The neural basis of metacognition in fronto-insular stroke and neurodegenerative diseases

MELLONI, MARGHERITA; GARCÍA-CORDERO, INDIRA; SEDEÑO, LUCAS; SIGMAN, MARIANO; MARTORELL CARO, MIGUEL; DOTTORI, MARTÍN; IBÁÑEZ, AGUSTÍN; MANES, FACUNDO; GARCÍA, ADOLFO M.

Sídney

Conferencia; 11th International Conference on Frontotemporal Dementias; 2018

Metacognition, the ability to ascertain and reflect on one?s own mental processes, is strongly linked to self-control and self-awareness. Only few studies have compared metacognitive performance across brain pathologies, and none has applied the lesion model approach combining relevant measures with neuroimaging analysis. To bridge this gap, we evaluated metacognition in patients with focal frontal-insular lesions (FIS), behavioral variant frontotemporal dementia (bvFTD), and Alzheimer?s disease (AD), who present damage in key metacognitive areas. Participants performed a visual perception task with two types of metacognitive report: confidence (judgment of trust about the performance) and wagering (betting on their accuracy in the perceptual task). Damaged areas were analyzed via structural MRI to identify an association with metacognitive outcomes. Results showed that, relative to controls, FIS and bvFTD patients did not present differences in confidence, whereas AD patients proved significantly overconfident. In contrast, wagering performance was affected in all patient groups. Lesions in orbitofrontal regions were involved in overconfidence, and damage in dorsolateral regions was associated with excessive wagering. This evidence supports a differentiation between metacognitive performance (confidence vs. wagering) and pathologies (orbitofrontal vs. dorsolateral lesions). The impairment of confidence and wagering in AD patients may reflect a lack of self-awareness in both types of metacognitive measures. In the frontal pathologies (FIS and bvFTD), excessive wagering may indicate a failure to use metacognitive information for strategic betting behavior. These results and the application of the lesion model approach across contrastive pathologies contributes to a better understanding of brain functions, in general, and metacognitive processes, in particular. Partially supported by grants from CONICET, CONICYT/FONDECYT Regular (1170010), FONDAP 15150012, INECO Foundation, and the Inter-American Development Bank.