Cognitive Mechanisms in Decision-Making in Patients With Mild Alzheimer Disease.

Abstract

Alzheimer's dementia is characterized by significant cortical and subcortical atrophy, causing diverse neuropsychological deficits. According to the somatic marker hypothesis, the areas responsible for generating the somatic markers that anticipate the consequences of a decision and thereby optimize the process would be affected in these patients. The aim of this experiment is to study the decision-making processes in Alzheimer type dementia patients to determine potential deficits in these processes as a result of the disease, aside from the cognitive impairment that is typical of aging. In addition, we wish to determine the defining characteristics of decision-making in these patients, on the basis of the prospect valence-learning parameters. We evaluated 30 patients with Alzheimer's disease and a control group of 30 healthy subjects. A short version of the Iowa Gambling Task was used. The results showed that patients made less advantageous choices than did controls. Group differences were quantitative and qualitative, as significant differences in cognitive mechanisms identified in the prospect valence-learning decisions were observed. These results are consistent with evidence from neuroimaging studies as well as with work carried out with amnesic patients. That problems in our patients' decision-making could be due to the characteristic memory deficits of this disease, which prevents them from establishing new stimulus-reward relationships and eliminating previously learned responses as a result of the parietal and temporal atrophy they present.