Diffusion tensor imaging tractography of the fornix and belief confidence in first-episode psychosis Lisa Buchy a, b, c , David Luck a, b, c , Yvonne Czechowska a , Ashok Malla b, d , Ridha Joober b, d , Martin Lepage a, b, c, d, ⁎ a Brain Imaging Group, Douglas Mental Health University Institute, Canada b Prevention and Early Intervention Program for Psychoses, Douglas Mental Health University Institute, Canada c Department of Neurology & Neurosurgery, Montreal Neurological Institute, McGill University, Canada d Department of Psychiatry, McGill University, Canada abstract article info Article history: Received 20 October 2011 Received in revised form 7 February 2012 Accepted 13 February 2012 Available online 13 March 2012 Keywords: Belief confidence Cognitive insight Diffusion tensor imaging tractography First-episode psychosis Fornix Self-certainty Schizophrenia Previous studies have demonstrated that patients with psychosis are more confident in beliefs and judgments compared to healthy participants and psychiatric controls with major depression. A recent study conducted by our research group has provided evidence for hippocampal pathology in association with overconfidence in a first-episode psychosis sample. The fornix is the primary efferent neural pathway of the hippocampus and may also play a role in self-certainty pathophysiology. The current investigation applied diffusion tensor imaging tractography to a first-episode psychosis sample to explore whether integrity of the fornix is associated with self- certainty. High resolution structural magnetic resonance and diffusion tensor images were obtained in 44 people with a first-episode psychosis. Diffusion tensor imaging tractography was used to estimate fractional anisotrophy (FA), a measure of white matter integrity, in the fornix. Confidence in beliefs and judgments was measured with the self-certainty subscale of the Beck Cognitive Insight Scale (BCIS). The analysis showed that self-certainty sig- nificantly correlated to FA values in the right fornix but was nonsignificant for the left fornix. The findings indi- cate anatomical dysconnectivity of the right fornix in correlation with BCIS-rated self-certainty in our first- episode psychosis sample. When considered with our previously published self-certainty—hippocampus result in a first-episode psychosis sample, overlapping with that of this study, the results indicate a concurrence of vol- umetric reductions in hippocampus and fornix pathology in correlation with self-certainty. © 2012 Elsevier B.V. All rights reserved. 1. Introduction A plethora of studies has demonstrated biases in reasoning and cog- nitive distortions in people with schizophrenia (Garety et al., 2005). For example, it has repeatedly been shown that schizophrenia patients show an enhanced need for closure (Colbert et al., 2006), jump to con- clusions (Garety et al., 1991) and attribute failure to others (Fornells- Ambrojo and Garety, 2009). Recently, the Beck Cognitive Insight Scale (BCIS) has proven to be helpful in our understanding of reasoning processes and cognitive distortions in psychosis (Beck et al., 2004; Riggs et al., 2012). In the BCIS, participants rate how much they agree with statements tapping two dimensions of cognitive insight: self- reflectiveness and self-certainty. Self-reflectiveness captures the will- ingness to acknowledge fallibility, corrigibility and recognition of dys- functional reasoning, and self-certainty refers to overconfidence in beliefs and judgments. Relative to healthy people and patients with major depression, individuals with psychotic disorders endorse signifi- cantly lower self-reflectiveness and higher self-certainty (Beck et al., 2004; Martin et al., 2010), suggesting that these reasoning styles may play an important role in psychosis. There is now evidence to suggest a relationship between cognitive insight in psychosis and neurocognitive deficits of hippocampal and frontally mediated functions. Several investigators have found self- certainty to be negatively correlated with performance on verbal mem- ory, (Lepage et al., 2008; Orfei et al., 2010), a fronto-hippocampal task, and executive cognitive functions including cognitive set switching (Orfei et al., 2010) and strategy formation (Cooke et al., 2010), associat- ed with frontal-lobe functioning. In an earlier study we have also reported a positive association between self-reflectiveness and verbal memory performance (Buchy et al., 2010). In order to address the question whether cognitive insight and memory and/or executive func- tions share qualitatively similar neural networks, we examined inter- relationships between self-certainty, verbal memory and hippocampal morphology in a first-episode psychosis sample (Buchy et al., 2010). Our results showed that participants who endorsed higher self- certainty had smaller bilateral hippocampal volumes than individuals Schizophrenia Research 137 (2012) 80–84 ⁎ Corresponding author at: Douglas Mental Health University Institute, 6875 LaSalle Blvd., Verdun, Quebec, Canada H4H 1R3. Tel.: + 1 514 761 6131x4393; fax: + 1 514 888 4064. E-mail address: martin.lepage@mcgill.ca (M. Lepage). 0920-9964/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.schres.2012.02.015 Contents lists available at SciVerse ScienceDirect Schizophrenia Research journal homepage: www.elsevier.com/locate/schres