Operant Conditioning RG 6c Modified PowerPoint from: Aneeq Ahmad -- Henderson State University. Worth Publishers © 2007

Operant & Classical Conditioning ● Classical conditioning forms associations between stimuli (CS and US). ● Operant conditioning on the other hand forms association between behaviors and resulting events.

E.L. Thorndike Law of effect ● responses that produce desirable results will be learned, or “stamped” into the organism Yale University Library Found that hungry cats in a puzzle box would work diligently to solve the puzzle by trial-and-error to obtain the food reward outside the box. Gradually, on succeeding trials, erroneous responses were eliminated & effective responses were “stamped in.”

B.F. Skinner -- Operant Chamber Using Thorndike's law of effect as a starting point, Skinner developed the Operant chamber or the “Skinner box” to study operant conditioning. From The Essentials of Conditioning and Learning, 3 rd Edition by Michael P. Domjan, Used with permission by Thomson Learning, Wadsworth Division

Operant Chamber Operant chamber or Skinner box comes with a bar or key that an animal manipulates to obtain a food or water reinforcer. It is connected to devices that record the animal’s responses and allows the researcher to have complete control over the animal’s environment.

Shaping Operant conditioning procedure in which reinforcers guide behavior closer towards target behavior through successive approximations. A rat shaped to sniff mines. A manatee shaped to discriminate objects with different shapes, colors and sizes. Khamis Ramadhan/ Panapress/ Getty Images Fred Bavendam/ Peter Arnold, Inc.

Types of Reinforcers Any event that strengthens the behavior it follows. A heat lamp positively reinforces a meerkat’s behavior in cold. Reuters/ Corbis

1. Primary Reinforcer: Innately reinforcing stimulus that usually satisfy some biological need like food or drink. 1. Conditioned (Secondary) Reinforcer: Is a learned reinforcer. It gets its reinforcing power through its association with primary reinforcer.  Examples…  Grades, praise, smiles of approval and applause Primary & Secondary Reinforcers

1. Immediate Reinforcer: A reinforcer that occurs closely to a behavior in time. Rat gets a food pellet for a bar press. 1. Delayed Reinforcer: A reinforcer that is delayed in time for a certain behavior. A paycheck that comes at the end of a week. Immediate & Delayed Reinforcers We may be more inclined to engage in small immediate reinforcers (watching TV) than large delayed reinforcers (Getting A in a course) which requires consistent study.

1. Positive Reinforcement: Increase in response by adding/giving a positive stimulus  Getting $5 for each A on your report card  Giving candy for every right answer in class 2. Negative Reinforcement: Increase in response by removing an aversive (negative) stimulus  Taking aspirin to relieve a headache  Faking an illness to avoid going to school  Using an umbrella to keep from getting wet Positive & Negative Reinforcers Add Subtract Add what? Subtract what?

Reinforcement Schedules 1. Continuous Reinforcement: Reinforcing the desired response each time it occurs. Needs to be used when initial learning is taking place 1. Partial (Intermittent) Reinforcement: Reinforcing a response only part of the time. Though results in slower acquisition in the beginning, shows greater resistance to extinction later on.

Ratio Schedules Fixed-ratio schedule: Reinforces a response only after a specified number of responses ex: piecework pay, reward cards (buy 10, get one free) Variable-ratio schedule: Reinforces a response after an unpredictable number of responses. Produces more responding than any other method and is hard to extinguish because of unpredictability. ex: gambling

Interval Schedules Fixed-interval schedule: Reinforces a response only after a specified time has elapsed ex: studying for an test the night before or getting paid every two weeks Variable-interval schedule: Reinforces a response at unpredictable time intervals, produces slow steady responding ex: pop quiz, fishing, stargazing

Schedules of Reinforcement

Let’s review… ● Reinforcer/reinforcment ● Primary reinforcer ● Secondary reinforcer ● Positive reinforcement ● Negative reinforcement ● Intermittent schedules of reinforcement o Fixed-ratio o Variable-ratio o Fixed-interval o Variable-interval

Punishment An aversive event that decreases the behavior that it follows. Give – Take away + omission training

Punishment 1. Punishment can result in unwanted fears. 2. Conveys no information to the organism. 3. Justifies pain to others. 4. Unwanted behaviors reappear in its absence. 5. Aggression towards the agent or aggression seen as “ok” or “right.” 6. One unwanted behavior appears in place of another. Although there may be some justification for occasional punishment (Larzelaere & Baumrind, 2002), it usually leads to negative effects.

Cognition & Operant Conditioning Evidence of cognitive processes during operant learning comes from rats during maze exploration, where they navigate it without an obvious reward. Edward Tolman found that the rats seemed to develop cognitive maps or mental representation of the layout of the maze (environment) b/c if blocked the “normal” route, the rat found an alternate path ● the detour would be the shortest path around the barrier, even though the rat had not been reinforced for that alt. short path ● brain imaging points to the hippocampus a the structure involved in “drawing” the cognitive map

Latent Learning Such cognitive maps are based on latent learning which is learning that occurs without reinforcement, but becomes apparent when an incentive is given (Tolman & Honzik, 1930). Tolman allowed rats to freely wander the maze for several hours…when the rats were later offered a reinforcement, the ones who “wandered around” ran through the maze more quickly than those who had not been in the maze

Biological Predisposition Biological constraints predispose organisms to learn associations that are naturally adaptive. Breland and Breland (1961) showed that animals drifted (instinctual drift) towards their biologically predisposed instinctive behaviors. Marian Breland Bailey Photo: Bob Bailey