Is it me? Verbal self-monitoring neural network and clinical insight in schizophrenia

Abstract

Self-monitoring, defined as the ability to distinguish between self-generated stimuli from other-generated ones, is known to be impaired in schizophrenia. This impairment has been theorised as the basis for many of the core psychotic symptoms, in particular, poor clinical insight. This study aimed to investigate verbal self-monitoring related neural substrates of preserved and poor clinical insight in schizophrenia. It involved 40 stable schizophrenia outpatients, 20 with preserved and 20 with poor insight, and 20 healthy participants. All participants underwent functional magnetic resonance imaging with brain coverage covering key areas in the self-monitoring network during a verbal self-monitoring task. Healthy participants showed higher performance accuracy and greater thalamic activity than both preserved and poor insight patient groups. Preserved insight patients showed higher activity in the putamen extending into the caudate, insula and inferior frontal gyrus, compared to poor insight patients, and in the anterior cingulate and medial frontal gyrus, compared to healthy participants. Poor insight patients did not show greater activity in any brain area compared to preserved insight patients or healthy participants. Future studies may pursue therapeutic avenues, such as meta-cognitive therapies to promote self-monitoring or targeted stimulation of relevant brain areas, as means of enhancing insight in schizophrenia.

Keywords: Anterior cingulate; Birchwood insight scale; Medial frontal gyrus; Psychosis; Putamen; Self-awareness; fMRI.

Fig. 1

Axial sections of a standard MNI brain with areas of greater activity in the preserved insight group, compared to the healthy participant and poor insight groups superimposed (height threshold p<0.05, cluster-corrected p<0.05). The MNI Z co-ordinate is given below each image. Right of image=left hemisphere.