The Relationship Between Apraxia of Speech and Oral Apraxia: Association or Dissociation?

Abstract

Acquired apraxia of speech (AOS) is a motor speech disorder that affects the implementation of articulatory gestures and the fluency and intelligibility of speech. Oral apraxia (OA) is an impairment of nonspeech volitional movement. Although many speakers with AOS also display difficulties with volitional nonspeech oral movements, the relationship between the 2 conditions is unclear. This study explored the relationship between speech and volitional nonspeech oral movement impairment in a sample of 50 participants with AOS. We examined levels of association and dissociation between speech and OA using a battery of nonspeech oromotor, speech, and auditory/aphasia tasks. There was evidence of a moderate positive association between the 2 impairments across participants. However, individual profiles revealed patterns of dissociation between the 2 in a few cases, with evidence of double dissociation of speech and oral apraxic impairment. We discuss the implications of these relationships for models of oral motor and speech control.

Pantomimic fossils in modern human communication

“…It also corroborates the view articulated in mimesis theory that mimetic communication arose prior to and is in principle independent from, post-mimetic communication, including language [14]. This view is further supported by research on apraxia and particularly ideomotor apraxia, which specifically targets the production of pantomime [86]. These lines of evidence give us grounds to argue that once cerebral damage leads to language loss, pantomime is used to facilitate communication.…”

Language and thought are not the same thing: evidence from neuroimaging and neurological patients

“…), although findings from fMRI generally do not support this claim . However, dissociations between speech production and the production of nonspeech oral movements have been reported . Furthermore, a recent fMRI study has reported selectivity for letters over nonletter symbols in written production.…”

“…29,37 However, dissociations between speech production and the production of nonspeech oral movements have been reported. 38 Furthermore, a recent fMRI study 39 has reported selectivity for letters over nonletter symbols in written production. Thus, the question clearly deserves further investigation.…”

Subjective experience of inner speech in aphasia: Preliminary behavioral relationships and neural correlates

“…The postlexical phase of word production encompasses several proposed processes and a disruption of any of them could lead to overt anomia after sIS, e.g., loss of the phonological trace or a failure of sensorimotor mapping, phonological assembly, phonetic encoding, or articulatory planning (Goldrick & Rapp, 2007; Indefrey & Levelt, 2004; Indefrey, 2011; Walker & Hickok, 2015). The last of these, a failure of articulatory motor planning, often falls under a diagnosis of verbal apraxia or acquired apraxia of speech (Duffy et al, 2015; Strand, Duffy, Clark, & Josephs, 2014; Whiteside, Dyson, Cowell, & Varley, 2015). Individuals with anomia who report frequent sIS should perform poorly on tasks that rely heavily on these output processing skills, such as repetition or oral reading.…”