ABSTRACT
One conclusion from the previous chapter is that the AFM may define stages in terms of clusters of interacting variables but has nothing to say about the processes in a particular stage. The present chapter revisits the stages, with an emphasis on processes within stages, which is done by considering theoretical notions on the effects of prototypical, experimental variables, many of which appear to have applied significance as well. Figure 3.2 depicts three major categories that presumably are concerned with perception, response selection, and motor aspects. The perceptual group consists of three stages that are concerned with early processing (preprocessing), the analysis of stimulus features (feature extraction), and the interpretation of a stimulus as a meaningful entity (identification). On the motor side, motor programming and motor adjustment were distinguished, and a further sequencing stage was called upon in the case of composite motor responses (Fig. 3.5). The stage structure is the organizing principle of this chapter, but the discussion is not limited to AFM-related research because much of the pertinent research emanated from other theoretical arguments. Hence, the forthcoming sections are not rigidly coupled to the stages of Fig. 3.2.
