Phonological simplifications, apraxia of speech and the interaction between phonological and phonetic processing

Abstract

Research on aphasia has struggled to identify apraxia of speech (AoS) as an independent deficit affecting a processing level separate from phonological assembly and motor implementation. This is because AoS is characterized by both phonological and phonetic errors and, therefore, can be interpreted as a combination of deficits at the phonological and the motoric level rather than as an independent impairment. We apply novel psycholinguistic analyses to the perceptually phonological errors made by 24 Italian aphasic patients. We show that only patients with relative high rate (>10%) of phonetic errors make sound errors which simplify the phonology of the target. Moreover, simplifications are strongly associated with other variables indicative of articulatory difficulties - such as a predominance of errors on consonants rather than vowels -but not with other measures - such as rate of words reproduced correctly or rates of lexical errors. These results indicate that sound errors cannot arise at a single phonological level because they are different in different patients. Instead, different patterns: (1) provide evidence for separate impairments and the existence of a level of articulatory planning/programming intermediate between phonological selection and motor implementation; (2) validate AoS as an independent impairment at this level, characterized by phonetic errors and phonological simplifications; (3) support the claim that linguistic principles of complexity have an articulatory basis since they only apply in patients with associated articulatory difficulties.

Publication DOI: https://doi.org/10.1016/j.neuropsychologia.2015.03.007
Divisions: College of Health & Life Sciences > School of Psychology
College of Health & Life Sciences > Clinical and Systems Neuroscience
College of Health & Life Sciences
College of Health & Life Sciences > School of Optometry > Vision, Hearing and Language
Additional Information: Copyright: 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license. Funding: British Academy.
Uncontrolled Keywords: apraxia of speech,conduction aphasia,markedness,phonological impairments,phonological simplifications,phonological/phonetic interactions,Behavioral Neuroscience,Cognitive Neuroscience,Experimental and Cognitive Psychology,Arts and Humanities (miscellaneous)
Publication ISSN: 1873-3514
Last Modified: 07 Oct 2024 07:21
Date Deposited: 02 Apr 2015 09:25
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
https://www.sci ... 1128?via%3Dihub (Publisher URL)
PURE Output Type: Article
Published Date: 2015-05-01
Published Online Date: 2015-03-13
Authors: Galluzzi, Claudia
Bureca, Ivana
Guariglia, Cecilia
Romani, Cristina (ORCID Profile 0000-0002-5693-4131)

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