Learning

This chapter focuses on the learning process of insects. Learning involves an enduring change in behavior with experience, the change usually progressing gradually with continued experience to some asymptote. Learned behavior is often modified by novel experiences, and effects of experience eventually wane if not reinforced. Learning can be categorized as nonassociative or associative. Nonassociative learning includes habituation and sensitization. Habituation involves the waning of a response to a stimulus upon repeated presentation of that stimulus. Associative learning involves pairing a stimulus with another stimulus, or with a motor pattern, such that the response to the first stimulus is altered as a consequence of the pairing. Associative learning is typically evaluated in two kinds of paradigms: classical, Pavlovian, conditioning, and instrumental conditioning. Additionally, in a sense, the function of associative learning is obvious. Animals learn by association to orient toward stimuli predicting positively rewarding resources such as sugar, pollen, food plants, hosts, and away from stimuli predicting negatively rewarding events, shock, heat, toxins, predators. Likewise, habituation is a means for reducing energy-wasteful, time-consuming responses to meaningless stimuli. In either case, however, learning is needed only if the appropriate responses cannot be predicted without benefit of experience, else an insect could respond (or not respond) innately.