Hofstadter, Dennett - The Mind's I

ence has begun to analyze the human mind into its functional components. This comesout most graphically in the famous split-brain cases. (See “Further Reading” for detailsand references.) There is noting very problematic in granting that the people who haveundergone severing of the corpus callosum have two somewhat independent minds, oneassociated with the dominant brain hemisphere, and another associated with the nondominantbrain hemisphere. This is not problematic, for we have grown used to thinkingof a person’s mind as an organization of communicating subminds. Here the lines ofcommunication have simply been cut, revealing the independent character of each partparticularly vividly. But what remains problematic is whether both subminds “have aninner life.” One view is that there is no reason to grant consciousness to the non-dominanthemisphere, since all that has been shown is that that hemisphere, like many unconsciouscognitive subsystems, can process a lot of information and intelligently control somebehaviour. But then we may ask what reason there is to grant consciousness to thedominant hemisphere, or even to the whole, intact system in a normal person. We hadthis thought this question frivolous and not worth discussing, but this avenue forces us totake it seriously again. If on the other hand we grant full “inner life” consciousness to thenon-dominant hemisphere (or more properly to the newly discovered person whose brainis the non-dominant hemisphere), what will be said about all the other informationprocessingsubsystems posited by current theory? Is the Freudian crutch to be taken awayagain at the expense of populating our heads, quite literally, with hosts of subjects ofexperience?Consider, for example, the striking discovery by the psycholinguists JamesLackner and Merril Garrett (see “Further Reading”) of what might be called anunconscious channel of sentence comprehension. In dichotic listening tests, subjectslisten through earphones to two different channels and are instructed to attend to just onechannel. Typically they can paraphrase or report with accuracy what they have heardthrough the attended channel but usually they can say little about what was going onconcomitantly in the unattended channel. Thus, if the unattended channel carries a spokensentence, the subjects typically can report they heard a voice, or even a male or femalevoice. Perhaps they even have a conviction about whether the voice was speaking in theirnative tongue, but they cannot report what was said. In Lackney and Garrett’sexperiments subjects heard ambiguous sentences in the attended channel, such as “He putout the lantern to signal the attack.” Simultaneously, in the unattended channel one groupof subjects received a sentence that suggested the interpretation of the sentence in