Esse est percipi: a neurophilosophical model of psychosis

Philosophers, psychiatrists and neuroscientists have all expressed interest in and formulated hypotheses on the nature of hallucinations, but no sufficient integration of these models exists to this date. The objective of this article is to present a neurophilosophical model of psychosis linking the neurobiology with the phenomenology of hallucinations and delusions. It is proposed that psychotic hallucinations could be regarded as 'intrusions' of subjective idealism, a condition where reality is mind dependent, into realism, a condition where reality is mind independent. Furthermore, delusions would be an attempt by the person to make sense of these intrusions. This approach is supported by phenomenological evidence of increased self-relatedness in hallucinations and delusions, and by current neurobiological evidence on the role of the reward system, default mode network and corollary discharge circuit in positive symptomatology. This model has clinical, research and therapeutic implications, and also demonstrates how scientific results can be informed and enhanced by philosophical theories and vice versa.