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Loetscher KB, Goldfarb EV. Integrating and fragmenting memories under stress and alcohol. Neurobiol Stress 2024; 30:100615. [PMID: 38375503 PMCID: PMC10874731 DOI: 10.1016/j.ynstr.2024.100615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/03/2024] [Accepted: 02/06/2024] [Indexed: 02/21/2024] Open
Abstract
Stress can powerfully influence the way we form memories, particularly the extent to which they are integrated or situated within an underlying spatiotemporal and broader knowledge architecture. These different representations in turn have significant consequences for the way we use these memories to guide later behavior. Puzzlingly, although stress has historically been argued to promote fragmentation, leading to disjoint memory representations, more recent work suggests that stress can also facilitate memory binding and integration. Understanding the circumstances under which stress fosters integration will be key to resolving this discrepancy and unpacking the mechanisms by which stress can shape later behavior. Here, we examine memory integration at multiple levels: linking together the content of an individual experience, threading associations between related but distinct events, and binding an experience into a pre-existing schema or sense of causal structure. We discuss neural and cognitive mechanisms underlying each form of integration as well as findings regarding how stress, aversive learning, and negative affect can modulate each. In this analysis, we uncover that stress can indeed promote each level of integration. We also show how memory integration may apply to understanding effects of alcohol, highlighting extant clinical and preclinical findings and opportunities for further investigation. Finally, we consider the implications of integration and fragmentation for later memory-guided behavior, and the importance of understanding which type of memory representation is potentiated in order to design appropriate interventions.
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Affiliation(s)
| | - Elizabeth V. Goldfarb
- Department of Psychiatry, Yale University, USA
- Department of Psychology, Yale University, USA
- Wu Tsai Institute, Yale University, USA
- National Center for PTSD, West Haven VA, USA
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Doss MK, de Wit H, Gallo DA. The Acute Effects of Psychoactive Drugs on Emotional Episodic Memory Encoding, Consolidation, and Retrieval. Neurosci Biobehav Rev 2023; 150:105188. [PMID: 37085021 DOI: 10.1016/j.neubiorev.2023.105188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [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.
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Affiliation(s)
- Manoj K Doss
- Department of Psychiatry and Behavioral Sciences, Center for Psychedelic & Consciousness Research.
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago
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Butterworth B, Hand CJ, Lorimer K, Gawrylowicz J. The impact of post-encoding alcohol consumption on episodic memory recall and remember-know responses in heavy drinkers. Front Psychol 2023; 14:1007477. [PMID: 36960000 PMCID: PMC10027770 DOI: 10.3389/fpsyg.2023.1007477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 02/14/2023] [Indexed: 03/09/2023] Open
Abstract
Introduction People often consume alcohol following trauma, particularly in response to distressing memories. To date, little is known about how post-encoding alcohol consumption influences episodic memory recall for negative events. Understanding these effects may help to improve support for trauma victims - for example, witnesses and victims of crimes. Methods We tested 60 participants who self-described as heavy drinkers. After watching an analog trauma film, half were allocated to consuming a moderate dose of alcohol (Alcohol-Exposed group), while half received a placebo drink (Placebo-Control group). Immediately and after a one-week delay, participants recalled the event via free and cued recall tasks. Participants also gave remember-know responses and confidence ratings, elucidating alcohol's effect on experiential memory. Results Free recall performance was similar for the Alcohol-Exposed group and the Placebo-Control group during Sessions 1 and 2. The Alcohol-Exposed group benefitted more from the delayed repeated retrieval attempt. For the cued recall task, the Alcohol-Exposed group provided more "Do not Know" responses compared to the Placebo-Control group in both sessions. For the Alcohol-Exposed group only "Correct Know" responses increased from Session 1 to 2. Although memory performance improved across sessions, confidence levels decreased from Session 1 to 2 in the Alcohol-Exposed group. Discussion Post-encoding alcohol consumption appears to impact immediate episodic memory retrieval; however, this effect is only temporary in nature. No evidence was found that alcohol primarily reduces remembering responses. Much like previous findings focusing on pre-encoding alcohol consumption (Hagsand et al., 2017), current findings suggest that providing individuals who drank alcohol after witnessing an incident with a delayed repeated retrieval attempt can lead to more complete and accurate testimonies.
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Affiliation(s)
- Benjamin Butterworth
- Glasgow Caledonian University, Glasgow, United Kingdom
- *Correspondence: Benjamin Butterworth, ; Julie Gawrylowicz,
| | | | - Karen Lorimer
- Glasgow Caledonian University, Glasgow, United Kingdom
| | - Julie Gawrylowicz
- Abertay University, Dundee, United Kingdom
- *Correspondence: Benjamin Butterworth, ; Julie Gawrylowicz,
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Huang S, White DR, Marinkovic K. Alterations of theta power and synchrony during encoding in young adult binge drinkers: Subsequent memory effects associated with retrieval after 48 h and 6 months. Front Psychol 2022; 13:1061016. [PMID: 36591031 PMCID: PMC9798430 DOI: 10.3389/fpsyg.2022.1061016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 11/22/2022] [Indexed: 12/23/2022] Open
Abstract
Introduction Young emerging adults commonly engage in binge drinking which is associated with a range of neurocognitive deficits, including memory impairments. However, evidence on neural oscillations mediating episodic memory in this population is lacking. To address this gap, we recorded theta oscillatory activity in young binge (BDs) and light drinkers (LDs) during memory encoding and analyzed it prospectively as a function of subsequent retrieval. Theta underlies successful encoding of novel items in memory through corticolimbic integration. Subsequent memory effects (SMEs) are reflected in stronger theta activity during encoding of the items that are later remembered compared to those that are later forgotten. Methods In the present study, 23 BDs (age: 23.3 ± 3.3) and 24 LDs (age: 23.4 ± 3.3) rated emotionally evocative images with negative, positive, and neutral themes during implicit encoding. They performed a recognition memory task on two follow-up occasions after a short (48 h), and long retention delay (6 months). Electroencephalography (EEG) signal was recorded during the encoding session and analyzed in time-frequency domain with Morlet wavelets in theta band (4-7 Hz). To evaluate SMEs, the event-related theta oscillations acquired during encoding were analyzed based on recognition outcomes after the two retention intervals. Results The BD and LD groups did not differ on recognition memory. However, BDs showed attenuated event-related theta power during encoding of images that were successfully retained after 6 months compared to LDs. In addition, theta synchronous activity between frontal and left posterior regions during encoding successfully predicted recognition of the images after both retention delays in LDs but not in BDs. These SMEs on theta power and synchrony correlated negatively with high-intensity drinking in the previous 6 months. No differences between men and women were observed for any analysis. Discussion It has been well established that long-range neural synchrony between cortical and limbic nodes underlies successful memory encoding and retention which, in turn, depends on neural excitation/inhibition (E/I) balance. Given that binge drinking is associated with E/I dysregulation, the observed SME deficiencies are consistent with other evidence of neural hyperexcitability in BDs, and may be indicative of increased risk of developing alcohol use disorders.
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Affiliation(s)
- Siyuan Huang
- Spatio-Temporal Brain Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, United States
| | - David R. White
- Spatio-Temporal Brain Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, United States
| | - Ksenija Marinkovic
- Spatio-Temporal Brain Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA, United States,Department of Radiology, University of California, San Diego, San Diego CA, United States,*Correspondence: Ksenija Marinkovic,
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Hamel R, Demers O, Lepage JF, Bernier PM. The Effects of Post-Learning Alcohol Ingestion on Human Motor Memory Consolidation. Eur J Neurosci 2022; 56:4600-4618. [PMID: 35841189 PMCID: PMC9544401 DOI: 10.1111/ejn.15772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 07/07/2022] [Indexed: 11/27/2022]
Abstract
The neurochemical mechanisms underlying motor memory consolidation remain largely unknown. Based on converging work showing that ethyl alcohol retrogradely enhances declarative memory consolidation, this work tested the hypothesis that post‐learning alcohol ingestion would enhance motor memory consolidation. In a within‐subject and fully counterbalanced design, participants (n = 24; 12M; 12F) adapted to a gradually introduced visual deviation and ingested, immediately after adaptation, a placebo (PBO), a medium (MED) or high (HIGH) dose of alcohol. The alcohol doses were bodyweight‐ and gender‐controlled to yield peak breath alcohol concentrations of 0.00% in the PBO, ~0.05% in the MED and ~0.095% in the HIGH condition. Retention was evaluated 24 h later through reach aftereffects when participants were sober. The results revealed that retention levels were neither significantly nor meaningfully different in both the MED and HIGH conditions as compared to PBO (all absolute Cohen's dz values < ~0.2; small to negligible effects), indicating that post‐learning alcohol ingestion did not alter motor memory consolidation. Given alcohol's known pharmacological GABAergic agonist and NMDA antagonist properties, one possibility is that these neurochemical mechanisms do not decisively contribute to motor memory consolidation. As converging work demonstrated alcohol's retrograde enhancement of declarative memory, the present results suggest that distinct neurochemical mechanisms underlie declarative and motor memory consolidation. Elucidating the neurochemical mechanisms underlying the consolidation of different memory systems may yield insights into the effects of over‐the‐counter drugs on everyday learning and memory but also inform the development of pharmacological interventions seeking to alter human memory consolidation.
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Affiliation(s)
- R Hamel
- Département de kinanthropologie, Faculté des sciences de l'activité physique, Université de Sherbrooke, Québec, Canada.,Département de pédiatrie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Québec, Canada.,Centre de recherche du Centre hospitalier de l'Université de Sherbrooke, Québec, Canada
| | - O Demers
- Département de kinanthropologie, Faculté des sciences de l'activité physique, Université de Sherbrooke, Québec, Canada.,Département de pédiatrie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Québec, Canada.,Centre de recherche du Centre hospitalier de l'Université de Sherbrooke, Québec, Canada
| | - J F Lepage
- Département de pédiatrie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Québec, Canada.,Centre de recherche du Centre hospitalier de l'Université de Sherbrooke, Québec, Canada
| | - P M Bernier
- Département de kinanthropologie, Faculté des sciences de l'activité physique, Université de Sherbrooke, Québec, Canada.,Centre de recherche du Centre hospitalier de l'Université de Sherbrooke, Québec, Canada
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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.
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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
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Freeman AM, Petrilli K, Lees R, Hindocha C, Mokrysz C, Curran HV, Saunders R, Freeman TP. How does cannabidiol (CBD) influence the acute effects of delta-9-tetrahydrocannabinol (THC) in humans? A systematic review. Neurosci Biobehav Rev 2019; 107:696-712. [PMID: 31580839 DOI: 10.1016/j.neubiorev.2019.09.036] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/23/2019] [Accepted: 09/23/2019] [Indexed: 01/08/2023]
Abstract
The recent liberalisation of cannabis regulation has increased public and scientific debate about its potential benefits and risks. A key focus has been the extent to which cannabidiol (CBD) might influence the acute effects of delta-9-tetrahydrocannabinol (THC), but this has never been reviewed systematically. In this systematic review of how CBD influences the acute effects of THC we identified 16 studies involving 466 participants. Ten studies were judged at low risk of bias. The findings were mixed, although CBD was found to reduce the effects of THC in several studies. Some studies found that CBD reduced intense experiences of anxiety or psychosis-like effects of THC and blunted some of the impairments on emotion and reward processing. However, CBD did not consistently influence the effects of THC across all studies and outcomes. There was considerable heterogeneity in dose, route of administration and THC:CBD ratio across studies and no clear dose-response profile emerged. Although findings were mixed, this review suggests that CBD may interact with some acute effects of THC.
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Affiliation(s)
- Abigail M Freeman
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Katherine Petrilli
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, WC1E 6BT, UK
| | - Rachel Lees
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, WC1E 6BT, UK; Addiction and Mental Health Group (AIM), University of Bath, Bath, BA2 7AY, UK
| | - Chandni Hindocha
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, WC1E 6BT, UK; Translational Psychiatry Research Group, Research Department of Mental Health Neuroscience, Division of Psychiatry, University College London, Gower Street, London, WC1E 6BT, UK
| | - Claire Mokrysz
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, WC1E 6BT, UK
| | - H Valerie Curran
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, WC1E 6BT, UK
| | - Rob Saunders
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, WC1E 6BT, UK
| | - Tom P Freeman
- Clinical Psychopharmacology Unit, University College London, Gower Street, London, WC1E 6BT, UK; Addiction and Mental Health Group (AIM), University of Bath, Bath, BA2 7AY, UK; National Addiction Centre, King's College London, London, SE5 8BB, UK
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