The next phase of the work was when Joseph LeDoux and I came up with the idea of the interpreter. Twenty-five years into studying these patients we finally got around to asking the patients, "Why did you do that?" after they had a response with the left hand that was being governed by the separated, silent, speechless right hemisphere. We began to understand that the left hemisphere "made up" a story as to why the patient did what he/she did, and in that moment we began to see the cardinal feature of the left hemisphere: the ability to interpret actions generated outside its realm of conscious awareness.
(12 April 2011). "Interview with Michael Gazzaniga". Annals of the New York Academy of Science.