Learning by Consequence

Part II

Higher National Diploma in PsychologyModule Code GP003

Kumari KarandawalaBA Psycology (Hons) (US)

MSc.(MSSW) In Social Enterprise Managementand International Social Work / Development

Extinction

• In Classical conditioning is a weakening Conditioned Response:The right circumstances produce extinction, which is the gradual weakening and disappearance of a conditioned response tendencyproduced by the consistent presentation of the conditioned stimulus alone, without the unconditioned stimulus.**

• In operant conditioning extinction refers to the gradual weakening and disappearance of a response tendency because the response is no longer followed by reinforcement.

For example, in lab studies with rats this situation usually occurs when the experimenter stops delivering food as reinforcement for lever pressing.*When extinction process begins a brief surge often occurs in the rat’s responding, followed by a gradual decline in response rate until it approaches zero.

Extinction

• In operant conditioning extinction refers to the gradual weakening and disappearance of a response tendency because the response is no longer followed by reinforcement.For example, in lab studies with rats this situation usually occurs when the experimenter stops delivering food as reinforcement for lever pressing.

*When extinction process begins a brief surge often occurs in the rat’s responding, followed by a gradual decline in response rate until it approaches zero.

Extinction

• Key issue: How much resistance to extinction an organism will display when reinforcement is halted.

• Resistance to extinction occurs when an organism continues to make a response after delivery of the reinforcer for it has been terminated.

• The greater the resistance to extinction the longer the responding will continue. If a researcher stops giving reinforcement for lever pressing and the response tapers off very slowly, the response shows high resistance to extinction.

• If the response tapers off quickly it shows relatively little resistance to extinction.

• Source: Weiten, W. (2005). Psychology Themes and Variations, Sixth Edition

Stimulus Control:Generalization and Discrimination

• Operant responding is ultimately controlled by its consequences, as organisms learn response-outcome (R-O) associations.

• Stimuli that precede a response, however, can also influence operant behavior

• When a response is consistently followed by a reinforcer in the presence of a particular stimulus, that stimulus comes to serve as a “signal” indicating that the response is likely to lead to a reinforcer.

For example, a pigeon quickly learns that pecking at the disk

only when the light is on elicits a reward. The light that signalsthe availability of reinforcement is called a discriminative stimulus.

Discrimination

• Discriminative Stimuli are cues that influence operant behavior by indicating the probable consequences (reinforcement or non-reinforcement of a response.)

• Discriminative stimuli play a key role in the relation of operant behavior. (For eg. Birds learn that hunting for worms is reinforced after a rain. Drivers learn to slow down when the highway is wet.)

• Reactions to a discriminative stimulus are governed by the processes of stimulus generalization and stimulus discrimination just like reactions to a CS in classical conditioning.

Delayed Reinforcement

• Reinforcement is delayed whenever there is period of time between the response producing the reinforcer and its subsequent delivery. This time period has been arranged in different ways. Skinner (1938) programmed the delay in the presence of the same stimuli that were in effect during the nondelayperiod.

Conditioned Reinforcement

• Conditioned or secondary reinforcers are events that acquire reinforcing qualities by being associated with primary reinforcers.

• Examples of common secondary reinforcers among humans are money, good grades, attention, flattery, praise, applause.

• Secondary because they people learn to earn them.

Schedules of ReinforcementReinforcement Schedules

Let’s say I want my boyfriend to lose weight and I am going to use operant conditioning to help him. There are several ways I can give him the reinforcements and each may have a different affect on both the acquisition and extinction of his behaviors.

• Fixed-Ratio Schedule: provides the reinforcement after a set number of responses. So I give my boyfriend a neck massage for every pound that he loses.

• Variable-Ratio Schedule: provide the reinforcement after a random number of responses. So I give my BF a massage after 1 pound, then maybe 3, then I might wait for 6 pounds, then go back to one pound. Here acquisition takes longer to set in, but it is also more resistant to extinction.

Can you think of why?

Schedules of Reinforcement

• Fixed-Interval Schedule: a fixed amount of time passes before the reinforcement is given. So I give my BF a massage for every 24 hours he stays on his diet.

• Variable- Interval Schedule: a random amount of time passes before the reinforcement is given. So I give my BF a massage after 24 hours and then 10 hours of dieting and then 5 and then 48 etc…. Once again the variable schedules (both ratio and interval) are more resistant to extinction but also more difficult to acquire acquisition.

Negative and Positive Reinforcement

• Negative Reinforcement when a response is strengthened because it is followed by the removal of an aversive (unpleasant) stimulus.

- Involves a favorable outcome that strengthens a response tendency resulting from the removal of an aversive stimulus.

• Positive Reinforcement occurs when a response is strengthened because it is followed by the presentation of a rewarding stimulus.

Escape

• In Escape Learning, an organism acquires a response that decreases or ends some aversive stimulation.

• Example: Dogs and rats experiment in Laboratory Shuttle box:

• Shuttle box has two compartments; animal is placed in the section that generates shocks. The animal learns to escape into the other compartment which has no shocks.

Avoidance

• Escape learning often leads to avoidance learning.

• In Avoidance learning, an organism acquires a response that prevents some aversive stimulation from occurring.*

• Eg. Shuttle box studies - experimenter gives the animal a signal that the shock is coming. This signal alone then has the animal running into the second compartment exhibiting avoidance learning.

Avoidance Learning

• where classical conditioning and operant conditioning work together to regulate behavior.

• In avoidance learning, the warning signal or light becomes a CS (through classical conditioning) eliciting reflexive, conditioned fear in the animal.

• The response of fleeing to the other side of the box is operant conditioning which is strengthened by negative reinforcement because it reduces the animal’s conditioned fear.

References• Skinner, B. F. (1938). The Behavior of Organisms: An Experimental

Analysis. New York: Appleton-Century.

• Skinner, B. F. (1948). 'Superstition' in the pigeon. Journal of Experimental Psychology, 38, 168-172.

• Thorndike, E. L. (1905). The elements of psychology. New York: A. G. Seiler.

• McLeod, S. A. (2007). B.F. Skinner | Operant Conditioning. Retrieved from http://www.simplypsychology.org/operant-conditioning.html

• http://www.appsychology.com/Book/Behavior/operant_conditioning.htm

• Source: http://www.southalabama.edu/oll/mobile/theory_workbook/social_learning_theory.htm

• Weiten, Wayne (2005). Psychology: Themes and Variations –Sixth Edition.

THE END

• QUESTIONS?

THANK YOU!