Thomas,

There is a saying, If you have seen one concussion, you have seen ONE concussion. No two are alike. Two different people with the same exact impacting force will have entirely personal experiences with symptoms. Prior impact history, differences in brain development, and a whole variety of differences may explain why some can tolerate more than others.

I don't understand what you refer to as 'gate.'

Some say we condition ourselves to tolerate different levels of stimuli. That may be true for an uninjured brain but the injured brain often has lost the ability to filter out certain kinds of stimuli.

If this is what you mean by gate, then, yes, it is an injury not a pattern that determines how much stimulation can be tolerated, at least for most of us with injured brains. Some can re-adapt to a level where they can tolerate the visual or auditory stimuli but from what I understand, this has more to do with some physical neurological recovery and maybe some learned skills at focusing despite the sensory overload. For example, I can tolerate and process more sounds if I close my eyes.

Years ago, a neuro did a AEP (Auditory Evoked Potential) exam. This measure the waveforms as auditory stimuli is taken in and processed. He was astounded that my brain have virtually no ability to 'gate' or filter out extraneous stimuli.

btw, Your friends who appear to tolerate head impacts may become more concussion symptomatic as they age. Anybody who allows their brain to be traumatized risks neurological deterioration. Studies have shown that the concussed brain has less tolerance for all kinds of stress factors.

Those with the higher intelligence tend to show more concussion symptoms.

Regarding blood flow, The Buffalo protocol has shown improvements in tolerance for physical exertion. It works by staying below the symptomatic level of effort and slowly increasing that level over a period of weeks.