Effects of Deep Pressure on Arousal and Performance in Adults With Autism: Examining the Efficacy of the Vayu Vest

PURPOSE: Our objective was to measure the therapeutic use of the Vayu Vest (Therapeutic Systems, Amherst, MA), a medical device designed for deep pressure application, for adults with autism spectrum disorder (ASD). Previous work with typical adults indicated that the Vayu Vest reduced sympathetic activity, increased parasympathetic activity, and reduced performance errors (Reynolds, Lane, & Mullen, 2015). The central hypothesis in the current study was that deep pressure input would have similar effects on adults with ASD. Our rationale for this study was that individuals with ASD have impairments in autonomic nervous system (ANS) regulation that impact social engagement, academic and work performance, and self-care activities (Cohen, Masyn, Mastergeorge, & Hessl, 2013; Kushki, Brian, Dupuis, & Anagnostou, 2014; Mathersul, McDonald, & Rushby, 2013); reducing ANS dysregulation could lead to improved performance.

DESIGN: A cross-sectional, repeated-measures, repeated baseline design was used, with participants (N = 10 men ages 18–45) randomized to vest-wearing conditions (i.e., vest worn prior to performance measure vs. vest worn during performance measure). Baseline, vest, and performance epochs within each condition were 3 min in length. All participants had a confirmed diagnosis of ASD; severity scores were generated using the Autism Spectrum Quotient (ASQ; Baron-Cohen, Wheelwright, Skinner, Martin, & Clubley, 2001).

METHOD: Physiological outcomes included respiratory sinus arrhythmia (RSA; parasympathetic measure) and skin conductance level (SCL; sympathetic measure); physiological data were acquired by placing electrodes on participants’ back, chest, and hand using established protocols (Reynolds et al., 2015). Performance was measured using the Path Memory Game, a visual sequencing task requiring participants to recall the order in which items are presented on a computer screen. Sequences in the game get progressively longer; if they made an error, participants continued game play from the beginning until the 3-min epoch was complete. Data collection included the number of correct responses, number of errors, and highest level achieved.

Physiological data were cleaned, reduced, and entered in IBM SPSS Statistics Version 23 along with ASQ scores. Separate repeated-measures analysis of variance tests were conducted for physiological variables of interest (e.g., RSA and SCL change); scores were examined within condition, across epochs, and across conditions. Paired-sample t tests were used to assess differences in performance within and between vest-wearing conditions.

RESULTS: Wearing the Vayu Vest for even short periods of time reduced sympathetic arousal as reflected in changes in SCL (p < .05). Participants made significantly fewer errors during the performance task after wearing the Vayu Vest (p = .044) and while wearing the vest (p = .045). However, no significant differences were seen in the number of correct responses or highest level achieved. When comparing vest-wearing conditions, significantly fewer errors were made when the vest was worn prior to, as opposed to during, game play (p = .011). No significant changes in parasympathetic arousal (RSA) were found.

CONCLUSION: This pilot study suggests that deep pressure stimulation is capable of eliciting changes in sympathetic arousal and may be useful for reducing errors during functional tasks. Further research is needed to translate these laboratory findings into real-world settings.

IMPACT STATEMENT: This research contribution is significant because it is the first step in a continuum of research that is expected to lead to effective clinical strategies for reducing regulatory deficits in adults with ASD, using a device that can readily be integrated into daily activities. As such, this line of research has the potential to enhance individuals’ ability to perform functional life skills and interact socially with others.

References

Baron-Cohen, S., Wheelwright, S., Skinner, R., Martin, J., & Clubley, E. (2001). The Autism-Spectrum Quotient (AQ): Evidence from Asperger syndrome/high-functioning autism, males and females, scientists and mathematicians. Journal of Autism and Developmental Disorders, 31, 5–17. https://doi.org/10.1023/A:1005653411471

Cohen, S., Masyn, K., Mastergeorge, A., & Hessl, D. (2013). Psychophysiological responses to emotional stimuli in children and adolescents with autism and fragile X syndrome. Journal of Clinical Child and Adolescent Psychology, 44, 250–263. https://doi.org/10.1080/15374416.2013.843462

Kushki, A., Brian, J., Dupuis, A., & Anagnostou, E. (2014). Functional autonomic nervous system profile in children with autism spectrum disorder. Molecular Autism, 5, 39. https://doi.org/10.1186/2040-2392-5-39

Mathersul, D., McDonald, S., & Rushby, J. A. (2013). Psychophysiological correlates of social judgment in high-functioning adults with autism spectrum disorder. International Journal of Psychophysiology, 87, 88–94. https://doi.org/10.1016/j.ijpsycho.2012.11.005

Reynolds, S., Lane, S. J., & Mullen, B. (2015). Effects of deep pressure stimulation on physiological arousal. American Journal of Occupational Therapy, 69, 6903350010. https://doi.org/10.5014/ajot.2015.015560