Automatic and controlled processing revisited.

The theory of automatic and controlled processing outlined in Schneider and Shiffrin (1977) and in Shiffrin and Schneider (1977) is defended in the present note. We argue that the criticisms of Ryan (1983) range from irrelevant to incorrect, based on a brief review of data from the 1977 articles and on some more recent publications. The evidence Ryan discusses comes from the prememorized-list paradigm, a paradigm that undoubtedly involves automatic and controlled processes but probably not automatic detection and controlled search. We argue that a variety of mechanisms consistent with our general theory, some automatic and some controlled, could be operating in the prememorized-list paradigm and can explain the observed results. A theory of automatic and controlled processing was outlined and given empirical support in the articles of Schneider and Shiffrin (1977) and Shiffrin and Schneider (1977). The characteristics of both types of processes were established through examination of particular examples of each of these classes of processes. These examples, of critical importance in many search and attention tasks, were termed automatic detection and controlled search, and their characteristics were determined empirically. In particular, in memory- or visual-search tasks, consistent mapping (CM) refers to paradigms in which targets and distractors never exchange roles over trials of the study. Varied mapping (VM) refers to paradigms in which targets on one trial may be distractors on another, and vice versa. We demonstrated that extended testing in CM paradigms led to a marked flattening of the set-size functions and to a number of other prominent effects. We termed the processes used by subjects, automatic detection. In contrast, the use of a VM procedure, however extended, leaves intact the form and the slope of the set-size function. We termed the processes used in this situation, controlled search. Based on the findings, we postulated that automatic processing is generally a fast, parallel, fairly