Sensory Processing & Integration

Table of Contents

1. What Is Sensory Processing and Integration?
2. The Eight Sensory Systems
3. What Are Sensory Processing Difficulties?
4. Who Is Affected?
5. Signs and Symptoms Across Age Groups
6. How Sensory Processing Is Assessed
7. Occupational Therapy and Sensory Integration
8. Ayres Sensory Integration® (ASI): The Evidence
9. Sensory-Based Interventions
10. Sensory Processing in School Settings
11. What Families Can Do
12. A Note for Clinicians
13. References

1. What Is Sensory Processing and Integration?

Sensory processing refers to how the nervous system receives, organizes, and interprets information from the senses — both from the external environment and from within the body. Sensory integration is the neurological process by which the brain combines signals from multiple sensory systems simultaneously and uses them to produce organized, adaptive responses that support daily function, learning, and participation (Acuña et al., 2025; Piller, Glennon et al., 2026).

The concept of sensory integration was first developed in the 1970s by Dr. A. Jean Ayres, a pioneering occupational therapist and neuroscientist. Ayres proposed that the ability to integrate sensory information from multiple systems — particularly touch, movement, and body position — is foundational to learning, behavior, and daily functioning. Her framework, now known as Ayres Sensory Integration® (ASI), remains the theoretical and clinical foundation for occupational therapy practice in this area (Acuña et al., 2025).

When sensory processing works well, it happens automatically and invisibly. A child reaches for a cup without looking, adjusts their posture when sitting, filters out background noise to focus on a teacher, and moves through a crowded hallway without bumping into others. These automatic responses depend on thousands of sensory integration processes operating simultaneously beneath conscious awareness (Piller, Glennon et al., 2026).

When sensory processing is disrupted — as it is in many children with autism spectrum disorder, ADHD, developmental coordination disorder, and other neurodevelopmental conditions — daily activities that most people perform without effort can become genuinely difficult, confusing, or distressing (Piller et al., 2025).

2. The Eight Sensory Systems

Most people are familiar with the five classic senses — sight, hearing, smell, taste, and touch. Occupational therapists working in sensory integration address eight sensory systems, including three that are less well known but critically important to daily function, learning, and behavior (Piller, Glennon et al., 2026; Acuña et al., 2025):

• Tactile system (touch): Processes information from receptors in the skin about pressure, temperature, pain, and texture. Foundational to manual dexterity, body awareness, and comfort with physical contact. Tactile hypersensitivity is among the most commonly reported sensory difficulties in children with autism spectrum disorder [LINK TO: autism-spectrum-disorder page].
• Vestibular system (movement and balance): Located in the inner ear, the vestibular system detects movement, gravity, and changes in head position. Essential for balance, postural control, eye movement, and the ability to sit still and attend. Vestibular processing difficulties can drive movement avoidance, gravitational insecurity, and coordination problems.
• Proprioceptive system (body position): Processes information from muscles, joints, and connective tissue about where the body is in space and how much force is being used. Supports motor planning — the ability to plan and execute unfamiliar movements, also called praxis — coordination, and emotional regulation. Children with poor proprioception often bump into others, use too much or too little force, and actively seek heavy input.
• Visual system: Processes light, color, motion, and spatial information. Visual processing difficulties can affect reading, handwriting, navigation, and social interaction, and often co-occur with tactile and vestibular processing differences.
• Auditory system: Processes sound, pitch, volume, and direction. Auditory processing difficulties can affect language development, attention, and the ability to filter background noise in busy environments like classrooms and cafeterias.
• Olfactory system (smell): Closely linked to emotional responses and memory. Hypersensitivity to smell is common in autism and can significantly affect eating, participation in activities, and comfort in public spaces.
• Gustatory system (taste): Processes flavor, texture, and temperature of food. Oral tactile and gustatory difficulties are a major driver of restricted eating patterns — a significant clinical challenge for many children with sensory processing differences.
• Interoceptive system (internal body signals): Processes signals from internal organs — hunger, thirst, heartbeat, bladder fullness, pain, and emotional states. Critically important to emotional regulation, self-care, and body awareness. Interoceptive processing difficulties contribute to emotional dysregulation, toileting challenges, and difficulty identifying and communicating internal states.

In Ayres’ framework, the tactile, vestibular, and proprioceptive systems are considered the most foundational for development — they provide the sensory base on which visual, auditory, and higher-level skills are built. Disruption in these three systems has the most far-reaching effects on learning and behavior (Acuña et al., 2025; Piller, Glennon et al., 2026).

3. What Are Sensory Processing Difficulties?

Sensory processing difficulties occur when the brain does not efficiently organize and respond to sensory information, resulting in responses that are poorly matched to the demands of the situation. These difficulties are not a single uniform condition — they vary widely across sensory systems, within the same individual, and across different environments and times of day (Piller et al., 2025).

Clinicians describe sensory processing patterns along two key dimensions: threshold (how much stimulation is needed before the nervous system registers and responds) and self-regulation (whether the individual actively or passively manages sensory input). These dimensions produce four recognizable sensory processing patterns:

• Sensory seeking (high threshold, active): The person actively seeks out intense sensory input — crashing, spinning, touching everything, making constant noise. The nervous system needs more stimulation than typical to register and respond. Common in ADHD and autism spectrum disorder [LINK TO: autism-spectrum-disorder page].
• Sensory avoiding (low threshold, active): The person actively avoids sensory input — refusing certain foods, textures, or clothing; avoiding crowds, loud environments, or unexpected physical contact. The nervous system registers stimulation too intensely.
• Sensory sensitivity (low threshold, passive): The person notices and is bothered by sensory input but does not actively avoid it — becoming distracted by background noise, bothered by lighting, or distressed by unexpected touch.
• Low registration (high threshold, passive): The person seems unaware of sensory input that others notice — appearing inattentive, missing verbal instructions, seeming not to feel pain or temperature, or appearing clumsy and poorly coordinated.

Many individuals show a mix of patterns across different sensory systems — for example, sensory avoiding for touch but sensory seeking for movement. This variability is one reason sensory processing difficulties can be challenging to identify without a thorough individualized assessment (Piller et al., 2025; Piller, Glennon et al., 2026).

4. Who Is Affected?

Sensory processing difficulties are far more common than many parents, educators, and clinicians realize. They affect children across a wide range of diagnoses and also occur in children without any other identified condition (Piller et al., 2025; Jurek et al., 2025).

In the general population: Approximately 1 in 6 children experience sensory processing difficulties significant enough to affect participation in daily activities, learning, or social functioning. These difficulties occur across socioeconomic, cultural, and geographic groups (Piller et al., 2025).

In autism spectrum disorder: Sensory differences are present in up to 90% of autistic children and are now included in the DSM-5 diagnostic criteria for autism spectrum disorder [LINK TO: autism-spectrum-disorder page]. They are among the most consistently reported and functionally significant features of autism, affecting eating, dressing, grooming, sleep, social participation, and learning (Acuña et al., 2025; Piller, Glennon et al., 2026).

In ADHD: A 2025 systematic review and meta-analysis of 30 studies involving 5,374 participants found that individuals with ADHD experience significantly more severe sensory atypicities than neurotypical controls across all four sensory processing patterns — sensory sensitivity (SMD = 1.17), sensory avoiding (SMD = 1.15), low registration (SMD = 1.22), and sensory seeking (SMD = 1.23). The authors concluded that sensory processing should be systematically assessed in all individuals referred for ADHD evaluation (Jurek et al., 2025).

In other conditions: Sensory processing difficulties also occur in children with developmental coordination disorder (DCD), cerebral palsy, Down syndrome, prenatal alcohol exposure, and other neurodevelopmental conditions. Sensory differences are not limited to childhood — they can persist across the lifespan and are increasingly recognized in adolescents and adults (Piller et al., 2025; Piller, Glennon et al., 2026).

5. Signs and Symptoms Across Age Groups

Sensory processing difficulties look different at different ages and across different sensory systems. The following are common signs that may warrant a referral to an occupational therapist with sensory integration training (Piller et al., 2025; Acuña et al., 2025):

Infants and toddlers:

• Extreme distress with bathing, diaper changes, or dressing
• Difficulty being held or comforted; arching away from touch
• Over- or under-reaction to sounds, lights, or movement
• Feeding difficulties related to food texture or temperature
• Delays in motor milestones — rolling, sitting, crawling, or walking
• Excessive mouthing of objects beyond the typical developmental age

Preschool and early school age:

• Extreme fussiness about clothing — refusing tags, seams, socks, or waistbands
• Meltdowns in busy, loud, or visually stimulating environments such as birthday parties, grocery stores, or cafeterias
• Avoidance of playground equipment, climbing, or physical play
• Extreme picky eating limited to specific textures, temperatures, or colors of food
• Difficulty sitting still, constantly in motion, crashing into furniture and people
• Distress with haircuts, nail cutting, tooth brushing, or face washing
• Poor coordination, frequent tripping and falls, difficulty with scissors or pencils

School age:

• Difficulty tolerating classroom noise or lighting — covering ears, avoiding the cafeteria, becoming dysregulated in group settings
• Difficulty with handwriting — poor pencil grip, excessive or insufficient pressure, rapid fatigue
• Avoiding physical education, recess, or team sports due to sensory demands
• Emotional dysregulation that seems disproportionate to the apparent trigger
• Difficulty transitioning between activities or tolerating changes in routine
• Social difficulties linked to sensory responses — avoiding physical contact with peers, distress with proximity to others

Adolescents and adults:

• Avoiding crowded places, public transportation, or social events due to sensory overwhelm
• Restricted diet based on texture, smell, or other sensory properties of food
• Difficulty in open-plan work environments with fluorescent lighting or background noise
• Emotional dysregulation, anxiety, or fatigue linked to the cumulative sensory demands of daily life
• Difficulties with personal care, grooming, or medical and dental procedures

6. How Sensory Processing Is Assessed

A thorough sensory processing assessment is a core competency of occupational therapy and requires specialized training in sensory integration theory and practice. A comprehensive OT sensory assessment typically includes multiple components (Acuña et al., 2025; Piller, Glennon et al., 2026):

• Caregiver and parent interview: Detailed history of the child’s sensory responses across environments — home, school, community, and social settings
• Standardized sensory questionnaires: Tools such as the Sensory Profile 2 (SP-2) and Sensory Processing Measure (SPM) provide structured, norm-referenced information about a child’s sensory processing patterns across all sensory systems as reported by caregivers and teachers
• Performance-based assessments: The Sensory Integration and Praxis Tests (SIPT) and Ayres Clinical Observations assess the neurological foundations of sensory integration through direct observation of the child performing structured motor and sensory tasks
• Structured clinical observation: Direct observation of the child’s responses to sensory input, motor coordination, postural control, bilateral coordination, praxis, and visual-motor integration during play and functional activities
• Teacher and school report: Information about sensory responses, attention, participation, and function in the school environment
• Review of medical and developmental history: Prenatal history, developmental milestones, medical diagnoses, prior therapies, and current concerns

Assessment findings are integrated into a clinical picture that identifies the specific sensory systems affected, the functional impact on daily activities and participation, and the most appropriate intervention approach. This guides whether ASI, sensory-based strategies, environmental modifications, or a combination is most indicated for the individual child (Piller, Glennon et al., 2026).

7. Occupational Therapy and Sensory Integration

Occupational therapists (OTs) are the primary clinical specialists for sensory processing assessment and intervention. OT training specifically addresses the relationship between sensory processing, neurological function, and participation in daily occupations — making OTs uniquely qualified to evaluate and treat sensory integration difficulties across the lifespan (Piller, Glennon et al., 2026; Acuña et al., 2025).

OT intervention for sensory processing difficulties may take several forms depending on the child’s age, diagnosis, sensory profile, and goals:

• Ayres Sensory Integration® (ASI) intervention: The most evidence-based approach — a structured, child-directed, play-based therapy delivered by an OT with specialized postgraduate training. See Section 8 for the full evidence summary.
• Sensory-based interventions (SBIs): Specific sensory strategies used within daily routines to temporarily modify arousal, improve regulation, and support participation. See Section 9.
• Environmental modifications: Adapting the sensory demands of the home, classroom, or workplace — adjusting lighting, reducing noise, creating sensory-friendly spaces, and modifying seating arrangements
• Caregiver and teacher education and training: Teaching parents, caregivers, and teachers to understand, recognize, and respond effectively to the child’s sensory needs — one of the most consistently evidence-supported approaches in the current literature (Piller et al., 2025)
• Sensory diet: A personalized schedule of sensory activities built into the child’s daily routine to maintain an optimal level of arousal and regulation throughout the day
• Occupation-based intervention: Embedding sensory support directly into meaningful daily activities — dressing, eating, grooming, school tasks, play, and social participation — to maximize carryover and functional outcomes

OT for sensory processing is delivered across outpatient clinics, early intervention programs, schools, homes, and community settings. The setting influences the approach — school-based OT focuses on educational participation; clinic-based OT may address a broader range of daily life goals (Piller, Glennon et al., 2026; Whiting et al., 2023).

8. Ayres Sensory Integration® (ASI): The Evidence

Ayres Sensory Integration® (ASI) is the most rigorously studied intervention for sensory processing difficulties in children. It is a child-directed, play-based intervention delivered by an OT with specialized postgraduate training. Key principles include active engagement of the child, individually tailored activities, play opportunities presented at the just-right challenge to facilitate adaptive responses, and therapeutic use of specialized equipment designed to provide controlled vestibular, tactile, and proprioceptive input (Acuña et al., 2025; Piller, Glennon et al., 2026).

ASI requires adherence to a Fidelity Measure — a structured protocol ensuring the intervention is delivered with the theoretical and clinical precision required to produce the outcomes demonstrated in research. This distinction is clinically important: not all sensory interventions are ASI, and ASI’s evidence base should not be applied to non-fidelity sensory approaches (Piller, Glennon et al., 2026).

What the current evidence shows:

A 2025 systematic review of randomized controlled trials evaluated ASI specifically in children ages 0–12 using only studies adhering to the ASI Fidelity Measure. Of 9 RCTs (n=344 participants), strong evidence from five RCTs (four Level 1b) indicates that ASI supports autistic children in meeting their individualized occupational goals related to performance, function, and participation. Moderate evidence from three RCTs indicates ASI does not benefit behaviors of concern such as noncompliance or irritability. More research is needed to determine ASI’s benefits for non-autistic child populations (Acuña et al., 2025).

A 2026 systematic review of ASI studies published between 2015 and 2024 (ages 0–21), conducted as part of AOTA’s Evidence-Based Practice Program, found good evidence supporting occupational therapy using ASI to improve participation for children and youth with sensory integration and processing challenges. The review covered 6 databases including MEDLINE, CINAHL, PsycINFO, OTseeker, Cochrane Reviews, and ERIC (Piller, Glennon et al., 2026).

A 2024 meta-analysis of 24 studies confirmed that sensory integration therapy produces meaningful positive effects across children with autism spectrum disorder , ADHD, cerebral palsy, and developmental disorders, including improvements in sensory integration ability, social skills, and motor function (Oh et al., 2024).

9. Sensory-Based Interventions

Sensory-based interventions (SBIs) are a distinct category from ASI. Where ASI is a direct, one-on-one, therapist-delivered intervention requiring specialized training and fidelity, SBIs are practitioner- or caregiver-implemented sensory strategies designed to temporarily modify a child’s physiological arousal level to improve regulation, attention, and participation in tasks (Piller et al., 2025).

SBIs can include techniques such as deep pressure touch, movement breaks, weighted vests, fidget tools, noise-canceling headphones, alternative seating, sensory environmental modifications, and structured caregiver-implemented sensory routines. They are widely used in school and home settings because they are flexible, low-cost, and do not require advanced OT training to implement once a qualified OT has assessed the child and designed the strategy (Piller et al., 2025).

What the current evidence shows for SBIs:

A 2025 systematic review of 21 studies found strong evidence supporting two specific SBI approaches: deep pressure tactile input — including weighted blankets, firm touch, and massage — for improving sleep, motor development, and regulation in children with sensory challenges and ADHD; and caregiver training in sensory strategies for improving caregiver confidence and strategy implementation across home and school settings. Moderate evidence supports multisensory approaches used consistently and sensory strategies individually matched to the child’s specific sensory profile (Piller et al., 2025).

• Deep pressure tactile input: Strongest SBI evidence — improves sleep, regulation, and motor development (Piller et al., 2025)
• Caregiver training in sensory strategies: Strong evidence for improving caregiver knowledge and strategy use; emerging evidence for functional outcomes in the child (Piller et al., 2025)
• Movement breaks and proprioceptive input: Widely used to support attention and regulation in classroom settings — evidence is promising but more rigorous studies are needed
• Alternative seating and fidget tools: Moderate evidence for improving attention in specific classroom contexts
• Noise-canceling headphones: Emerging evidence for supporting participation in children with auditory hypersensitivity

10. Sensory Processing in School Settings

The school environment presents significant sensory demands — fluorescent lighting, crowded hallways, cafeteria noise, physical proximity to peers, and the sustained sensory-motor requirements of sitting, writing, and attending for hours at a time. For children with sensory processing difficulties, these demands can profoundly affect their ability to access the curriculum, participate in school activities, and sustain appropriate behavior across the school day (Whiting et al., 2023; Piller, Glennon et al., 2026).

Research shows that 65% of school-based occupational therapy practitioners report that sensory-related issues are frequently or always the primary reason for OT referrals in their schools. Children’s sensory integration and processing challenges affect their ability to sustain upright posture for desk work, coordinate head and eye movements for reading and writing, organize multi-step activities, and maintain the regulated arousal state needed for learning (Piller, Glennon et al., 2026).

A 2023 multiple-baseline study in a public elementary school tested the effectiveness of an ASI intervention paired with teacher consultation for students ages 5–8 whose sensory integration and processing differences were affecting their school occupational performance. All three participants showed improvements in functional regulation and active participation in school following the intervention, supporting ASI paired with teacher consultation as a viable school-based OT model (Whiting et al., 2023).

What school-based sensory support can include:

• Direct ASI intervention in a sensory-equipped therapy space, pulled out from class (Tier 3 support)
• Consultation with teachers on classroom-level sensory modifications and universal design (Tier 1 support)
• Small-group sensory programs for students with shared sensory needs (Tier 2 support)
• Environmental modifications — seating, lighting, noise reduction, and movement breaks built into the school day
• Teacher and staff training on recognizing and responding to sensory dysregulation
• Collaboration with parents to ensure carryover between school and home environments

11. What Families Can Do

Families are essential partners in sensory processing intervention. Research consistently shows that carryover of strategies at home significantly improves outcomes — what happens between therapy sessions matters as much as the sessions themselves (Piller et al., 2025; Piller, Glennon et al., 2026).

• Seek an OT evaluation early: If you are concerned about your child’s sensory responses, ask your pediatrician for a referral to an occupational therapist with sensory integration training. Early assessment leads to earlier, more effective intervention.
• Learn your child’s sensory profile: Understanding which sensory systems are affected and whether your child tends to seek, avoid, or under-register helps you anticipate challenges and design effective responses rather than reacting after dysregulation has already occurred.
• Build sensory strategies into daily routines: Consistent daily sensory input — heavy work before school, a calming routine before bed, a predictable morning sequence — is more effective than reactive strategies used only when dysregulation has already peaked.
• Communicate with your child’s school: Share the OT’s assessment findings and recommendations with teachers and school staff. Request that sensory accommodations be built into the IEP or 504 plan if appropriate.
• Reframe behavior as communication: A child who refuses to wear certain clothing, melts down in the grocery store, or crashes into everything is not misbehaving — they are communicating a sensory need their nervous system cannot yet manage independently.
• Seek support for yourself: Parenting a child with significant sensory processing difficulties is demanding. Connecting with other families, parent support groups, and therapist-guided parent training programs can meaningfully reduce caregiver stress and improve outcomes for the child.

12. A Note for Clinicians

Sensory processing difficulties are among the most common referral reasons in pediatric occupational therapy and among the most frequently misunderstood across disciplines. Clear clinical communication — distinguishing ASI from SBIs, fidelity-adherent ASI from non-fidelity sensory approaches, and sensory processing difficulties from purely behavioral presentations — is essential for appropriate service planning, realistic family expectations, and defensible clinical documentation (Acuña et al., 2025; Piller, Glennon et al., 2026).

The evidence base for ASI has strengthened substantially in the last decade. The 2025 Acuña et al. systematic review — restricted exclusively to RCTs adhering to the ASI Fidelity Measure — found strong evidence for ASI supporting autistic children’s individualized occupational goals. The 2026 Piller, Glennon et al. systematic review adds good evidence across a broader age range (0–21) and population. Both reviews emphasize that fidelity is a prerequisite for outcome validity — interventions described as ASI but delivered without adherence to the fidelity measure are not the same intervention and cannot claim the same evidence base (Acuña et al., 2025; Piller, Glennon et al., 2026).

The 2025 Jurek et al. meta-analysis of sensory processing in ADHD — 30 studies, 5,374 participants — makes a clear clinical argument: sensory processing should be systematically assessed in all individuals referred for ADHD, not treated as an incidental or co-occurring curiosity. The large, consistent effect sizes across all four sensory processing patterns (SMD range 1.15–1.23) indicate that atypical sensory processing is a significant and consistent feature of ADHD that warrants direct clinical attention and intervention planning (Jurek et al., 2025).

Caregiver training is among the most consistently evidence-supported approaches across both the ASI and SBI literature. It is not a lower tier of intervention — it is a high-leverage strategy that extends the impact of direct therapy into the environments where children spend most of their time. Building structured caregiver training into every sensory processing treatment plan is both evidence-based and clinically efficient (Piller et al., 2025).

13. References

1. Acuña, C., Gallegos-Berrios, S., Barfoot, J., Meredith, P., & Hill, J. (2025). Ayres Sensory Integration® with children ages 0 to 12: A systematic review of randomized controlled trials. American Journal of Occupational Therapy, 79(3), 7903205180. https://doi.org/10.5014/ajot.2025.051023
2. Jurek, L., Duchier, A., Gauld, C., Hénault, L., Giroudon, C., Fourneret, P., Cortese, S., & Nourredine, M. (2025). Sensory processing in individuals with attention-deficit/hyperactivity disorder compared with control populations: A systematic review and meta-analysis. Journal of the American Academy of Child & Adolescent Psychiatry, 64(10), 1132–1147. https://doi.org/10.1016/j.jaac.2025.02.019
3. Oh, S., Jang, J. S., Jeon, A. R., Kim, G., Kwon, M., Cho, B., & Lee, N. (2024). Effectiveness of sensory integration therapy in children, focusing on Korean children: A systematic review and meta-analysis. World Journal of Clinical Cases, 12(7), 1260–1271. https://doi.org/10.12998/wjcc.v12.i7.1260
4. Piller, A., McHugh Conlin, J., Glennon, T. J., Andelin, L., Auld-Wright, K., Teng, K., & Tarver, T. (2025). Systematic review of sensory-based interventions for children and youth (2015–2024). Frontiers in Pediatrics, 13, 1720179. https://doi.org/10.3389/fped.2025.1720179
5. Piller, A., Glennon, T. J., Andelin, L., Auld-Wright, K., McHugh Conlin, J., Teng, K., & Tarver, T. (2026). Occupational therapy interventions using Ayres Sensory Integration® for children and youth (2015–2024): A systematic review. American Journal of Occupational Therapy, 80(1), 8001185030. https://doi.org/10.5014/ajot.2025.051130
6. Whiting, C. C., Schoen, S. A., & Niemeyer, L. (2023). A sensory integration intervention in the school setting to support performance and participation: A multiple-baseline study. American Journal of Occupational Therapy, 77(2), 7702205060. https://doi.org/10.5014/ajot.2023.050135

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