Abstract
Despite substantial comorbidity of sensory dysfunction and autism spectrum disorder (ASD), there are few evidence-based sensory interventions for educators to implement in their classrooms. Nonetheless, recent research has found that early childhood educators are frequently implementing sensory strategies in the classroom despite this lack of evidence. This article provides educators with an evidence-informed roadmap for choosing interventions to address sensory needs in children with ASD, and steps for implementing and evaluating the impact of these interventions in their classrooms. Each child with ASD is unique, and therefore it is imperative to work with an occupational therapist to determine the child’s sensory processing needs and tailor interventions to meet these individualized needs.
Leo is a 4-year-old boy with autism spectrum disorder (ASD) enrolled in an early childhood special education classroom of 16 students, eight of whom receive special education services. Leo is a beginning communicator. He uses words effectively to meet basic needs but struggles to communicate more complex needs or in social situations. Leo is highly active and struggles to remain engaged in seated activities for more than 1 to 2 min. He also seeks sensory stimulation by pressing his body into objects or people and engaging in rough-and-tumble play. These behaviors cause social difficulties, as he may not realize when he is too rough with his peers. At other times, he seems hyper-responsive to sensory stimulation. For example, he becomes quickly overwhelmed in noisy or busy environments. Leo’s teachers believe that his sensory difficulties are interfering with his participation in the school setting. However, they are unsure how to address his sensory needs best. See Note 1.
Sensory processing differences are common in children with ASD; around 90% of children with ASD have sensory hypo-reactivity (i.e., less sensitivity to sensory input) or sensory-seeking behaviors; and 67% of children with ASD have tactile hypersensitivity (i.e., heightened sensitivity to sensory input) behaviors (Tomchek & Dunn, 2007). Sensory differences can affect multiple areas of classroom participation, such as the ability to follow school routines, participate in classroom activities, or maintain seated attention during teacher instruction. However, teachers may struggle to know which classroom strategies are most useful or considered evidence-based for managing sensory concerns in the classroom.
The recent push for early childhood educators to use evidence-based practices has been further motivated by the Every Student Succeeds Act (ESSA; U.S. Department of Education, 2015), which includes guidelines for evidence-based practices in early childhood education. The ESSA defines evidence-based practices as “an activity, strategy, or intervention that demonstrates a statistically significant effect on improving student outcomes or other relevant outcomes” (ESSA, 2015–2016, p. 393). It also defines four tiers of confirmation: (a) strong evidence, (b) moderate evidence, (c) promising evidence, and (d) demonstration of a rationale. A variety of research teams have worked to identify evidence-based practices for children with ASD (Division of Early Childhood, 2014; Hume et al., 2021; National Autism Center, 2015; Wong et al., 2015). A recent review by Hume et al. (2021) included sensory integration as developed by Ayers (2005) as an evidence-based practice. Previous reviews did not identify any other sensory-based intervention as an evidence-based practice.
Recent literature has also sought to describe teachers’ use of evidence-based and non-evidence-based practices in the classroom, including strategies to address sensory needs (Brock et al., 2019; Dynia et al., 2020). One study on early childhood educators’ use of evidence-based practices with children with ASD found that more than half of the educators described using sensory-related strategies in their classrooms, despite the limited evidence of efficacy for these practices (Dynia et al., 2020). Furthermore, research has found that over 70% of parents of children with ASD reported implementing sensory-based interventions (Green et al., 2006). These findings suggest that both early childhood teachers and parents perceive a substantial need for sensory-based interventions for children with ASD and frequently implement sensory-related interventions, despite limited evidence of effectiveness. Therefore, the purpose of this article is (a) to provide an overview of the evidence for different sensory-based interventions, and (b) in the face of limited evidence for the efficacy of specific practices in this area, provide teachers with an evidence-informed, collaborative framework for implementing sensory-based strategies that are most likely to be successful in their classrooms.
Overview of Evidence for Sensory-Based Interventions
Approaches that are sensory or sensorimotor aim to meet the child’s sensory needs by using specific sensory stimuli. Given the paucity of evidence for the use of sensory approaches or sensory stimuli, it is difficult for educators to make evidence-based decisions on how to address sensory-related issues for children with ASD in their classrooms. Using the ESSA four-tier framework, this article describes the evidence for different sensory-based interventions that educators can feasibly implement in classroom settings. It should be noted that the information presented might not apply across all age groups and environments. Specifically, there is currently limited information focusing on preschool children, and many studies took place in a clinic rather than a classroom setting.
Tiers 1 and 2: Strong to Moderate Evidence
Tier 1 or strong evidence includes interventions supported by one or more well-designed randomized control trials (RCTs) that meet the What Works Clearinghouse (WWC, 2017) standards without reservations. Tier 2 or moderate evidence includes interventions supported by one or more experimental or quasi-experimental studies that meet the WWC standards with reservations. For Tier 1 and Tier 2, interventions should have a significant positive effect, a sample size of at least 350 children (i.e., studies can be combined to get the required sample size), and include at least two educational sites. Currently, there does not appear to be any sensory-based interventions that meet these criteria.
Tier 3: Promising Evidence
Tier 3 (i.e., promising evidence) includes studies supported by one or more correlational studies (i.e., with statistical controls). Experimental and quasi-experimental studies are eligible for Tier 3 if they do not meet with sample size or setting requirements for Tiers 1 and 2. Sensory-based interventions that are feasible for classroom use and meet this requirement include (a) sensorimotor enrichment, (b) sensory integration, (c) yoga, (d) alternative seating, and (e) environmental stimuli. One small RCT found benefits of sensorimotor enrichment for children with ASD ages 3 to 12 years. After 6 months of daily olfactory and tactile stimulation paired with other sensory modalities, children with ASD made improvements in autism severity and cognition (Woo & Leon, 2013). Three small RCTs have found positive effects for the use of sensory integration for children with ASD (Kashefimehr et al., 2018; Pfeiffer et al., 2011; Schaaf et al., 2014). There have been two small RCTs on the effectiveness of yoga interventions for children with ASD (Koenig et al., 2012; Sotoodeh et al., 2017). Sotoodeh et al. (2017) found that an 8-week yoga training program reduced the severity of autism symptoms in an RCT with 29 children with autism ages 7 to 15.
Alternative seatings, such as therapy balls or air cushions, have been found to be effective for improving attention and in-seat behaviors in children with ASD in multiple single-case design studies (Bagatell et al., 2010; Krombach & Miltenberger, 2020; Matin Sadr et al., 2015; Schilling & Schwartz, 2004). For example, Schilling and Schwartz (2004) used a single-subject withdrawal design and found that the use of therapy balls increased engagement and in-seat behavior for four preschool-age children with ASD. Similarly, Krombach and Mittenberger (2020) found the use of therapy balls increased attention and in-seat behavior for four children with ASD ages 4 to 12 years using a multiple baseline design. There is also some evidence for the effectiveness of modifying environmental stimuli to alter the sensory environment on improving mood and behavior. For example, Kinnealey et al. (2012) found that using sound-absorbent wall paneling and replacing fluorescent lights with halogen lights improved the mood and behavior of four adolescents with ASD ages 13 to 20.
Tier 4: Demonstrates a Rationale
Tier 4 demonstrates a rationale that includes interventions supported by a well-defined logic model or theory of action. One intervention that demonstrates a rationale for use with children with ASD is The Alert Program (Williams & Shellenberger, 1996). This program teaches children strategies to identify their alertness levels and sensorimotor strategies to change alertness levels. It uses the simple analogy of a car’s engine to teach children how to self-monitor and select and implement sensorimotor strategies. Some researchers have argued that the program may help children with ASD attain and maintain appropriate arousal levels (Sarracino et al., 2002).
No Evidence
Unfortunately, several sensory-based interventions commonly used in early childhood classrooms have no evidence to support their use. These interventions include body brushing, joint compressions, deep pressure, therapeutic listening, weighted vests, and other weighted modalities. Brushing, joint compressions, and deep pressure are techniques that have been used on their own but are often used together in a “sensory diet.” There is very little support for the effectiveness of these techniques used either individually or in combination, and there is some evidence that these interventions are not effective (Davis et al., 2011; Devlin et al., 2011; George & Foley, 2000; Moore et al., 2015; Watkins & Bunce, 1996). Therapeutic listening (i.e., specific sounds or music are played through special headphones) also has limited evidence for use with children with ASD (Gee, 2001; Gee et al., 2015).
Weighted vests also lack evidence of effectiveness, and there are also concerns about the safety of weighted modalities used for children with ASD. There is no clear evidence for weighted vests’ effectiveness to improve a child with ASD’s engagement or attention to a task (Cox et al., 2009; Reichow et al., 2009; Reichow et al., 2010). A systematic review examined the effects of weighted vests and found across seven studies that children with ASD wearing weighted vests did not significantly improve problem behavior, joint attention, motor stereotypy, or engagement (Case-Smith et al., 2015; Watling & Hauer, 2015). In addition to concerns regarding the effectiveness of weighted vests for children with ASD, there are significant safety concerns regarding the use of weighted modalities. Although most research has been done on weighted vests, there is a small amount of evidence that these results of limited effectiveness may extend to other weighted modalities, such as weighted blankets, lap pads, and belts (Zimmerman et al., 2019). There can be serious safety risks in addition to limited evidence, such as when a 9-year-old boy with ASD tragically died of suffocation after being wrapped in a weighted blanket by his teacher following a behavioral outburst in his classroom (Gordon, 2008). Of note, there are no current standards or regulations regarding how much weight to use or how long to use the weighted item. To this point, Stephenson and Carter (2008) expressed some safety concerns about the potential harm from children wearing weighted vests for prolonged periods, indicating that it is recommended that children carry no more than 10% of their body weight in a backpack. Children sometimes wear weighted vests for more extended periods than a backpack would typically be carried, questioning the effect of young children carrying this amount of weight for an extended period (Stephenson and Carter, 2008).
Strategies for Using Sensory-Based Interventions in the Classroom
Leo’s teachers bring up their concerns about his sensory function to his individualized educational program (IEP) team. The team suggests that Leo’s occupational therapy practitioner (OTP), who is already part of the IEP team, conduct an in-depth assessment of Leo’s sensory needs to make support recommendations. The school OTP asks both Leo’s parents and teachers to complete a questionnaire about sensory-related behaviors and observe his classroom behavior on several occasions. Results suggest that Leo seeks proprioceptive stimulation (i.e., activities that increase body awareness through pressure) and is hypersensitive to auditory stimulation (i.e., sensitivity to certain sounds or noises). Based on these results, Leo’s OTP suggests some focused work on sensory regulation during his bi-monthly OTP sessions.
Strategy 1: Collaborate With an Occupational Therapy Practitioner
Most children with ASD being served within the public school system have access to professionals with expertise in understanding and managing sensory concerns. An OTP is commonly a school-based treatment team member for a child with ASD. An OTP is trained to assess and intervene in many areas, including daily living, fine motor, and sensory function. An OTP is likely to have the skills and expertise needed to understand the nature of a child’s sensory difficulties and suggest interventions to improve sensory functioning. Therefore, if a child has sensory-related concerns, it is essential to consult with the OTP on the child’s treatment team (or request a consult if an OTP is not already involved). An OTP, in collaboration with the classroom teacher, can conduct an evaluation to understand the child’s unique sensory processing needs. An evaluation is crucial because sensory interventions are not one size fits all (American Occupational Therapy Association, 2018).
Carefully considering the results of the sensory assessment is key to designing appropriate interventions. For example, one child’s results might indicate that their sensory processing pattern is primarily one of sensitivity to sensory input, particularly to visual input, which means that the child notices sights around him more than others. Based on these results, an OTP might make recommendations to adapt the classroom environment to be less visually stimulating by covering fluorescent lights with a cloth to make them less harsh, asking the teacher to dim the lights when possible, or creating a reminder for the student to make sure his desk is clear. In contrast, another child’s assessment results might indicate a sensory seeking pattern, meaning he seeks more sensory input than others. For this child, an OTP might recommend scheduling sensory-motor breaks to meet the child’s sensory needs.
Strategy 2: Create Goals
Children with ASD typically have multiple support needs across domains. While sensory-related interventions may be appropriate for targeting some of these needs, the interventions are not likely to improve behaviors across all domains. Therefore, understanding what skills or behaviors the intervention is expected to improve is key to understanding its success. It is often helpful to identify both proximal outcomes (i.e., those directly related to sensory and motor functions being targeted by the intervention) and distal outcomes (i.e., participation-related areas in which the child is believed to be struggling because of sensory challenges) (Schaaf, 2015). The child’s team should work together to identify goals and outcomes that are important to the teachers and family, aligned with the child’s broader classroom goals (e.g., IEP goals), and likely to be affected by the chosen intervention (i.e., directly or indirectly related to the sensory functions targeted by the intervention). For example, “To improve classroom participation, Leo will demonstrate increased seated attention following proprioceptive input as evidenced by remaining seated during circle time for 2 min with less than two verbal prompts over three consecutive opportunities.”
Strategy 3: Progress Monitoring
Different children, even those with similar diagnoses and sensory profiles, may respond differently to the same interventions. Many factors can influence an intervention’s efficacy, such as consistent implementation, child preferences, classroom structure and routines, and other child characteristics. This means that even when sensory-based interventions are designed thoughtfully and in consultation with appropriate professionals (e.g., an OTP), they may not be guaranteed to work immediately and often need some adjustments over time to ensure they are maximally effective. The potential need to make adjustments is why it is essential to use a data-driven approach (Schaaf & Mailloux, 2015) to monitor and modify interventions. See Figure 1 for a template and example for tracking goals, strategies, and behaviors. Individualized data tracking is a critical strategy in both school-based and individual interventions used with children with ASD. A data-driven decision-making approach is a helpful framework for collecting and using data during sensory-based interventions. This process has several keys components that follow (Schaaf & Mailloux, 2015).
Template and example of goals, sensory strategies, and target behaviors to track.
Measurement
After deciding upon goals, the next step is to select ways to measure these goals. Measurement can occur in myriad ways, including taking data in the classroom (e.g., tracking how long the child engages in seated activities or the number of aggressive or disruptive acts) or using questionnaires completed by teachers or parents. If information is needed about intervention efficacy over a relatively short period (e.g., a few weeks) to make intervention modifications, direct tracking methods such as collecting data in the classroom may be most sensitive to change. To track data, teachers can complete a behavior tally sheet. The sheet can be on a clipboard for portability, or the teacher can track using sticky notes or bookmarks contemporaneously and then transfer the data. If teachers have access to smartphones or tablets, data tracking apps are available, or teachers can use the notes app to make quick notes about a child’s behavior. In addition to tracking the frequency of the behavior, teachers can also track the level of support the child needed or what level of prompt was used. The child’s care team, including the OTP and classroom teacher, should work together to decide on a data tracking method that produces reliable and valid data that are also feasible within the classroom setting.
Baseline data
After a data tracking method is identified, it is essential to collect baseline data. Baseline data are taken immediately before the intervention starts to understand how the child performs in the targeted goal areas before intervention implementation and will serve as a benchmark to measure change. After the intervention is put into place, data typically should be collected for a minimum of 2 weeks before considering plan modifications. Although it can be tempting to try a new plan for a few days and conclude it is ineffective if results are not immediate, changes may be more gradual. Both teachers and students often need some time to adjust to new routines. In some cases, changes in expectations may even cause brief negative changes in behaviors, even if the interventions are effective in the medium or long term.
After the new intervention is implemented and data are collected for some time, the team, including the OTP and classroom teacher, should meet to assess the intervention’s efficacy and make any necessary changes to the plan. For repeated data collection (e.g., daily behavior data), graphing data to see trends over time can be helpful, as simply taking averages from before and after intervention might obscure patterns if changes are gradual. As the plan is modified over time, the team should continue tracking data to monitor efficacy and consider plan modifications. If a plan is stable and appears to be effective, it may be possible to fade data collection frequency or intensity.
Conclusion
Despite the dearth of evidence regarding the impact of specific sensory interventions for children with ASD, teachers can incorporate multiple strategies for addressing children’s sensory needs in the classroom. It is also important to note that using sensory-based interventions with either no evidence or evidence of harm can have additional consequences, including replacing the use of actual evidence-based practices. There are only so many hours in a day to intervene, so children should be spending their time using practices that have shown to be effective. Drawing from evidence in multiple areas of OTP and behavior change practice, recommendations for addressing sensory needs in an evidence-informed way include (a) collaboration with an OTP to assess sensory needs and design interventions informed by the child’s individual needs, (b) identification of specific, relevant goals related to sensory needs and strategies, and (c) using a data-based approach to tracking change to gauge the intervention’s effectiveness and make adjustments over time. These strategies highlight the importance of collaboration between the OTP and classroom teacher, which may not always occur at each stage of the process. It is important to note that students’ sensory processing differences are unique and affect their day-to-day function in the classroom in different ways. Therefore, each sensory-based intervention should be correctly developed and tailored for that child and not treated as a one-size-fits-all approach.
