Sublexical units in aphasic jargon and in the standard language: Comparative analyses of neologisms in connected speech

Background: It is a well-documented finding that phonemic speech errors in aphasia reflect certain characteristics of their intended targets. However, only few studies have investigated spontaneous speech productions of jargon-aphasic patients, in which lexical targets may be completely unrecognisable (abstruse phonemic neologisms). There is some evidence that these neologisms correspond to the standard language concerning phonemic content and structure. Aims: The present study further explores similarities of aphasic neologisms and the standard language, to contribute to the discussion about the origin of non-target-related errors in jargon aphasia. It investigates whether similarities at the phoneme level can be confirmed even in connected, severely jargonised speech that does not allow identification of lexical targets. Moreover, it raises the question whether other sublexical units like syllables contribute to the formation of phonemic neologisms. Methods & Procedures: Neologisms in spontaneous speech of a German-speaking jargon-aphasic patient were compared to the standard language concerning phoneme and syllable inventory, structural aspects, and distributional frequencies of sublexical measures. Data of the standard language were derived from meta-analyses of a German phonological word form database. Outcomes & Results: A strong relatedness to the standard language was demonstrated for the aphasic neologisms in connected speech. Similarities regarded phoneme inventory, phonotactics, and phoneme frequency distributions. The patient data point to a preferred use of high-frequency phonemes and syllables in neologisms. In addition, a similar distribution of syllable frequencies and structures was observed in the neologisms and in standard German. Results indicate that syllable frequency serves as a predictor for the neologisms’ distributional frequencies. Conclusions: The present study indicated that phonemic neologisms with no or weak evidence for a lexical origin still conformed to the phonological characteristics of the standard language, suggesting undisturbed segmental phonological processing. With respect to processing levels in speech production, results specifically pointed to a prominent role of syllabic units. The present findings are compatible with the assumption that syllabic representations, like structural information of syllables, are constrained in neologism formation.