Metacognitive Performance on Memory and Visuospatial Tasks in Functional Cognitive Disorder

Abstract

Functional Cognitive Disorder (FCD) is a common diagnosis at the memory clinic. FCD is characterised by significant self-reported cognitive symptoms in the absence of external evidence of cognitive dysfunction. A potential explanation for this is a deficit in metacognition, the process by which we internally judge our own abilities. Here we investigated differences in accuracy, confidence, and metacognition between people with FCD (N = 20), neurodegenerative mild cognitive impairment (nMCI; N = 14), and healthy controls (N = 23). The groups were assessed on forced choice memory and perceptual tasks, with trial by trial confidence ratings. FCD and nMCI participants showed lower accuracy on the memory task (means FCD 63.65%, nMCI 63.96%, HC 71.22%), with a significant difference between the FCD and HC groups after controlling for age and sex. There were no between-group differences in memory task confidence (means FCD 3.19, nMCI 3.59, HC 3.71). The FCD group showed greater confidence when longer time was allowed on the memory task. No between group differences in perceptual task accuracy (means FCD 63.97%, nMCI 64.50%, FCD 65.86%) or confidence (means FCD 3.71, nMCI 3.43, HC 3.88) were found. No differences in metacognitive efficacy emerged between the groups, either on the memory or perceptual task (Memory Meta-d’/d’:FCD 0.63, nMCI 0.94 HC 0.85; Perceptual Meta-d’,d’: FCD 0.50, nMCI 0.51, HC 0.72). Participants showed greater metacognitive efficacy on the memory task compared to the perceptual task. The difficulties experienced by people with FCD do not appear to be due to metacognitive deficits. Their performance was similar to people with nMCI over aspects of the memory tasks, which suggests that the primary issue may lie with memory encoding or retrieval, rather than with their judgement of performance accuracy.

Metacognition in functional cognitive disorder: contradictory or convergent experimental results?

“…However, Pennington et al . 4 had previously reported that they ‘did not find metacognitive deficits in groups of well characterized patients with FCD’, a study finding not discussed by Bhome et al . This former report may thus potentially jeopardise proposed Bayesian and metacognitive models of FCD.…”

“…Both groups used forced choice (working) memory and (visual) perceptual tasks with trial-by-trial confidence ratings to assess metacognitive efficiency 3 or efficacy 4 with a hierarchical meta-d’/d’ model (ideal = 1). Although there were some methodological differences (e.g.…”

“…exposure time for memory trials), the overall experimental approach was very similar. FCD patients were recruited from different settings (tertiary neuropsychiatry clinical services 3 versus tertiary referral cognitive disorders clinic 4 ), and control groups were constituted from either historical data from healthy controls 3 or contemporaneously investigated patients with neurodegenerative mild cognitive impairment and healthy individuals. 4 FCD patients were younger in the neuropsychiatry cohort (mean age 49.2 years) than in the cognitive disorders cohort (57.2 years).…”

“…FCD patients were recruited from different settings (tertiary neuropsychiatry clinical services 3 versus tertiary referral cognitive disorders clinic 4 ), and control groups were constituted from either historical data from healthy controls 3 or contemporaneously investigated patients with neurodegenerative mild cognitive impairment and healthy individuals. 4 FCD patients were younger in the neuropsychiatry cohort (mean age 49.2 years) than in the cognitive disorders cohort (57.2 years). As the numbers of FCD participants were small (18 and 20, respectively), it remains a possibility that one study result may reflect a Type I error (detecting an effect that does not exist) and/or that the other study may reflect a Type II error (failing to detect an effect that does exist).…”

“…Bhome et al . 3 characterize these findings as preserved local (bottom-up) metacognitive efficiency, in contrast with impaired overall or global metacognitive (top-down) efficiency (measures of the latter are not presented in the Pennington paper 4 ).…”