It is always useful for parents and professionals to ask the question, “Could something else be going on that could account for the lack of speech or communication skills?” According to Dr. Barry Prizant, there is increasing evidence that a lack of speech or gestures, in a subset of children with autism, may be related to issues other than social-cognitive abilities [Prizant, 1996]. One area that should be investigated includes general motor or specific motor speech impairments involving motor planning. This would include limb apraxia or oral/verbal apraxias. Because research on typically developing children has found a correlation between speech and language development and cognitive skills it is often presumed that the reason a child with autism does not speak is related to cognitive or receptive language ability. Prizant argues that clinical evidence suggests that motor speech impairments can be a significant factor inhibiting the development of speech in some children with autism. For instance:
- Some children are able to acquire the ability to meaningfully communicate via nonspeech symbolic alternative systems such as communication devices and sign language, despite the fact that their speech production may be severely limited. This fact may demonstrate adequate cognitive and linguistic skills.
- Some children demonstrate the classic symptoms of oral motor problems such as difficulty in coordinating movement of the articulators (lips, tongue, jaw, etc.), feeding difficulties, drooling past the age when most children are able to control saliva, and low facial muscle tone.
- Symptoms that are consistent with a diagnosis of developmental apraxia of speech. These symptoms may include: use of primarily vowel-like vocalizations and limited consonant repertoire (consonants require greater motor-planning ability); intelligibility which decreases with length of utterance (single word and single syllable production may be more clear than extended utterances or multisyllabic words); differences in automatic versus volitional speech (echolalia may be more clearly articulated compared to spontaneous speech attempts) [Prizant, 1996].
Just as with other children who exhibit limited, absent, or severely unclear speech, evaluation of the communication skills of children with autism should include observation and comprehensive assessment, including assessment of the oral motor and speech motor systems. Dr. Michael Crary outlines a number of areas for clinical observation and evaluation, including:
- Nonspeech motor functions: posture and gait, gross and fine movement coordination; oral movement coordination, mouth posture, drooling, swallowing, chewing, oral structures, symmetry, volitional vs. spontaneous movement
- Speech motor functions: struggle and strain during speech attempts, visible groping of mouth, deviations in prosody (rate, volume, intonation, etc.), fluency of speech, hyper/hyponasality, speech diodochokinesis (alternative and sequential speed on consecutive trials, i.e. “puh-puh-puh”, “puh-tuh-kuh” repetitively), volitional versus spontaneous attempts.
- Articulation and phonological performance: amount of verbal output, sound repertoire, reluctance to speak, interactive ability, intelligibility and type of errors, effects of performance load and increasing complexity; connected speech sampling; standardized test results.
- Language performance: comprehension and expression, type of utterances, semantic and syntactic ability, effect of increased length of input, conversational abilities.
- Other: ability to sustain and shift attention, reaction to speech, distractibility [Crary, 1993]
Clinicians report that it can be difficult to evaluate the oral-motor and speech-motor control of children with autism due to difficulties in getting the children to try some of the typical ways that these processes are assessed. Another primary difficulty may be a high degree of hypersensitivity of the oral mechanism. Lack of proprioceptive awareness and other sensory related issues may impact speech as well. Severely restricted diets may have prevented some of these children from experiencing normal biting, chewing and swallowing patterns and sensations [Vail, 2000].
In summary, all aspects of communication, speech and language need evaluated in children with autism, just as with children who have other speech and language diagnoses.
Crary, Michael A. “Developmental motor speech disorders”. San Diego, CA: Singular Publishing Group, 1993.
Prizant, Barry M. “Brief report: communication, language, social and emotional development.” Journal of Autism and Developmental Disorders, Vol. 26, No. 2, 1996.
Vail, Tracy. Personal Correspondence. October 2000.