As part of a national, multi-center, NIH-sponsored study, Baylor Scott & White The Heart Hospital – Plano is comparing the effect of deep, low and moderate hypothermia during aortic arch surgery on post-surgery brain function and functional connectivity. Studies have confirmed the protective effect of induced hypothermia during cardiac surgery, but the new trial will analyze the ideal temperature for hypothermic circulatory arrest in collaboration with the National Institutes of Health (NIH).