We often talk of memory as though the things we know were stored away in boxes of the mind, like objects we keep in closets in our homes. But this raises many questions.
How is knowledge represented? How is it stored? How is it retrieved? Then, how is it used?
Whenever we try to answer any of these, others seem to get more complicated, because we can't distinguish clearly what we know from how it's used. The next few sections explain a theory of memory that tries to answer all these questions at once by sug- gesting that we keep each thing we learn close to the agents that learn it in the first place. That way, our knowledge becomes easy to reach and easy to use. The theory is based on the idea of a type of agent called a Knowledge-line, or K-line for short.
Whenever you get a good idea, solve a problem, or have a memorable experience, you activate a K-line to represent it. A K-line is a wirelike structure that attaches itself to whichever mental agents are active when you solve a problem or have a good idea. When you activate that K-line later, the agents attached to it are aroused, putting you into a mental state much like the one you were in when you solved that problem or got that idea. This should make it relatively easy for you to solve new, similar problems!
In other words, we memorize what we're thinking about by making a list of the agents involved in that activity. Making a K-line is like making a list of the people who came to a successful party. Here is another image of how K-lines work, suggested by Kenneth Haase, a student at the MIT Artificial Intelligence Laboratory who had a great deal of influence on this theory.
You want to repair a bicycle. Before you start, smear your hands with red paint. Then every tool you need to use will end up with red marks on it. When you're done, just remember that red means ‘good for fixing bicycles.’ Next time you fix a bicycle, you can save time by taking out all the red-marked tools in advance.
If you use different colors for different jobs, some tools will end up marked with several colors. That is, each agent can become attached to many different K-lines. Later, when there's a job to do, just activate the proper K-line for that kind of job, and all the tools used in the past for similar jobs will automatically become available.
This is the basic idea of the K-line theory. But suppose you had tried to use a certain wrench, and it didn't fit. It wouldn't be so good to paint that tool red. To make our K-lines work efficiently, we'd need more clever policies. Still, the basic idea is simple: for each familiar kind of mental job, your K-lines can refill your mind with fragments of ideas you've used before on similar jobs. In such a moment, you become in those respects more like an earlier version of yourself.