Cognitive insight in first-episode schizophrenia: Further evidence for a role of the ventrolateral prefrontal cortex

Abstract

In people with psychoses, Self-Reflectiveness may rely on the right ventrolateral prefrontal cortex (VLPFC). We used functional magnetic resonance imaging (fMRI) and a novel virtual reality paradigm to evaluate the role of the VLPFC for Self-Reflectiveness in 25 first-episode of schizophrenia (FES) participants and 24 controls. Participants first viewed 20 characters each paired with a unique object/location, and later completed source memory judgements during fMRI scanning. Self-Reflectiveness, measured with the Beck Cognitive Insight Scale, was significantly and positively correlated to activation in bilateral VLPFC in FES, but not in controls, providing further evidence that the VLPFC supports Self-Reflectiveness in FES.

Introduction

The Beck Cognitive Insight scale (BCIS) (Beck et al., 2004) was designed to evaluate how people with psychotic disorders understand their own beliefs, reasoning and judgments. Two core processes are evaluated: Self-Reflectiveness, capturing one's willingness to acknowledge fallibility, corrigibility and recognition of maladaptive reasoning, and Self-Certainty, reflecting overconfidence (Beck et al., 2004). Early works with the scale established that people with psychoses showed lower Self-Reflectiveness and higher Self-Certainty than control subjects, and this has been interpreted as “poorer” cognitive insight (Beck et al., 2004, Riggs et al., 2012). Follow-up studies have identified a link between poorer cognitive insight and greater positive symptom severity (Warman et al., 2007, Engh et al., 2009), lower functional outcome (Favrod et al., 2008), poorer verbal memory (Lepage et al., 2008, Buchy et al., 2010, Engh et al., 2011) and executive dysfunctions (Lysaker et al., 2008, Cooke et al., 2010, Kao et al., 2013). These latter neurocognitive findings have been supported by structural neuroimaging data indicating lower hippocampal volumes and greater fractional anisotropy in the fornix in patients with a first-episode of psychosis (FEP) with low Self-Certainty (Buchy et al., 2010, Buchy et al., 2012).

Very recent research on the neural underpinnings of cognitive insight has identified a role of the right ventrolateral prefrontal cortex (rVLPFC) for Self-Reflectiveness. One study reported that higher Self-Reflectiveness correlated to increased rVLPFC gray matter volume in people with schizophrenia (Orfei et al., 2013). Pu et al. (2013) used near infrared spectroscopy to demonstrate in people with schizophrenia that Self-Reflectiveness modulates rVLPFC activation during verbal fluency task performance. Very recently, in a functional magnetic resonance imaging (fMRI) study we demonstrated in a non-clinical sample that Self-Reflectiveness was also modulated by rVLPFC activity while subjects performed an external source memory task (Buchy et al., 2014). In two studies we have used this latter paradigm to evaluate 1) neural activation to source memory relative to object memory in people with a first-episode schizophrenia (FES) vs. controls (Hawco et al., 2015), and 2) neural correlates of cognitive insight in non-clinical subjects. The purpose of the current work was to use this same fMRI and external source memory paradigm to perform a novel and never reported analysis of the role of the rVLPFC for cognitive insight in a FES sample. In line with the literature, we hypothesized that higher Self-Reflectiveness would correlate with greater neural activation in rVLPFC.