DELAY DISCOUNTING OF QUALITATIVELY DIFFERENT REINFORCERS IN RATS

Delay discounting of qualitatively different reinforcers in rats.

Humans discount larger delayed rewards less steeply than smaller rewards, whereas no such magnitude effect has been observed in rats (and pigeons). It remains possible that rats' discounting is sensitive to differences in the quality of the delayed reinforcer even though it is not sensitive to amount. To evaluate this possibility, Experiment 1 examined discounting of qualitatively different foo...

Discounting of Probabilistic Reinforcers by Pigeons

Pigeons' discounting of probabilistic and delayed reinforcers.

Pigeons' discounting of probabilistic and delayed food reinforcers was studied using adjusting-amount procedures. In the probability discounting conditions, pigeons chose between an adjusting number of food pellets contingent on a single key peck and a larger, fixed number of pellets contingent on completion of a variable-ratio schedule. In the delay discounting conditions, pigeons chose betwee...

MODELING DELAY DISCOUNTING 1 Modeling Choices in Delay Discounting

Interactions between deliberation and delay-discounting in rats.

When faced with decisions, rats sometimes pause and look back and forth between possible alternatives, a phenomenon termed vicarious trial and error (VTE). When it was first observed in the 1930s, VTE was theorized to be a mechanism for exploration. Later theories suggested that VTE aided the resolution of sensory or neuroeconomic conflict. In contrast, recent neurophysiological data suggest th...