Theories of Reinforcement

1
Theories of Reinforcement

• Why is a reinforcer effective?
• Why does a reinforcer increase the probability of
  a response?

2
Two Approaches

• Reinforcers are certain kinds of stimuli
• Drive Reduction Theory of Hull
• Reinforcers are certain kinds of responses
• Premack Principle of David Premack

3
Drive Reduction Theory

• Organisms attempt to maintain a state of
  physiological equilibrium, or homeostasis
• Deviations from homeostasis produce biological
  drives
• examples hunger, thirst, pain
• Reinforcers are events that reduce biological
  drives
• examples food to a hungry organism, water to a
  thirsty one

4
Premack Principle

• Organisms have baseline levels of engaging in
  different behaviors
• examples drinking, running
• Organisms will work at a less probable behavior
  for the opportunity to engage in a more probable
  behavior
• examples run to drink, when thirsty

5
Implications of Premack Principle

• Reinforcers are individualized, not intrinsic
• the candy/pinball experiment
• Reinforcers are reversible
• the run to drink/drink to run experiment

6
Newer Views

• Response deprivation hypothesis
• reinforcers are responses that have been
  deprived
• Behavioral regulation
• reinforcement contingencies impose constraints on
  behavior
• organisms seek their behavioral bliss points

7
Behavioral Regulation

• Measure time spent in behavior when there is no
  constraint
• behavioral bliss point
• Schedule imposes a constraint
• schedule line
• Time spent in behavior under a constraint will
  minimize distance from bliss point