we can either modify a memory or change how we represent the present scene. For example, suppose you need a hammer but can only find a stone. One way to turn that stone to you, p,rrpbres would be to make it fit your memory of a hammer's appearance-for example, by making your description of the stone include an imaginary boundary that divides it into two parts, to serve as handle and as head. Another way would be to make your hammer frame accept the entire stone as a hammer without a handle. Either scheme will make the memory match the description