ABSTRACT
In this chapter, the author concerns control of cognitive operations lasting seconds and fractions of a second. At the time-scale of minutes and seconds, the time-scale with which the analysis of cognitive skill has been mostly concerned, a natural unit of analysis of mental activity seems to be the cognitive task. Much of the success of the cognitive psychology has been manifest in its analysis of the performance of the particular tasks, such as comprehension of a spoken sentence, deciding the truth or falsity of a syllogism, deciding whether two visual forms are the same or different, recalling the words in a list, naming a familiar face or object, performing mental arithmetic, searching an array of the visual objects for a target, and many, many others. Norman and Shallice proposed a psychological model based on the production system architecture.
