How do you go from left brain activity to right brain without having a stroke? I think the most traditional way is through extensive meditative practices. I have the sense that when I meditate, all I am doing is slowing the activity of the left brain. Good things then result from the right brain becoming more dominant.
Those few folks labeled "idiot savants" who have such amazing special skills seem to be operating almost entirely through the right brain. Sometimes they acquire this "skill" by accidental injury to the left brain, and sometimes they are born without the corpus callosum which is the structure which connects the two sides of the brain.
Here is what writer Peter Clothier has to say about brain hemispheres and meditation:
"One other thing I'd add: as a meditation practitioner, I have noticed that I can actually watch the mind switch from activity in one lobe to activity in the other. In this circumstance, I believe there is a choice. The "monkey mind" with its distracting thought processes is clearly the activity of the verbal, thinking left brain; as the mind moves more deeply into the meditative state, it can abandon left-brain activity in favor of a sense of total right-brain oneness with the ambient, sensate world, and relax into that state of bliss that Jill Bolte Taylor describes in her video. It's one of the great benefits one can reap in following the path the Buddha laid out. It's worth a try..."