Barker's Chapter 7: Reinforcement and Behavior Control

A. Traditional Theories of Reinforcment.

Fig 7.1
Increased Rate of Response Decreased Rate of Response
Outcome Produced Positive Reinforcement

Positive Reinforcers

Positive Punishment

Positive Punishers

Outcome Withdrawn or Omitted Negative Reinforcement

Negative Reinforcers

Negative Punishment

Negative Punishers

B. Schedules of Operant Reinforcrs

  1. Continuous reinforcement (CRF)
  2. Extinction (EXT)
  3. Schedules that Shape High Rate of Responding (DRH reinforces a burst of response) or Low Rate of Responding (DRL reinforces pausing between responses).
  4. Intermittent Reinforcement - Switch between EXT and CRF according to a "rule." Intermittent reinforcement often SHAPES a particular kind of responding (e.g., fast or slow).
  5. Ratio Schedules determine reinforcement by the number of responses.
  6. Fixed (e.g., FR 25) - Pause and Run (post-reinforcement pause followed by rapid responding in a steady run). Example: stairway, sales commission, piece work.
  7. Variable (e.g., VR 25) - Steady, rapid responding. Example: Slot Machine.
  8. Interval Schedules deterrmine reinforcement by time.
  9. Fixed (e.g., FI 2 min) - Pause followed by a slow acceleration of responding (scalloping) until the time arrives when the final response produces the reinforcer. Example: Checking the mail box to see if a delivery has been made -- postal worker has regular hours)
  10. Variable (e.g., VI 2 min) - Steady, slow responding. Example: Fishing.
  11. Pattern and rate of responding are shown in Cumulative Records that allow you to assess the rate of responding (i.e., probability of responding) at each point in time (and also mark where reinforcers occur)..
  12. Log Response Rate = f(Log Reinforcement Rate) [Fig. 7.4]
  13. The Partial Reinforcement Effect [PRE] (including Frustration Theory -- learning to persist in the face of frustration)
  14. Intermittent Reinforcement and Everyday Life -- Pay schedules, feedback from others, etc. often shape our behavior through intermittent reinforcement.
C. Contemporary Theories of Reinforcement
  1. Access to a higher probability activity (HPA) will reinforce a lower probability activity (LPA). That is, if an LPA is REQUIRED to gain access to an HPA, then the LPA will INCREASE in probability (reinforcement).
  2. Measure of probability: percent of time spent when access is free. Can compare two or more kinds of activity to judge their relative probability
  3. Examples: Running and drinking; Eating candy, playing pinball; Studying, watching Soaps.
  4. Note: These probabilities can change with deprivation and other conditions. Thus, the "reinforcement relationship is reversible."
  1. Olds and Milner's observe that rats returned to the place where they received an electrical stimulus to their medial forebrain bundle (MFB) or mesotelencephalic dopamine system (ESB). They later showed that rats would learn to press a bar in order to receive ESB.
  2. The study by Anderson and colleagues (1992) demonstrates the strength of these reinforcers --
  1. An extreme example of the power of ESB is shown in the Routtenberg & Lindy (1965) study where rats had two levers to press. One produced ESB and the other produced their daily food ration. They spent their time pressing for ESB and some died of starvation! Thus reinforcers are not always adaptive.
  2. Harriman's study on rats with their adrenal glands removed (adrenalectomized). These rats excrete too much salt and therefore need to eat extra salt to stay alive. They will do so EXCEPT when a highly sweet diet sugary diet was also available. Then some rats switched to the sugary diet and died of salt depletion.
  3. Conclusion: We often choose wisely between alternatives -- selecting the best option. We and other animals, however, do not always choose what is best for us. One way to look at this is that evolution has not prepared us to choose wisely between certain alternatives.
  1. Many of our powerful reinforcers involve interactions with other individuals -- i.e., they are social. Are these Primary reinforcers? Acquired (secondary) reinforcers? "Social approval" is clearly (a) very powerful for most individuals but (b) not universal (e.g., the sociopath). Perhaps social reinforcers are something in between primary and secondary.
  2. Imitation (i.e., observational learning) is a very common way to encourage someone else to emit a behavior. "Please, do thisÖ" Once emitted, then the behavior can be influenced by its consequences.
  3. Vicarious reinforcement and punishment (i.e., seeing the outcome of someone else's behavior) influences our behavior. If they are reinforced, we also can be reinforcedÖ when they are punished, we too are punished. (for enemies this may be reversed).
D. Issues of Behavioral Control