Telling true from false: cannabis users show increased susceptibility to false memories
Jordi Riba, Marta Valle, Frederic Sampedro, Aina Rodríguez‐pujadas, Saül Martínez‐Horta, Jaime Kulisevsky, Antoni Rodríguez‐fornells
Molecular Psychiatry March 31, 2015 DOI: 10.1038/mp.2015.36 via OpenAlex
Summary
Chronic cannabis users, even after a period of abstinence, are more prone to false memories—mistaking events that never occurred for real ones. Using functional magnetic resonance imaging, the study found that abstinent cannabis users showed reduced brain activity in areas critical for memory processing, including the lateral and medial temporal lobe, as well as in parietal and frontal regions involved in attention and monitoring. Cannabis consumption was inversely correlated with medial temporal lobe activity, indicating a specific detriment to episodic memory. These results suggest long-lasting impairments in memory and cognitive control mechanisms that support reality monitoring.
Study at a glance
| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Population | Chronic cannabis users |
| Topics | Cannabis |
| Keywords | Neurocognitive Effects of cannabis Cognition False memory Episodic memory |
| Citations | 41 |
| Key finding | Abstinent cannabis users show increased susceptibility to false memories and reduced activation in brain regions involved in memory processing and cognitive control. |
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.