The entropic tongue: Disorganization of natural language under LSD.
Camila Sanz, Carla Pallavicini, Facundo Carrillo, Federico Zamberlán, Mariano Sigman, Natalia Mota, Mauro Copelli, Sidarta Ribeiro, David Nutt, Robin Carhart-Harris, Enzo Tagliazucchi
Conscious Cogn December 8, 2020 DOI: 10.1016/j.concog.2020.103070 via PubMed
Summary
AI-generated from the abstractLanguage produced under the influence of LSD shows increased entropy and reduced semantic coherence, consistent with a state of heightened neural entropy. Non-semantic analysis of speech organization revealed increased verbosity and a reduced lexicon, changes more similar to manic psychoses than to schizophrenia, as confirmed by direct comparison with reference samples. Features related to language organization allowed machine learning classifiers to identify speech under LSD with accuracy comparable to that obtained by examining semantic content. These results provide a quantitative characterization of disorganized natural speech as a landmark feature of the psychedelic state.
Study at a glance
| Characteristics | Observational study Peer reviewed |
|---|---|
| Intervention | Lysergic acid diethylamide (LSD) |
| Dose | 75 μg |
| Keywords | LSD Language Effects Speech disorganization Psychedelic neuroscience |
| Citations | 34 |
| Key finding | Language produced under LSD exhibits increased entropy and reduced semantic coherence, with speech organization changes more similar to manic psychoses than to schizophrenia. |
Abstract
Serotonergic psychedelics have been suggested to mirror certain aspects of psychosis, and, more generally, elicit a state of consciousness underpinned by increased entropy of on-going neural activity. We investigated the hypothesis that language produced under the effects of lysergic acid diethylamide (LSD) should exhibit increased entropy and reduced semantic coherence. Computational analysis of interviews conducted at two different time points after 75 μg of intravenous LSD verified this prediction. Non-semantic analysis of speech organization revealed increased verbosity and a reduced lexicon, changes that are more similar to those observed during manic psychoses than in schizophrenia, which was confirmed by direct comparison with reference samples. Importantly, features related to language organization allowed machine learning classifiers to identify speech under LSD with accuracy comparable to that obtained by examining semantic content. These results constitute a quantitative and objective characterization of disorganized natural speech as a landmark feature of the psychedelic state.