OPERANT CONDITIONING Strengthening Operant Behavior: Schedules of Reinforcement CONTINUOUS REINFORCEMENT SCHEDULE reinforcement occurs after every desired behavior is exhibited pro: necessary for initial learning con: subject comes to expect reinforcement each time; when not provided, the stimulus-response connection may quickly become extinct e.g., rewarding a dog with a treat every time it obeys a command PARTIAL (INTERMITTENT) REINFORCEMENT SCHEDULE reinforcement for the desired behavior is given occasionally or periodically elicits a greater number of the desired responses (compared to continuous reinforcement) in the long term because it is unknown when the reinforcement will take place four types of partial reinforcement schedules (see next slide...)
OPERANT CONDITIONING: Strengthening Operant Behavior SKINNER INTERVIEW FOUR BASIC TYPES OF PARTIAL (INTERMITTENT) REINFORCEMENT SCHEDULE (Note that ratio schedules of reinforcement are based on behaviors performed; interval schedules of reinforcement are based on time elapsed.) 1. Fixed-Ratio (FR) reinforcement provided after a set number of correct responses e.g., factory workers paid $15 for every five pair of gloves produced 2. Variable-Ratio (VR) reinforcement provided after a varying number of correct behaviors e.g., a slot machine at a casino rewarding the player after a varying number of pulls 3. Fixed-Interval (FI) reinforcement provided for the first desired response after a set amount of time has elapsed no matter how many responses have been made during the interval e.g., radio stations telling listeners who just won a prize they are not eligible to win again for thirty days 4. Variable-Interval (VI) reinforcement provided after the first desired response after a varying amount of time has elapsed e.g., father checking son s room randomly throughout the week to see if his room has been cleaned; if so, the son gets more time on the computer to play video games
OPERANT CONDITIONING: Strengthening Operant Behavior Schedules of Reinforcement and Response Patterns Both fixed- and variable-ratio schedules produce very high rates of responding because the frequency of reward depends on the rate of responding. Under a fixed-interval scheduling, the rate of responding typically drops dramatically immediately after the reinforcement and then increases as the time for another reward approaches. A variable-interval schedule typically generates slow but steady responding Schedules and Extinction When a reinforcer no longer follows an operant response, the response will eventually disappear. Partial Reinforcement Extinction Effect Behaviors learned under a partial reinforcement schedule are more difficult to extinguish than those learned through continuous reinforcement due to the uncertainty about reinforcement under the partial schedule. Accidental Reinforcement When a reinforcer happens to follow a behavior by chance, it can function like a partial reinforcement schedule. This may explain learned superstitions.
OPERANT CONDITIONING: Why Reinforcers Work! Primary reinforcers satisfy basic survival needs (such as hunger and thirst). Premack Principle Each person has a hierarchy of behavioral preferences at any given moment. The higher on the hierarchy an activity is, the greater it s power as a reinforcer. Preferences differ from person to person and from occasion to occasion. Reinforcers may also work by exerting particular effects within the brain. Olds and Milner found that mild electrical stimulation of certain areas of the hypothalamus activates the pleasure centers of the brain. Activation of systems that use the neurotransmitter dopamine is associated with the pleasure of many stimuli (including food, sex, and addictive drugs).
OPERANT CONDITIONING: Punishment PUNISHMENT reduces the frequency of an operant behavior by presenting an unpleasant stimulus or removing a pleasant one. This removal is called a penalty. Remember that reinforcement strengthens behavior; punishment weakens it. Drawbacks of Punishment 1. It only suppresses behavior; it does not erase it. 2. It can produce unwanted side effects such as associating the punisher with the punishment. 3. It s often ineffective unless it is given immediately after the response AND each time the response is made. 4. Physical punishment can become aggressive, even abusive, if administered in anger. 5. Children frequently punished may be more likely to behave aggressively. 6. Punishment conveys information that inappropriate behavior has occurred but does not specify correct alternatives.
OPERANT CONDITIONING: Punishment Spanking and Other Forms of Punishment Used by Parents New studies have shown spanking can be effective behavior control technique for children between 3 and 13. Studies show it is NOT detrimental to children s development IF combined with other disciplinary practices such as: requiring child to pay some penalty for his actions having him provide some sort of restitution to the victims making him aware of what he did that was wrong Guidelines for Effective Punishment 1. Punisher should specify why punishment is being given and that the behavior, not the person, is being punished. 2. Punishment should be immediate and severe enough to eliminate the undesirable behavior. 3. More appropriate behaviors/responses should be identified by the punisher and positively reinforced.
OPERANT CONDITIONING: Applications of Operant Conditioning Parents, teachers, coaches, bosses, doctors, and wardens all use Skinner s principles every day. BEHAVIOR MODIFICATION Behavior modification is simply a change in a previous behavior to a newly desired one. e.g., teacher ignoring inappropriate behavior and rewarding appropriate behavior TOKEN ECONOMY A token economy is an environment that reinforces desirable behavior by rewarding the behavior with secondary reinforcers that can be exchanged for other reinforcers. This form of behavior modification is seen in elementary schools, prisons, and psychiatric hospitals. e.g., A teacher places gold stars next to students names on the board when they raise their hands before talking. After a given number of stars have been obtained, the students are rewarded with a new pencil.
COGNITIVE PROCESSES IN LEARNING Behaviorists (like Skinner) tried to identify stimuli and responses that build and alter behavior WITHOUT any consideration of conscious mental activity. Cognitive psychologists believe that the mental interpretation or representation of an event is necessary for learning to take place. Cognitivists (and cognitive-behaviorists) argue that both classical conditioning and operant conditioning help organisms detect causality--an understanding of what causes what. This means the conscious mental processes organisms use to understand their environments and to interact with them adaptively are important. How people represent, store, and use information is important in learning. Learning is affected by our expectations and the meaning we attach to events--both conscious mental processes.
COGNITIVE PROCESSES IN LEARNING Learned Helplessness Martin Seligman proposed the idea of learned helplessness--failure to continue exerting effort for an outcome because all previous attempts have failed. Operant conditioning teaches organisms they have at least some control over their environment. However, when people (or animals) perceive that their behaviors do not influence outcomes or consequences, they GIVE UP. e.g., A student tries multiple study techniques but continues to fail AP Psychology tests. The student ultimately quits studying because his mental interpretation (or thinking) causes him to feel hopeless and to believe no matter what he does or how hard he tries, he will still fail. personal example:
COGNITIVE PROCESSES IN LEARNING Latent Learning and Cognitive Mapping Edward Tolman s experiment with three groups of rats in a maze suggests learning takes place cognitively and is not always immediately observable. Group A: rewarded for learning maze by finding food at the end; gradually improved until they were making only a couple of mistakes in the entire maze Group B: received no rewards and continued to make errors throughout the experiment Group C: received no reinforcement for running the maze for the first ten days and made many mistakes; on the 11th day, the Group C rats received a food reward for successfully completing the maze; on day 12, Group C demonstrated the same knowledge of the maze as Group A that had been reinforced from day 1 Tolman argued that these rats demonstrated latent learning--learning that is not evident when it first occurs. Tolman further argued the rats developed a cognitive map--a mental representation to understand complex patterns (e.g., the maze). He suggested cognitive maps develop naturally as a result of experience, even in the absence of any response or reinforcement. personal example:
COGNITIVE PROCESSES IN LEARNING Insight and Learning Wolfgang Köhler, a Gestalt psychologist, placed chimpanzees in a cage and placed pieces of fruit so they were visible but out of the animals reach. Many of the chimps overcame obstacles to reach the food easily. Köhler introduced harder tasks the chimps again solved, leading him to suggest they were NOT demonstrating the results of gradually formed associations of responses to consequences NOR practicing trial and error. Instead, Köhler believed the chimps suddenly saw new relationships that were never learned in the past. They had insight--an understanding of the problem as a whole. Köhler s observations about the animals problem-solving behaviors: 1. Once a chimp solved a problem it would immediately do the same thing if faced with a similar situations. 2. The chimps rarely tried a solution that did not work. 3. the chimps often reached a solution quite suddenly. Some cognitive psychologists now think insight results from a mental trial and error --envisioning course of action, mentally simulating results, comparing to imagined outcomes of other alternatives, then settling on course of action deemed most likely to aid complex problem-solving and decision-making. In other words, insight might be a result of learning to learn-- instantly applying previous experiences to new ones. personal example:
COGNITIVE PROCESSES IN LEARNING Observational Learning: Learning by Imitation Watching what another person does can affect your own behavior. Albert Bandura conducted The Bobo Doll Experiment on a group of young children to determine the effects of observational learning (social learning)--acquiring knowledge by watching others perform a task. This experiment proved to be one of the most influential studies in psychology. What did he find? The children who had seen the adult rewarded for abusing and yelling at the Bobo doll imitated the aggressive adult the most. They received vicarious conditioning--learning by seeing or hearing about the consequences of other people s behavior. The children who saw the adult punished tended not to perform aggressive behaviors, but they still learned the behaviors. Observational learning can occur even when there are no consequences. Many children in the neutral condition also imitated aggressive behaviors. Bandura s Bobo study concluded that modeling--the imitation of behavior directly observed--plays an important role in influencing children s behavior. His work is the basis for the campaign against media violence because of the negative impact such exposure can have on children. There are important criticisms of Bandura s work worth noting. The confounding variables of previous exposure to violence and previous exposure to the Bobo doll toy raise legitimate questions about the degree to which social learning theory influences our behaviors. Children see, children do.