An interoceptive view into psychopathology: schizophrenia and interoceptive illusions

Abstract: Under new emerging views interoception is no longer seen as a merely sensory-driven, bottom-up process, but also as an active process in which the brain acts as a generator of inferences based on our expectations or beliefs, even when they are misleading, following a Bayesian account of hypothesis. Our recent studies observed that predictive processes indeed shape interoception, illusorily distorting heartbeat perception towards prior subjective beliefs, such that threat expectations suffice to induce a misperception of heartbeat frequency. These previous results prompt fascinating inquiries into how deceptive interoceptive experiences might intertwine with the understanding and management of our inner states, potentially contributing to dysfunctional conditions. The notion that psychopathology could stem from abnormal predictions isn't groundbreaking and hinges on the concept of atypical, evidence-resistant predictions despite evidence suggesting otherwise, explaining for example hallucinations or delusions in schizophrenia and related conditions. In light of this, the present study investigates whether this illusory misperception can be observed also among people affected by Schizophrenia. In fact, evidence exists that interoceptive processes seem compromised in this clinical population, which also shows decreased levels of interoceptive accuracy compared to healthy controls. Taken together, this evidence led us to hypothesize that given the patients’ decreased interoceptive abilities, they would end up with an abundance of prediction errors when generating inferences about the external world. In time, this caused patients to rely less on what they internally perceive and more on external stimuli. We will present preliminary results on a small sample of patients and healthy controls.