Speech segmentation in aphasia

Background: Speech segmentation is one of the initial and mandatory phases of language learning. Although some people with aphasia have shown a preserved ability to learn novel words, their speech segmentation abilities have not been explored. Aims: We examined the ability of individuals with chroni...

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Bibliographic Details
Authors: Peñaloza, Claudia, Benetello, Annalisa, Tuomiranta, Leena, Heikius, Ida Maria, Järvinen, Sonja, Majos, Maria Carmen, Cardona Portela, Pere, Juncadella i Puig, Montserrat, Laine, Matti, Martin, Nadine, Rodríguez Fornells, Antoni
Format: article
Status:Versión aceptada para publicación
Publication Date:2014
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/125357
Online Access:https://hdl.handle.net/2445/125357
Access Level:Open access
Keyword:Afàsia
Trastorns del llenguatge
Trastorns de la parla
Processament de la parla
Aphasia
Language disorders
Speech disorders
Speech processing systems
Description
Summary:Background: Speech segmentation is one of the initial and mandatory phases of language learning. Although some people with aphasia have shown a preserved ability to learn novel words, their speech segmentation abilities have not been explored. Aims: We examined the ability of individuals with chronic aphasia to segment words from running speech via statistical learning. We also explored the relationships between speech segmentation and aphasia severity, and short-term memory capacity. We further examined the role of lesion location in speech segmentation and short-term memory performance. Methods & Procedures: The experimental task was first validated with a group of young adults (n = 120). Participants with chronic aphasia (n = 14) were exposed to an artificial language and were evaluated in their ability to segment words using a speech segmentation test. Their performance was contrasted against chance level and compared to that of a group of elderly matched controls (n = 14) using group and case-by-case analyses. Outcomes & Results: As a group, participants with aphasia were significantly above chance level in their ability to segment words from the novel language and did not significantly differ from the group of elderly controls. Speech segmentation ability in the aphasic participants was not associated with aphasia severity although it significantly correlated with word pointing span, a measure of verbal short-term memory. Case-by-case analyses identified four individuals with aphasia who performed above chance level on the speech segmentation task, all with predominantly posterior lesions and mild fluent aphasia. Their short-term memory capacity was also better preserved than in the rest of the group. Conclusions: Our findings indicate that speech segmentation via statistical learning can remain functional in people with chronic aphasia and suggest that this initial language learning mechanism is associated with the functionality of the verbal short-term memory system and the integrity of the left inferior frontal region.