Psychedelics and Facial Expressions: the impact of an LSD microdose on the process of encoding emotional facial expressions
Alicia Rowland
University of Chicago August 1, 2022 DOI: 10.6082/9w10z-k1e64 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Double-blind Peer reviewed |
|---|---|
| Sample size | 20 |
| Population | Healthy men and women ages 18 to 35 |
| Intervention | LSD |
| Dose | 13 µg and 26 µg |
| Topics | LSD |
| Keywords | Electroencephalography Scalp Placebo Oddball paradigm Facial expression Cognition Electrophysiology Polygraph Audiology Stimulus psychology Event-related potential Cognitive psychology |
| Key findings | Microdoses of LSD (13 µg and 26 µg) reduce P300 and N170 amplitudes during a visual oddball task, similar to full doses. |
Abstract
While LSD may have had a harsh reputation in decades previous, current research has been investigating its potential as a therapeutic modality. It has been shown that full doses of LSD are capable of providing therapeutic effects however, the concept of "microdosing", or the repeated use of very low doses has become increasingly popular. Yet, the literature does not provide consistent results to explain LSD's effects. The objective of the current study was to examine the effects of LSD (13 µg and 26 µg) versus placebo by use of electroencephalogram, event-related potential (ERP), event-related spectral perturbation (ERSP), and intertrial coherence (ITC) responses in healthy adults. Twenty healthy men and women, ages 18 to 35, participated in three EEG sessions in which they received placebo or LSD (13 µg and 26 µg) under double-blind conditions. During peak drug effect, EEG recordings were obtained by use of electrodes placed on scalp to identify the P300 and N170 components evoked during the visual oddball task. During the oddball task, LSD reduced ERP amplitudes of the P300 and N170 components. ERSPs exhibited decreases in power for the alpha frequency band and some theta frequencies. ITCs displayed relatively uniform distribution between trials. The reductions in P300 and N170 amplitudes were similar to those seen in full doses of LSD. Therefore, it is feasible to predict that microdoses of LSD may result in subtle behavioral and cognitive changes without requiring the full psychedelic effects of the drug.
Comparable studies
Other randomized controlled trials on LSD, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Safety and Efficacy of Lysergic Acid Diethylamide-Assisted Psychotherapy for Anxiety Associated With Life-threatening Diseases Patients with anxiety associated with life-threatening diseases | 2014 | Randomized controlled trial | n = 12 |
| Dose-Response Study of N,N-Dimethyltryptamine in Humans Experienced hallucinogen users | 1994 | Double-blind, saline placebo-controlled, randomized study | n = 12 |
| Acute Effects of Lysergic Acid Diethylamide in Healthy Subjects Healthy subjects (8 women, 8 men) | 2014 | Double-blind, randomized, placebo-controlled, crossover study | n = 16 |
| Changes in global and thalamic brain connectivity in LSD-induced altered states of consciousness are attributable to the 5-HT2A receptor Healthy human participants | 2018 | Double-blind, randomized, counterbalanced, cross-over study | n = 24 |
| LSD-induced entropic brain activity predicts subsequent personality change. Healthy adults | 2016 | Balanced-order, placebo-controlled study | n = 19 |