Sense of reality, metacognition, and culture in schizophrenic and drug-induced hallucinations

Hallucinations have sensory content and a sense that the content is real. Some models of schizophrenic hallucination attribute both to metacognitive dysfunction. This chapter argues the sense of reality is not a single thing and should be divided into distinct kinds. Monitoring-based models fail to explain important aspects of hallucinations. The main mechanisms of serotoninergic hallucinogens are not metacognitive, while anticholinergic hallucinogens tap into subpersonal metacognitive processes. Among Amazonian indigenous groups using ayahuasca, cultural expectations can either exploit or ignore the metacognitive properties of hallucinogenic experiences.

Study at a glance

Abstract

Hallucinations possess two main components: (i) a sensory content; (ii) a sense that the sensory content is real. Influential models of schizophrenic hallucination claim that both the sensory content and the sense of reality can be explained in terms of metacognitive dysfunction. This chapter assesses whether such a claim holds for schizophrenic and drug-induced hallucinations; it further attempts to determine the actual role of metacognition in hallucination and how this role is liable to vary across cultures. It is first argued that the notion of sense of reality is heterogeneous and should therefore be divided into distinct kinds. Next, some monitoring-based models of hallucination are presented, and it is shown that they fail to explain important aspects of hallucinations. It is subsequently suggested that the main mechanisms of serotoninergic hallucinogens are not metacognitive, whereas those of anticholinergic hallucinogens importantly tap into subpersonal metacognitive processes. Finally, after specific consideration of the use of ayahuasca across different Amazonian indigenous groups, it is proposed that the metacognitive properties of hallucinogenic experiences can be variously exploited or ignored depending on cultural expectations.