The Attention Operating Characteristic: Examples from Visual Search

Even in the absence of eye movements, we show that subjects are able, upon instruction, to selectively attend to certain kinds of targets and parts of visual arrays. The major mechanism of altering attention is the switching of attention from trial to trial, although intermediate states of shared attention do occur. Attention operating characteristics are shown to be a useful way of describing such data and of assessing the compatibility of tasks to be performed simultaneously.