[john70t]

We were genetically made to walk delicately in the woods. Our mind to seek out new stimulus that is barely precept-able: Which way is north. Temperature changes meaning rain. A bird over the hill being upset by something. That deer head peeking through the shrubs a few hundred yards away. Inflections in another persons face and voice which indicate their true thinking and true feelings.
There is no danger of overload. The mind is free to finely tune itself to all.
Pull it all in.
=Vacuum mode.

Modern society is full of over-stimulus danger to the sensory system. Honking. Loud sounds. Fatal traffic. Bright lights. Flashing colors on screens everywhere. Signs to read everywhere but only a few are very important. Unpredictable and sometimes randomly aggressive human behavior. Ultimatum personalities. Small lies and big ones. People filling every square foot of our surroundings which we have to adapt and respond to accordingly. Hurry up and rush rush rush.
Have to filter most of it out, to be able to hear our own brain.
Too much stimulus.
=Protective mode

I've read autism is actually hypersensitivity that shuts everything down under duress. Not sure.
Great thread.