Error Monitoring Failure in Metamemory Appraisal: A Visuospatial-Driven Feature of Mild Cognitive Impairment due to Alzheimer’s Disease

Objective: Anosognosia for memory deficits is frequently observed in patients with Alzheimer’s disease (AD). Despite its relevance, this phenomenon is understudied in individuals with Mild Cognitive Impairment (MCI). People with MCI often struggle to update self-referential beliefs about memory functioning. Nonetheless, findings on error monitoring capacity are mixed and methodologically weak, especially in visuospatial tasks. Here, we investigated online metamemory appraisal for verbal and visuospatial material in patients with MCI due to AD. The potential diagnostic utility of metamemory accuracy was evaluated. Methods: Sixteen patients with MCI and 19 healthy controls completed metamemory tasks involving predictions on list and position memory performance. Metamemory accuracy was quantified using the Objective Judgment Discrepancy (OJD) index, the percentage difference between predicted and actual performance. Linear mixed-effects models were used to analyze main effects and interactions. Results: Compared to controls, patients overestimated their memory performance (P < 0.001, d = 0.51), with greater overestimation in the visuospatial task (P < 0.001, d = 0.57). After adjusting for cognitive functioning, only overestimation in visuospatial memory persisted. Visuospatial OJD correlated significantly with executive and visuospatial abilities (all rho ≥ −0.50, P < 0.05). Clinimetric analyses highlighted visuospatial OJD as a promising marker for diagnostic use (AUC = 0.814, P < 0.001, sensitivity = 0.67, specificity = 0.95). Conclusion: Overestimation in verbal memory reflects a statistical artifact consistent with the Dunning-Kruger effect. A selective metacognitive deficit was found in visuospatial memory. Our results support the view of AD as a visuospatial-driven disease and underscore the diagnostic potential of visuospatial metamemory assessments.