What are the eight sensory systems in autism?

The five familiar ones (sight, hearing, touch, taste, smell) plus three that matter a lot for regulation: vestibular (balance and movement), proprioception (where your body is in space) and interoception (signals from inside the body such as hunger, heartbeat and needing the toilet). Autistic children often process some of these more or less intensely than other children.

What is the difference between sensory over-responsiveness and under-responsiveness?

An over-responsive child reacts strongly to input others barely notice: labels, hand dryers, light touch. An under-responsive child needs more input to register it, so they may crash into things, chew, spin, or not notice pain or a full bladder. Many children are both, in different senses, on different days.

What is co-regulation and why does it come first?

This guide uses co-regulation to describe adult support during distress. Children differ in the help they need. The ladder is an editorial organizing aid, not a validated developmental sequence or proof that a child cannot regulate independently.

Is polyvagal theory scientifically proven?

No. Its core claims about vagus nerve anatomy and evolution are disputed by physiologists, and the debate is ongoing in peer-reviewed journals. Its practical idea, that people move between a calm-and-social state, a fight-or-flight state and a shutdown state, is still a useful map for parents, as long as it is treated as a map and not a diagnosis.

Sensory Systems and the Regulation Ladder

You have a diagnosis, or you are far enough along to know that your child's body reacts to the world differently. Some days the tag on a shirt is a crisis. Other days they crash into the sofa for an hour and seem to need it. This page gives you the vocabulary for that, and a ladder you can use at home tonight.

The eight senses, in plain words

Most of us learned five senses. Occupational therapists work with eight, and the extra three explain most regulation trouble in young autistic and ADHD children.

Sense	What it does	What it can look like when it is off
Sight	Light, colour, movement	Squinting under fluorescent lights, staring at spinning things
Hearing	Sound, pitch, background noise	Hands over ears at the hand dryer, or not answering to their name in a noisy room
Touch	Pressure, texture, temperature	Hates labels and haircuts, or does not notice a scraped knee
Taste and smell	Flavour, odour	Refuses foods by texture or smell, gags at the cafeteria
Vestibular	Balance and movement, from the inner ear	Spins without getting dizzy, or panics on a swing
Proprioception	Where your body is in space, from muscles and joints	Crashes, squeezes, chews, pushes; seems "too rough"
Interoception	Signals from inside: hunger, thirst, heartbeat, needing the toilet, feeling hot	Melts down "out of nowhere" when actually hungry; toileting is hard; cannot say "I feel sick"

Notice which sensations your child seeks or avoids, and bring those observations to an occupational therapist. We do not claim that one sensory system is the foundation of regulation or attention.

Over-responsive, under-responsive, and both

Sensory differences run in two directions, and one child can run both ways.

Over-responsive: the volume knob is turned up. Light touch feels like a shove; a vacuum cleaner is unbearable; new food smells make them gag. These children avoid, cover, flee.
Under-responsive: the volume knob is turned down. They need more input to register it. They seek: spinning, jumping, chewing, mouthing, crashing, loud noises. They may not notice pain, cold or a full bladder.

The pattern often flips by sense: hates the blender, loves to be squeezed. Responses can also differ from day to day. Motor differences sit alongside this. A large meta-analysis found motor coordination differences big enough that the authors called them a core feature of autism. ¹ Discuss movement concerns with a clinician; one behaviour does not identify its cause.

The regulation ladder

This is an editorial organizing aid, not a validated sequence or a test of your child. A person may not fit one description, and the labels do not identify the cause of distress.

Comfortable and engaged. Note what your child enjoys; eye contact is not required.
More active or unsettled. Notice changes without assuming they need to be stopped.
Having difficulty with demands. Consider whether a pause, fewer choices, or a familiar support would help.
Very distressed. Follow the individual safety plan agreed with the adults supporting your child.
Quiet or tired afterwards. Offer space or company according to their needs; do not assume a fixed recovery time.

Discuss the patterns you observe with your child’s clinician. Do not use these labels to prescribe deep pressure, restraint, weighted products or a particular movement activity. See the support plan.

Co-regulation first

Our practical starting point is adult support and a predictable environment. The amount and kind of help a child needs varies; the ladder below is an organizing aid, not a validated developmental hierarchy.

Check what support you need too. Taking a pause or asking another adult for help can be part of the plan; a difficult moment is not proof that you failed to stay calm. See parent support.

You might try a shared activity your child enjoys, such as walking or dancing. Stop or adapt it if it adds discomfort. We have not established a research-backed claim that shared rhythm calms two nervous systems.

Where the disagreement is

Polyvagal theory’s neuroscience is contested. A 2023 critique challenged five core premises about vagus-nerve anatomy and evolution. The Polyvagal Institute publishes the proponents’ response. These are opposing positions, not a settled mechanism for this ladder. ^{2, 3}

We use the three-state map as a way to organize observations, not to explain a child's vagus nerve or diagnose their state. Ask a qualified clinician about any proposed sensory program and its goals. Try things; keep what your child responds to.

Discuss supports that fit your child

You might ask your child or clinician about a chosen retreat spot, tolerable clothing, or ways to preview a change in routine. Notice comfort and preferences rather than assuming a particular sensory activity will work. These are editorial prompts, not treatment instructions.

For children under 7, ask your CLSC about Agir tôt. ⁵ See who does what.

This week

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Write the five rungs on a card and stick it on the fridge. For two days, note which rung your child is on at breakfast, after daycare, and at bedtime.
Ask your child’s clinician about one difficult transition and which supports to try.
Notice your own rung once a day before you respond to your child.