Inference comprehension from reading in individuals with mild cognitive impairment.

Abstract

Inference comprehension is a complex ability that recruits distinct cognitive domains, such as language, memory, attention, and executive functions. Therefore, it might be sensitive to identify early deficits in subjects with MCI. To compare the performance of subjects with mild cognitive impairment (MCI) in an inference reading comprehension task, and to analyze the correlations between inferential comprehension and other cognitive functions. We studied 100 individuals aged 60 and over, divided into MCI (50) [aMCI (35), naMCI (15)], and cognitively healthy individuals [controls (50)]. The Implicit Management Test (IMT) was used to assess inference in reading comprehension in five categories: explicit, logical, distractor, pragmatic, and "others". MCI group performed worse than controls in logical, pragmatic, distractor, and "others" questions (p < 0.01). The aMCI and naMCI subgroups presented a similar performance in all types of questions (p > 0.05). We observed significant correlations between the total IMT score and the TMT-A in the naMCI group (r = - 0.562, p = 0.036), and the Rey-Osterrieth Complex Figure and RAVLT tasks in the aMCI group (r = 0.474, p = 0.010 and r = 0.593, p = 0.0001, respectively). The MCI group as a whole performed worse than controls on the logical, pragmatic, other and distractor questions, and consequently on the total score. There were no differences in explicit questions, which impose lower inferential demands. The aMCI group suffered a significant impact from memory on inference comprehension, and difficulties in executive functions impacted naMCI performance. The IMT was useful to differentiate MCI patients from cognitively healthy individuals, but not MCI subgroups among themselves.