I saw a demonstration of something like this when I first started working in nuclear power plants.
At nuke plants, the Health Physics workers are the ones who have ultimate control in all radiation areas. They are, in effect, the controllers of everyone’s exposure to radiation. Sometimes they are required to tell people to evacuate an area, to stop working immediately, down tools, and walk away. Sometimes also, construction workers (and supervisors) being as they are, and radiation being completely undetectable by feel, smell, taste or any kind of visible cue, the workers are not willing to simply walk away on someone’s say-so.
The Health Physics workers on plants in the USA, coast to coast, and without regard to what company they work for, wear a particular shade of purple hard hat. (It’s the same color purple that is used in US radiation safety signs.)
In the demonstration I witnessed, an HP trainer had a construction worker in a radiation safety class (a mandatory class for all new workers at all plants) hold his arm out straight and resist the trainer’s attempt to deflect it downward. It was no contest; the construction worker was much larger and stronger than the HP guy, who could barely move the construction worker’s arm. Then the HP guy put on his hard hat, and had the construction worker simply focus his view on that hard hat as he attempted the same demonstration of strength. This time, the construction worker couldn’t hold his arm up, no matter how hard he tried. As long as he was looking at that particularly colored hard hat, he had much less strength than he normally would.
I don’t know the biochemical or biomechanical reason why this was so, but I have no doubt that it was an honest demonstration. Pretty impressive, I thought.