ABSTRACT
Researchers often start with a simple model, system, or paradigm with which to derive some first principles, and progress to more complex phenomena and laws. Learning about single stimuli, uncomplicated by associations or rules relating them to other events, would seem to offer such a simple learning situation. This chapter discusses that stimulus repetitions reduce one form of responsiveness to a stimulus. It explains that stimulus exposure potentially can produce a number of other reactions: greater responsiveness, preference and liking, and speeded reactions. Habituation is a simple form of learning in which the organism learns something about a single stimulus. Habituation tasks have been used to study perception, learning, and even reasoning in infants. The cognitive capabilities of preverbal children are difficult to measure. The absence of a response does not mean an absence of knowledge. The dual-memory theory describes why massed stimulus presentations can produce more habituation than spaced presentations.
