Low Speech Connectedness in Alzheimer’s Disease is Associated with Poorer Semantic Memory Performance

Article type: Short Communication

Authors: Malcorra, Bárbara Luzia Covatti^{a; *} | Mota, Natália Bezerra^b | Weissheimer, Janaina^c | Schilling, Lucas Porcello^d | Wilson, Maximiliano Agustin^e | Hübner, Lilian Cristine^f

Affiliations: [a] School of Humanities, Graduate Course in Linguistics, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil | [b] Department of Physics, Federal University of Pernambuco (UFPE), Recife, PE, Brazil | [c] Brain Institute, Department of Foreign Languages and Literatures, Federal University of Rio Grande do Norte (UFRN), Natal, RN, Brazil; CNPq - National Council for Scientific and Technological Development - Brasília, DF, Brazil | [d] School of Medicine, Pontifical Catholic University of Rio Grande do Sul (PUCRS); Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (InsCer - PUCRS) - Porto Alegre, RS, Brazil; Neurology Service, São Lucas Hospital, Pontifical Catholic University of Rio Grande do Sul (PUCRS) – Porto Alegre, RS, Brazil | [e] Centre de recherche CERVO and Département de réadaptationé Laval, Québec City, QC, Canada | [f] School of Humanities, Graduate Course in Linguistics, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil; CNPq - National Council for Scientific and Technological Development - Brasília, DF, Brazil

Correspondence: [*] Correspondence to: Bárbara Luzia Covatti Malcorra, Ipiranga Ave, 6681, PUCRS, 90619-00, Porto Alegre, RS, Brazil. Tel.: +55 51 3320 3500; E-mails: barbaraluz.malcorra@gmail.com, barbara.malcorra@edu.pucrs.br.

Abstract: Connected speech is an everyday activity. We aimed to investigate whether connected speech can differentiate oral narrative production between adults with Alzheimer’s disease (AD; n = 24) and cognitively healthy older adults (n = 48). We used graph attributes analysis to represent connected speech. Participants produced oral narratives and performed semantic, episodic, and working memory tasks. AD patients produced less connected narratives than cognitively healthy older adults. Connectedness was associated with semantic memory in AD and with episodic memory in controls. Word-graphs connectedness represents a practical tool to assess cognitive impairment in AD patients.

Keywords: Alzheimer’s disease, cognitive decline, graph theory, natural language processing, semantic memory

DOI: 10.3233/JAD-210134

Journal: Journal of Alzheimer's Disease, vol. 82, no. 3, pp. 905-912, 2021