SI therapy, short for sensory integration therapy, is a type of occupational therapy designed to help people (most often children) whose brains have difficulty processing information from their senses. Developed by occupational therapist and neuroscientist A. Jean Ayres in the 1970s, the approach uses guided, play-based activities to help the nervous system get better at receiving, sorting, and using sensory input from touch, movement, balance, body position, sight, sound, smell, and taste. It is most commonly used with children who have autism spectrum disorder, ADHD, or sensory processing difficulties that interfere with everyday life.
How Sensory Processing Problems Show Up
Your brain constantly takes in information from your senses and organizes it so you can respond appropriately. For some children, that process doesn’t work smoothly. They may be hypersensitive, reacting intensely to sounds, textures, or lights that don’t bother other kids. Or they may be hyposensitive, barely registering sensations and actively seeking out intense input by rocking, spinning, mouthing non-food objects, or crashing into things.
These processing difficulties often ripple outward. Children with sensory processing deficits frequently struggle with motor skills, balance, and hand-eye coordination. They may have trouble with tasks like getting dressed, using utensils, handwriting, or tolerating a noisy classroom. The behaviors that result, from meltdowns in a grocery store to avoidance of playground equipment, can look like defiance or anxiety, but the root is neurological: the brain isn’t organizing sensory information efficiently.
The Idea Behind SI Therapy
Ayres’ central insight was that the brain can change in response to the right kind of sensory experience, a concept now understood as neuroplasticity. SI therapy is built on the premise that when a child engages in carefully chosen activities rich in the specific sensory input they need, the nervous system gradually improves its ability to process and integrate that information. Over time, this is meant to translate into better self-regulation, stronger motor skills, and greater ability to participate in daily life.
Ayres’ original work emphasized three sensory systems that are less obvious than sight and hearing: the tactile system (touch), the vestibular system (balance and movement through space), and the proprioceptive system (awareness of where your body is and how much force your muscles are using). Modern SI practice still prioritizes these three but incorporates all sensory systems when relevant.
One important principle is that the sensory input needs to be active, not passive. A child swinging on a trapeze, timing a release to land on a pile of cushions, is simultaneously processing proprioceptive input from gripping and flexing, vestibular input from the swinging motion, and visual input from spotting the target. That kind of natural, multi-sensory challenge is what the therapy aims for. Simply spinning a child in a chair or brushing their skin without their active participation doesn’t appear to create the same opportunity for the brain to integrate information.
What a Typical Session Looks Like
SI therapy takes place in a clinic equipped with specialized tools: platform swings, trampolines, climbing walls, ball pits, textured surfaces, resistance tunnels, and weighted items. A session looks a lot like structured play. The therapist guides the child through activities tailored to their specific sensory profile, adjusting the challenge in real time to keep the child engaged but slightly outside their comfort zone.
A child who avoids touch might gradually explore bins filled with sand, dried beans, or textured objects. A child who craves movement might work on a suspended swing that demands core strength and balance. A child with poor body awareness might push heavy carts, carry weighted backpacks, or navigate obstacle courses that require precise coordination. The specific equipment isn’t the point. What matters is the individualized sensory-motor experience the activity provides.
Sessions typically run 45 to 60 minutes. Research protocols that have shown positive outcomes generally use a high-frequency model: two to three sessions per week for six to ten weeks. That adds up to roughly 18 to 30 sessions in a full course of treatment, though many children continue longer depending on their needs and progress.
SI Therapy vs. Sensory-Based Interventions
One source of confusion is that “sensory integration” gets used loosely to describe things that aren’t actually SI therapy. Weighted vests in the classroom, fidget tools at a desk, “sensory diets” of scheduled movement breaks, and brushing protocols are all sensory-based interventions (SBIs). They borrow individual elements from sensory integration theory, but they aren’t the same thing as formal SI therapy.
True Ayres Sensory Integration therapy is delivered by a trained occupational therapist in a clinic setting, involves individualized assessment, and uses progressively challenging activities that target identified sensory processing deficits. SBIs, by contrast, are typically simpler accommodations applied in a classroom or home. Both can be useful, but the research evidence behind them is different, and conflating the two has muddied the conversation about whether “sensory integration” works.
What the Evidence Says
A large meta-analysis reviewing 23 randomized controlled trials found that SI therapy produced meaningful improvements in two key areas. Motor skills improved with a moderate effect size, and daily functioning (things like self-care, participation in school, and social engagement) showed even stronger gains. The biggest improvements appeared in individualized goals, the specific targets a therapist and family set together for each child.
The picture isn’t uniformly positive, though. The same analysis found that balance, visual construction skills, and general sensory processing scores did not show statistically significant improvement. And while children with autism are more likely than their peers to have sensory processing problems, the evidence for SI therapy as a standalone treatment for autism remains limited and inconclusive. It appears most useful as one piece of a broader support plan rather than a cure-all.
What Families Can Do at Home
Therapists often recommend carrying sensory strategies into daily life between sessions. These don’t replace clinic-based therapy, but they can help a child stay regulated throughout the day. Common suggestions include letting a child sit on an air cushion that allows gentle movement during homework, using a weighted lap blanket during calm activities, and setting up play stations with sand, water, beans, or textured materials that invite exploration.
For children who seek heavy input, wearing a snug weighted hat or a backpack loaded with books (padded straps, weight adjusted to the child’s comfort) can provide the proprioceptive feedback their nervous system craves. The goal with all of these is the same as in clinic: giving the nervous system organized, purposeful sensory input so the child can focus, self-regulate, and engage more comfortably with the world around them.