Pursuing some of my recent posts on the idea that listening and reading create different experiences–without making a judgment regarding superiority–a forum on myspace directed my attention to the following study from Carnegie Mellon demonstrating that listening and reading activate different parts of the brain, and especially that listening requires a great deal more working memory–what used to be called short-term memory–in order to do the semantic processing necessary for understanding.
“The brain constructs the message, and it does so differently for reading and listening. The pragmatic implication is that the medium is part of the message. Listening to an audio book leaves a different set of memories than reading does. A newscast heard on the radio is processed differently from the same words read in a newspaper,” said Carnegie Mellon Psychology Professor Marcel Just, coauthor of the report that appears in this month’s issue of the journal Human Brain Mapping.
This seems to go along with my general perception in yesterday’s post that in reading to a text we are experiencing a different object of consciousness–in some sense a different work of literature–that we do when we listen to a text. I’m not exactly a phenomenologist, but we might be able to go with this to say that our experiences of texts are how they appear in consciousness. To the degree that listening and reading activate the brain differently, I would hypothesize that the conscious mind is experiencing two completely different “objects,” objects here understood to mean our mental experience of words and their meanings.
First, during reading, the right hemisphere was not as active as anticipated, which opens the possibility that there were qualitative differences in the nature of the comprehension we experience in reading versus listening. Second, while listening was taking place, there was more activation in the left hemisphere brain region called the pars triangularis (the triangular section), a part of Broca’s area that usually activates when there is language processing to be done or there is a requirement to maintain some verbal information in an active state (sometimes called verbal working memory). The greater amount of activation in Broca’s area suggests that there is more semantic processing and working memory storage in listening comprehension than in reading.
Because spoken language is so temporary, each sound hanging in the air for a fraction of a second, the brain is forced to immediately process or store the various parts of a spoken sentence in order to be able to mentally glue them back together in a conceptual frame that makes sense. “By contrast,” Just said, “written language provides an “external memory” where information can be reread if necessary. But to replay spoken language, you need a mental playback loop, (called the articulatoryphonological loop) conveniently provided in part by Broca’s area.”
This makes a great deal of sense to me and is consonant with some other things that I’ve read about how literacy accompanies the general atrophy of personal and cultural memory. Oral cultures require much more prodigious uses of memory, and I would suspect that people who train themselves to listen well–perhaps like those who listen to audiobooks!–are also developing memory capacities. At least, following this study, the short term memory would have to become much more exercised and probably developed by the consistent effort to remember the passing sounds and having to fit them together into meaningful units of language.
(Side note along these lines, my colleague who is visually impaired has a prodigious memory of detail of what seems to me to be almost everything. By comparison, I remember vaguely that an idea is found somewhere in a particular part of a book that I underlined at one point).
Following this out, and thinking through my earlier statements that what we need is more careful consideration of what kinds of things are lost and what kinds of things are gained through certain kinds of reading (or listening), we might well say that if we are entering into what is called a secondary oral culture this could signal good things for memory.
At least this would be the case if the culture that’s developing is one that would put a high premium on listening skills. I’m not really sure that it is given the dominance of the visual on the internet and in film and television. Still, it’s and interesting idea. It would be interesting to figure out if people who listen to audiobooks in a regular and devoted fashion show more highly development memory capacity–either short or long term–than those of us who spend more time reading.
This would leave for further study the question of what reading develops in the brain. I suspect it would be something along the lines of analytical skills, but I’m not sure. It also may explain the stereotype of the absent-minded professor. Maybe we really are absent-minded because in being devoted to books our short-term memory has atrophied!