Effect of Engagement in Sensory-Based Tasks on Autonomic Nervous System Activity and Attention

SIGNIFICANCE: This study is the first to examine the feasibility of measuring changes in autonomic nervous system (ANS) responses and attention following tasks based on specific occupational therapy–sensory integration. Such proof of concept work is important as a foundation for the examination of occupational therapy–sensory integration treatment efficacy.

INNOVATION: Although clinical judgment and observation of behavioral responses to stimuli have been used to define sensory responsivity, we report on the use of mobile technology documenting objective physiological responses to clinic-based sensory task. Use of this innovative methodology brings us one step closer to analyzing outcomes immediately following treatment.

APPROACH: Difficulties with self-regulation, arousal, and attention can be primary barriers for children with sensory processing disorders (SPDs). There is a need for scientifically grounded, evidence-based interventions that can facilitate the development of these abilities and enable engagement in daily life tasks. By identifying tasks effective in changing levels of arousal and attention, we enrich the foundation for clinical trials to improve functional outcomes in children with SPDs. We tested the central hypothesis that carefully chosen sensory-based activities would change levels of physiological arousal and would result in measurable improvements in attention. Specifically, we hypothesized that (1) engagement in tasks identified as alerting would lead to increased sympathetic (SYMP) activity and decreased parasympathetic (PSYMP) activity (the reverse pattern of ANS change was expected for engagement in calming tasks), and (2) changes in attention would occur following completion of calming or alerting tasks.

METHOD: A quasi-experimental cohort design, with activities randomized within category (calming, alerting) and counterbalanced for subjects over two test sessions, was used in a clinical setting. The inclusion criteria for the convenience sample included the following: IQ > 70 and aged 6 to 10 yr (typical: n = 13; diagnostic: data not reported here). We used the Child Symptom Inventory–4 (CSI–4) to confirm or rule out diagnosis and the Wechsler Abbreviated Scale of Intelligence to ensure that IQs were >70. We used the Sensory Profile to determine presence or absence of sensory-based regulation disorders; we also measured electrodermal response (SYMP) and heart rate variability (PSYMP). To measure attention, we used an adapted version of the Attention Network Test as well as computerized measures of alerting, orienting, and executive function aspects of attention. Analyses included repeated measures analysis of variance between baseline, postalerting, postcalming, and recovery for all variables.

RESULTS: SYMP activity was increased from baseline at both postcalm and postalert (F[1.4, 8.3] = 7.99, p < .016). Expected trends were noted in PSYMP activity; no significant changes were found in attention.

CONCLUSION: Engagement in activity, regardless of type, increases SYMP activity when compared to passive “rest,” supporting the importance of engagement. PSYMP may be more responsive to type of activity, but additional data are needed. The shift in balance between PSYMP and SYMP following engagement helps to show the effectiveness of sensory-based activities in changing ANS. Clinical measures of attention may be inappropriate for capturing immediate effects of sensory-based activities; observation of time on task may be more effective in capturing change. Additional investigation is warranted.