Modularity of prosody: autonomy of phonological quantity and intonation in aphasia

The Finnish language is used here to enrich our conception of the dysprosody hypothesis of the output in Broca's agrammatism, i.e., of the claim that agrammatic speech is characterized by aberrant timing and intonation patterns. The native language of the two agrammatic aphasics of the present study places a high functional load on quantity (acoustically: timing/duration) in its phonology, as the short-long quantity opposition concerns both vowels and consonants. Moreover, the quantity opposition in Finnish is not local, i.e., syllable-internal as in many Germanic languages, because the phonetic quantity values are determined by a disyllabic sequence. In contrast to the high functional load of quantity in its lexical phonology, Finnish makes little, if any, grammatical use of intonation. In the present acoustic analyses it was noted that the two Broca's aphasics have preserved the disyllabically determined quantity oppositions, although the speech of the aphasics is characterized by long interword pauses, i.e., by syntactic dysprosody. In contrast to the asyntactic timing patterns, the declination line of intonation is retained in the output of the present aphasics in spite of the low grammatical value of intonation in the language. The present results further dispute the characterization of agrammatic speech output as being dysprosodic, or more specifically atemporal, as lexical quantity and syntactic tonal patterns can be retained in a speech mode that is replete with long interword pauses. More generally, the observations will corroborate the autonomy (modularity) of lexical and syntactic processes in oral language production.