Empirically Based Practice in Psychology is "the integration of the best available research with clinical expertise in the context of patient characteristics, culture, and preferences" (Levant, 2005)"Its purpose is to promote effective psychological practice and enhance public health by applying empirically supported principles and requires the appreciation of the value of multiple sources of scientific evidence."(Evidence-based practice in, 2006)"EBPP is a means to enhance the delivery of services to patients within an atmosphere of mutual respect, open communication, and collaboration among researchers, policymakers, patients, and practitioners."(Evidence-based practice in, 2006)




















Introduction to the Principles of Behavior Analysis


Experimental studies of operant conditioning have been around for thousands of years; however, it was not subjected to scientific analysis until the late 1800's. Operant conditionin was activated by Edward L. Thorndike who was interested in animal intelligence and then later conducted the first experimental studies of operant conditioning. With his most famous experiment being the puzzle box, Thorndike classified his famous law of effect. Law of effect states that behaviors leading to a satisfactory state of affairs are strengthened or "stamped in," while behaviors leading to an unsatisfactory or annoying state of affairs are weakened or "stamped out." Thorndike's law of effect being a major part in the field of psychology, it was B.F. Skinner who established a true understanding of behavior through operant conditioning.
Burruhus Fredrick Skinner believed that behavior was a reflex of sorts and thus invented the best-known apparatus in experimental psychology, the Skinner box. A chamber for rats, so that when the rat presses a bar, a pellet of food drops into a food tray. Later in his experiment, Skinner started using pigeons. This chamber consisted of a pigeon pecking at a disc to give access to a food bin. Skinner eventually discarded the notion that behaviors are simply just reflexes and came to believe that they were either voluntary (operant behaviors) or involuntary (respondent behaviors) and are governed by consequences rather than stimuli.


 Four Types of Contingencies

Positive Reinforcement

  • Positive reinforcement consists of the presentation of a stimulus (one that is usually considered pleasant or rewarding) following a response, which then leads to an increase in the future strength of that response. (lecture notes from Theories)

An example of positive reinforcement is if you were to smile at a person on the street and they return a smile to you.
    • Immediate Versus Delayed Reinforcements are the more immediate the reinforcers, the stronger its effect on the actual behavior.
    • A primary reinforcer (unconditioned reinforcer) is an event that is innately reinforcing or something we are born to like rather than something we have to learn to like.
    • A secondary reinforcer (unconditioned reinforcer) is an event that is reinforcing because it has been associated with some other reinforcer. In other words, one has learned to like because they have become associated with, such as name brand clothing or fancy high dollar cars.
    • Intrinsic reinforcement is reinforcement provided by the mere act of performing the behavior.
      • example: people workout/exercise because it is invigorating
    • Extrinsic reinforcement is the reinforcement provided by some consequence that is external to the behavior.
      • example: doing this assignment because my grade depends on it
    • Natural reinforcers are reinforcers that are provided for a certain behavior, and are always an intrinsic reinforcer.
    • Artificial reinforcers have been set in motion on purpose to adjust behaviors. Can either be intrinsic or extrinsic reinforcers.

Negative Reinforcement

  • Negative reinforcement is the removal of a stimulus (one that is usually considered unpleasant or aversive) following a response that then leads to an increase in the future strength of that response. (lecture notes from theories)
  • Involves two types of behavior: escape and avoidance,
    • Escape behavior results in the termination of an aversive stimulus.
    • Avoidance behavior occurs before the aversive stimulus is presented and therefore prevents its delivery.
      • making an instrumental response in order to prevent the occurence of an aversive stimulus.

An example of negative reinforcement is if it starts to rain while one is walking down the street, they open an umbrella to escape the rain. The rain is being taken out of the situation; therefore, the behavior has been increased.

Positive Punishment

  • Positive punishment consists of the presentation of a stimulus (one that is usually considered unpleasant or aversive) following a response, which then leads to a decrease in the future strength of that response. (lecture notes from Theories)

An instance of positive punishment is when a person swats at a bee or wasp, they get stung, therefore decreasing the behavior.

Negative Punishment

  • Negative punishment consists of the removal of a stimulus (one threat is usually considered pleasant or rewarding) following a response, which then leads to a decrease in the future strength of that response. (lecture notes from Theories)

An example of negative punishment would be if a toddler/child were playing with their food, instead of eating, they would in return not get dessert for that behavior.



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Ways of Shifting Behaviors


Shaping

  • Shaping behaviors were developed by B.F.Skinner.
  • Shaping is defined as the gradual creation of new operant behaviors through reinforcement of successive approximations to that behavior. (lecture notes from Theories)
    • most often carried out with a secondary reinforcer


Extinction

  • The weakening of a behavior through the withdrawal of reinforcement for that behavior is known as extinction. (lecture notes from Theories)
  • Omission: a selected response prevents the administration of a positive reinforcement.
    • Time-out: removing a subject from a situation where an opportunity for obtaining a reinforcement is present.
  • SIDE EFFECTS OF: (lecture notes from Theories)
    • Can produce unpleasant emotional side effects, such as frustration.
    • Extinction bursts, where a non-reinforced behavior is temporarily increased.
    • Spontaneous recovery of the extinguished behavior may occur.
    • A behavior can also be made resistant to extinction if:
      • the response was trained with small rewards, compared to large rewards,
      • if the rewards were not presented immediately,
      • if training responses were conditioned on partial reinforcement schedules.



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Schedules of Reinforcement 

A schedule of reinforcement is the response requirement that must be met in order to obtain reinforcement. In other words, a schedule indicates what exactly has to be done for the reinforcer to be delivered. Different response requirements can have very different effects on behavior and can also explain aspects of human behavior that are often attributed to some desires and/or traits. (lecture notes from Theories)

Continuous Versus Intermittent Schedules

  • Continuous Reinforcement occurs when reinforcement is administered each and every time the response is reinforced.
  • Intermittent Reinforcement occurs when only some responses are reinforced.


Four Basic Intermittent Schedules

  • Fixed Ratio (FR) schedule of reinforcement is contingent upon a fixed, predictable number of responses. (lecture notes from Theories)
    • example: doing a certain number of math problems correctly
      • Ratio strain is a disruption in responding due to an overly demanding response requirement. (lecture notes from Theories)
  • Variable Ratio (VR) schedule of reinforcement is contingent upon a varying, unpredictable number of responses. (lecture notes from Theories)
    • example: working as a waitress, you never know how many tips you will receive or fishing is another example
  • Fixed Interval (FI) schedule of reinforcement is contingent upon the first response after a fixed, predictable period of time. (lecture notes from Theories)
    • example: payday, comes on the 1st and 16th of every month
  • Variable Interval (VI) schedule of reinforcement is contingent upon the first response after a varying, predictable period of time. (lecture notes from Theories)
    • example: waiting for a bus, you know it will be there you just don't know approximately when



Simple Schedules of Reinforcement

  • Duration Schedules of reinforcement are contingent on behaviors performed continuously throughout a period of time.
    • Fixed duration (FD) is when the behavior is performed continuously for a fixed, predictable amount of time. (lecture notes from Theories)
    • Variable duration (VD) is when the behavior is performed continuously for a varying, unpredictable amount of time. (lecture notes from Theories)
  • Response-Rate Schedules, reinforcement is directly contingent upon the organism's rate of response.
    • Differential reinforcement of high rates (DRH) is contingent upon emitting at least a certain number of responses in a certain period of time. (lecture notes from Theories)
      • example: athletic events
    • Differential reinforcement of low rates (DRL) is when a minimum amount of time must pass between each response before the reinforcer will be delivered. (lecture notes from Theories)
      • example: praising a child for taking his/her time on homework to get good results
    • Differential reinforcement of paced responding (DRP), reinforcement is contingent upon emitting a series of responses at a set rate-neither too fast nor too slow. (lecture notes from Theories)
      • example: swimming and/or running competitively, one must pace themselves to have sufficient energy for a last minute burst to the finish
  • Noncontingent Schedules are when the reinforcer is delivered independently of any response.
    • Fixed time (FT) schedule, the reinforcer is delivered following a fixed, predictable period time, regardless of the organism's behavior. (lecture notes from Theories)
      • example: Christmas gifts
    • Variable time (VT) schedule, the reinforcer is delivered following a varying, unpredictable period of time, regardless of the organism's behavior. (lecture notes from Theories)
      • example: Skinner's pigeons




Complex Schedules of Reinforcement

A combination of two or more simple schedules.
  • Conjunctive schedules are the requirements of two or more simple schedules must be met before a reinforcer can be delivered. (lecture notes from Theories)
    • example: how much you earn monthly at your job depends on the number of hours you spend working
  • Adjusting schedules are when the requirement changes as a function of the organism's performance while responding to a previous reinforcer. (lecture notes from Theories)
    • example: The whole class doing bad on an exam; therefore, next time the teacher won't put as much information.
  • Chained schedules consist of a sequence of two or more simple schedules.
    • example: taking classes to obtain a degree
      • A goal gradient effect is an increase in the strength and/or efficiency of responding as one draws near to the goal. (lecture notes from Theories)



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Assessments

When behavior treatments and modification plans are being designed, there are Functional Behavioral Assessments the trainer must administer before you will get a successful outcome. If the treatment plan is not designed to fit the trainee, you will not see any results.






 Best Available Research Evidence, (Levant, 2005)

  • A balance of internal and external validity is needed.
  • It is important not to assume that treatments that have not been studied are ineffective.
  • Good practice and science calls for the testing of practices.
  • Combines scientific commitment with an emphasis on human relationships and individual differences.
  • Must address:
    • level of intervention
    • appropriateness of treatments for racial/ethnic minority and other marginalized populations
    • weighting of different methodologies

Types of Research Evidence, (Levant, 2005)

  • Clinical observation
  • Qualitative research
  • Systematic case studies
  • Single-case experimental designs
  • Effectiveness research in naturalistic settings


According to Lightner Witmer, "the pure and the applied sciences advance in a single front. What retards the progress of one, retards the progress of the other; what fosters one, fosters the other." (Evidence-based practice in, 2006) 

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References


Evidence-based practice in psychology. (2006). American Psychologist, 61(4), 271-285.
Levant, R.F. (2005). Evidence based practice in psychology. Retrieved from http://afta.org
Lecture notes from Theories. (2010). Dr. Thomas Hancock.