Anosognosia and metacognition in Alzheimer's disease : insights from experimental psychology

Abstract : While metacognition and anosognosia have long been studied as distinct concepts, more recently we have endeavored to construct a theoretical framework for exploring how metacognition can contribute to our understanding of anosognosia and vice versa. Following this approach, with a particular focus on Alzheimer's disease (AD), this chapter first gives an overview of the key experimental findings and issues on metacognition in AD patients: in particular, overconfidence and absolute awareness; the sensitivity approach; the fractionation of metacognition in AD; the neural substrates of metacognition in the Alzheimer brain; and metacognitive control in these patients. Second, the chapter discusses the concept of anosognosia in AD patients from a cognitive neuropsychological viewpoint. It addresses models such as the cognitive awareness model and evidence from metacognition studies, and how they contribute to disentangle the issue of measuring anosognosia in AD patients. Finally, it develops the emerging concept of "implicit awareness" in AD patients