ISSN:
1432-2072
Keywords:
Caffeine
;
Coffee
;
Concurrent schedules
;
Drug self-administration
;
Humans
;
Methodology
;
Reinforcement
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Methodological comparisons of procedures for drug self-administration are rare. In studies examining the reinforcing effect of caffeine in humans, caffeine self-administration usually has been inferred from performance under forced-choice procedures. In the present experiment, caffeine self-administration via coffee was compared under forced-choice and free-choice conditions; i.e., when subjects were and were not required to use a minimum number of coffees. Ten moderate coffee drinkers (2–7 cups/day) were assigned to forced- and free-choice conditions using a randomized cross-over design. Under each choice condition, subjects completed six independent, double-blind trials, consisting of a 2-day exposure period followed by a 2-day test period. During exposure, subjects consumed either decaffeinated or caffeinated (100 mg/serving) coffee on day 1 and the other coffee on day 2. During the test period, subjects had concurrent access to the same decaffeinated and caffeinated coffees. Under the forced-choice condition, subjects were required to drink at least four cups of coffee per day during the test period. Under the free-choice condition, subjects did not have a minimum-cup requirement. In general, the relative rate at which subjects self-administered caffeinated versus decaffeinated coffee was similar across choice conditions, even though subjects self-administered significantly fewer cups of both coffee types under the free-choice than the forced-choice condition. These results suggest that, at least for caffeine, forced-choice and free-choice procedures produce comparable results. Whether this finding generalizes to a context in which caffeine or another drug is more robustly self-administered, remains to be determined.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02245484
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