2.1 Major theories and models of learning  (Page 2/14)

In classrooms, behaviorism is most useful for identifying relationships between specific actions by a student and the immediate precursors and consequences of the actions. It is less useful for understanding changes in students’ thinking; for this purpose we need a more cognitive (or thinking-oriented) theory, like the ones described later in this chapter. This fact is not really a criticism of behaviorism as a perspective, but just a clarification of its particular strength or source of usefulness, which is to highlight observable relationships among actions, precursors and consequences. Behaviorists use particular terms (or “lingo”, some might say) for these relationships. They also rely primarily on two basic images or models of behavioral learning, called respondent (or “ classical ”) conditioning and operant conditioning . The names are derived partly from the major learning mechanisms highlighted by each type, which I describe next.

Respondent conditioning: learning new associations with prior behaviors

As originally conceived, respondent conditioning (sometimes also called classical conditioning ) begins with the involuntary responses to particular sights, sounds, or other sensations (Lavond, 2003). When I receive an injection from a nurse or doctor, for example, I cringe, tighten my muscles, and even perspire a bit. Whenever a contented, happy baby looks at me, on the other hand, I invariably smile in response. I cannot help myself in either case; both of the responses are automatic. In humans as well as other animals, there is a repertoire or variety of such specific, involuntary behaviors. At the sound of a sudden loud noise, for example, most of us show a “startle” response—we drop what we are doing (sometimes literally!), our heart rate shoots up temporarily, and we look for the source of the sound. Cats, dogs and many other animals (even fish in an aquarium) show similar or equivalent responses.

Involuntary stimuli and responses were first studied systematically early in the twentieth-century by the Russian scientist Ivan Pavlov (1927). Pavlov’s most well-known work did not involve humans, but dogs, and specifically their involuntary tendency to salivate when eating. He attached a small tube to the side of dogs’ mouths that allowed him to measure how much the dogs salivated when fed ( [link] shows a photograph of one of Pavlov's dogs). But he soon noticed a “problem” with the procedure: as the dogs gained experience with the experiment, they often salivated before they began eating. In fact the most experienced dogs sometimes began salivating before they even saw any food, simply when Pavlov himself entered the room! The sight of the experimenter, which had originally been a neutral experience for the dogs, became associated with the dogs’ original salivation response. Eventually, in fact, the dogs would salivate at the sight of Pavlov even if he did not feed them.

This change in the dogs’ involuntary response, and especially its growing independence from the food as stimulus, eventually became the focus of Pavlov’s research. Psychologists named the process respondent conditioning because it describes changes in responses to stimuli (though some have also called it “classical conditioning” because it was historically the first form of behavioral learning to be studied systematically). Respondent conditioning has several elements, each with a special name. To understand these, look at and imagine a dog (perhaps even mine, named Ginger) prior to any conditioning. At the beginning Ginger salivates (an unconditioned response (UR) ) only when she actually tastes her dinner (an unconditioned stimulus (US) ). As time goes by, however, a neutral stimulus—such as the sound of opening a bag containing fresh dog food—is continually paired with the eating/tasting experience. Eventually the neutral stimulus becomes able to elicit salivation even before any dog food is offered to Ginger, or even if the bag of food is empty! At this point the neutral stimulus is called a conditioned stimulus (UCS) and the original response is renamed as a conditioned response (CR) . Now, after conditioning, Ginger salivates merely at the sound of opening any large bag, regardless of its contents. (I might add that Ginger also engages in other conditioned responses, such as looking hopeful and following me around the house at dinner time.)