Association for Behavior Analysis International

Experimental analyses of resistance to change and relapse with rats, zebrafish and pigeons will be presented. Teixeira and Cançado studied, with rats, how baseline-response rates modulate the effects of the response-reinforcer dependency on resistance to extinction. Resistance to extinction was greater in the lower-dependency multiple-schedule component only when baseline-response rates were lower in this component. Kuroda et al. studied the effects of baseline reinforcement rates on resistance to extinction and resurgence with zebrafish. Resistance to extinction and the magnitude of resurgence were directly related to baseline reinforcement rates. Calmon-Rodegheri and Abreu-Rodrigues studied, with pigeons, a procedure to assess resurgence within sessions. That is, target and alternative responding were reinforced in the first and second parts of a session. Resurgence occurred reliably whether test sessions alternated or not with reinforcement of target and alternative responses. Similarly, Bai et al. studied resurgence on local time-scale with pigeons by using a procedure in which target and alternative responses were reinforced in the first and second parts of a trial. In extended extinction trials, the onset and magnitude of resurgence were greater when signaling extinction of the alternative response. These experiments inform, theoretically and methodologically, future experimental analyses of resistance to change and relapse.

An experiment with rats assessed how baseline-response rates modulate the effects of the response-reinforcer dependency on resistance to change. In baseline, reinforcers occurred at the same rate after variable interreinforcer intervals in each component of a two-component multiple schedule. The dependency was 10%, in one component (i.e., a concomitant VI-VT schedule), and 100%, in the other. In one condition, baseline-response rates were equated between components (a tandem VI DRL was in effect in the 100% component); the response-rate difference between components was not controlled in a second condition (i.e., VI in effect in the 100% component). In two subsequent conditions, response rates in the 100% component (i.e., tandem VI DRL) were, respectively, 40-60% and 70-90% higher than those in the 10% component. Resistance to extinction was not differential when baseline-response rates were equated between components, but was greater in the 10% than in the 100% component when baseline-response rates were higher in the latter. Additionally, the magnitude of this differential resistance was related to the difference in baseline-response rates between components. These results replicate previous findings (i.e., greater resistance of lower response rates) and suggest that the dependency affected resistance to change as one procedure that alters baseline-response rates.

Zebrafish (Danio rerio) is a promising animal model for studying how genes interact with environmental factors in determining behavior. In operant research with this species, a major question relates to whether their behavior follows the same principles as other model species (e.g., rats and pigeons). Previous studies showed that resurgence occurs in zebrafish after their behavior was reinforced and then extinguished. The present study investigated whether the magnitude of resurgence is a function of baseline reinforcement rate with zebrafish, as previously shown with rats, pigeons, and humans. In Phase 1, a multiple schedule delivered food reinforcers according to variable-interval 10 s and 60 s schedules for approaching a target sensor. In Phase 2, the target response was extinguished while reinforcing approach to an alternative sensor with a variable-interval 10-s schedule in both components. Resistance to disruption of target responding in Phase 2 was greater in the richer Phase-1 component. Finally, Phase 3 extinguished both responses in both components and also revealed greater resurgence in the richer Phase-1 component. These results are consistent with previous findings with other species, suggesting the processes underlying persistence and relapse are conserved across a diverse range of species.

Resurgence is the reappearance of an extinguished response when the reinforcer for an alternative response is no longer delivered. The standard procedure to investigate resurgence includes three successive conditions. In the Training Condition, a target response (R1) is reinforced; in the Elimination Condition, R1 is extinguished while an alternative response (R2) is reinforced; finally, in the Test Condition, both responses do not produce reinforcers. In this last condition, resurgence of R1 is often observed. In the present study, this procedure was modified in two different ways. The Training (mult tand VI FR tand VI DRL) and Elimination (mult conc EXT VI conc EXT VI) conditions occurred in the first and second parts, respectively, of a session. When stable behavior was observed in both conditions, Training+Elimination sessions were alternated with Test sessions (Alternating Phase) or were discontinued and only Test sessions occurred for five or seven consecutive days (Successive Phase). Response rates were higher in the tand VI FR component, but reinforcement rates were similar between components in Training. Resurgence was greater in the component correlated with the tand VI FR, despite the procedure used (Alternating or Successive Phase).

Resurgence refers to relapse of extinguished behaviors following extinction of an alternative source of reinforcement, and has been found in both clinical settings and animal models of relapse. In laboratory models, resurgence is typically studied across three successive phases: (1) reinforcement of a target response, (2) extinction of the target and concurrent reinforcement of an alternative response, and (3) re-emergence of the target response when the alternative is extinguished. Each phase typically spans multiple sessions, however resurgence can also occur on smaller time-scales. The present study assessed resurgence using pigeons in a within-trial procedure. In each trial, target (left-key) responding was reinforced and alternative (right-key) responding was extinguished in the first half, before the contingencies reversed in the second half. Pigeons reliably switched from target to alternative responding within baseline trials. Target responding then resurged in extended probe trials, which arranged extinction for both responses. The onset and magnitude of resurgence was greater when signaling extinction of the alternative. Furthermore, resurgence sustained across two cycles of baseline and probe conditions, despite decreases in the magnitude of resurgence within and across cycles. Therefore, the within-trial procedure produces durable resurgence effects and could be used to assess factors across repeated resurgence tests.