The "paralysis of the mind" that I enjoy is not a species of stupor. Fishing can do it for me, of course, but so can a long walk or a cold dawn, a well-written novel, an unexpected road trip, a stained-glass window, a cattail marsh.
What I seek is not relief, precisely, although it does feel good to forget that part of your brain which is responsible for fear, doubt, and expectation. Environmental psychologists (they exist!) describe this as "attentional restoration." Which might be related to what Mihaly Csikszentmihalyi, who studies the state of being intensely absorbed in a task, calls flow.
According to the Edge Foundation, the name is pronounced "chick-SENT-me-high."