It has been noted previously that larger reinforcers tend to be associated with higher values of the 'response time' parameter, δ, possibly reflecting a greater contribution of post-prandial behaviour to post-reinforcement pauses in the case of larger reinforcers [16,17].
However, as previously reported by Olarte-Sánchez et al. (2013), the parameters expressing the minimum post-reinforcement pause (T0) did differ significantly between the two reinforcers, possibly reflecting the occurrence of more protracted post-prandial orofacial grooming following ingestion of the more viscous reinforcer (see also Bradshaw and Killeen, 2012).
Overall response rate was calculated for each ratio using the total time taken to complete the ratio, including the post-reinforcement pause, measured from the end of the preceding reinforcer delivery until the emission of the last response of the ratio [17].
Overall response rate (ROVERALL) was calculated for each ratio by dividing the number of responses by the total time taken to complete the ratio, including the post-reinforcement pause, measured from the end of the preceding reinforcer delivery until the emission of the last response of the ratio (Bizo and Killeen, 1997).
Post-reinforcement pause duration was measured from the end of the reinforcer delivery until the emission of the first response of the following ratio.
The post-reinforcement pause was defined as the time from the end of the preceding reinforcer delivery until the first response of the ratio.
Furthermore, the distribution of AE events strongly correlated with that of compressive stress, especially in the post-reinforcement yielding stage.
Post-reinforcement pause increased monotonically, and running response rate declined monotonically, as a function of ratio size.
The upper panels of Fig. 3 show the relationship between post-reinforcement pause and the ratio requirement in the three phases of the experiment.
Incorporation of the linear waiting parameters in the new model provides a basis for estimating δ without contaminating it with post-reinforcement pausing.
An important feature of the model is the decomposition of maximum response rate, allowing post-reinforcement pausing to be treated separately from purely motor constraints on responding.
