title: Telling true from false: cannabis users show increased susceptibility to false memories.
abstract: Previous studies on the neurocognitive impact of cannabis use have found working and declarative memory deficits that tend to normalize with abstinence. An unexplored aspect of cognitive function in chronic cannabis users is the ability to distinguish between veridical and illusory memories, a crucial aspect of reality monitoring that relies on adequate memory function and cognitive control. Using functional magnetic resonance imaging, we show that abstinent cannabis users have an increased susceptibility to false memories, failing to identify lure stimuli as events that never occurred. In addition to impaired performance, cannabis users display reduced activation in areas associated with memory processing within the lateral and medial temporal lobe (MTL), and in parietal and frontal brain regions involved in attention and performance monitoring. Furthermore, cannabis consumption was inversely correlated with MTL activity, suggesting that the drug is especially detrimental to the episodic aspects of memory. These findings indicate that cannabis users have an increased susceptibility to memory distortions even when abstinent and drug-free, suggesting a long-lasting compromise of memory and cognitive control mechanisms involved in reality monitoring.
authors.affiliation: 1] Human Neuropsychopharmacology Group, Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Sant Antoni María Claret 167, Barcelona, Spain [2] Centre d'Investigació de Medicaments, Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain [3] Departament de Farmacologia i Terapèutica, Universitat Autònoma de Barcelona, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Riba
authors.affiliation: 1] Centre d'Investigació de Medicaments, Servei de Farmacologia Clínica, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain [2] Departament de Farmacologia i Terapèutica, Universitat Autònoma de Barcelona, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Barcelona, Spain [3] Pharmacokinetic and Pharmacodynamic Modelling and Simulation, IIB-Sant Pau, Sant Antoni María Claret, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Valle
authors.affiliation: School of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Sampedro
authors.affiliation: Human Neuropsychopharmacology Group, Sant Pau Institute of Biomedical Research (IIB-Sant Pau), Sant Antoni María Claret 167, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Rodríguez-Pujadas
authors.affiliation: Movement Disorders Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona. Barcelona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Martínez-Horta
authors.affiliation: 1] Movement Disorders Unit, Neurology Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona. Barcelona, Spain [2] Centro Investigación Biomedica en Red-Enfermedades Neurodegenerativas (CIBERNED), Spain.
authors.forename: J
authors.initials: J
authors.lastname: Kulisevsky
authors.affiliation: 1] Cognition and Brain Plasticity Group (Bellvitge Biomedical Research Institute) IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain [2] Department of Basic Psychology, University of Barcelona, Barcelona, Spain [3] Catalan Institution for Research and Advanced Studies, ICREA, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Rodríguez-Fornells
mesh_terms: D003072:Cognition Disorders / Q000209:etiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008306:Malingering / Q000473:pathology*; D002189:Marijuana Abuse / Q000150:complications / Q000473:pathology / Q000523:psychology; D008569:Memory Disorders / Q000209:etiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011569:Psychiatric Status Rating Scales; D013702:Temporal Lobe / Q000098:blood supply / Q000473:pathology*
chemical_list: D010100:Oxygen
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