"...makes sense that cramming into cities with unnatural lights and disrupting biological rhythm would make them go haywire"

Then what does this suggest? Why does "unnatural light" (ignoring that humans have built "unnatural light" fires for ~1.7 million years) make a brain go haywire, but not, say, clipping one's toenails? Or reading books, or sitting on chairs, or being blasted by radio waves, or running on treadmills, or traveling over 15mph, or wearing clothes, or flying in airplanes, etc. What are you saying?