Just Because: 'The Future of the Mind' (Part 1)

I am currently reading Michio Kaku's The Future of the Mind, which I got as a birthday present (thank you, Nancy!). I'm not even a fifth of the way through it and will undoubtedly stumble upon many more fascinating passages (which is why I titled this post "Part 1"), but I did come upon one the other day that had me almost breathless with wonder. The author had been discussing the corpus callosum, which links the two sides of our brain, and patients whose corpus callosum was severed in an effort to mitigate their epileptic seizures. He was discussing the work in this area by Dr. Roger Sperry of the California Institute of Technology. The following excerpt is from pages 38-39:

   Dr. Sperry, after detailed studies of split-brain patients, finally concluded that there could be two distinct minds operating in a single brain. He wrote that each hemisphere is "indeed a conscious system in its own right, perceiving, thinking, remembering, reasoning, willing, and emoting, all at a characteristically human level, and ... both the left and right hemisphere may be conscious simultaneously in different, even in mutually conflicting, mental experiences that run along in parallel."
   When I interviewed Dr. Michael Gazzaniga of the University of California, Santa Barbara, an authority on split-brain patients, I asked him how experiments can be done to test this theory. There are a variety of ways to communicate separately to each
hemisphere without the knowledge of the other hemisphere. One can, for example, have the subject wear special glasses on which questions can be shown to each eye separately, so that directing questions to each hemisphere is easy. The hard part is trying to get an answer from each hemisphere. Since the right brain cannot speak (the speech centers are located only in the left brain), it is difficult to get answers from the right brain. Dr. Gazzaniga told me that to find out what the right brain was thinking, he created an experiment in which the (mute) right brain could "talk" by using Scrabble letters.
   He began by asking the patient's left brain what he would do after graduation. The patient replied that he wanted to become a draftsman. But things got interesting when the (mute) right brain was asked the same question. The right brain spelled out the words: "automobile racer." Unknown to the dominant left brain, the right brain secretly had a completely different agenda for the future. The right brain literally had a mind of its own.
   Rita Carter writes, "The possible implications of this are mind-boggling. It suggests that we might all be carrying around in our skulls a mute prisoner with a personality, ambition, and self-awareness quite different from the day-to-day entity we believe ourselves to be."