AUTHOR=Favaro Anna , Moro-Velázquez Laureano , Butala Ankur , Motley Chelsie , Cao Tianyu , Stevens Robert David , Villalba Jesús , Dehak Najim 

TITLE=Multilingual evaluation of interpretable biomarkers to represent language and speech patterns in Parkinson's disease

JOURNAL=Frontiers in Neurology

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1142642

DOI=10.3389/fneur.2023.1142642

ISSN=1664-2295

ABSTRACT=Motor impairments are only one aspect of Parkinson's Disease (PD), which also includes cognitive and linguistic impairments. Speech-derived interpretable biomarkers may help clinicians diagnose PD at earlier stages and monitor the disorder's evolution over time. This work focuses on the multilingual evaluation of a composite array of biomarkers that facilitate PD evaluation from speech. Hypokinetic dysarthria, a motor speech disorder associated with PD, has been extensively analyzed in previously published works on automatic PD evaluation, with a relative lack of inquiry into language and task variability. In this manuscript, we explore certain acoustic, linguistic, and cognitive information encoded within the speech of several cohorts with PD. Twenty-four biomarkers were analyzed from American English, Italian, Castilian Spanish, Colombian Spanish, German, and Czech by conducting a statistical analysis to evaluate which biomarkers best differentiate people with PD from healthy participants. The study leverages conceptual \textit{robustness} as a criterion in which a biomarker behaves the same, independently of the language. Hence, we propose a set of speech-based biomarkers that can effectively help evaluate PD while being language-independent. In short, the best acoustic and cognitive biomarkers permitting discrimination between experimental groups across languages were: fundamental frequency standard deviation, pause time, pause percentage, silence duration, and speech rhythm standard deviation. Linguistic biomarkers representing the length of the narratives and the number of nouns and auxiliaries also provided discrimination between groups. Altogether, besides being significant, these biomarkers satisfied the robustness requirements.