I think they are looking at a middle set of symptoms and secondary brain activity and deluding themselves into thinking they are at a primary cause level. The closest to primary I've seen is the mini-column cortex research which offers at least a partial cause perspective.
However, the mini-column size/distribution doesn't seem to be a sufficient cause. Combined with "intense world"/saturated sensory information seems to give a pretty good range of coverage. I think ultimately the fuzzy boundaries and symptoms are an overlap of 3 to 4 different brain variants, none of which are singularly an issue a few are related to giftedness.
