Psychol 45(2):177–192Google Scholar
- Cohen JD, O’Reilly RC (1996) A preliminary theory of the interactions between prefrontal cortex and hippocampus that contribute to planning and prospective memory. In: Brandimonte M, Einstein GO, McDaniel MA (eds) Prospective memory: theory and applications. Erlbaum, Mahwah, NJ, pp 267–295Google Scholar
- Diana RA, Reder LM (in press) The low frequency encoding disadvantage: word frequency affects processing demands. J Exp Psychol Learn Mem CognGoogle Scholar
- Ebbinghaus H (1913) Memory: a contribution to experimental psychology. Teachers College, Columbia University, New York (reprinted Thoemmes, Bristol, 1999)Google Scholar
- Eichenbaum H, Cohen NJ (2001) From conditioning to conscious recollection: memory systems of the brain. Oxford University Press, New YorkGoogle Scholar
- Kirkby KC, Montgomery IM, Badcock R, Daniels BA (1995) A comparison of age-related deficits in memory and frontal lobe function following oral lorazepam administration. J Psychopharmacol 9(4):319–325Google Scholar
- Lovett MC, Reder LM, Lebiere C (1997) Modeling individual differences in a digit working memory task. Proceedings of the Nineteenth Annual Cognitive Science Conference. Mahwah, NJ: Erlbaum, 460–465Google Scholar
- Lovett MC, Reder LM, Lebiere C (1999) Modeling working memory in a unified architecture: an ACT-R perspective. In: Miyake A, Shah P (eds) Models of working memory. Cambridge University Press, pp 135–182Google Scholar
- Miller EK, Freedman DJ, Wallis JD (2003) The prefrontal cortex: categories, concepts and cognition. In: Parker A, Derrington A, Blamore C (eds) The physiology of cognitive processes. Oxford University Press, New York, NY, pp 252–273Google Scholar
- Reder LM, Oates JM, Dickison D, Anderson JR, Gyulai F, Quinlan JJ, Ferris JL, Dulik M Jefferson B (in press) Retrograde facilitation under midazolam: the role of general and specific interference. Psychon Bull RevGoogle Scholar