Dissociative | EPFL Graph Search

Dissociatives, colloquially dissos, are a subclass of hallucinogens which distort perception of sight and sound and produce feelings of detachment – dissociation – from the environment and/or self. Although many kinds of drugs are capable of such action, dissociatives are unique in that they do so in such a way that they produce hallucinogenic effects, which may include dissociation, a general decrease in sensory experience, hallucinations, dream-like states or anesthesia. Despite most dissociatives’ main mechanism of action being tied to NMDA receptor antagonism, some of these substances, which are nonselective in action and affect the dopamine and/or opioid systems, may be capable of inducing more direct and repeatable euphoria or symptoms which are more akin to the effects of typical “hard drugs” or common drugs of abuse. This is likely why dissociatives are considered to be addictive with a fair to moderate potential for abuse, unlike psychedelics. Despite some dissociatives, such as phencyclidine (PCP) possessing stimulating properties, most dissociatives seem to have a general depressant effect and can produce sedation, respiratory depression, nausea, disorientation, analgesia, anesthesia, ataxia, cognitive and memory impairment as well as amnesia. The effects of dissociatives can include sensory dissociation, hallucinations, mania, catalepsy, analgesia and amnesia. According to Pender (1972), "the state has been designated as dissociative anesthesia since the patient truly seems disassociated from his environment." Both Pender (1970) and Johnstone et al. (1959) reported that patients under anaesthesia due to either ketamine or phencyclidine were prone to purposeless movements and had hallucinations (or "dreams") during and after anaesthesia. Some patients found the hallucinations euphoric while others found them disturbing. At sub-anesthetic doses, dissociatives alter many of the same cognitive and perceptual processes affected by other hallucinogenic drugs such as mescaline, LSD, and psilocybin; hence they are often contrasted and also considered hallucinogenic.

Computational models of intrinsic motivation for curiosity and creativity

Wulfram Gerstner, Alireza Modirshanechi, Sophia Becker

We link Ivancovsky et al.'s novelty-seeking model (NSM) to computational models of intrinsically motivated behavior and learning. We argue that dissociating different forms of curiosity, creativity, and memory based on the involvement of distinct intrinsic ...

2024