Variables affecting choice behaviour: choice behaviour and deprivation
Pigeons were studied in concurrent chain schedules in which the terminal links were variable-interval (aperiodic) and fixed-interval (periodic) schedules. Choice was studied at various maintained percentages of body weight, (Experiment 1) and after various amounts of food had been pre-fed (Experiment 2). No effects on choice of the level of deprivation were found except in those choice conditions in which both terminal-link schedules were variable-interval schedules. Choice behaviour was further studied with equal, but increased magazine durations (Experiment 3) and no reliable effects were found. Explicit discrimination training established control over choice behaviour by the amounts pre-fed (Experiment 4) and generalisation gradiets of choice showed that this control was reliable. The differences found between aperiodic and periodic schedules were probably related to the different patterns of behaviour maintained by these schedules and an attempt was made to relate the results to overall models of behaviour and the 'value' of food.