Pre-reflective and reflective abnormalities in cortical midline structures in schizophrenia

BACKGROUND & HYPOTHESIS: Self-disorders (SDs), central features of schizophrenia spectrum disorders, primarily affect the pre-reflective sense of self, the fundamental experience of existing as a conscious subject. This disruption also impacts reflective self-consciousness. This study aims to further explore the neural correlates of self-disorders in individuals with schizophrenia spectrum disorders by using a cognitive task designed to target approximate pre-reflective and reflective self-experience during fMRI.

STUDY DESIGN: 27 individuals with schizophrenia spectrum disorders (patients, PT) and 32 healthy controls (HC) completed the cognitive task during 7 T fMRI scanning. The task involved a trait-judgment paradigm, where participants read three-word sentences (pronoun, verb, trait adjective) referencing themselves (self) or a well-known other (other), then provided a yes/no response upon reflection. SDs were examined with the Examination of Anomalous Self-Experience (EASE).

STUDY RESULTS: For the pre-reflective component, the activity in the rostral posterior cingulate cortex was negatively correlated with the severity of SDs. For the reflective component, HC exhibited bilateral activations in the frontopolar cortex, the anterior part of the anterior cingulate cortex, and the pre-supplementary motor area, while PT showed activations in the left caudate nucleus, the anterior part of the anterior cingulate cortex, the right frontopolar cortex, and the left language area.

CONCLUSIONS: At the pre-reflective level, abnormalities in the rostral posterior cingulate cortex are associated with SDs. For reflective self-experience, individuals with self-disorders appear to engage more in analytical thinking and deeper brain networks than HC, who rely more on interoceptive processes based on the frontopolar cortex.