The effects of schedule history and the opportunity for adjunctive responding on behavior during a fixed-interval schedule of reinforcement.
The effects of schedule history and the availability of an adjunctive response (polydipsia) on fixed-interval schedule performance were investigated. Two rats first pressed levers under a schedule of food reinforcement with an interresponse time greater than 11 s, and 2 others responded under a fixed-ratio 40 schedule. All 4 were then exposed to a fixed-interval 15-s schedule. Water was continuously available under these conditions, but after responding became stable on the fixed-interval schedule, access was experimentally manipulated. With water freely available, subjects did not display characteristic fixed-interval response rates and patterns (i.e., scalloping or break-and-run). Instead, they exhibited predictable, stable patterns of behavior as a function of their schedule histories: Subjects with the interresponse-time history exhibited low response rates, and those with the fixed-ratio history exhibited high rates. Manipulating the amount of water available resulted in marked changes in response rates for rats with the interresponse-time history but not for those with the fixed-ratio history. The results illustrate the multiple causation of behavior by its previous and current schedules of reinforcement and other concurrent factors.
Johnson
L M
LM
Department of Human Development, University of Kansas, Lawrence 66045-2133.
Bickel
W K
WK
Higgins
S T
ST
Morris
E K
EK
D000818:Animals; D001070:Appetitive Behavior; D001143:Arousal; D003216:Conditioning, Operant; D004327:Drinking Behavior; D008297:Male; D011597:Psychomotor Performance; D051381:Rats; D011919:Rats, Inbred Strains; D012055:Reinforcement Schedule