Presented in this article is a discussion of current progress in behavioral, cognitive,
and neuroanatomic definitions of apraxia of speech (AOS). A behavioral definition
summarizes the speech symptoms that should be considered diagnostic of AOS with or
without co-occurring aphasia and dysarthria. AOS is defined in cognitive terms as
an impairment in the translation of phonological representations into specifications
for articulation. Progress toward a neuroanatomic definition of AOS will rely on mapping
the processes described by increasingly sophisticated cognitive models of normal speech
production to the brain. The article describes criteria that have been proposed for
differentiating apraxic from phonological and dysarthric disorders and suggests that
syndrome-based approaches to the diagnosis of AOS may obscure important differences
between individual presentations of apraxic disruption as well as similarities between
AOS and other speech-language disorders.
Speech production - clinical syndrome - cognitive model - brain mapping
