Under the influence of mushrooms, overall brain activity drops, particularly in certain regions that are densely connected to sensory areas of the brain. When functioning normally, these connective “hubs” appear to help constrain the way we see, hear and experience the world, grounding us in reality. It seems that a lot of brain activity is used to keep the world very ordinary and very familiar. They are also the key nodes of a brain network linked to self-consciousness and depression. Psilocybin cuts activity in these nodes and severs their connection to other brain areas, allowing the senses to run free.