Choice responding following multiple schedule training

Abstract

Pigeons' choice responding on 10-sec interpolated probes was studied after baseline training on multiple variable-interval variable-interval schedules of food reinforcement. Unreinforced choice following training with three different relative reinforcement rates (Experiment 1), with a 3-ply multiple schedule (Experiment 2), and with three different relative reinforcement durations (Experiment 3) was examined. Least squares lines were fit to choice relative response rate and schedule relative response rate as functions of training relative reinforcement rate; choice slope was significantly greater than schedule slope in all three experiments. This result is counter to the prediction of Herrnstein's (1970) theory that these slopes should not differ. Lues's (l959l theory also failed to account for the data. It was concluded that choice responding was controlled by both approach to the stimulus associated with the smaller mean interreinforcerinterval or the longer duration, and avoidance of the other stimulus.Herrnstein's (1970) theory specifies the relation between response strength and reinforcement rate in the components of multiple and concurrent schedules. Since Herrnstein further proposes that "choice is nothing but behavior set into the context of other behavior" (p. 255), relative response frequency should be the same whether measured simultaneously or successively, once component response strengths are established by the schedule. That is, Herrnstein's equation for multiple-schedule relative response frequency is also the equation for choice relative response frequency following multiple-schedule training. This prediction, that schedule and choice relative rates should be equivalent functions of reinforcement, was evaluated by investigating choice responding on interpolated probes following asymptotic multiple-schedule training.The choice probe results also permit further evaluation of the applicability of Luce's (1959) choice model in extinction tests. Luce (1977) has noted that matching on concurrent schedules is consistent with his model. However, Herrnstein and Loveland (1976), who employed a transfer test similar to that used here, found that choice results were more extreme than predicted by Luce's model. Herrnstein and Loveland (1976) employed this scale in predicting choice. The question of interest here is whether or not the model applies when choice is predicted by a scale derived from previous choice tests, not schedule responding. If the theory applies in this situation, we would have a basis for a ratio scale of relative response strength as a function of relative reinforcement rate for multipleschedule training, which is what the matching law provides for concurrent-schedule training. Nevin (1974) has reviewed arguments for the desirability of such a scale, with response strength conceived as a psychological construct that varies with parameters of reinforcement.Experiment 1 studied choice following three different relative reinforcement rates. To extend the generality of the results and...

Resistance to Extinction and Relapse in Combined Stimulus Contexts

“…Conversely, when the two separately trained responses produced the same relative reinforcement rates as the two alternatives in the DRA component, we found greater persistence for the richer alternative response when combining those responses in extinction (see Figure 7, top-right panel). These findings are consistent with those of Edmon et al (1980), who assessed relative baseline response rates in pairwise comparisons between separate multiple-schedule components presenting either a VI 15-s, a VI 60-s, or a VI 120-s schedule. They again assessed relative response rates in pairwise combinations during brief, 10-s preference-probe extinction trials.…”

“…The present findings of greater DRA target responding in extinction when combining the alternative response (see Figure 7, bottom panel) take the findings of Edmon et al (1980) one step further: Responding in combined extinction tests is a function not only of the rate of reinforcement for target responding but also of reinforcement obtained from any concurrently available sources in that stimulus context. Although this pattern of responding in extinction is consistent with behavioral momentum theory, other studies assessing resistance to disruption with concurrent schedules suggest a more complicated picture.…”

“…Studies observing summation of response rates record the same response both in the presence of the individual training stimuli and when combining stimuli in extinction. Other studies in which each discriminative stimulus and corresponding response were arranged at separate locations have found more responding to the stimulus associated with the higher reinforcement rate or greater excitatory value (Edmon, Lucki, & Grisham, 1980; Honig, 1962). This pattern of results is consistent with the hypothesis that the training stimuli retain the individual associative values when combined; however, most studies do not allow for the appropriate comparison of responding both to the individual discriminative stimuli alone and in combination during extinction tests.…”

Effects of Signaled Versus Unsignaled Delay of Reinforcement on Choice

“…For example, Edmon, Lucki, and Grisham (1980) first presented pigeons with a multiple schedule with two or three components, and then presented pairs of the components together (with extinction in effect) in a choice procedure. On these trials, the subjects were exposed separately to the individual delay values, which presumably made it easier to discriminate the different contingencies.…”

“…This possibility is supported by previous studies that trained two response alternatives separately and then combined them in a choice procedure. For example, Edmon, Lucki, and Grisham (1980) first presented pigeons with a multiple schedule with two or three components, and then presented pairs of the components together (with extinction in effect) in a choice procedure. Preference in the choice procedure was considerably more extreme than that predicted by the relative reinforcement rates used during prior training with the multiple schedule.…”