CLASSICAL Conditioning and INSTRUMENTAL Conditioning

>> Tuesday, April 24, 2012


CLASSICAL Conditioning and INSTRUMENTAL Conditioning

Classical Conditioning

Classical conditioning involves the association of an unconditioned and a conditioned stimulus in such a way that the conditioned stimulus elicits unconditioned response. There is the formation or strengthening of an association between a conditioned stimulus in a controlled relationship with an unconditioned stimulus that originally elicits that response.  Classical conditioning has revealed facts concerning conditions of acquisition, extinction, generalization and discrimination. Once a conditioned response is established to a stimulus of a certain kind, the response will also occur to stimuli which are similar to the original stimulus. This is stimulus generalization. No learning occurs unless there is generalization. No two stimuli or stimulus situations are exactly alike. They must be treated as if they were exactly alike in order to elicit the same response.

Discrimination refers to eliciting different responses to two different stimuli. A dog, trained to withdraw a paw from an electric grid at the sound of a tone, will learn in time that he need not move his paw at the sound of a tone very slightly different in pitch. The dog will learn this discrimination if one tone is consistently reinforced while another is not.

Responses that are no longer reinforced tend to disappear from the organism’s repertoire of behavior. This is called extinction. Pavlov’s dog will not salivate at all times at the sound of a buzzer. If the buzzer is presented time after time without being paired with meat, extinction will occur.

Spontaneous recovery refers to the return of a conditioned response, following experimental extinction, after periods of no reinforcements. If the buzzer is sounded many times without presenting any food, the dog will reach a situation wherein it will ignore the buzzer. Although there will be times when the dog would salivate again at the sound of the buzzer. Studies have shown that once a conditioned response is established, it never completely disappears from the behavioral repertoire of an organism. After periods of rest or disuse, a conditioned response often reappears. If there is no reinforcement, it will extinguish again. Classical conditioning requires the association of two stimuli, with one of them gradually acquiring a significance it did not possess before.

Instrumental Conditioning

Instrumental conditioning involves the selection of a response from among a series of responses. It needs the strengthening of a stimulus-response association by following the response with a reinforcing stimulus.

Instrumental conditioning (Operant Conditioning) is another kind of simple learning. It involves a selection from many responses of the one that habitually will be given in a stimulus situation. Instrumentally conditioned response states that the behavior of the animal in the learning situation is the basis of reinforcement. The organism gets nothing until he emits the desired response. Instrumental conditioning was first tried by EDWARD L. THORNDIKE (1898) using a puzzle box served as the instrument that elicited the reinforced behavior of the cat.

There are four (4) kinds of instrumental conditioning. They are all similar in that the learned response is instrumental in getting the organism biologically ahead. The simplest kind is called primary reward conditioning where the learned response is instrumental in obtaining a biologically significant reward, such as a pellet of food or an amount of water. Escape conditioning is one where the organism learns a response that is instrumental in getting out of a place one prefers not to be in. Avoidance conditioning is a kind of learning where a response to a cue is instrumental in avoiding a painful experience. Secondary reward conditioning is where there is instrumental behavior to get a stimulus which has no biological utility itself but which has in the past been associated with a biologically significant stimulus.

In recent years, device known as SKINNER box, named after B. F Skinner, has been widely used in laboratory studies. A fully equipped Skinner box is a device containing a bar to press, string to pull, a button to peck or some other stimulus which, if appropriately dealt with, automatically supplies the animal with a measured amount of food.


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Two Theories of Thinking

>> Wednesday, April 18, 2012

Thinking is a type of behavior that uses symbols as “inner representations” of objects and events. Symbolic references are remembered, absent or imagined things and events, including those that are currently impinging on the sensory system. It reflects and elaborates on what is present in perception and movement. Most thinking occurs in the process of active exploration of the environment. Because of the circuits and networks described above, human thinking goes on and on, day in and day out.

There are two theories that suggest differing functions of the brain. The peripheralists hold that all thinking goes on in the muscular movement. The centralists hold that thinking goes on inside the brain and nervous system, and muscular movements merely accompany the central process. There are also two ways of thinking. Directed thinking has an aim, goal or endpoint. It includes the kind of critical thinking when making judgments on propositions. Creative thinking is an attempt to discover new solutions to problems, invent new methods or devices and produce new artistic forms.

Learning

Learning may be defined as a process that brings about a change in the individual’s way of responding as a result of practice or other experiences. Learning may also be defined as a relatively permanent change in behavior. Behavior changes with experience. New patterns of behavior take place when the organism senses its world, interprets it, responds to it, and then responds to the consequences of its own responses. Once the organism has passed through this cycle, it is never the same again. It thereby learns.

Learning is pervasive especially in human beings. Our knowledge and skills accumulate throughout our lives. Learning is developmental and interactive. It comes about through active interchange with the environment. Simple responses, motor habits, perceptual responses, motives, attitudes, emotional responses, problem solving, language and personality are learned.

There are old and new theories that explain learning. Here are some.

Classical Conditioning

The simplest form of learning is classical conditioning. Ivan PAVLOV (1849-1936), a Russian physiologist and Nobel Prize awardees was the first to conduct systematic studies on conditioned responses.

The basic phenomenon he studied is represented in this way:

             A                    1                               2
CS ------> UCS ------> UCR ------> CS ------>CR
Buzzer    meat               salivation         buzzer         salivation

As shown in the diagram, a buzzer is sounded and after a brief interval, meat is presented to the dog. The dog responds to the food in the usual manner: it salivates, chews, and swallows. The arrow 1 signifies that the food elicits a response that is automatic, that is unconditioned. The dotted arrow a represents the fact that the sound of the buzzer is present when the meat, the unconditioned stimulus, is presented. While the unconditioned response is taking place, the dog associated the buzzer with the meat and its reaction to the meat. After repeated pairings of the CS (the buzzer) with the UCS (the meat), the dog salivates at the sound of the buzzer alone. The buzzer now elicits a response formerly elicited by the meat. A conditioned response, which was a part of the original unconditioned response, is now established.

An unconditioned stimulus is a stimulus which is adequate at the outset of training to produce the response in question. The response to such a stimulus is called unconditioned response. In Pavlov’s experiment, the sight or taste of food was an unconditioned stimulus for the unconditioned response of salivating.

A conditioned stimulus is one which is initially inadequate to evoke the response in question but will do so if paired with the unconditioned stimulus. The learned process is called conditioned response. In Pavlov’s experiment, the buzzer was the conditioned stimulus for the conditioned response of salivating.

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