“
“Primary progressive aphasia (PPA) is a group of neurodegenerative find more disorders which presents with impairment of language (Mesulam,
2001 and Mesulam, 2003). Several canonical subtypes have been identified: semantic dementia (SD), led by verbal semantic impairment; progressive nonfluent aphasia (PNFA), led by, apraxia of speech and agrammatism; progressive logopenic/phonological aphasia (LPA) led by word-finding difficulty with impaired sentence repetition and comprehension (Gorno-Tempini et al., 2004 and Gorno-Tempini et al., 2008); and an aphasic syndrome associated with mutations in the progranulin (GRN) gene (progranulin-associated aphasia, GRN-PPA), which shares some features of LPA but with expressive agrammatism and more marked semantic impairment ( Rohrer et al., 2010a and Rohrer et al., 2010b). Whereas the production and processing of verbal material in PPA have been extensively studied, less
attention has been paid to nonverbal aspects of vocal communication. Expressive prosody, or the ‘melody’ of speech, is abnormal in many patients with PPA ( Josephs et al., 2006): apraxia of speech or expressive agrammatism in PNFA, and word-finding pauses in LPA tend to disrupt the rhythm and intonational structure of utterances, rendering their speech dysprosodic. However, it is not clear whether such patients have an underlying deficit in the comprehension of prosody, ‘receptive dysprosodia’ ( Ross, 1981). This issue Androgen Receptor Antagonist in vivo is of both neurobiological and clinical importance: neurobiologically, such a deficit would signify a pervasive derangement in the processing of vocal signals in PPA, while clinically, there would be important implications for everyday communication. Prosody is complex and conveys multidimensional information about the speaker’s intentions and emotional state, while facilitating disambiguation of Elongation factor 2 kinase the meaning of an utterance (e.g.,
statement vs question). At the most fundamental acoustic level, prosody comprehension depends on an ability to process variations in vocal pitch, duration and intensity (loudness) that constitute the building blocks of prosodic contours. Processing of prosodic patterns in words, phrases and sentences is required to determine lexical stress and declarative versus interrogative intention (linguistic prosody). Representation of vocal affective information is required to decode the speaker’s emotional state (emotional prosody). Here we conducted a systematic investigation of different dimensions of prosody processing (acoustic, linguistic and emotional) in a cohort of patients with PPA versus healthy older control subjects. For the purposes of this study, we focus on nonfluent variants of PPA rather than SD. ‘Nonfluent’ is a problematic term but is used here as elsewhere in the PPA literature, i.e., to indicate reduced overall quantity of speech produced.