Sensory-based interventions to enhance communication intervention in preverbal children with autism spectrum disorder

Thesis (PhD (Speech-Language Pathology))--University of Pretoria, 2023.Problem statement and rationale: Speech-language therapists (SLTs) play a central role in the assessment and treatment of individuals with Autism Spectrum Disorder (ASD). The speech-language therapist’s role is to understand and address sensory difficulties in this population to enhance intervention outcomes. However, training opportunities and limited guidelines and efficacy studies in the implementation of sensory-based interventions result in SLTs blindly implementing such interventions. Aim: To investigate the implementation of sensory-based interventions by SLTs and how such interventions influence the communication and responses of children with ASD. Methods: Three studies were conducted. Study 1 involved 65 SLTs from different settings across South Africa responding to an online questionnaire related to the nature, knowledge, perceived role, and outcomes of sensory-based interventions as implemented by SLTs. Studies 2 and 3 implemented an alternating treatment design involving two participants in Study 2, and three participants in Study 3. Preverbal children with ASD participated in either of two forms of vestibular input or a control activity before engaging in an interactive activity in Study 2 and a picture exchange activity in Study 3. Treatment 1 involved swinging whereas Treatment 2 involved rocking. The control activity involved a familiar matching activity. Results: The findings of Study 1 indicated that SLTs often implement sensory-based interventions using a variety of strategies and equipment despite the lack of guidelines and evidence base for such interventions. Accurate responses for more than half of the items were achieved in the knowledge section related to the prevalence and nature of sensory difficulties in children with ASD and strategies implemented in sensory-based interventions. SLTs achieved fewer accurate responses related to the differences between sensory-based interventions, and sensory integration therapy. Most respondents agreed that they have a role in addressing sensory difficulties in the children they treat. Respondents acknowledged the value of collaboration with occupational therapists (OTs) by indicating that they often consult OTs regarding the treatment of shared clients and engage with these professionals in joint collaborative therapy. Working alongside OTs was identified as the main source of training and knowledge gained in addressing sensory difficulties in children with ASD. Positive outcomes of sensory-based interventions were indicated in engagement, responsiveness, communicative behaviours, and self-regulation of children with ASD during speech-language therapy. Findings for Study 2 indicated that Participant 1 showed significantly more spontaneous communicative attempts after receiving vestibular input from Treatment 1 and Treatment 2 compared to the baseline condition. Positive findings were also indicated for Treatment 2 compared to the control condition and Treatment 1. Results for Participant 2 indicated a higher rate of spontaneous communicative attempts for Treatment 1 and 2 compared to the baseline phase. However, although a significant increase in spontaneous communicative attempts during both treatments appeared evident upon visual inspection of line graphs, no significant differences occurred for either treatment when compared to the control condition upon statistical analysis. In Study 3 an increase was indicated in the frequency of responses from the baseline condition and Treatment 1 for all three participants. Treatment 2 only brought about an increase in the frequency of responses for Participants 1 and 3. A significant improvement was also found for Participants 1 and 2 when receiving Treatment 1 and Treatment 2 compared to when they participated in the control activity. Conclusion: There is a gap between clinical practice and empirical research in the implementation of sensory-based interventions by SLTs. SLTs in this study acknowledged that they have a role in addressing sensory difficulties in the children they treat. However, most participants did not receive any formal training in providing sensory-based interventions. Despite the small sample sizes in the single-subject alternating treatment design implemented in Studies 1 and 2 some evidence of the positive influence of vestibular input on the responses and communicative attempts of participants was indicated. These novel findings hold valuable insights for clinical practice in speech-language pathology regarding training and the implementation of sensory-based interventions, collaboration with OTs as well as future research on the efficacy of vestibular input to enhance speech-language therapy outcomes.Speech-Language Pathology and AudiologyPhD (Speech-Language Pathology)Unrestricte