Assessing and treating vocal stereotypy in children with autism
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Ahearn, W., Clark, K., & MacDonald, R. (2007). Assessing and treating vocal stereotypy in children with autism. Journal of Applied Behavior Analysis, 40 (2), 263-275. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1885411/
In this study, the participants are two girls and two boys who are known to be suffering from autism, as well as their teacher. A medical diagnosis of autistic spectrum behavior has been made in this subject. The autistic participant is a child of the school-going age, whose selection has been made based on a teacher’s selection. The teacher, a special education instructor, is also a participant in this study. For purposes of obtaining consent, the parents of the children have co-operated extensively.
The research questions in this study were as follows:
- Does an autistic child exhibit stereotypic behavior that is characterized by vocal and motor responses?
- Is to try to isolate the actual source of stimulation, which maintains such response an effective treatment for stereotypy in this child?
- Do sensory consequences that emanate from engagement of behavior have the ability to reinforce stereotypy?
- What effect does stereotypy controlled by various sources of reinforcement have on sensory consequences?
The target behavior was vocal stereotypic behavior in an autistic child. Operationally, vocal stereotypy is defined as repetitive behavior not appearing to be a function of any social consequences. For instance, social escape or attention from task demands is often skipped. Researchers say it is an extremely common problem in children with autism disorders, and at times affects significantly social inclusion and learning. This behavior can also be referred to as automatically reinforced behavior or simply stereotypy. Often, the reinforcing features of the behavior itself usually maintain stereotypy. For instance, an autistic child might spin a truck’s wheels simply because it looks appealing visually. Other examples of stereotypy that occur commonly include hand flapping, vocalizing television scripts or portions of video, eating non-edibles, turning in circles, shredding or ripping items, as well as producing vocal noises. The researchers defined vocal stereotypy as an instance of nonfunctional or noncontextual speech that may include babbling, squeals, singing, phrases, as well as repetitive grunts unrelated to the prevailing situation.
The intervention was the delivery of certain demands by the special teacher. Data on vocal stereotypy was then collected, where 10 seconds momentary time was used to sample. For each 10-second session, an observation lasting 2 seconds took place. During this time, the nonoccurrence or occurrence of vocalized stereotypy was noted (Richards & Taylor, 2013). The moments of observation started with the elapse of every 10-second interval within each session. This lasted for an extra two seconds. Momentary sampling of time was preferred as it provided an accurate and more efficient estimate of duration and frequency for stereotypic behavior compared to partial-interval recording.
The other step was the calculation of interobserver agreement that involved division of the number of each interval with the agreements and by the sum of intervals (Gast & Ledford, 2010). This was then added to the disagreements and multiplied by 100 percent. Scoring of the agreement was done for a minimum range of between 33 to 57 percent of each participant’s condition. The average sum of agreements for stereotypy amounted to 95 percent, with a range of 91 to 100 percent. The first participant, Mitch scored 91 percent, a range of 86 to 98 percent. Peter scored 95 percent. He ranged between 92 to 100 percent. Alice had 94 percent, ranging between 87 to 100 percent while Nicki came last. The integrity of the treatment was established by close follow up of the participants to ensure they did not engage in any other treatment (Kratochwill, 2008).
The results for Mitch showed moderate to high level of vocal stereotypy. For Peter, the stereotypy was moderate and appropriate vocalizations occurred infrequently. Alice had a high stereotypy with appropriate vocalizations not previously observed. For Nicki, stereotypy was ranged between moderate to high in the initial baseline. It can be concluded that the sensory impact of vocal stereotypy can be dampened by the interruption of response. Additionally, stereotypy resembles other kinds of stereotypic tendencies in that it is not mediated socially (Ahearn, Clark, & MacDonald, 2007).
There were limitations in this study on which future ones should improve. One, different procedures for data-collection were used across treatment and for both appropriate and inappropriate response. Ideally, identical procedures for data-collection should be used in all phases of the experiment. Nevertheless, comparisons of the response levels during assessment were not germane to the purpose of this investigation. Measures used were less time-intensive to proceed well to treatment with the required rapidity. More significantly, the difference in procedures of measurement across responses did not retain constancy. Responses, both appropriate and inappropriate could have been measured simultaneously with recording. However, the former was usually briefer than the latter, evoking a scripted response from the teacher. Such responses could potentially have interrupted the lengthy utterances. In the future, alterations should be made to address similar concerns.
Another limitation was the brevity of the Peter’s return to the baseline. Although the trend went downwards as expected, there was no recovery of the baseline for vocal stereotypy. Other minor limitations included the scarcity of resources necessary to provide these intense interventions. Initially, it was common for session length to exceed with over 10 minutes. However, every child complied readily with the demands that the teacher issued.