1
|
Doss MK, Mallaroni P, Mason NL, Ramaekers JG. Psilocybin and 4-Bromo-2,5-Dimethoxyphenethylamine (2C-B) at Encoding Distort Episodic Familiarity. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2024:S2451-9022(24)00166-6. [PMID: 38942147 DOI: 10.1016/j.bpsc.2024.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 06/30/2024]
Abstract
BACKGROUND As research on psychedelics (hallucinogenic 5-HT2A agonists) progresses, it is important to delineate the reliability of supposedly unique effects across this drug class. One such effect is how psychedelics impair the formation (i.e., encoding) of hippocampal-dependent recollections (retrieval of specific details) while potentially enhancing the encoding of cortical-dependent familiarity (a feeling of knowing that a stimulus has been previously experienced). METHODS In a double-blind, placebo-controlled, within-subjects study (N = 20), we tested the acute effects of two distinct psychedelics, psilocybin and 4-bromo-2,5-dimethoxyphenethylamine (2C-B), on the encoding of emotional episodic memories. During acute drug effects, participants viewed negative, neutral, and positive pictures. The following day (while sober), participants completed two separate memory tests for these pictures. RESULTS Using computational models of memory confidence, we found trends for psilocybin and 2C-B at encoding to impair estimates of recollection that were supported by other measures/analyses. Surprisingly, psilocybin and 2C-B at encoding impaired estimates of familiarity, but these impairments were likely due to a misattribution of heightened familiarity, as both drugs at encoding selectively increased familiarity-based false alarms, especially for negative and positive stimuli. Psilocybin and 2C-B at encoding also tended to impair estimates of metamemory (understanding one's own memory) for negative and neutral memories but enhance estimates of metamemory for positive memories, though these effects were less reliable in additional analyses. CONCLUSIONS Despite differences in their chemistry, pharmacology, and subjective effects, both psilocybin and 2C-B distort episodic familiarity, alluding to a common neurocognitive mechanism across psychedelics that may drive other phenomena.
Collapse
Affiliation(s)
- Manoj K Doss
- Department of Psychiatry and Behavioral Sciences, Center for Psychedelic Research & Therapy, The University of Texas at Austin Dell Medical School; Department of Psychiatry and Behavioral Sciences, Center for Psychedelic & Consciousness Research, Johns Hopkins University School of Medicine.
| | - Pablo Mallaroni
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University
| | - Natasha L Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University
| | - Johannes G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University
| |
Collapse
|
2
|
Doss MK, de Wit H, Gallo DA. The acute effects of psychoactive drugs on emotional episodic memory encoding, consolidation, and retrieval: A comprehensive review. Neurosci Biobehav Rev 2023; 150:105188. [PMID: 37085021 PMCID: PMC10247427 DOI: 10.1016/j.neubiorev.2023.105188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/13/2023] [Accepted: 04/17/2023] [Indexed: 04/23/2023]
Abstract
Psychoactive drugs modulate learning and emotional processes in ways that could impact their recreational and medical use. Recent work has revealed how drugs impact different stages of processing emotional episodic memories, specifically encoding (forming memories), consolidation (stabilizing memories), and retrieval (accessing memories). Drugs administered before encoding may preferentially impair (e.g., GABAA sedatives including alcohol and benzodiazepines, Δ9-tetrahydrocannabinol or THC, ketamine), enhance (e.g., dextroamphetamine and dextromethamphetamine), or both impair and enhance (i.e., ± 3,4-methylenedioxymethylamphetamine or MDMA) emotionally negative and positive compared to neutral memories. GABAA sedatives administered immediately post-encoding (during consolidation) can preferentially enhance emotional memories, though this selectivity may decline or even reverse (i.e., preferential enhancement of neutral memories) as the delay between encoding and retrieval increases. Finally, retrieving memories under the effects of THC, dextroamphetamine, MDMA, and perhaps GABAA sedatives distorts memory, with potentially greater selectively for emotional (especially positive) memories. We review these effects, propose neural mechanisms, discuss methodological considerations for future work, and speculate how drug effects on emotional episodic memory may contribute to drug use and abuse.
Collapse
Affiliation(s)
- Manoj K Doss
- Department of Psychiatry and Behavioral Sciences, Center for Psychedelic & Consciousness Research, USA.
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, USA
| | - David A Gallo
- Department of Psychology, University of Chicago, USA
| |
Collapse
|
3
|
Niloy N, Hediyal TA, Vichitra C, Sonali S, Chidambaram SB, Gorantla VR, Mahalakshmi AM. Effect of Cannabis on Memory Consolidation, Learning and Retrieval and Its Current Legal Status in India: A Review. Biomolecules 2023; 13:biom13010162. [PMID: 36671547 PMCID: PMC9855787 DOI: 10.3390/biom13010162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/31/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Cannabis is one of the oldest crops grown, traditionally held religious attachments in various cultures for its medicinal use much before its introduction to Western medicine. Multiple preclinical and clinical investigations have explored the beneficial effects of cannabis in various neurocognitive and neurodegenerative diseases affecting the cognitive domains. Tetrahydrocannabinol (THC), the major psychoactive component, is responsible for cognition-related deficits, while cannabidiol (CBD), a non-psychoactive phytocannabinoid, has been shown to elicit neuroprotective activity. In the present integrative review, the authors focus on the effects of cannabis on the different cognitive domains, including learning, consolidation, and retrieval. The present study is the first attempt in which significant focus has been imparted on all three aspects of cognition, thus linking to its usage. Furthermore, the investigators have also depicted the current legal position of cannabis in India and the requirement for reforms.
Collapse
Affiliation(s)
- Nandi Niloy
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
| | - Tousif Ahmed Hediyal
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
| | - Chandrasekaran Vichitra
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
| | - Sharma Sonali
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
| | - Saravana Babu Chidambaram
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
| | - Vasavi Rakesh Gorantla
- Department of Anatomical Science, St. George’s University, University Centre, St. Georges FZ818, Grenada
- Correspondence: (V.R.G.); (A.M.M.)
| | - Arehally M. Mahalakshmi
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education & Research, SS Nagar, Mysore 570015, Karnataka, India
- Correspondence: (V.R.G.); (A.M.M.)
| |
Collapse
|
4
|
Kloft L, Otgaar H, Blokland A, Toennes SW, Ramaekers JG. Remembering Molly: Immediate and delayed false memory formation after acute MDMA exposure. Eur Neuropsychopharmacol 2022; 57:59-68. [PMID: 35124400 DOI: 10.1016/j.euroneuro.2022.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/24/2021] [Accepted: 01/12/2022] [Indexed: 11/04/2022]
Abstract
The entactogen 3,4-Methylenedioxymethamphetamine (MDMA) is increasingly being recognized for its therapeutic potential but is also widespread in nightlife settings where it may co-occur with crime. Since previous research detected impaired verbal memory during acute MDMA intoxication, understanding the drug's ramifications in an applied legal context becomes crucial. We conducted a double-blind, placebo-controlled trial to examine acute and delayed effects of MDMA (75 mg) on false memory in 60 healthy volunteers with a history of MDMA use, using three well-established false memory methods: a basic, associative word list (Deese/Roediger-McDermott (DRM)) paradigm and two applied misinformation tasks using a virtual reality crime. Memory was tested immediately (encoding and retrieval under drug influence) and 1 week later (retrieval when sober). Small MDMA-induced impairments of true memory in the word list task were detected at both time points. MDMA increased false memory for related but non-critical lures during the immediate test, and decreased false memory for critical lures after a delay. Episodic memory assessed in the misinformation tasks was not consistently affected. Findings indicate a complex memory profile but no heightened vulnerability to external suggestion in response to MDMA intoxication. Recommendations for future applied legal psychological research include adding measures of recall on top of recognition, using study designs that separate the different memory phases, and potentially testing higher doses. Further research on false memories and suggestibility using imagination procedures can also be relevant for the clinical context.
Collapse
Affiliation(s)
- Lilian Kloft
- Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands.
| | - Henry Otgaar
- Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands; Faculty of Law, Catholic University of Leuven, Belgium
| | - Arjan Blokland
- Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
| | - Stefan W Toennes
- Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany
| | | |
Collapse
|
5
|
Mindthoff A, Evans JR, Compo NS, Polanco K, Hagsand AV. No evidence that low levels of intoxication at both encoding and retrieval impact scores on the Gudjonsson Suggestibility Scale. Psychopharmacology (Berl) 2021; 238:1633-1644. [PMID: 33646341 DOI: 10.1007/s00213-021-05797-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 02/09/2021] [Indexed: 11/25/2022]
Abstract
RATIONALE It is not uncommon for police to question alcohol-intoxicated witnesses and suspects; yet, the full extent to which intoxication impacts individuals' suggestibility in the investigative interviewing context remains unclear. OBJECTIVE The present study sought to measure the effect of alcohol-intoxication on interviewee suggestibility by implementing a standardized suggestibility test with participants whose intoxication-state was the same at both encoding and recall. METHODS We randomly assigned participants (N = 165) to an intoxicated (mean breath alcohol level [BrAC] at encoding = 0.06%, and BrAC at retrieval = 0.07%), active placebo (participants believed they consumed alcohol but only consumed an insignificant amount to enhance believability), or control (participants knowingly remained sober) group. An experimenter then implemented the Gudjonsson Suggestibility Scale (GSS), which produced free recall outcomes (number of correct details and memory confabulations) and suggestibility outcomes (yielding to leading questions and changing answers in response to negative feedback from the experimenter). RESULTS Intoxicated participants recalled fewer correct details than did placebo and control participants but did not make more confabulation errors. No effects of intoxication on suggestibility measures emerged. CONCLUSIONS Moderately intoxicated interviewees may not be more suggestible during investigative interviews than sober interviewees. However, before concrete evidence-based policy recommendations are made to law enforcement, further research is needed examining the effects of alcohol on suggestibility in conditions that are more reflective of the legal context.
Collapse
Affiliation(s)
- Amelia Mindthoff
- Department of Psychology, Florida International University, 11200 S.W. 8th Street, DM 256, Miami, FL, 33199, USA
- Department of Psychology, Iowa State University, 1347 Lagomarcino Hall, 901 Stange Rd., Ames, IA, 50011, USA
| | - Jacqueline R Evans
- Department of Psychology, Florida International University, 11200 S.W. 8th Street, DM 256, Miami, FL, 33199, USA.
| | - Nadja Schreiber Compo
- Department of Psychology, Florida International University, 11200 S.W. 8th Street, DM 256, Miami, FL, 33199, USA
| | - Karina Polanco
- Department of Psychology, Florida International University, 11200 S.W. 8th Street, DM 256, Miami, FL, 33199, USA
| | - Angelica V Hagsand
- Department of Psychology, University of Gothenburg, Haraldsgatan 1, 413 14, Gothenburg, Sweden
| |
Collapse
|
6
|
The why behind the high: determinants of neurocognition during acute cannabis exposure. Nat Rev Neurosci 2021; 22:439-454. [PMID: 34045693 DOI: 10.1038/s41583-021-00466-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2021] [Indexed: 11/08/2022]
Abstract
Acute cannabis intoxication may induce neurocognitive impairment and is a possible cause of human error, injury and psychological distress. One of the major concerns raised about increasing cannabis legalization and the therapeutic use of cannabis is that it will increase cannabis-related harm. However, the impairing effect of cannabis during intoxication varies among individuals and may not occur in all users. There is evidence that the neurocognitive response to acute cannabis exposure is driven by changes in the activity of the mesocorticolimbic and salience networks, can be exacerbated or mitigated by biological and pharmacological factors, varies with product formulations and frequency of use and can differ between recreational and therapeutic use. It is argued that these determinants of the cannabis-induced neurocognitive state should be taken into account when defining and evaluating levels of cannabis impairment in the legal arena, when prescribing cannabis in therapeutic settings and when informing society about the safe and responsible use of cannabis.
Collapse
|
7
|
Kloft L, Monds LA, Blokland A, Ramaekers JG, Otgaar H. Hazy memories in the courtroom: A review of alcohol and other drug effects on false memory and suggestibility. Neurosci Biobehav Rev 2021; 124:291-307. [PMID: 33587958 DOI: 10.1016/j.neubiorev.2021.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 01/26/2021] [Accepted: 02/04/2021] [Indexed: 12/25/2022]
Abstract
Alcohol and other psychoactive drugs are oftentimes implicated in legal cases. A pertinent question herein is whether such substances might adversely affect testimonies of victims, eyewitnesses, or suspects by propelling the formation of false memory and increasing susceptibility to suggestion. In the current review, we amassed all available evidence on the effects of intoxication on false memory formation and suggestibility, including the substances alcohol, benzodiazepines, cannabis, stimulants, hallucinogens, and antipsychotics. Our review indicated that alcohol and cannabis under certain conditions increased the susceptibility to false memories and/or suggestion with effect sizes ranging from medium to large. When intoxicated during an event, alcohol is most likely to increase this susceptibility at high intoxication levels or after a delay, whereas cannabis exerts detrimental effects during acute intoxication but not necessarily once sober. For other substances, ecologically valid research separating different memory phases is needed. Overall, differences between substances regarding false memory effects exist, suggesting that a nuanced approach is needed when dealing with intoxicated individuals in a legal context.
Collapse
Affiliation(s)
- Lilian Kloft
- Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands.
| | - Lauren A Monds
- Faculty of Medicine and Health, The University of Sydney, Australia
| | - Arjan Blokland
- Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
| | | | - Henry Otgaar
- Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands; Faculty of Law, Catholic University of Leuven, Belgium
| |
Collapse
|
8
|
Adam KCS, Doss MK, Pabon E, Vogel EK, de Wit H. Δ 9-Tetrahydrocannabinol (THC) impairs visual working memory performance: a randomized crossover trial. Neuropsychopharmacology 2020; 45:1807-1816. [PMID: 32386395 PMCID: PMC7608353 DOI: 10.1038/s41386-020-0690-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/01/2020] [Accepted: 04/23/2020] [Indexed: 01/02/2023]
Abstract
With the increasing prevalence of legal cannabis use and availability, there is an urgent need to identify cognitive impairments related to its use. It is widely believed that cannabis, or its main psychoactive component Δ9-tetrahydrocannabinol (THC), impairs working memory, i.e., the ability to temporarily hold information in mind. However, our review of the literature yielded surprisingly little empirical support for an effect of THC or cannabis on working memory. We thus conducted a study with three main goals: (1) quantify the effect of THC on visual working memory in a well-powered sample, (2) test the potential role of cognitive effects (mind wandering and metacognition) in disrupting working memory, and (3) demonstrate how insufficient sample size and task duration reduce the likelihood of detecting a drug effect. We conducted two double-blind, randomized crossover experiments in which healthy adults (N = 23, 23) performed a reliable and validated visual working memory task (the "Discrete Whole Report task", 90 trials) after administration of THC (7.5 and/or 15 mg oral) or placebo. We also assessed self-reported "mind wandering" (Exp 1) and metacognitive accuracy about ongoing task performance (Exp 2). THC impaired working memory performance (d = 0.65), increased mind wandering (Exp 1), and decreased metacognitive accuracy about task performance (Exp 2). Thus, our findings indicate that THC does impair visual working memory, and that this impairment may be related to both increased mind wandering and decreased monitoring of task performance. Finally, we used a down-sampling procedure to illustrate the effects of task length and sample size on power to detect the acute effect of THC on working memory.
Collapse
Affiliation(s)
- Kirsten C S Adam
- Department of Psychology, University of California San Diego, San Diego, CA, USA.
- Institute for Neural Computation, University of California San Diego, San Diego, CA, USA.
| | - Manoj K Doss
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD, USA
- Center for Psychedelic and Consciousness Research, Johns Hopkins University, Baltimore, MD, USA
| | - Elisa Pabon
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
- Grossman Institute for Neuroscience, Quantitative Biology, and Human Behavior, University of Chicago, Chicago, IL, USA
| | - Edward K Vogel
- Grossman Institute for Neuroscience, Quantitative Biology, and Human Behavior, University of Chicago, Chicago, IL, USA
- Department of Psychology, University of Chicago, Chicago, IL, USA
- Institute for Mind and Biology, University of Chicago, Chicago, IL, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
| |
Collapse
|
9
|
Effects of ∆ 9-tetrahydrocannabinol on aversive memories and anxiety: a review from human studies. BMC Psychiatry 2020; 20:420. [PMID: 32842985 PMCID: PMC7448997 DOI: 10.1186/s12888-020-02813-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 08/05/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Posttraumatic stress disorder (PTSD) may stem from the formation of aberrant and enduring aversive memories. Some PTSD patients have recreationally used Cannabis, probably aiming at relieving their symptomatology. However, it is still largely unknown whether and how Cannabis or its psychotomimetic compound Δ9-tetrahydrocannabinol (THC) attenuates the aversive/traumatic memory outcomes. Here, we seek to review and discuss the effects of THC on aversive memory extinction and anxiety in healthy humans and PTSD patients. METHODS Medline, PubMed, Cochrane Library, and Central Register for Controlled Trials databases were searched to identify peer-reviewed published studies and randomized controlled trials in humans published in English between 1974 and July 2020, including those using only THC and THC combined with cannabidiol (CBD). The effect size of the experimental intervention under investigation was calculated. RESULTS At low doses, THC can enhance the extinction rate and reduce anxiety responses. Both effects involve the activation of cannabinoid type-1 receptors in discrete components of the corticolimbic circuitry, which could couterbalance the low "endocannabinoid tonus" reported in PTSD patients. The advantage of associating CBD with THC to attenuate anxiety while minimizing the potential psychotic or anxiogenic effect produced by high doses of THC has been reported. The effects of THC either alone or combined with CBD on aversive memory reconsolidation, however, are still unknown. CONCLUSIONS Current evidence from healthy humans and PTSD patients supports the THC value to suppress anxiety and aversive memory expression without producing significant adverse effects if used in low doses or when associated with CBD. Future studies are guaranteed to address open questions related to their dose ratios, administration routes, pharmacokinetic interactions, sex-dependent differences, and prolonged efficacy.
Collapse
|
10
|
Withey SL, Bergman J, Huestis MA, George SR, Madras BK. THC and CBD blood and brain concentrations following daily administration to adolescent primates. Drug Alcohol Depend 2020; 213:108129. [PMID: 32593153 PMCID: PMC7371526 DOI: 10.1016/j.drugalcdep.2020.108129] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Cannabis availability with high concentrations of Δ-9-tetrahydrocannabinol (THC) and a range of THC to cannabidiol (CBD) ratios has increased in parallel with a rise in daily cannabis consumption by adolescents. Unanswered questions in adolescents include: 1) whether THC blood concentrations and THC metabolites remain stable or change with prolonged daily dosing, 2) whether CBD modulates THC pharmacokinetic properties and alters THC accumulation in brain, 3) whether blood THC levels reflect brain concentrations. METHODS In adolescent squirrel monkeys (Saimiri boliviensis), we determined whether a four-month regimen of daily THC (1 mg/kg) or CBD (3 mg/kg) + THC (1 mg/kg) administration (IM) affects THC, THC metabolites, and CBD concentrations in blood or brain. RESULTS Blood THC concentrations, THC metabolites and CBD remained stable during chronic treatment. 24 h after the final THC or CBD + THC injection, blood THC and CBD concentrations remained relatively high (THC: 6.0-11 ng/mL; CBD: 9.7-19 ng/mL). THC concentrations in cerebellum and occipital cortex were approximately twice those in blood 24 h after the last dose and did not significantly differ in subjects given THC or CBD + THC. CONCLUSIONS In adolescent monkeys, blood levels of THC, its metabolites or CBD remain stable after daily dosing for four months. Our model suggests that any pharmacological interactions between CBD and THC are unlikely to result from CBD modulation of THC pharmacokinetics. Finally, detection of relatively high brain THC concentrations 24 h after the final dose of THC suggests that the prolonged actions of THC may contribute to persistent cognitive and psychomotor disruption after THC- or cannabis-induced euphoria wane.
Collapse
Affiliation(s)
- SL Withey
- Laboratory of Addiction Neurobiology, McLean Hospital, 115 Mill St, Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA
| | - J Bergman
- Behavioral Biology Program, McLean Hospital, 115 Mill St, Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA
| | - MA Huestis
- Institute of Emerging Health Professions, Thomas Jefferson University, 130 S. 9th Street Philadelphia, PA 19107
| | - SR George
- Department of Pharmacology, University of Toronto, Toronto, ON, M5S 1A8, Canada; Department of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - BK Madras
- Laboratory of Addiction Neurobiology, McLean Hospital, 115 Mill St, Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA
| |
Collapse
|
11
|
Kloft L, Otgaar H, Blokland A, Monds LA, Toennes SW, Loftus EF, Ramaekers JG. Cannabis increases susceptibility to false memory. Proc Natl Acad Sci U S A 2020; 117:4585-4589. [PMID: 32041881 PMCID: PMC7060677 DOI: 10.1073/pnas.1920162117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
With the growing global acceptance of cannabis and its widespread use by eyewitnesses and suspects in legal cases, understanding the popular drug's ramifications for memory is a pressing need. In a double-blind, randomized, placebo-controlled trial, we examined the acute and delayed effects of Δ9-tetrahydrocannabinol (THC) intoxication on susceptibility to false memory in 64 healthy volunteers. Memory was tested immediately (encoding and retrieval under drug influence) and 1 wk later (retrieval sober). We used three different methods (associative word lists and two misinformation tasks using virtual reality). Across all methods, we found evidence for enhanced false-memory effects in intoxicated participants. Specifically, intoxicated participants showed higher false recognition in the associative word-list task both at immediate and delayed test than controls. This yes bias became increasingly strong with decreasing levels of association between studied and test items. In a misinformation task, intoxicated participants were more susceptible to false-memory creation using a virtual-reality eyewitness scenario and virtual-reality perpetrator scenario. False-memory effects were mostly restricted to the acute-intoxication phase. Cannabis seems to increase false-memory proneness, with decreasing strength of association between an event and a test item, as assessed by different false-memory paradigms. Our findings have implications for how and when the police should interview suspects and eyewitnesses.
Collapse
Affiliation(s)
- Lilian Kloft
- Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands;
| | - Henry Otgaar
- Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
- Faculty of Law, Catholic University of Leuven, 3000 Leuven, Belgium
| | - Arjan Blokland
- Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Lauren A Monds
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- The Langton Centre, South Eastern Sydney Local Health District, NSW Health, Taren Point, NSW 2229, Australia
| | - Stefan W Toennes
- Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of Frankfurt, 60323 Frankfurt, Germany
| | - Elizabeth F Loftus
- Department of Psychological Science, University of California, Irvine, CA 92697
| | - Johannes G Ramaekers
- Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands;
| |
Collapse
|
12
|
Doss MK, Weafer J, Gallo DA, de Wit H. Δ 9-Tetrahydrocannabinol During Encoding Impairs Perceptual Details yet Spares Context Effects on Episodic Memory. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2020; 5:110-118. [PMID: 31668830 PMCID: PMC6954333 DOI: 10.1016/j.bpsc.2019.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/25/2019] [Accepted: 08/20/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND With the growing acceptance of cannabis use, it is crucial to understand the drug's effects on episodic memory accuracy and distortion. We investigated the impact of the administration of Δ9-tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis, on a context-based memory illusion. METHODS In a double-blind, placebo-controlled, within-subjects design, healthy infrequent cannabis users (N = 24) memorized object pictures that were superimposed over scenes (e.g., gray cat on beach) after pretreatment with placebo or THC (15 mg oral). Two days later under sober conditions, memory for the object pictures was tested by asking participants to discriminate between previously seen objects or perceptually similar lures (e.g., different gray cat). Context reinstatement was manipulated by presenting objects on their original or different scenes (e.g., beach or forest). RESULTS THC impaired memory for perceptual details of objects compared with placebo, and the context illusion was obtained in each condition: context reinstatement increased high-confidence false recognition along with correct recognition of previously seen objects. Although THC did not interact with these context effects overall, post hoc analyses showed that THC magnified the context illusion when objects were semantically congruent with their encoding contexts but abolished the context illusion when objects were incongruent with their encoding contexts. CONCLUSIONS These results are consistent with the hypothesis that THC impairs the encoding of specific object information more than item-context associations. As a result, THC may spare the distorting effects of context reinstatement on memory. In fact, THC may increase these distorting effects under conditions when objects are semantically congruent with context.
Collapse
Affiliation(s)
- Manoj K Doss
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland; Department of Psychology, University of Chicago, Chicago, Illinois.
| | - Jessica Weafer
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, Illinois; Department of Psychology, University of Kentucky, Lexington, Kentucky
| | - David A Gallo
- Department of Psychology, University of Chicago, Chicago, Illinois
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, Illinois
| |
Collapse
|
13
|
Raymond DR, Paneto A, Yoder KK, O'Donnell BF, Brown JW, Hetrick WP, Newman SD. Does Chronic Cannabis Use Impact Risky Decision-Making: An Examination of fMRI Activation and Effective Connectivity? Front Psychiatry 2020; 11:599256. [PMID: 33329150 PMCID: PMC7728610 DOI: 10.3389/fpsyt.2020.599256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/03/2020] [Indexed: 11/16/2022] Open
Abstract
With the increase in use of cannabis and its shifting legal status in the United States, cannabis use has become an important research focus. While studies of other drug populations have shown marked increases in risky decision-making, the literature on cannabis users is not as clear. The current study examined the performance of 17 cannabis users and 14 non-users on the Balloon Analog Risk Task (BART) using behavioral, fMRI and effective connectivity methods. Significant attenuation was found in a functional pathway projecting from the dorsal anterior cingulate cortex (dACC) to the nucleus accumbens (NAc) in cannabis users compared to non-using controls as well as decreases in risk-taking behaviors. These findings suggest that cannabis users may process and evaluate risks and rewards differently than non-users.
Collapse
Affiliation(s)
- David R Raymond
- Department of Psychological and Brain Sciences, Indiana University Bloomington, Bloomington, IN, United States
| | - Adrian Paneto
- Department of Counseling Psychology, Indiana University Bloomington, Bloomington, IN, United States
| | - Karmen K Yoder
- Department of Radiology, Indiana University Medical School, Indianapolis, IN, United States
| | - Brian F O'Donnell
- Department of Psychological and Brain Sciences, Indiana University Bloomington, Bloomington, IN, United States.,Program in Neuroscience, Indiana University Bloomington, Bloomington, IN, United States
| | - Joshua W Brown
- Department of Psychological and Brain Sciences, Indiana University Bloomington, Bloomington, IN, United States.,Program in Neuroscience, Indiana University Bloomington, Bloomington, IN, United States
| | - William P Hetrick
- Department of Psychological and Brain Sciences, Indiana University Bloomington, Bloomington, IN, United States.,Program in Neuroscience, Indiana University Bloomington, Bloomington, IN, United States
| | - Sharlene D Newman
- Department of Psychological and Brain Sciences, Indiana University Bloomington, Bloomington, IN, United States.,Program in Neuroscience, Indiana University Bloomington, Bloomington, IN, United States.,Department of Psychology, Alabama Life Research Institute, University of Alabama Tuscaloosa, Tuscaloosa, AL, United States
| |
Collapse
|
14
|
Dopamine Enhances Item Novelty Detection via Hippocampal and Associative Recall via Left Lateral Prefrontal Cortex Mechanisms. J Neurosci 2019; 39:7920-7933. [PMID: 31405927 DOI: 10.1523/jneurosci.0495-19.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 07/04/2019] [Accepted: 07/16/2019] [Indexed: 11/21/2022] Open
Abstract
The involvement of fronto-striatal circuits in item and associative memory retrieval as well as in the stabilization of memories by retrieval practice suggests that both retrieval and re-encoding of stored memories might rely on dopaminergic mechanisms in humans. We tested these hypotheses in a placebo-controlled pharmacological fMRI study using 2 mg of the D2 antagonist haloperidol administered acutely before a cued associative recall task of previously encoded picture-word pairs in 53 healthy humans of both sexes. The cued associative recall was moreover repeated 3 d later outside the scanner without pharmacological intervention. Dopaminergic modulation significantly improved associative recall performance and recognition accuracy of verbal items. Moreover, we observed a significant dopamine effect on re-encoding in terms of increased specificity of associative memories from the first to the second cued associative recall. Better association memory under haloperidol was linked with higher activity in the left lateral prefrontal cortex and right parietal cortex, suggesting that dopamine facilitates associative retrieval through increased recruitment of frontoparietal monitoring processes. In contrast, improved recognition of verbal items under haloperidol was reflected by enhanced novelty detection in the hippocampus and increased activity in saliency networks. Together, these results show distinct but concomitant positive effects of dopamine on associative recall and item recognition and suggest that the specificity of associative recall through re-encoding mechanisms is likewise augmented by dopamine.SIGNIFICANCE STATEMENT Although the neurotransmitter dopamine has been linked with learning and memory for a long time, dopaminergic effects on item recognition in humans were demonstrated only recently. The involvement of fronto-striatal monitoring processes in association retrieval suggests that associative memory might be particularly affected by dopamine. Moreover, fronto-striatal dopaminergic signals have been hypothesized to determine the updating and re-encoding of previously retrieved memories. We here demonstrate clear facilitative effects of dopamine on associative recall and item recognition mediated by prefrontal and hippocampal mechanisms respectively. Additionally, effects on re-encoding were reflected by increased specificity of associative memories. These results augment our understanding of dopaminergic processes in episodic memory retrieval and offer new perspectives on memory impairments in dopamine-related disorders and their treatment.
Collapse
|
15
|
Ney LJ, Matthews A, Bruno R, Felmingham KL. Cannabinoid interventions for PTSD: Where to next? Prog Neuropsychopharmacol Biol Psychiatry 2019; 93:124-140. [PMID: 30946942 DOI: 10.1016/j.pnpbp.2019.03.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/20/2019] [Accepted: 03/29/2019] [Indexed: 01/18/2023]
Abstract
Cannabinoids are a promising method for pharmacological treatment of post-traumatic stress disorder (PTSD). Despite considerable research devoted to the effect of cannabinoid modulation on PTSD symptomology, there is not a currently agreed way by which the cannabinoid system should be targeted in humans. In this review, we present an overview of recent research identifying neurological pathways by which different cannabinoid-based treatments may exert their effects on PTSD symptomology. We evaluate the strengths and weaknesses of each of these different approaches, including recent challenges presented to favourable options such as fatty acid amide hydrolase (FAAH) inhibitors. This article makes the strengths and challenges of different potential cannabinoid treatments accessible to psychological researchers interested in cannabinoid therapeutics and aims to aid selection of appropriate tools for future clinical trials.
Collapse
Affiliation(s)
- Luke J Ney
- School of Psychology, University of Tasmania, Australia.
| | | | | | - Kim L Felmingham
- School of Psychological Sciences, University of Melbourne, Australia
| |
Collapse
|
16
|
Abizaid A, Merali Z, Anisman H. Cannabis: A potential efficacious intervention for PTSD or simply snake oil? J Psychiatry Neurosci 2019; 44:75-78. [PMID: 30810022 PMCID: PMC6397040 DOI: 10.1503/jpn.190021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Alfonso Abizaid
- From the Department of Neuroscience, Carleton University (Abizaid, Anisman); and the Royal’s Institute of Mental Health (Merali), Ottawa, Ont., Canada
| | - Zul Merali
- From the Department of Neuroscience, Carleton University (Abizaid, Anisman); and the Royal’s Institute of Mental Health (Merali), Ottawa, Ont., Canada
| | - Hymie Anisman
- From the Department of Neuroscience, Carleton University (Abizaid, Anisman); and the Royal’s Institute of Mental Health (Merali), Ottawa, Ont., Canada
| |
Collapse
|
17
|
Clos M, Bunzeck N, Sommer T. Dopamine is a double-edged sword: dopaminergic modulation enhances memory retrieval performance but impairs metacognition. Neuropsychopharmacology 2019; 44:555-563. [PMID: 30356095 PMCID: PMC6333779 DOI: 10.1038/s41386-018-0246-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 10/09/2018] [Accepted: 10/12/2018] [Indexed: 12/30/2022]
Abstract
While memory encoding and consolidation processes have been linked with dopaminergic signaling for a long time, the role of dopamine in episodic memory retrieval remained mostly unexplored. Based on previous observations of striatal activity during memory retrieval, we used pharmacological functional magnetic resonance imaging to investigate the effects of dopamine on retrieval performance and metacognitive memory confidence in healthy humans. Dopaminergic modulation by the D2 antagonist haloperidol administered acutely during the retrieval phase improved recognition accuracy of previously learned pictures significantly and was associated with increased activity in the substantia nigra/ventral tegmental area, locus coeruleus, hippocampus, and amygdala during retrieval. In contrast, confidence for new decisions was impaired by unsystematically increased activity of the striatum across confidence levels and restricted range of responsiveness in frontostriatal networks under haloperidol. These findings offer new insights into the mechanisms underlying memory retrieval and metacognition and provide a broader perspective on the presence of memory problems in dopamine-related diseases and the treatment of memory disorders.
Collapse
Affiliation(s)
- Mareike Clos
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Nico Bunzeck
- 0000 0001 2180 3484grid.13648.38Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany ,0000 0001 0057 2672grid.4562.5Institute of Psychology I, University of Lübeck, Lübeck, Germany
| | - Tobias Sommer
- 0000 0001 2180 3484grid.13648.38Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
18
|
Kloft L, Otgaar H, Blokland A, Garbaciak A, Monds LA, Ramaekers JG. False memory formation in cannabis users: a field study. Psychopharmacology (Berl) 2019; 236:3439-3450. [PMID: 31250074 PMCID: PMC6892757 DOI: 10.1007/s00213-019-05309-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/18/2019] [Indexed: 12/20/2022]
Abstract
RATIONALE Cannabis use is widespread and has previously been associated with memory impairments. However, the role of cannabis in relation to false memory production, i.e., memories of events that were not experienced, is less well-understood. OBJECTIVE The aim of the current field study was to examine the impact of cannabis use on false memory production. METHODS The Deese/Roediger-McDermott (DRM) paradigm was used to induce false memories. In this paradigm, participants study word lists that are associatively related to a non-presented word, termed the critical lure. In a later memory test, true recognition rates and false alarm rates toward critical lures and unrelated items are assessed. Memory performance was compared between three groups: regular cannabis consumers who were acutely intoxicated (n = 53), regular cannabis consumers who were sober (n = 50), and cannabis-naïve controls (n = 53). The participants were approached in Dutch coffee shops (cannabis outlets) and cafes and asked to participate in our study. After collecting general information on their cannabis use, they were subjected to the DRM procedure. RESULTS Although false memory rates for critical lures did not statistically differ between groups, both intoxicated and sober cannabis consumers falsely recognized more unrelated items than control participants. Also, individuals without a history of cannabis use demonstrated higher memory accuracy compared with the intoxicated group. CONCLUSION It is concluded that cannabis intoxication and history of cannabis use induce a liberal response criterion for newly presented words for which the level of association with previously learned words is low and uncertainty is high.
Collapse
Affiliation(s)
- Lilian Kloft
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - Henry Otgaar
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands ,Faculty of Law, Catholic University of Leuven, Leuven, Belgium
| | - Arjan Blokland
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Alicja Garbaciak
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Lauren A. Monds
- Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - Johannes G. Ramaekers
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| |
Collapse
|
19
|
Layher E, Santander T, Volz LJ, Miller MB. Failure to Affect Decision Criteria During Recognition Memory With Continuous Theta Burst Stimulation. Front Neurosci 2018; 12:705. [PMID: 30364307 PMCID: PMC6193108 DOI: 10.3389/fnins.2018.00705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
A decision criterion establishes the minimum amount of memory evidence required for recognition. When a liberal criterion is set, items are recognized based on weak evidence whereas a conservative criterion requires greater memory strength for recognition. The decision criterion is a fundamental aspect of recognition memory but little is known about the underlying neural mechanisms of maintaining a criterion. We used continuous theta burst stimulation (cTBS) with the goal of inhibiting prefrontal cortex excitability while participants performed recognition tests. We hypothesized that inhibiting the right inferior frontal gyrus (rIFG), right middle frontal gyrus (rMFG), and right dorsolateral prefrontal cortex (rDLPFC) would cause participants to establish less conservative decision criteria without affecting recognition memory performance. Participants initially performed recognition memory tests while maintaining conservative decision criteria during fMRI scanning. Peak activity in the successful retrieval effect contrast (Hits > Correct Rejections) provided subject-specific cTBS target sites. During three separate sessions, participants completed the same recognition memory paradigm while maintaining conservative and liberal decision criteria both before and after cTBS. Across two experiments we failed to significantly alter decision criteria placement by applying cTBS to the rIFG, rMFG, and rDLPFC despite efforts to precisely target individualized brain areas. However, we unexpectedly improved discriminability following cTBS to the rDLPFC specifically when participants maintained a liberal criterion. Although this finding may guide future studies investigating the neural mechanisms underlying discriminability in recognition memory, cTBS proved ineffective at altering decision criteria.
Collapse
Affiliation(s)
- Evan Layher
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Tyler Santander
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Lukas J. Volz
- Department of Neurology, University Hospital Cologne, Cologne, Germany
- SAGE Center for the Study of the Mind, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Michael B. Miller
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, United States
| |
Collapse
|
20
|
Doss MK, Weafer J, Ruiz NA, Gallo DA, De Wit H. Alcohol and pharmacologically similar sedatives impair encoding and facilitate consolidation of both recollection and familiarity in episodic memory. Cogn Neurosci 2018; 9:89-99. [PMID: 30044718 DOI: 10.1080/17588928.2018.1504764] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Alcohol and other pharmacologically similar sedatives (i.e., GABAA positive allosteric modulators or PAMs) impair the encoding of new episodic memories but retroactively facilitate the consolidation of recently encoded memories. These effects are consistent for recollection (i.e., the retrieval of details) but some mixed results have been reported for familiarity (i.e., a feeling of knowing a stimulus was presented). Here, with dual-process models, we reanalyzed prior work testing the effects of GABAA PAMs at encoding or consolidation. Contrary to previous conclusions, we show that GABAA PAMs at encoding consistently impair both recollection and familiarity when an independence correction is applied to familiarity-based responses. These findings were further confirmed and extended in a dual-process signal detection analysis of a recent study on the effects of alcohol during encoding or consolidation: Alcohol at encoding impaired both recollection and familiarity, whereas alcohol at consolidation enhanced both recollection and familiarity. These findings speak to the ability of alcohol and other GABAA PAMs to induce 'blackouts,' highlighting the importance of dual-process approaches when analyzing drug manipulations at different phases of episodic memory.
Collapse
Affiliation(s)
- Manoj K Doss
- a Department of Psychology , The University of Chicago , Chicago , IL , USA
| | - Jessica Weafer
- b Department of Psychiatry and Behavioral Neuroscience , The University of Chicago , Chicago , IL , USA
| | - Nicholas A Ruiz
- b Department of Psychiatry and Behavioral Neuroscience , The University of Chicago , Chicago , IL , USA
| | - David A Gallo
- a Department of Psychology , The University of Chicago , Chicago , IL , USA
| | - Harriet De Wit
- b Department of Psychiatry and Behavioral Neuroscience , The University of Chicago , Chicago , IL , USA
| |
Collapse
|