Analysis of speech fluency in Williams syndrome

Williams syndrome (WS) is a neurodevelopmental genetic disorder, often referred as
being characterized by dissociation between verbal and non-verbal abilities, although the
number of studies disputing this proposal is emerging. Indeed, although they have been
traditionally reported as displaying increased speech fluency, this topic has not been fully
addressed in research. In previous studies carried out with a small group of individuals
with WS, we reported speech breakdowns during conversational and autobiographical
narratives suggestive of language difficulties. In the current study, we characterized the
speech fluency profile using an ecologically based measure – a narrative task (story
generation) was collected from a group of individuals with WS (n = 30) and typically
developing group (n = 39) matched in mental age. Oral narratives were elicited using a
picture stimulus – the cookie theft picture from Boston Diagnosis Aphasia Test. All
narratives were analyzed according to typology and frequency of fluency breakdowns
(non-stuttered and stuttered disfluencies). Oral narratives in WS group differed from
typically developing group, mainly due to a significant increase in the frequency of
disfluencies, particularly in terms of hesitations, repetitions and pauses. This is the first
evidence of disfluencies in WS using an ecologically based task (oral narrative task),
suggesting that these speech disfluencies may represent a significant marker of language
problems in WS.
Conselho Nacional de Desenvolvimento Cientı´fico e Tecnolo´ gico (CNPq, Process
GM/GD 141307/2006-4, MCT/CNPq 14/2009-474092/2009-7), Brazil, Coordenac¸a˜o de Aperfeic¸oamento de Pessoal de Nı´vel
Superior (CAPES) - Programa de Doutorado no Paı´s com Esta´ gio no Exterior (PDEE, Process 1551/08-6), Brazil and Fundac¸a˜o
para a Cieˆncia e Tecnologia (FCT, Process PTDC/PSI-PCL/115316/2009), Portugal