- The study found that low doses of LSD (15μg, administered four times) significantly decreased EEG power in the delta, theta, and alpha frequency bands, with effects persisting over a one-week follow-up period.
- Individual responses to LSD varied based on baseline cognitive states, showing that the strongest positive effects were experienced by those with lower baseline arousal levels, while those with high memory performance experienced inhibitory effects.
- The researchers suggest that low doses of LSD disrupt normal perceptual learning and memory processes while enhancing pre-attentive processing, indicating potential neuroadaptive changes in cognitive function over time.
Introduction
The increasing interest in using low doses of psychedelics, commonly known as microdosing, for potential cognitive and emotional benefits has prompted scientific scrutiny. While some anecdotal evidence supports these claims, controlled studies have frequently observed substantial variability in individual responses, which makes it difficult to ascertain definitive conclusions about the efficacy of these practices. Prior research has indicated that numerous factors can influence an individual’s reaction to microdosing. These include the dose, the drug’s concentration in the bloodstream, genetic differences influencing drug metabolism, and personality traits. Arousal states can be assessed using resting state electroencephalography (EEG), an established method for measuring general brain activity and its fluctuations related to attention and memory.Methodology
The study involved 53 healthy participants who were randomly assigned to receive either low doses of LSD (15 mcg) or a placebo over four sessions within two weeks. Participants underwent comprehensive medical screenings prior to the study and were compensated for their time. The study design required the recording of EEG data to observe brain activity during resting states and various cognitive tasks, including an auditory oddball task to assess pre-attentive processing, and a visual long-term potentiation (LTP) task to evaluate memory functions. Blood samples were also collected to measure LSD concentration levels.Results
The study recorded significant findings from EEG measurements, revealing lower power in delta, theta, and alpha waves among participants who took LSD compared to those who received a placebo. This reduction in EEG power was noted consistently during both dosing sessions and the follow-up period. The authors also identified that baseline EEG power was negatively correlated with the extent of LSD’s impact. In the context of the auditory oddball task, significant effects were observed in the latency and amplitude of specific event-related potentials associated with attention and memory, particularly in participants receiving LSD. Moreover, participants demonstrated habituation effects concerning their neural responses across repeated presentations of stimuli.Discussion
The findings from this research highlight how low doses of LSD can induce notable variations in cognitive functioning based on individual baseline states. Specifically, the stimulatory effects of LSD are more pronounced in individuals with lower arousal at baseline, whereas those with higher memory capabilities appeared to experience impairments in perceptual learning due to the drug’s influence. The researchers noted that LSD may exert its effects on cognitive performance by interacting with dopaminergic systems or influencing stress responses, although it remains unclear how these acute effects translate into the sustained changes observed in follow-up assessments. Interestingly, the study suggests that while low doses of LSD may impair certain cognitive functions, repeated use could contribute to long-term neuroplastic changes within the brain. This finding could have far-reaching implications not only for potential therapeutic uses in various psychological disorders—such as ADHD—but also for understanding the intricate relationships between psychedelics and cognitive processes. Limitations related to treatment blinding and the scope of motivational effects were acknowledged, emphasizing the need for further research to confirm these initial observations and explore the potential for LSD as a treatment modality in psychological contexts. Ultimately, the findings serve to inform ongoing discussions about the applications of psychedelics in enhancing cognitive abilities and therapeutic outcomes.See also our coverage of Low-Dose LSD Alters Early and Late Event-Related Potentials, and our explainers on James Fadiman. Read the full paper summary on Blossom.
