Resurgence and downshifts in alternative reinforcement rate

Abstract

Resurgence refers to an increase in a previously suppressed target behavior with a relative worsening of conditions for a more recently reinforced alternative behavior. This experiment examined the relation between resurgence and the magnitude of a reduction in the rate of reinforcement for the alternative behavior. Groups of both male and female rats initially pressed a target lever for food on a variable-interval (VI) 30-s schedule. In a second phase, responding to the target lever was extinguished for all groups and pressing an alternative lever was reinforced on a VI 10-s schedule. Next, the rate of reinforcement for alternative behavior was reduced differentially across groups by arranging extinction, VI 80-s, VI 40-s, VI 20-s, or continued VI 10-s reinforcement. Target responding increased as an exponential function of the magnitude of the reduction in alternative reinforcement rates. With the exception that males appeared to show higher rates of target responding in baseline and higher rates of alternative responding in other phases, the overall pattern of responding across phases was not meaningfully different between sexes. The pattern of both target and alternative response rates across sessions and phases was well described quantitatively by the Resurgence as Choice in Context model.

Keywords: discrimination; lever pressing; matching law; operant behavior; rats; resurgence.

© 2020 Society for the Experimental Analysis of Behavior.

Figures

Figure 1

Target Response Rates in the Last Three Sessions of Phase 1 and Target and Alternative Response Rates Across All Sessions of Phase 2 for Both Males (Left Panel) and Females (Right Panel) Note. Symbols represent each group and are consistent across sex. Target and alternative responding are represented by the solid and dotted lines, respectively. Error bars represent standard error of the mean.

Figure 2

Target Response Rates in the Last Session of Phase 2 and the First Session of Phase 3 for Each Group for Males (Left Panel) and Females (Right Panel) Note. Symbols represent each group and are consistent across sex. Error bars represent standard error of the mean.

Figure 3

Target Response Rates in the Last Session of Phase 2 and the First Session of Phase 3 for Rats in Each Group for Males (Left Panel) and Females (Right Panel) Note. Each line corresponds to a single rat.

Figure 4

Target Response Rates in the First Session of the Phase 3 as a Function of the Downshift in Alternative Reinforcement in the Transition from Phase 2 to Phase 3 Note. The small data points represent individual rats and the line is a linear regression fitted to all individual-subject data. The large data points represent geometric means and are presented only as a visual aid. Note the logarithmic y-axis. The inset panel shows the same function and means but presented in arithmetic space.

Figure 5

Response Rates for Target (Top Panels) and Alternative (Bottom Panels) Behaviors Across Sessions of Phase 3 for Each Group for Males (Left Panels) and Females (Right Panels) Note. Symbols represent each group and are consistent across sex. Error bars represent standard error of the mean.

Figure 6

Target Response Rates in the Last Session of Phase 3 and the First Session of Phase 4 for Each Group for Females (Left Panel) and Males (Right Panel) Note. Symbols represent each group and are consistent across sex. Error bars represent standard error of the mean.

Figure 7

Response Rates for Target (Top Panels) and Alternative (Bottom Panels) Behaviors Across Sessions of Phase 4 for Each Group for Males (Left Panels) and Females (Right Panels) Note. Symbols represent each group and are consistent across sex. Error bars represent standard error of the mean.

Figure 8

Response Rates for Target (Top Panels) and Alternative (Bottom Panels) Behaviors Across Sessions Presented Separately for Males (Left Panels) and Females (Right Panels) Note. Data for the different groups are represented by differently colored solid lines. Mean target behavior response rates in the final three sessions of Phase 1 are presented above zero on the x axis in the top panels. The predictions of RaC2 for each group are shown as dotted lines of the same color as for the data. Data were fitted simultaneously for target and alternative behaviors, but separately for the sexes. Note the logarithmic y axes.