Abstract:

Objective To review the effect of response interruption and redirection intervention on vocal stereotypy in children with autism spectrum disorder (ASD).

Methods Literatures on response interruption and redirection intervention for vocal stereotypy in children with ASD were retrieved from databases of EBSCO, PubMed, Web of Science, CNKI, and Wanfang data. The information of the literatures was extracted to conduct a scoping review.

Results A total of 16 English literatures were included. All researches employed a single-subject time series study design. A total of 41 children with ASD were involved. Significant differences were found in levels of basic verbal functioning of children with ASD. Vocal stereotypy was characterized by both verbal and nonverbal forms. Most of the reviewed researches used experimental functional assessment to analyze the function of vocal stereotypy. In most cases, the function of vocal stereotypy was automatic reinforcement. Iwata et al.'s paradigm was dominantly adopted in performing experimental functional assessment across researches. Other related paradigms developed based on Iwata et al.'s paradigm to make operating process more concise were also used for experimental functional assessment in reviewed researches. Response disruption and redirection was often conducted in individualized setting, with a few researches conducted in special education classes. The time and frequency of interventions varied widely across subjects due to the levels of impairment in vocal stereotypy and other behaviors. According to a comparison of the effects of traditional response interruption and redirection and its morphing procedures, it was found that changing the content of the redirection task, reducing the number of redirection tasks, and varying the duration of execution did not impact the improvement of vocal stereotypy. Based on the comparisons of response interruption and redirection with matched stimuli, response cost, verbal manipulation training, and medication, it was found that both response interruption and redirection and other methods (except for medication) could reduce vocal stereotypy and promote the emergence of appropriate behaviors in children with ASD. Combining response interruption and redirection with other techniques, such as stimulus matching and response costs, yielded more favorable improvement of vocal stereotypy in children with ASD.

Conclusion ASD children with vocal stereotypy show different levels of functional language, and vocal stereotypy is generally characterized by both verbal and nonverbal formats. The function of vocal stereotypy is mostly automatic reinforcement. Response interruption and redirection as a behavioral intervention is mostly conducted in individualized setting, and the time and frequency of interventions depend on the levels of vocal stereotypy and other behaviors problems. Changing the content and number of redirection instructions does not significantly influence the improvement of vocal stereotypy in children with ASD. Other intervention methods such as matching stimulus and response cost are able to reduce vocal stereotypy in children with ASD, but response interruption and redirection used in conjunction with these methods show more favorable improvements. Response interruption and redirection interventions can not only reduce vocal stereotypy in children with ASD, but also increase appropriate vocalizations, task engagement and command obedience.

Key words: autism spectrum disorder, vocal stereotypy, response interruption and redirection, scoping review