Cross-Lingual Examination of Language Features and Cognitive Scores From Free Speech

Speech analysis is gaining significance for monitoring neurodegenerative disorders, but with a view of application in clinical practice, solid evidence of the association of language features with cognitive scores is still needed. A cross-linguistic investigation has been pursued to examine whether language features show significance correlation with two cognitive scores, i.e. Mini-Mental State Examination and ki:e SB-C scores, on Alzheimer’s Disease patients. We explore 23 language features, representative of syntactic complexity and semantic richness, extracted on a dataset of free speech recordings of 138 participants distributed in four languages (Spanish, Catalan, German, Dutch). Data was analyzed using the speech library SIGMA; Pearson’s correlation was computed with Bonferroni correction, and a mixed effects linear regression analysis is done on the significant correlated results. MMSE and the SB-C are found to be correlated with no significant differences across languages. Three features we re found to be significantly correlated with the SB-C scores. Among these, two features of lexical richness show consistent patterns across languages, while determiner rate showed language-specific patterns.