Abstract
Rationale
Several psychoactive drugs are known to influence episodic memory. However, these drugs’ effects on false memory, or the tendency to incorrectly remember nonstudied information, remain poorly understood.
Objectives
Here, we examined the effects of two commonly used psychoactive drugs, one with memory-enhancing properties (dextroamphetamine; AMP), and another with memory-impairing properties (Δ9-tetrahydrocannabinol; THC), on false memory using the Deese/Roediger–McDermott (DRM) illusion.
Methods
Two parallel studies were conducted in which healthy volunteers received either AMP (0, 10, and 20 mg) or THC (0, 7.5, and 15 mg) in within-subjects, randomized, double-blind designs. Participants studied DRM word lists under the influence of the drugs, and their recognition memory for the studied words was tested 2 days later, under sober conditions.
Results
As expected, AMP increased memory of studied words relative to placebo, and THC reduced memory of studied words. Although neither drug significantly affected false memory relative to placebo, AMP increased false memory relative to THC. Across participants, both drugs’ effects on true memory were positively correlated with their effects on false memory.
Conclusions
Our results indicate that AMP and THC have opposing effects on true memory, and these effects appear to correspond to similar, albeit more subtle, effects on false memory. These findings are consistent with previous research using the DRM illusion and provide further evidence that psychoactive drugs can affect the encoding processes that ultimately result in the creation of false memories.
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Notes
Reanalysis of true memory data using change-from-placebo scores confirmed a significant effect of drug type (p = 0.011).
Reanalysis of false memory data using change-from-placebo scores approached significance for an effect of drug type (p = 0.07).
References
American Psychiatric Association (1994) Diagnostic and statistical manual of mental disorders, 4 edn. American Psychiatric Association, American Psychiatric Association
Capek S, Guenther RK (2009) Caffeine’s effects on true and false memory. Psychol Rep 104:787–795
Craik FI, Tulving E (1975) Depth of processing and the retention of words in episodic memory. J Exp Psychol Gen 104:27
Curran HV, Brignell C, Fletcher S, Middleton P, Henry J (2002) Cognitive and subjective dose-response effects of acute oral Delta 9-tetrahydrocannabinol (THC) in infrequent cannabis users. Psychopharmacol (Berl) 164:61–70
Deese J (1959) On the prediction of occurrence of particular verbal intrusions in immediate recall. J Exp Psychol 58:17–22
D’Souza DC, Ranganathan M, Braley G, Gueorguieva R, Zimolo Z, Cooper T, Perry E, Krystal J (2008) Blunted psychotomimetic and amnestic effects of delta-9-tetrahydrocannabinol in frequent users of cannabis. Neuropsychopharmacology 33:2505–2516
Fischman MW, Foltin RW (1991) Utility of subjective-effects measurements in assessing abuse liability of drugs in humans. Br J Addict 86:1563–1570
Folstein MF, Luria R (1973) Reliability, validity, and clinical application of the visual analog mood scale. Psychol Med 3:8
Gallo DA (2006) Associative illusions of memory: false memory research in DRM and related tasks, 1st edn. Psychology Press, New York
Gallo DA (2010) False memories and fantastic beliefs: 15 years of the DRM illusion. Mem Cognit 38:833–848
Garfinkel SN, Dienes Z, Duka T (2006) The effect of alcohol and repetition at encoding on implicit and explicit false memories. Psychopharmacol (Berl) 188:498–508
Huron C, Servais C, Danion JM (2001) Lorazepam and diazepam impair true, but not false, recognition in healthy volunteers. Psychopharmacol (Berl) 155:204–209
Hurst PM, Radlow R, Chubb NC, Bagley SK (1969) Effects of d-amphetamine on acquisition, persistence, and recall. Am J Psychol 82:307–319
Leweke M, Kampmann C, Radwan M, Dietrich DE, Johannes S, Emrich HM, Munte TF (1998) The effects of tetrahydrocannabinol on the recognition of emotionally charged words: an analysis using event-related brain potentials. Neuropsychobiology 37:104–111
Milani R, Curran HV (2000) Effects of a low dose of alcohol on recollective experience of illusory memory. Psychopharmacol (Berl) 147:397–402
Miller LL, Cornett TL (1978) Marijuana: dose effects on pulse rate, subjective estimates of intoxication, free recall and recognition memory. Pharmacol Biochem Behav 9:573–577
Miller LL, McFarland D, Cornett TL, Brightwell D (1977) Marijuana and memory impairment: effect on free recall and recognition memory. Pharmacol Biochem Behav 7:99–103
Mintzer MZ, Griffiths RR (2000) Acute effects of triazolam on false recognition. Mem Cognit 28:1357–1365
Mintzer MZ, Griffiths RR (2001a) Acute dose-effects of scopolamine on false recognition. Psychopharmacol (Berl) 153:425–433
Mintzer MZ, Griffiths RR (2001b) Alcohol and false recognition: a dose-effect study. Psychopharmacol (Berl) 159:51–57
Mintzer MZ, Griffiths RR (2003) Triazolam-amphetamine interaction: dissociation of effects on memory versus arousal. J Psychopharmacol 17:17–29
Mintzer MZ, Griffiths RR (2007) A triazolam/amphetamine dose-effect interaction study: dissociation of effects on memory versus arousal. Psychopharmacol (Berl) 192:425–440
Roediger HL 3rd (1996) Memory illusions. J Mem Lang 35:76–100
Roediger HL, McDermott KB (1995) Creating false memories: remembering words not presented in lists. J Exp Psychol Learn Mem Cogn 21:803–814
Roediger HL 3rd, Watson JM, McDermott KB, Gallo DA (2001) Factors that determine false recall: a multiple regression analysis. Psychon Bull Rev 8:385–407
Schacter DL, Verfaellie M, Pradere D (1996) The neuropsychology of memory illusions: false recall and recognition in amnesic patients. J Mem Lang 35:319–334
Soetens E, D’Hooge R, Hueting JE (1993) Amphetamine enhances human-memory consolidation. Neurosci Lett 161:9–12
Soetens E, Casaer S, D’Hooge R, Hueting JE (1995) Effect of amphetamine on long-term retention of verbal material. Psychopharmacol (Berl) 119:155–162
Thapar A, McDermott KB (2001) False recall and false recognition induced by presentation of associated words: effects of retention interval and level of processing. Mem Cognit 29:424–432
Wachtel SR, de Wit H (2000) Naltrexone does not block the subjective effects of oral Delta(9)-tetrahydrocannabinol in humans. Drug Alcohol Depend 59:251–260
Wachtel SR, ElSohly MA, Ross SA, Ambre J, de Wit H (2002) Comparison of the subjective effects of Delta(9)-tetrahydrocannabinol and marijuana in humans. Psychopharmacol (Berl) 161:331–339
White TL, Justice AJ, de Wit H (2002) Differential subjective effects of d-amphetamine by gender, hormone levels and menstrual cycle phase. Pharmacol Biochem Behav 73:729–741
White TL, Lott DC, de Wit H (2006) Personality and the subjective effects of acute amphetamine in healthy volunteers. Neuropsychopharmacology 31:1064–1074
White TL, Lejuez CW, de Wit H (2007) Personality and gender differences in effects of d-amphetamine on risk taking. Exp Clin Psychopharmacol 15:599–609
Zeeuws I, Soetens E (2007) Verbal memory performance improved via an acute administration of d-amphetamine. Hum Psychopharmacol 22:279–287
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Funding
This research was supported by DA02812. Michael Ballard was supported by T32 DA007255.
Declaration on interests
The authors have no conflicts of interests regarding the integrity of the reported findings.
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Ballard, M.E., Gallo, D.A. & de Wit, H. Psychoactive drugs and false memory: comparison of dextroamphetamine and delta-9-tetrahydrocannabinol on false recognition. Psychopharmacology 219, 15–24 (2012). https://doi.org/10.1007/s00213-011-2374-5
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DOI: https://doi.org/10.1007/s00213-011-2374-5