Much of this should be review by now, but there are still good insights in this chapter. Economy of representation is rarely discussed in the psychological literature; one of the best analysis ever written on this topic (although it may appear to be about something else) is James' chapter on habit. Note the adaptive benefits of habit as an economical mechanism. James begins the chapter with a discussion of pasticity; one of the central issues in plasticity is the sensitivity/stability issue. This issue regards the need for learning (sensitivity) as balanced against the need to retain what one already knows (stability). An emphasis in the chapter that surprises some readers concerns the moral dimension. How does the central role of frequency in habit lead into the moral concern?
Note the importance of habit in the functioning of an organism. Consider how effective an organism that relies primarily on processing information would be in a hostile environment if it could not form habits.
Booker and Kaplan look at the issue of learning rules, that is, under what circumstances is the learning of the system enhanced. We've talked about the two molecular learning rules: contiguity and repetition/frequency, and you will see them referred to in this paper. But you will also get your first glimpse at the four molar learning rules: importance, payoff, impact, and match/mismatch. The four molar learning rules make use of the two molecular learning rules by enhancing their effect under certain circumstances. What are these circumstances and in what way is this enhanced learning adaptive?