Discourse performance and related cognitive function in mild cognitive impairment and dementia: A preliminary study

Objectives This study applied the discourse task and related cognitive items of the Brief Test of Cognitive-Communication Disorders (BCCD) to normal, mild cognitive impairment (MCI), and moderate dementia groups and compared the scores of each area. In addition, the cognitive functions affecting the discourse performance were investigated by group. Participants 117 normal adults, 38 MCI, and 31 patients with moderate dementia (DEM) conducted BCCD, including discourse and cognitive items. Design/setting The discourse item included repeating an explanatory discourse, and the total discourse score was calculated by summing the scores for each of the four areas of coherence, cohesion, proposition, and pause. The cognitive areas of BCCD were attention, visuospatial ability, memory, organization, reasoning, problem-solving, and executive function. This study performed a one-way multivariate analysis of covariance to compare the scores of the three groups and multiple regression analysis determined the cognitive functions influencing the total discourse score. Measurements The discourse scores reporting differences among all groups were the pause and the total discourse scores, with the normal group showing a higher performance than the patient groups in the cohesion score and the DEM group in the propositions score, respectively. In addition, the cognitive functions affecting discourse performance were attention, organization, and problem-solving in the normal group, and organization and problem-solving in the MCI group. Conclusions Organizing information into a series of semantic units related to each other is necessary for coherent and efficient utterances, and the ability to correctly recognize the task and establish a strategy to grasp the core content is necessary for pragmatic language.