Document Detail

Discounting of delayed food rewards in pigeons and rats: is there a magnitude effect?
MedLine Citation:
PMID:  15113132     Owner:  NLM     Status:  MEDLINE    
Temporal discounting refers to the decrease in the present, subjective value of a reward as the time to its receipt increases. Results from humans have shown that a hyperbola-like function describes the form of the discounting function when choices involve hypothetical monetary rewards. In addition, magnitude effects have been reported in which smaller reward amounts are discounted more steeply than larger amounts. The present research examines the cross-species generality of these findings using real rewards, namely food pellets, with both pigeons and rats. As with humans, an adjusting amount procedure was used to estimate the amount of immediate reward judged equal in value to a delayed reward. Different amounts of delayed food rewards (ranging from 5 to 32 pellets in pigeons and from 5 to 20 pellets in rats) were studied at delays varying from 1 s to 32 s. A simple hyperbola, similar to the hyperbola-like mathematical function that describes the discounting of hypothetical monetary rewards in humans, described the discounting of food rewards in both pigeons and rats. These results extend the generality of the mathematical model of discounting. Rates of discounting delayed food rewards were higher for pigeons than for rats. Unlike humans, however, neither pigeons nor rats showed a reliable magnitude effect: Rate of discounting did not vary systematically as a function of the amount of the delayed reward.
Leonard Green; Joel Myerson; Daniel D Holt; John R Slevin; Sara J Estle
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of the experimental analysis of behavior     Volume:  81     ISSN:  0022-5002     ISO Abbreviation:  J Exp Anal Behav     Publication Date:  2004 Jan 
Date Detail:
Created Date:  2004-04-28     Completed Date:  2004-07-29     Revised Date:  2014-09-19    
Medline Journal Info:
Nlm Unique ID:  0203727     Medline TA:  J Exp Anal Behav     Country:  United States    
Other Details:
Languages:  eng     Pagination:  39-50     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Behavior, Animal / physiology
Choice Behavior
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Effects of experience on preference between forced and free choice.
Next Document:  The effects of behavioral history on response acquisition with immediate and delayed reinforcement.