Abstract
Several sources of evidence suggest that people can maintain only 3–4 items in visual working memory, each of which contains multiple features (but not multiple parts). Is the working memory system that stores these items best conceived as (a) a set of discrete, fixed-resolution “slots,” or (b) a resource that can be allocated flexibly to provide more or less accurate representations depending on the number of items represented? To address this question, we are conducting a series of experiments examining change-detection performance for simple features such as color and orientation. In some experiments, we are manipulating the discriminability of the change and the number of items to be stored in memory. In others, we are using attention-directing cues to examine whether working memory resources can be flexibly allocated. Preliminary results are consistent with the proposal that the basic elements of visual working memory are stored as discrete, fixed-resolution, slot-like representations, although continuously variable resources may be used to combine these primitive elements into more complex structures.