Sentence comprehension in semantic dementia: a longitudinal case study

Abstract

Sentence comprehension abilities were investigated in a patient with semantic dementia who was administered tests of semantic knowledge and sentence comprehension over a 5-year period. Results showed that despite a severe and continual degradation in semantic knowledge, syntactic comprehension abilities remained largely intact. Evidence was also found for a codependency between semantics and syntax in a task in which knowledge about conceptual number influenced subject-verb agreement in the patient and in control participants. Results are discussed in relation to the nature of the sentence comprehension impairment in semantic dementia and with reference to the modularity of the components of the language processing system.

Structurally well-formed narrative production in the face of severe conceptual deterioration: A longitudinal case study of a woman with semantic dementia

“…In striking contrast to these findings regarding AK's conceptual knowledge, when structural aspects of her language were examined, little deviation from normal performance was observed, similar to previous reports about SD (e.g., Breedin & Saffran, 1999;Rochon et al, 2004). The integrity of AK's structural knowledge during the course of the three years of the current investigation was reflected in a number of measures.…”

“…She was first diagnosed as having AD, but later testing supported a diagnosis of SD. AK's severe anomia was previously described by Jokel, Rochon, and Leonard (2002), her sentence comprehension was investigated by Rochon et al (2004), and a clinical treatment study designed to improve her anomia was carried out by Jokel, Rochon, and Leonard (2006).…”

“…SD is characterized by a breakdown of word meaning, defined by impaired word comprehension and severe anomia, in the presence of effortless, fluent speech (Hodges, 2001;Neary et al, 1998). Alongside a progressive worsening of lexical-conceptual singleword knowledge, syntactic comprehension abilities appear to remain intact in SD (e.g., Breedin & Saffran, 1999;Hodges & Patterson, 1996;Hodges, Patterson, Oxbury, & Funnell, 1992;Hodges, Patterson, & Tyler, 1994;Rochon, Kave´, Cupit, Jokel, & Winocur, 2004). Our previous work with AK, a woman with SD whose language production will be analyzed below, illustrated that syntactic comprehension could remain largely unaffected despite a significant loss of semantic-conceptual knowledge (Rochon et al, 2004).…”

“…Alongside a progressive worsening of lexical-conceptual singleword knowledge, syntactic comprehension abilities appear to remain intact in SD (e.g., Breedin & Saffran, 1999;Hodges & Patterson, 1996;Hodges, Patterson, Oxbury, & Funnell, 1992;Hodges, Patterson, & Tyler, 1994;Rochon, Kave´, Cupit, Jokel, & Winocur, 2004). Our previous work with AK, a woman with SD whose language production will be analyzed below, illustrated that syntactic comprehension could remain largely unaffected despite a significant loss of semantic-conceptual knowledge (Rochon et al, 2004). AK's sentence comprehension pattern demonstrated reliance on syntactic and morphological frames, such as thematic roles or subject-verb agreement, in the absence of core semantic knowledge about single words.…”

Behavioural and neuroimaging changes after naming therapy for semantic variant primary progressive aphasia

“…As a result of semantic loss in svPPA, the accompanying language disorder is characterized by progressively empty, though fluent and well articulated speech, with semantic paraphasias (e.g., potato"apple") and relatively spared syntax (Neary et al, 1998;Rochon et al, 2004;Breedin & Saffran, 1999).…”