Neuroscience and biobehavioral reviews
July 1, 2023
Manoj K Doss, Harriet de Wit, David A Gallo
30 citations
Psychoactive drugs affect emotional episodic memory at three stages: encoding, consolidation, and retrieval. Drugs given before encoding can impair (e.g., alcohol, benzodiazepines, THC, ketamine), enhance (e.g., dextroamphetamine), or both impair and enhance (e.g., MDMA) emotional memories compared to neutral ones. Sedatives given after encoding can preferentially boost emotional memories during consolidation, but this selectivity may weaken or reverse over time. Retrieving memories under THC, dextroamphetamine, MDMA, or sedatives can distort memory, especially for positive emotional content. The review proposes neural mechanisms and discusses how these effects might influence drug use and abuse.
Psychological review
March 1, 2024
Manoj K Doss, Jason Samaha, Frederick S Barrett et al.
24 citations
Psychoactive drugs produce unique subjective states, but their effects on episodic memory often overlap. This reanalysis of 10 data sets (28 drug conditions) used signal detection models to separate three memory processes: recollection (retrieving specific details), familiarity (recognizing without details), and metamemory (introspecting about memory accuracy). Sedatives impaired both recollection and familiarity during encoding but enhanced recollection during consolidation. Dissociatives and cannabinoids impaired recollection during encoding, and cannabinoids increased false recollections during retrieval. Psychedelics impaired recollection during encoding but tended to enhance familiarity. Stimulants enhanced metamemory during encoding and retrieval but impaired metamemory during consolidation. These distinct patterns help explain drug-specific phenomena like sedative-induced blackouts and psychedelic presque vu, and suggest that memory quantity and stability influence metamemory.
Biological psychiatry. Cognitive neuroscience and neuroimaging
January 1, 2020
Manoj K Doss, Jessica Weafer, David A Gallo et al.
A double-blind, placebo-controlled experiment with 24 healthy infrequent cannabis users tested how THC (15 mg oral) affects context-based memory illusions. Participants memorized object pictures on scenes (e.g., a cat on a beach) after THC or placebo. Two days later sober, they discriminated seen objects from similar lures, with context reinstated or changed. THC impaired memory for perceptual details compared to placebo. Context reinstatement increased both correct recognition and false recognition in both conditions. THC did not interact with context effects overall, but post hoc analyses showed THC magnified the context illusion when objects were semantically congruent with their encoding contexts and abolished it when incongruent. Results suggest THC impairs encoding of specific object information more than item-context associations, potentially sparing or increasing distorting effects of context.