Understanding source monitoring subtypes and their relation to psychosis: a systematic review and meta‐analysis

Abstract

Aims: Source monitoring (SM) is the metacognitive ability to determine the origin of one's experiences. SM is altered in primary psychiatric psychosis, although relationships between SM subtypes, other cognitive domains and symptoms are unclear. Our aims were to synthesize evidence comparing psychosis -with and without hallucinations-and healthy controls classifying SM subtypes by source discrimination (internal/external/reality monitoring) and stimulus modality (visual/auditory/imagined/performed).Methods: This systematic review adopted Preferred Reporting Items for Systematic Reviews and Meta-Analyses, Meta-analyses Of Observational Studies in Epidemiology and Population, Intervention, Comparison and Outcomes guidelines. Core demographical and clinical parameters were extracted. Newcastle-Ottawa Scale was used as quality check. SM differences between (i) psychosis patients versus healthy controls and (ii) patients with versus without hallucinations were investigated via random-effect model meta-analysis. The primary effect size measure was standardized mean difference (SMD) in each SM subtype performance (error or accuracy). Heterogeneity, publication biases and meta-regressions were assessed.Results: Five thousand two hundred and fifty-six records were screened to finally include 44 studies (1566 patients, 1175 controls). Mean Newcastle-Ottawa score was 7.41 out of 9. Few studies measured SM associations with cognition (n = 9) and symptoms (n = 19), with heterogeneous findings. SM performance across all measures was reduced in psychosis versus healthy controls (SMD = 0.458). Internal SM (SMD: errors = 0.513; accuracy = 0.733) and imagined stimuli (SMD: errors = 0.688; accuracy = 0.978) were specifically impaired. Patients with versus without hallucinations showed SM deficits only for externalizing (SMD = 0.410) and imagined/auditory (SMD = 0.498/0.277) errors. Conclusion:The proposed classifications highlight specific SM deficits for internal/imagined stimuli in psychosis, providing evidence-based indications to design and interpret future studies.

Posture, gait and self‐disorders: An empirical study in individuals with schizophrenia

“…Finally, the capacity to discriminate between self and exogenous stimulations, underpinned by CD systems, is also a central feature of source monitoring (SM), that is, the meta-cognitive ability to determine the origin of one's experiences. A recent systematic review (Damiani et al, 2022) has demonstrated a clear relationship between impaired SM performance and psychosis (including at-risk mental states), positing SM at the core of the developmental neurocognitive pathways underpinning the construction of a basic sense of self and as putative objective measure of anomalous self-experiences.…”

Aberrant thalamocortical connectivity and shifts between the resting state and task state in patients with schizophrenia

“…Fornito et al, 2012; Minzenberg et al, 2009; Wheeler & Voineskos, 2014) have led to the hypothesis that SZ is a brain ‘dysconnection’ syndrome (Friston et al, 2016; Stephan et al, 2009). Therefore, there is an increasing need to investigate the pathophysiology of SZ from a network or connectome perspective (Damiani et al, 2022; Gao et al, 2023; Kitajima et al, 2023; Tagawa et al, 2022). Clinically, SZ is a debilitating psychotic disorder characterized by a heterogeneous array of symptoms, such as auditory hallucinations, delusions, disorganized thoughts, ego disturbances, passivity phenomena and cognitive deficits (Onitsuka, Hirano, Nakazawa, et al, 2022).…”

Examining the relationships between cognition and auditory hallucinations: A systematic review

“…14 group contrasts for internal–external source misattributions). Given that the primary aim of the systematic review was to compare results across the range of proposed cognitive mechanisms, and that meta-analysis of source-monitoring data has been well documented (see Brookwell et al, 2013 ; Damiani et al, 2022 ; Waters et al, 2012b ), performing a quantitative synthesis for this single sub-domain was considered unsuitable. It is possible to conduct meta-analysis of broader, collapsed groups of data, with follow-up statistics to accommodate study deviations (e.g.…”

“…Previous meta-analyses, focusing on specific domains of cognition, have demonstrated moderate-to-large associations between hallucinations and a self-monitoring bias ( Waters et al, 2012b ), increased externalising source-monitoring errors ( Brookwell et al, 2013 ; Damiani et al, 2022 ) and reduced left-hemispheric language lateralisation ( Ocklenburg et al, 2013 ). Source-monitoring difficulties were observed in the context of auditory stimuli and imagined mental events ( Damiani et al, 2022 ), and identified in spite of intact broader memory function ( Waters et al, 2012b ). While such reviews have provided valuable integration of findings, some methodological inconsistencies are evident.…”