Phonological encoding in apraxia of speech and aphasia

Edwin Maas, Keila Gutiérrez, Kirrie J. Ballard

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Background: Apraxia of speech (AOS) is considered a speech motor planning/programming disorder. While it is possible that co-occurring phonological impairments exist, the speech motor planning/programming deficit often makes it difficult to assess the phonological encoding stage directly. Studies using online methods have suggested that activation of phonological information may be protracted in AOS.Aims: The present study was designed to investigate the integrity of the phonological encoding stage in AOS and aphasia. We tested two specific hypotheses, the Frame Hypothesis and the Segment Hypothesis. According to the Frame Hypothesis, speakers with AOS have an impairment in retrieving metrical frames (e.g., number of syllables); according to the Segment Hypothesis, speakers with AOS have an impairment in retrieving segments (e.g., consonants).Methods & Procedures: Four individuals with AOS and varying degrees of aphasia, two speakers with aphasia, and 13 age-matched control speakers completed an online priming task in which participants name pictures in sets that do or do not share number of syllables (e.g., balcony-coconut-signature vs. balcony-carrot-sock), the initial consonant (e.g., carpenter-castle-cage vs. carpenter-beaver-sun), or both (e.g., boomerang-butterfly-bicycle vs. boomerang-sausage-cat). Error rates and reaction times were measured.Outcomes & Results: Data for controls replicated previous literature. Reaction time data supported the Segment Hypothesis for speakers with AOS and for one speaker with aphasia without AOS, with no differences in pattern from controls for the other speaker with aphasia without AOS.Conclusions: These results suggest that speakers with AOS may also have difficulties at the phonological encoding stage. Theoretical and clinical implications of these findings are discussed.

Original languageEnglish (US)
Pages (from-to)25-48
Number of pages24
Issue number1
StatePublished - Jan 2014


  • Aphasia
  • Apraxia of speech
  • Phonological encoding
  • Priming
  • Reaction time
  • Speech production

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Language and Linguistics
  • Developmental and Educational Psychology
  • Linguistics and Language
  • Neurology
  • Clinical Neurology
  • LPN and LVN


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