Why Sensory Overload Isn’t About “Too Much”

Why Sensory Overload Isn’t About “Too Much”

A neuroscientist's view of sensory effort in Autism & ADHD

I’m starting a new series of articles in Psychology Today focused on demystifying sensorimotor issues in autism and ADHD—translating the science into plain speak without losing what actually matters.

In the first piece [link to article], I take on one of the most common misunderstandings: that sensory overload is about too much sound, light, or movement. What I argue instead is that overload is really about effort—the effort the brain has to put in when the world becomes hard to interpret.

Your brain is constantly trying to answer a simple question: What is happening right now, and does it matter? To do that, it has to stitch together sight, sound, touch, motion, and timing into a single coherent picture. When those signals line up, the brain relaxes. When they don’t, it has to work harder.

As I write in the article, “the brain works harder when information is unclear, and it eases off when things are easy to interpret.”

One of the examples I use is deliberately ordinary. A faint sound by itself is easy to ignore. A tiny flicker in your peripheral vision is easy to ignore. But when they happen together, your brain snaps to attention. “The world doesn’t just suddenly get loud. Instead, uncertainty skyrockets.”

That uncertainty is what creates overload.

What looks like hypersensitivity from the outside is often relentless problem-solving on the inside. The brain is constantly checking: Was that important? Was that a person? A threat? A mistake? In everyday environments—overlapping conversations, out-of-sync audio and visuals, visual clutter, subtle vibrations—those micro-decisions never really stop.

As I put it in the piece, “From the outside, this appears to be oversensitivity. From the inside, it often feels like work that never quite lets up.” For autistics and ADHDers, that work doesn’t fade quickly. It accumulates into fatigue, shutdown, or distress.

That’s why the solution isn’t just “make things quieter” or “reduce stimulation.” What really helps is making environments more predictable, more legible, and easier to parse. When the brain can quickly tell what’s happening and what matters, it doesn’t have to stay in high-alert mode.

Sensory overload isn’t about too much.
It’s about too much uncertainty for too long.