||Attention Routines and the Architecture of Selection.
Although we might all know what attention is (James, 1890), we do not all agree on what it does, except that it only does a limited amount of it. This limit, as described by Broadbent (1958), restricts the amount of the available information that can be passed on to higher processing. However, I show that this capacity limit is only one of three independent limits on the information available to higher processing. There is as well an acuity limit: a restriction on the density of items that still permits access to individual items. This resolution of selection is unexpectedly coarse in both space and time. In addition, there is a third bottleneck that I call the coding singularity. I argue that the information available from a selection is neither the raw image detail nor, when there is more than one item in the selection, the set of identities of the items. It is, instead, a single label for the entire pattern. These last two limits, acuity and singularity, may appear to be redescriptions of the same limit but they are not, as I describe later. The three limits--capacity, acuity, and singularity--are part of a framework for attention that I describe in this chapter. In this framework, attention is not one thing but a set of routines that are called on to perform specific functions during a task (cf. Shimamura, 2000; Ullman, 1984). The set of attention routines is identified by one defining characteristic: the initial and final states are reportable but intermediate states are not. I briefly outline this proposal and then I focus on the details of one of these functions, selection. (PsycINFO Database Record (c) 2007 APA, all rights reserved)