Neuroscientists are excited by technological progress that facilitates brain mapping, the most sanguine of them  comparing their  growing abilities to tremendous advances that led to the unimaginable success of the Human Genome Project

请问老师，红字部分是独立主公还是表伴随呢？因为从句的主语和主句不同，个人认为应该是独立主格。但是从句和主语和主句的主语又存在联系，所以也不太确定。