Markedness analysis of consonant error productions in apraxia of speech.

This study applied a markedness analysis of consonant error productions to three adult aphasic patients with apraxia of speech. Single consonants and initial consonant clusters were investigated, employing both naming tasks and spontaneous narrative tasks. Results showed that phonemes of lower complexity values tended to substitute for phonemes of higher complexity values more than the reverse, and successive attempts at self-correction tended to reveal a progression toward the target segment in terms of markedness complexity. Theoretical and clinical implications are discussed.