Operant Analyses of Choice Involving Probabilistic Reinforcers

• Author / Creator

  Pisklak, Jeffrey

• In the natural world, for both human and non-human animals alike, the consequences of choices can be delayed, infrequent, and often highly uncertain (probabilistic). These factors, and their resulting interactions, can have diverse effects that, at face value, seem to control the allocation of behaviour in counterintuitive ways. This dissertation investigates two distinct paradigms of choice that examine the role of probabilistic reinforcement on choice behaviour. More specifically, in Chapter 2, the conditionally reinforcing function of stimuli in a concurrent-chains pigeon (Columba liva) “suboptimal” choice paradigm were manipulated. Findings revealed that, contrary to the predictions of some theories of suboptimal choice, the frequency of reinforcement, and not just its signal value, was a necessary factor in determining how pigeons allocated their responding across choice alternatives. Chapter 3 assessed the impact of increased initial-link ratio requirements on a similar pigeon task to that of Chapter 2. As predicted, increasing the response requirement attenuated the effect of suboptimal preference. Chapter 4 evaluated the role of probabilistic outcomes in the context of the extreme-outcome effect in both pigeons and humans (Homo sapiens). Findings revealed that, like humans, pigeons will exhibit greater preference of a probabilistic (“risky”) alternative for high-value choices relative to low-value choices. However, this finding was found to be limited only to cases where a zero-value outcome (extinction) is a possible extreme within the choice context. When zero was removed from this context, only humans, and not pigeons, continued to display the extreme- outcome effect.

• Subjects / Keywords

  • suboptimal
  • pigeon
  • reinforcement
  • risky
  • human
  • choice

• Graduation date

  Fall 2019

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/r3-07fj-9g58

• License

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