LEArniNG Dr Nesif Al-Hemiary MBChB – FICMS(Psych) International Associate of the RCPsych(UK)

LEARNING Learning is a relatively permanent change in behavior that occurs as the result of experience. Behavior changes that are due to maturation or temporary conditions of the organism (such as fatigue or drug induced states ) are not included.

Basic types of learning classical conditioning instrumental( operant) conditioning. complex learning

Classical conditioning Classical conditioning is a learning process in which a previously neutral stimulus becomes associated with another stimulus through repeated pairing with that stimulus. Ivan Pavlov –Nobel prize

Pavlov’s experiment A researcher first attaches a fistula or tube to the dog’s salivary flow . Then the dog is placed in front of a pan into which meat powder can be delivered automatically. A researcher turns on a light in a window in front of the dog. After a few seconds , some meat powder is delivered to the pan and the light is turned off. The dog is hungry ,and the recording device registers copious salivation. This salivation is an unconditioned response( an innate or unlearned response elicited by the UCS). The meat powder is an unconditioned stimulus (a stimulus that automatically elicits a response without prior conditioning) .The salivation that result from exposure to meat powder is called unconditioned response(UCR). After a few presentations of the light followed by meat powder ,the dog will salivate in response to the light ,even if no meat powder is delivered. This anticipatory salivation is a conditioned (CR), and the light is a conditioned stimulus( CS). In other words, the CR is a learned response evoked by a CS that has come to predict the occurrence of the UCS.

Acquisition & Extinction Each pair of the CS and the UCS is called trial. The trials when the organism is learning the association between the two stimuli are the acquisition stage of conditioning. During this stage repeated pairings of the CS (light) and UCS (food) strengthen the association between the two. Extinction : represents learning that the conditioned stimulus (CS) is no longer predicts the unconditioned stimulus (UCS). Extinction is not the” unlearning “of the original CS-UCS association; in fact extinction involves the formation of a new CS- no UCS memory that inhibits expression of the CS-UCS association.

Inhibitory conditioning Excitatory conditioning :the ability of a CS to increase the probability or magnitude of a given behavior. Inhibitory conditioning : the ability of a CS to decrease the probability or magnitude of a behavior. This can occur, for example , when a CS that has come to predict the occurrence of a UCS is presented alone, as occurs during extinction. Inhibitory conditioning also occurs when a CS that predicts a UCS is presented with a new CS on trials in which the UCS is omitted, for example, when a tone that predicts forefinger shock is presented together with a light ( a compound CS presentation) in the absence of shock, the light becomes a conditioned inhibitor ;that is, the light comes to predict the absence of shock.

Instrumental (operant) Conditioning Learning of novel things is not possible by classical conditioning. Instrumental or operant conditioning : certain responses are learned because they operate on, or affect, the environment. much real–life learning occur by this type of learning.

The law of effect L.E. Thorndike ( a psychologist who is pioneer in this type of conditioning) the cat and fish experiment: a hungry cat is placed in a cage whose door is held fast by a simple latch, and a piece of fish is placed just outside the cage . Initially ,the cat tries to reach the food by extending its paws through the bars. When this fails , the cat moves about the cage ,engaging in a variety of behaviors. At some point it inadvertently hits the latch, frees itself, and eats the fish. The researchers then place the cat back and put a new piece of fish outside. The cat goes through roughly by the same set of behaviors until once more it happens to hit the latch. The procedure is repeated again and again. Over a no. of trials ,the cat eliminates many of its irrelevant behaviors ,and eventually it opens the latch and frees itself as soon as it is placed in the cage .The cat has learned to open the latch to obtain the food.

Trial and Error Trial-and-Error behavior: it may sound as if the cat is acting intelligently ,but Thorndike argued that there is little “intelligence” operating here. There is no moment in time when the cat seems to have an insight about the solution to its problem. In stead the cat performance improves gradually over a series of trials. The cat appears to be engaging in trial-and-error behavior, and when a reward immediately follows one of those behaviors the learning of the action is strengthened. Thorndike referred to this strengthening as the law of effect the law of effect selects from a set of random responses only those that are followed by positive consequences . This is similar to evolution (genes that promote survival or fitness are selected across generations ).

Reinforcement Reinforcement : the delivery of an appetitive stimulus or the removal of an aversive stimulus increases the probability of a behavior. Positive reinforcement : behavior that produces an appetitive stimulus. Negative reinforcement : occurs when a behavior prevents an aversive stimulus.

Punishment The converse of reinforcement. It is the process by which the delivery of an aversive stimulus or the removal of an appetitive stimulus decreases the probability of a behavior. Positive contingency :behavior leads to aversive stimulus. Negative contingency : behavior prevents an appetitive stimulus (omission training). Reinforcement produces GOOD outcomes. Punishment produces BAD outcomes. These principles can be implicated for child rearing. The temporal relationship between a response and its reinforcer ( immediate reinforcement is more effective than delayed reinforcement ).

Complex Learning According to the cognitive perspective ,the crux of learning lies in an organism’s ability to mentally represent aspects of the world and then operates on these mental representations rather than on the world itself. In classical & instrumental conditioning what is represented is an association between events. In other cases what is represented seems more complex : It might be a map of one’s environment or an abstract concept like the notion of cause. The operations performed on mental representations are more complex than associative processes. the operations may take the form of mental trial & error , in which the organism tries out different possibilities in its mind. Or the operations may be a strategy in which we take some mental steps only because they make possible subsequent steps.

Cognitive maps & Abstract concepts Edward Tolman: his research dealt with the problems of rats learning their way through complex mazes. In his view, a rat running through a complex maze was not learning a sequence of right & left turning responses but rather was developing a cognitive map: a mental representation of the layout of the maze. More recent research provides strong evidence for this view. Experiments on rats and chimpanzees : Chimpanzees can acquire abstract concepts that were once believed to be the sole province of humans.

Insight learning Insight learning involves three critical aspects: 1. suddenness 2. its availability once it is discovered. 3. transferability These aspects are at odds with trial & error behaviors of the type observed by Thorndike ,Skinner, & their students. Complex learning involves two phases : 1. Initial phase :problem solving is used to arrive at a solution. 2. Second phase :the solution is stored in memory & retrieved whenever a similar problem is faced. So, complex learning is intimately related to memory & thinking.

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