Processing of emotional and self-related stimuli in regular users of classic psychedelics: an EEG study

Abstract

Classic psychedelics – such as psilocybin, LSD (lysergic acid diethylamide), or DMT (N,N-Dimethyltryptamine) – are psychoactive substances able to cause altered states of consciousness. Such states are characterized by profound alterations of sensory perception, perception of reality, mood, thoughts, and the sense of self. Importantly, a growing body of evidence suggests that using classic psychedelics might lead to various long-lasting psychological benefits, including an increase in well-being and in quality of life, and reduced symptoms of depression and anxiety. These findings are in stark contrast to the fact that, with rare exceptions, psychedelics remain illegal worldwide. One of the most striking subjective effects induced by classic psychedelics is the phenomenon of “ego-dissolution”, which is characterized by an experience of unity and transcendence, disintegration of the coherent self, and loss of a feeling of self-control over one’s autonomy. These subjective reports are in line with an observation that activity of the default mode network (DMN), which is thought to provide a neuronal basis for the “self” construct, is reduced during a psychedelic state. However, it is not known whether using psychedelics and experiencing the “ego-dissolution” regularly is associated with a long-lasting alteration of self-awareness and the concept of “self”. Another important effect is attenuated reactivity to negative emotions during a psychedelic experience, which is associated with a reduced activation of amygdala. While this might translate into the observed increase in well-being and the antidepressant effect, few studies investigated whether using psychedelics regularly is related to long-lasting changes in processing of emotions. The present project will test the hypothesis that regular users of classic psychedelics exhibit reduced reactivity to stimuli that are emotionally negative and to stimuli that represent themselves. We recruited a group of psychedelics users (with >15 experiences with psychedelics) and a matched group of non-users will be recruited. We will conduct neuroimaging experiments, in which participants will be presented with affective stimuli (faces with emotional expression and emotional scenes), self-related stimuli (names, including participants' own name), and they will complete resting state and rumination tasks while their brain activity will be recorded with electroencephalography (EEG). To test our hypotheses, event-related potentials (ERPs), with the focus on the P3 component, and source-localized activity of the Default Mode Network (DMN). The proposed project will thus allow a complex and detailed characterization of regular, recreational users of classic psychedelics. While the described study is correlational in nature, it will contribute to a better understanding of how using psychedelics is related to the concept of “self” and to processing of emotional information. The project will also allow a more general assessment of the risks and benefits of using psychedelics recreationally, beyond the specific mechanisms of interest. Therefore, within the scientific context the project will broaden our knowledge of the mechanisms behind psychedelics-induced effects, while in the social context it might contribute to developing a knowledge-based drug policy.

Topics & conditions

Detected automatically by Psychedelic Commons from the title and abstract, not labels from the source. They may be incomplete.

Keywords