What is autism spectrum disorder?
Autism is not a disease. It simply means that the person’s brain functions differently from the majority of the people. It is a spectrum disorder, which is a developmental disorder. Children and adults with autism spectrum disorder can show a variety of signs and symptoms that are atypical. They primarily exhibit deficits in areas of social interactions and repetitive behaviour.
People who fall under the ASD often show difficulties in the interpretation of nonverbal behaviour, social interactions, and reciprocal relationships. Additional criteria for the diagnosis of autism include repetitive or restrictive behaviours, fixations or restrictive interests, under or overreaction to sensory stimuli, repetitive movements and inflexibility in behaviour.
Relationship between autism spectrum disorder and speech fluency
Autism can vary significantly in severity – Profound (severe) Autism, Moderate, Mild (High Functioning) and Asperger Syndrome. The spectrum sees a high variation of different types of intelligence, motor skills, verbal communication and social-emotional interaction.
The social deficits observed in autism, people within the spectrum can face difficulties in verbal communication. It calls for the intervention of speech-language pathologists (SLPs) for support in certain areas of language as well as communication. The documentation of fluency issues in autism is still expanding and much remains to be observed, and learnt about the atypical speech dysfluencies that occur along with ASD.
Over the last couple of decades, several different types of dysfluencies have been identified which include –
- Excessive non-stuttering-like disfluencies (NSLDs)
- Word final dysfluencies (WFD) or atypical dysfluencies
SLPs have identified these types of speech dysfluencies in preschool-aged children as well as adults.
How do the cognitive features of autism relate to fluency?
Till date, several theories have emerged regarding the cognitive uniqueness of autism that might influence the fluency of the individuals. These theories attempt to explain the manifestation of all the symptoms of autism and the variation of the intensity of symptoms across the spectrum. The most popular theories include the Theory of Mind (Baron-Cohen, 1995), Executive Functioning Deficits (Ozonoff, Pennington and Rogers, 1991), Impairments in Central Coherence (Frith, 1989), Information Processing (Minshew and Williams, 2008).
However, to date, no one theory has successfully explained all the aspects of ASD and the different intensities of symptoms across the spectrum in individuals of different age groups. Among all the theories mentioned above, Executive Functioning Deficits draws attention to the weakness or even lack of working memory in many cases. Working memory includes the skill of holding information in one’s mind to carry out a task. Interruptions in the functioning of the working memory can lead to the loss of one’s train of thought. Working memory is crucial in carrying a conversation forward. In such cases, conversational speech can be highly disfluent including non-stuttering like dysfluencies like revisions and interjections.
Why are fluency disorders so common among people with autism spectrum disorder?
The further examination of existing literature on autism and its relation to working memory revealed quite a few conflicts. Studies by Joseph et. al. (2005) discovered that during self- ordered pointing test in school-aged children those with ASD did not rely on verbal communication to meet the demands of their short-term working memory like the control participants without ASD. Similarly, fMRI studies by Koshino et. al (2005) shows that adults with ASD used visual cues instead of verbal codes to complete tasks.
These results go on to show that people in the spectrum use different mechanisms or strategies to use working memory than those outside the spectrum. Therefore, the literature suggests that individuals with ASD not only think differently but also respond to the demands of their working memory very differently from those with ASD. There is a good chance that these strategies take care of any overload on the working memory. At the same time, when there is an overload, the person may use NSLDs as placeholders to regain their train of thought during a conversation.
At the same time, individuals within the spectrum may use WFDs as atypical strategies to compensate for an overload of their working memory. That is evident from research by Scaler Scott et al (2013) that shows that people with ASD who use WFDs have reduced the frequency of WFDs with a controlled increase of pausing during a conversation.
What is the treatment for typical and atypical disfluencies for individuals within the spectrum?
SLPs trained in the assessment and therapy of speech dysfluency can help in assessing the level of disfluency of SLDs and NSDLs in individuals with ASD. Their first goal is to typically identify the type of dysfluency and then work with the individual to set goals.
- If the individual has stuttering or SLDs, the SLP can help by teaching breath control, speech exercises and control of muscle tension that govern stuttering. You can find many similar exercises and literature on stuttering and stuttering like disorders on Stamurai.
- In the case of cluttering, the SLP will work with the individual to regulate the rate of speech, timed pauses and emphasis on clarity.
- For atypical disfluencies like WFDs, the SLP may try to identify the root cause of the disfluency. They might work with a psychologist or therapist to explore the extent of the symptoms of ASD and the atypical disfluency/disfluencies as a coping mechanism(s).
Treatment programs for speech dysfluency can be highly varied depending on the intensity of the stuttering, NSLDs and WFDs, and the features of autism that manifest within the individual. Till now the only published work on the complete treatment plan is only for stuttering like dysfluencies by Brundage, Whelan and Burgess (2012). In this case study, the team reported success in the treatment of an adult within the spectrum with SLDs.
The existing literature on autism and the treatment of WFDs suggests that there is the chance of spontaneous recovery in younger children with ASD, and the management of long-term challenges that come with WFDs in ASD. However, it is clear that the world needs a large-scale study that involves more people (with ASD and control), with varying ability levels, age groups and different approaches to treatment.