Sensory overload is that subjective feeling that the world is coming at you too fast, too loud, too big, too smelly, too rough, too bright. You want to run.
A cloudy day is like the sun high in the sky burning your retinas. A car travelling at 50kph feels like being in a jet fighter plane screaming down to earth. Auditory inputs are like pulsating rock concert speakers centimeters from your ears. A whispered conversation behind you drowns out your own conversation. Anything that touches irritates the skin. It literally hurts. Shaking hands with another burns and makes your bones feel like they’re being crushed. Taste turns odd. Olfactory hallucinations become the norm. Nothing is more disappointing than smelling French Toast, wobbling to the kitchen to find the stove off and the table clean with no French Toast or maple syrup in sight. On the other hand, smells grow like some sort of cartoon cloud hovering under your nostrils. After brain injury a boiled egg smells like rancid sulphur.
Sensory overload isn’t subjective though. It happens because of damage to the related networks and areas of the brain. It also happens because neurons are communicating slowly. Neural networks are propagating messages below average speed. And/or external inputs and outputs may occur at less-than-real-time speed so that the brain cannot process, analyze, integrate, and formulate output in normal time, giving rise to a feeling of being chronically behind the rest of the world. Or, worse, unable to keep up at all.
Neurostimulation therapies dial down sensory overload. Until they do, this kind of brain injury symptom will make it difficult to socialize, work, commute, attend medical appointments in a busy clinic, enjoy life.