Sense of reality, metacognition and culture in schizophrenic and drug-induced hallucinations, Martin Fortier, 2018

Sense of reality, metacognition and culture in schizophrenic and drug-induced hallucinations :  An interdisciplinary approach

Martin Fortier

In J. Proust & M. Fortier (Eds.) : “Metacognitive Diversity : An Interdisciplinary Approach”, 2018.

Oxford/New York, Oxford University Press.



Hallucinations possess two main components : (i) a sensory content; and (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. After having briefly distinguished between different levels of metacognitive processing, I show that these monitoring-based models are metacognitive only to a limited extent and that they fail to explain important aspects of the content and sense of reality of hallucinations. I subsequently suggest that the main mechanisms of serotoninergic-hallucinogens are not metacognitive whereas those of anticholinergic-hallucinogens importantly tap into subpersonal metacognitive processes. Looking specifically at the use of ayahuasca across different Amazonian indigenous groups, I put forward the idea that the metacognitive properties of hallucinogenic experiences can be variously exploited or ignored depending on cultural expectations. Finally, I examine how anthropological and linguistic evidence of the ritualized use of hallucinogens supports the existence of multiple metacognitive norms in religion.

Keywords : Amazonia, Anticholinergics, Cognitive Science of Religion, Hallucination, Hallucinogens, Metacognition, Neuroanthropology, Predictive Coding, Psychedelics, Reality Monitoring, Shamanism, Schizophrenia, Sense of Reality


The heterogeneity of the sense of reality

Metacognition in a nutshell

Homogeneous theories of the sense of reality

The case against homogeneous theories of the sense of reality

From the senses of reality to the judgments of reality

Metacognitive models of hallucination and reality

The reality monitoring model

The self-monitoring model

The online reality monitoring model

A critical assessment of monitoring models of hallucination

The heterogeneity of metacognition: subpersonal, personal and supra-personal levels

Metacognition in monitoring models of hallucination

The limits of monitoring models of hallucination

Schizophrenic and psychedelic double bookkeeping vs. deliriant single bookkeeping

The role of metacognition in hallucinogenic experiences

Metacognition and serotoninergic hallucinogens

Metacognition and anticholinergic hallucinogens

The enculturation of metacognition : ayahuasca rituals in three Amazonian cultures

Ayahuasca ritual among the Cashinahua: the dampening of emotional arousal

Ayahuasca ritual among the Shipibo: the search for fluency

Ayahuasca ritual among the Jivaro: the search for specific visual contents

Hallucinations and religious metacognition: epistemic status of the supernatural in Amazonian shamanism

Opaque religious traditions: supernatural thinking and the norm of deference

Lifting the veil of opacity: supernatural thinking and the norm of accuracy

Supra-personal metacognition: the epistemic status of supernatural beings in Amazonian shamanism