Understanding your child’s sensory system

Your child’s brain, in plain words

Think of the brain like a computer. There’s the hardware, the physical parts, and the software, the way those parts talk to each other. A child can have a perfectly healthy brain and still have trouble with the “software”: how their nervous system takes in touch, movement, sound and sight, and turns it into action.

When that information comes in a little too strong, a little too weak, or a little jumbled, everyday things like getting dressed, sitting at dinner or riding in the car can feel much harder than they should. That’s what our occupational therapists work on. And just like software, it can be updated.

About 80 percent of the brain is involved in processing what we sense. That’s why sensory differences can show up almost anywhere: in behavior, sleep, eating, handwriting and play.

The three foundation senses

Everyone learns about the five senses. Three “hidden” senses do just as much work, and they form the foundation for almost everything else your child learns.

Touch (tactile)

Touch develops first, about nine weeks into pregnancy. It does two jobs: it keeps your child safe (“something touched me!”) and it tells them what they’re touching (soft, rough, cold, round). Touch supports bonding, calm behavior, eating a variety of foods, and fine motor skills like buttons, zippers and writing.

Movement and balance (vestibular)

Inside the inner ear, this system senses gravity and movement. It’s fully adult-sized before birth, which shows how important it is. It anchors every other sense and supports balance, coordination, focusing the eyes, muscle tone, using both hands together, and even following steps in order.

Body awareness (proprioception)

Sensors in the muscles and joints tell your child where their body is without looking, and how much force to use. It’s how they know to hold a cup firmly without crushing it, or press hard enough to write without tearing the paper. Heavy muscle work, like climbing, pushing and jumping, naturally helps kids feel calm and organized.

Development builds from the ground up

Picture a house. The three foundation senses are the base. Balance, body awareness and motor planning sit on top of them. Then eye-hand coordination, attention and language. Then learning, reading, math and behavior.

If there’s a crack in the foundation, it can show up in the walls and the ceiling. That’s why our therapists often work on sensory foundations, not only on the handwriting or the meltdown you’re seeing.

The same need can look different at every age

• Babies: fussiness with textures, trouble sleeping, feeding challenges.
• Toddlers: big meltdowns, avoiding things, slower motor milestones.
• Preschoolers: clumsiness, big feelings, hard transitions.
• School age: handwriting, reading, focus and classroom behavior.

Four kinds of sensory challenge

Many kids show a mix of these. They often overlap, and none of them are “bad behavior.” They’re the nervous system doing its job a little too much or too little.

1. Sensory defensiveness

Everyday sensations feel like threats. You might see strong reactions to tags, haircuts, nail clipping, messy hands or unexpected touch; trouble in crowds; very particular food choices; or a child who seems bossy or controlling, often a smart way of avoiding surprises.

2. Sensory modulation

The brain’s filter for “important” versus “background” doesn’t work the same way every time. Some kids notice everything: the hum of the lights, the kid tapping two desks away. Others need to keep moving, fidgeting or humming to stay alert. These kids usually do best with routine.

3. Sensory registration

The nervous system needs a stronger signal before it notices. Your child may not seem to hear their name, may not notice a scrape, may slouch and tire easily, or may crash, jump and spin to “wake up” their body.

4. Sensory integration

The senses need to work as a team. When they don’t, movement can look clumsy, learning a new physical skill takes longer, and using both sides of the body together (catching, cutting, riding a bike) is harder.

Why some days are harder than others

Every child moves between three zones: under-alert (slow, sleepy, hard to engage), just right (calm and ready to learn), and over-alert (anxious, reactive, overwhelmed). No child can fully control which zone they’re in. Therapy and home routines help them spend more time in “just right.”

After a meltdown, stress hormones really can wipe out short-term memory. If your child can’t explain what happened, they likely aren’t avoiding the question. Wait until everyone is calm, then keep it short and kind.

What helps at home

• Keep routines steady. Same time, same place, same tools. Predictability lowers stress.
• Give a heads-up before changes. “Five more minutes, then shoes on.”
• Add heavy work. Carrying groceries, pushing a laundry basket, animal walks and pillow crashes help bodies feel organized.
• Turn down the background. TV off during homework, a quiet corner for breaks.
• Plan movement before hard tasks. Our therapists find that the calming effect of heavy work and deep pressure often lasts an hour or two, and a good dose of movement in the morning can help for much of the day.
• Follow your home program. Clinic sessions challenge the nervous system; daily practice at home is where the change happens.

Our free Home Programs Handbook has dozens of these activities, in English and Spanish.

What therapy looks like

Sensory-based occupational therapy looks like play, because play is how kids learn best. It starts with an evaluation to understand which systems need support. Then your child’s therapist plans activities that gently challenge the nervous system: swings, climbing, crash pads, textures, obstacle courses. We check progress regularly and coach you on what to do at home.

Our occupational therapists focus on how sensory differences affect everyday life: getting dressed, eating with the family, sitting in class, playing with friends. The goal is a calmer, more confident kid.

When to ask for help

Reach out if sensory reactions are getting in the way of daily life: meals, sleep, dressing, school, friendships or family outings. You don’t need to be sure. Our free milestone checklist can help you organize what you’re seeing, and our team is happy to talk it through.

Adapted from Oaklin Lane’s family presentation “Understanding Your Child: A Family Guide to Sensory Processing and Development.” For education, not a diagnosis.