Neural Correlates of Aberrant Salience and Source Monitoring in Schizophrenia and At-Risk Mental States-A Systematic Review of fMRI Studies.

Joachim Kowalski,Łukasz Gawęda,Małgorzata Dąbkowska,Adrianna Aleksandrowicz

doi:10.3390/jcm10184126

Joachim Kowalski, Łukasz Gawęda + Show 2 more

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https://doi.org/10.3390/jcm10184126

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Abstract

Cognitive biases are an important factor contributing to the development and symptom severity of psychosis. Despite the fact that various cognitive biases are contributing to psychosis, they are rarely investigated together. In the current systematic review, we aimed at investigating specific and shared functional neural correlates of two important cognitive biases: aberrant salience and source monitoring. We conducted a systematic search of fMRI studies of said cognitive biases. Eight studies on aberrant salience and eleven studies on source monitoring were included in the review. We critically discussed behavioural and neuroimaging findings concerning cognitive biases. Various brain regions are associated with aberrant salience and source monitoring in individuals with schizophrenia and the risk of psychosis. The ventral striatum and insula contribute to aberrant salience. The medial prefrontal cortex, superior and middle temporal gyrus contribute to source monitoring. The anterior cingulate cortex and hippocampus contribute to both cognitive biases, constituting a neural overlap. Our review indicates that aberrant salience and source monitoring may share neural mechanisms, suggesting their joint role in producing disrupted external attributions of perceptual and cognitive experiences, thus elucidating their role in positive symptoms of psychosis. Account bridging mechanisms of these two biases is discussed. Further studies are warranted.

Highlights

Cognitive biases are identified as an important factor in the development and sustainment of symptoms of schizophrenia spectrum disorders (SSD) and positive symptoms in particular [1]
We summarised the results of studies on functional and structural neuroimaging results concerning aberrant salience and source monitoring biases, i.e. two cognitive biases that have a prominent role in theoretical accounts [14,21] and empirical studies of psychotic symptoms
The longitudinal study by Schmidt and colleagues [34] showed a significantly higher implicit aberrant salience (IAbS) in UHR participants across both measurements with a large effect size. This effect was only significant in the second measurement, where the difference between groups was very large in effect size and driven by a drop of IAbS score in the HC group compared to the first measurement

Summary

Introduction

Cognitive biases are identified as an important factor in the development and sustainment of symptoms of schizophrenia spectrum disorders (SSD) and positive symptoms in particular [1]. In line with cognitive approaches to psychosis [14,15] as well as with the observations that different factors may have additive effect on the risk of psychosis [16,17], different combinations of cognitive biases may play a role. Various cognitive biases are relatively rarely investigated simultaneously, despite the fact that such studies could advance understanding of how these biases interact and how they lead to the development of psychotic symptoms in combination. Such studies could help to find answers for another vital question—whether cognitive biases share similar mechanisms. One of the proposed levels of understanding of the mechanisms of cognitive biases is brain functioning [18,19,20]

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