Discounting of Delayed Food Rewards in Pigeons and Rats: Is There a Magnitude Effect

Autor/inn/en	Green, Leonard; Myerson, Joel; Holt, Daniel D.; Slavin, John R.; Estle, Sara J.
Titel	Discounting of Delayed Food Rewards in Pigeons and Rats: Is There a Magnitude Effect
Quelle	In: Journal of the Experimental Analysis of Behavior, 81 (2004) 1, S.39-50 (12 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0022-5002
Schlagwörter	Rewards; Behavioral Science Research; Animals; Animal Behavior; Food; Reinforcement; Delay of Gratification; Mathematical Models + Suchen Sie Ihr Suchwort? Reward; Belohnung; Animal; Tier; Tiere; Tierverhalten; Lebensmittel; Positive Verstärkung; Mathematical model; Mathematisches Modell
Abstract	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. (Contains 1 table and 6 figures.) (As Provided).
Anmerkungen	Society for the Experimental Analysis of Behavior. Available from: Indiana University Department of Psychology. Bloomington, IN 47405. Tel: 812-334-0395; Fax: 812-855-4691; e-mail: jeab@indiana.edu; Web site: http://seab.envmed.rochester.edu/jeab/index.html
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10