Phonetic and/or phonological paraphasias in aphasia: An acoustic study of speech output in two aphasic patients
-
1
University of Mons, Metrology and Language Sciences Unit, Belgium
-
2
National Fund for Scientific Research, Belgium
In aphasia, the phonological or phonetic origin of language production errors affecting phonemes is often discussed. However, the distinction between phonological and phonetic paraphasias is generally based on perceptual analyses that could be influenced by the experimenter’s perceptual system and/or expectations (Marczyk & Baqué, 2013).
In our study, in order to distinguish between these paraphasias, by means of evidence-based procedures, we conducted acoustic analyses of the productions of two French-speaking aphasic patients, CL (aged 65) and TM (aged 62). Both patients were non fluent and produced errors affecting phonemes on a picture description and a picture naming task. We mainly focused on the analyses of voice onset time (VOT) in stop consonants, a reliable cue of motor speech control that may be affected in patients with phonemic impairment (Laganaro, 2015). We assumed that in case of phonetic deficits, patients would experience difficulties to coordinate their articulators and to maintain both voicing and supra-glottal closure, especially for French voiced stops that have a long and negative VOT (as defined by Lisker & Abramson, 1964). Therefore, we may observe a great tendency to devoice voiced stops in these patients or VOT values that fell between the voiced and voiceless categories in French. On the other hand, in case of phonological deficit, patients would experience difficulties to select phonemes within the phonological system, leading to no clearly-established tendency in voicing errors (Blumstein, Cooper, Goodglass, Statlender, & Gottlieb, 1980; Nespoulous, Baqué, Rosas, Marczyk & Estrada, 2013).
Patients’ VOT durations were analyzed in a repetition task of 84 CVCV non-words, including the six French stop consonants /p,t,k,b,d,g/ combined with the three cardinal vowels /a,i,u/. VOT was estimated for each CV couple. Table 1 shows VOT values for each patient in consideration of the expected type of consonant (voiced or voiceless). The presence of voicing in the consonant was evidenced by the observation of periodicity in the spectrogram. The binary decision (voiced/voiceless) was taken on the basis of numerical criteria involving zero-crossing and HNR ratios, allowing to put emphasis on discrete and possibly infra-clinic attempts of voicing.
The results showed voicing difficulties in both patients suggesting phonetic impairment. For instance, as indicated on Table 1, CL showed a great tendency to devoice voiced stops while TM presented shorter VOT values for voiced stops (Laeufer, 1996). Moreover, we also observed great diversity in the manifestations of the patients’ difficulties as well as palliative strategies used by the patients to compensate for their voicing difficulties in voiced stops. These mechanisms suggest that our patients correctly selected the target phoneme within the phonological system but had difficulties to produce it at the phonetic level.
Our results reveal the importance of conducting acoustic analyses in order to distinguish between phonetic and phonological errors. Moreover, the great diversity in the patients’ production highlights the need to use multiple acoustic measures and indexes to objectify the observed phenomena.
Acknowledgements
Support for this research was provided by the ARC Grant "Parolpathos" (ARC AUWB-2012-12/17-UMONS-N°1 , B. Harmegnies, M.-C. Haelewyck, W. Lahaye, S. Saussez).
References
Blumstein, S. E., Cooper, W. E., Goodglass, H., Statlender, S., & Gottlieb, J. (1980). Production deficits in aphasia: a voice-onset time analysis. Brain and Language, 9(2), 153-170.
Laeufer, C. (1996). The acquisition of a complex phonological contrast: voice timing patterns of English initial stops by native French speakers. Phonetica, 53, 86–110.
Laganaro, M. (2015). Paraphasies phonémiques et/ou phonétiques ? Des raisons et des difficultés de cette distinction. Revue de neuropsychologie, 7, 27-32.
Lisker, L., & Abramson, A. S. (1964). A cross-language study of voicing in initial stops: Acoustical measurements. Word, 20, 384-422.
Marczyk, A., & Baqué, L. (2013). De l’origine des erreurs de substitution consonantique chez les patients aphasiques hispanophones : une étude acoustique. Recherches en Parole : La voix et la parole perturbées, Travaux en Phonétique Clinique, 1(1), 157-170.
Nespoulous, J.-L., Baqué, L., Rosas, A., Marczyk, A., & Estrada, M. (2013). Aphasia, phonological and phonetic voicing within the consonantal system: preservation of phonological oppositions and compensatory strategies. Language Sciences, 39, 117-125.
Keywords:
Phonetic errors,
Phonological errors,
Aphasia,
acoustic analysis,
voice onset time
Conference:
54th Annual Academy of Aphasia Meeting, Llandudno, United Kingdom, 16 Oct - 18 Oct, 2016.
Presentation Type:
Poster Sessions
Topic:
Academy of Aphasia
Citation:
Verhaegen
C,
Delvaux
V,
Fagniart
S,
Huet
K,
Piccaluga
M and
Harmegnies
B
(2016). Phonetic and/or phonological paraphasias in aphasia: An acoustic study of speech output in two aphasic patients.
Front. Psychol.
Conference Abstract:
54th Annual Academy of Aphasia Meeting.
doi: 10.3389/conf.fpsyg.2016.68.00023
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
22 Apr 2016;
Published Online:
15 Aug 2016.
*
Correspondence:
Dr. Clémence Verhaegen, University of Mons, Metrology and Language Sciences Unit, Mons, 7000, Belgium, clemence.verhaegen@umons.ac.be