The Processing Demands of Writing
Mark Torrance and David Galbraith
To facilitate the production of the text that you are now reading I (Torrance) am using a common word processing application running on a personal computer. As I write, the word processor is monitoring what I typed for spelling errors. If I asked it to, it would also check to see whether the text I produced is grammatical (according to its own, somewhat arcane, criteria). Elsewhere on the computer, an e-mail application is running, monitoring for incoming mail, as is bibliographic software that communicates with the word processor when I require it to do so. These are just the things I know about. In the background there appear to be a further 28 processes running, at least some of which are, I assume, essential to the effective working of the computer. Each of these is constantly either manipulating information or standing ready to do so. To accomplish all of this, each process draws, to varying degrees, on both the computer's random-access memory and its central processor. My current computer has plenty of RAM and a fast processor, and will multitask quite happily across all of these processes. This would definitely not have been true of the computer that I used 10 years ago. On that machine, running just two applications at once resulted in a radical reduction in performance and any further demands would make it grind to a halt.
There is, of course, another informationprocessing device involved in the production of this text. While I am Writing, my mind is either simultaneously engaged in or rapidly switching between processes that perform all or most of the following functions: monitoring the thematic coherence of the text; searching for and retrieving relevant content; identifying lexical items associated with this content; formulating syntactic structure; inflecting words to give them the necessary morphology; monitoring for appropriate register; ensuring that intended new text is tied into the immediately preceding text in a way that maintains cohesion; formulating and executing motor plans for the key strokes that will form the text on the screen; establishing the extent to which the just-generated clause or sentence moves the text as a whole nearer to the intended goal; and revising goals in the light of new ideas cued by the just-produced text. These processes cannot all be performed simultaneously. Attempting to do so, as with a 10-year-old computer, would result in overload and Writing would stop. The fact that I am Writing this at all, therefore, is testament to the Writing system's ability to coordinate and schedule a number of different processes within the limited processing resources afforded it by my mind.
Even with this coordination, the production of anything other than trivial text often comes close to crashing the system, as the following quote graphically describes:
The initial gurgitation of material builds up a
high pressure of nervous excitement leading to
such physical symptoms as redness in the face,