Metacognition in Functional Cognitive Disorder

Functional cognitive disorder (FCD) is common but underlying mechanisms remain poorly understood. Metacognition, an individuals ability to reflect on and monitor cognitive processes, is likely to be relevant. Local metacognition refers to an ability to estimate confidence in cognitive performance on a moment-to-moment basis, whereas global metacognition refers to long-run self-evaluations of overall performance. Using a novel protocol comprising task-based measures and hierarchical Bayesian modelling, we compared local and global metacognitive performance in individuals with FCD and evaluated interactions between these levels of metacognition. We also investigated how local and global metacognition were related to the presence of affective symptomatology. Eighteen participants with FCD were recruited to this cross-sectional study. Participants completed computerised tasks that enabled local metacognitive efficiency for perception and memory to be measured using the hierarchical meta-d (HMeta-d) model within a signal detection theory framework. Participants also completed the Multifactorial Memory Questionnaire (MMQ) measuring global metacognition (beliefs about memory performance), and questionnaires measuring anxiety and depression. Estimates of local metacognitive efficiency were compared to those estimated from two control groups who had undergone comparable metacognitive tasks. Global metacognition scores were compared to existing normative data. A hierarchical regression model was used to evaluate associations between global metacognition, depression and anxiety and local metacognitive efficiency, while simple linear regressions were used to evaluate whether affective symptomatology and local metacognitive confidence were associated with global metacognition. Participants with FCD had intact local metacognition for perception and memory when compared to controls, with the 95% highest-density intervals for metacognitive efficiency overlapping with the two control groups in both cognitive domains. FCD participants had significantly lower global metacognition scores compared to normative data; MMQ-Ability (t=6.54, p<0.0001) and MMQ-Satisfaction (t=5.04, p<0.0001). Mood scores, global metacognitive measures and metacognitive bias were not significantly associated with local metacognitive efficiency. Increased local metacognitive bias ({beta}= -0.20 (SE=0.09), q= 0.01) and higher depression scores as measured by Patient Health Questionnaire-9 ({beta}= -1.40 (SE=2.56), q= 0.01) were associated with lower global metacognition scores. We show that local metacognition is intact, whilst global metacognition is impaired, in FCD, suggesting a decoupling between the two metacognitive processes. In a Bayesian model, an aberrant prior (impaired global metacognition), may override bottom up sensory input (intact local metacognition), giving rise to the subjective experience of abnormal cognitive processing. Future work should further investigate the interplay between local and global metacognition in FCD and aim to identify a therapeutic target to recouple these processes.