Preference for reinforcers under progressive- and fixed-ratio schedules: a comparison of single and concurrent arrangements

Abstract

Progressive-ratio (PR) schedules were used to identify the break point (i.e., the last schedule value completed) for 2 reinforcers under single and concurrent schedules. After the respective break points were established, the same reinforcers were presented under concurrent fixed-ratio (FR) schedules that were yoked to the break points obtained with the PR schedules. Results suggested that the participants responded more for the high-preference item than for the low-preference item, regardless of the presentation arrangement (single or concurrent presentations). This pattern of responding was maintained when the reinforcers were presented under dissimilar FR schedules. The results suggest that responding for differentially preferred stimuli may vary as a function of differences in schedule requirements.

Figure 1

Rate of task completion during the single and concurrent PR conditions for Calvin (top), Kyle (middle), and Allen (bottom). Numbers represent the break point for the session.

Figure 2

Frequency of task completion during the single and concurrent FR analysis for Calvin (top), Kyle (middle), and Allen (bottom). The upper horizontal dashed lines indicate the maximum number of tasks that could be completed under the FR values for the HP stimulus. The lower horizontal dashed lines indicate the maximum number of tasks that could be completed under the FR values for the LP stimulus.