Extinction Of Operant Behavior Research Articles

Evidence for Distinct Forms of Compulsivity in the SAPAP3 Mutant-Mouse Model for Obsessive-Compulsive Disorder.

The specific mechanisms underlying compulsive behavior in obsessive-compulsive disorder (OCD) are unknown. It has been suggested that such compulsivity may have its origin in cognitive dysfunction such as impaired processing of feedback information, received after the completion of goal-directed actions. The signal attenuation (SA) task models such a processing deficit in animals by attenuating the association strength between food reward and audiovisual feedback (signal) presented after performance of an operant response. The compulsive-like responding resulting from SA is well characterized in rats, but was so far not established in mice, a species for which powerful genetic OCD models exist. Thus, first, we demonstrate that the SA task can be implemented in mice and show that attenuation of reward-associated response feedback produces similar behavior in C57BL/6 mice as previously reported in rats. Second, we tested the hypothesis that SAPAP3 knock-out mice (SAPAP3-/-), prone to exhibit several OCD-like abnormalities including excessive grooming, show enhanced compulsive-like behavior in the SA task compared with their wild-type (WT) littermates. However, task-related compulsivity measures in SAPAP3-/- and WT did not yield significant differences, neither following SA nor during “regular” extinction of operant behavior. Thus, compulsive-like instrumental behavior following feedback distortion was not potentiated in compulsively grooming mice, implicating specifically that (1) a general deficit in feedback processing is not related to excessive grooming in SAPAP3-/- and (2) different manifestations of compulsivity may be driven by independent mechanisms.

An Inexpensive Method to Study Response Variability in Acquisition and Extinction of Operant Behavior

To examine operant response variability in detail, a lever was attached to the Thumbstick of a videogame controller, which functions as a joystick. The controller was mounted outside of a standard rodent operant chamber with the lever extending into the chamber. Movement of the lever was restricted to a vertical downward distance of 2 cm. Food pellet delivery was used as reinforcement of lever movement. Criteria for reinforcement were that the lever should be held between two criteria distances, one from the top resting position of the lever and one from the end position of full movement, and the holding response should last a certain duration. Apparatus construction and development of algorithms for response detection and display in graph format as actograms are described in detail. The use of the equipment is illustrated with two demonstration experiments that examined response variability in extinction and during acquisition. The recording method allows for display of considerable detail regarding variability in real time with a resolution of 100 ms. For example, for Experiment 1, extinction of a relatively “simple” operant generated considerably new response forms with very little repetition of the form of the previously reinforced operant.

Towards mouse models of perseveration: A heritable component in extinction of operant behavior in fourteen standard and recombinant inbred mouse lines

Extinction of instrumental responses is an essential skill for adaptive behavior such as foraging. So far, only few studies have focused on extinction following appetitive conditioning in mice. We studied extinction of appetitive operant lever-press behavior in six standard inbred mouse strains (A/J, C3H/HeJ, C57BL/6J, DBA/2J, BALB/cByJ and NOD/Ltj) and eight recombinant inbred mouse lines. From the response rates at the end of operant and extinction training we computed an extinction index, with higher values indicating better capability to omit behavioral responding in absence of reward. This index varied highly across the mouse lines tested, and the variability was partially due to a significant heritable component of 12.6%.To further characterize the relationship between operant learning and extinction, we calculated the slope of the time course of extinction across sessions. While many strains showed a considerable capacity to omit responding when lever pressing was no longer rewarded, we found a few lines showing an abnormally high perseveration in lever press behavior, showing no decay in response scores over extinction sessions.No correlation was found between operant and extinction response scores, suggesting that appetitive operant learning and extinction learning are dissociable, a finding in line with previous studies indicating that these forms of learning are dependent on different brain areas. These data shed light on the heritable basis of extinction learning and may help develop animal models of addictive habits and other perseverative disorders, such as compulsive food seeking and eating.

Effects of chlordiazepoxide on extinction of operant behaviour in mice vary with time of administration and rate of extinction

Relatively little is known about the neural basis of operant extinction, although both glutamatergic and GABAergic processes have been shown to be involved in extinction following aversive Pavlovian conditioning. Following training of lever pressing by mice on a discrete-trial fixed-ratio food reinforcement schedule, chlordiazepoxide (CDP) and other GABAergic drugs facilitate extinction, but only after a number of brief extinction sessions have occurred. In the present experiment, the effects of chlordiazepoxide were assessed when administered prior to or after brief extinction sessions, or prior to longer “massed trial” extinction sessions (with 60 or 96 trials rather than the six used previously).With short extinction sessions, CDP facilitated extinction after a delay when administered prior to extinction sessions but not when administered afterwards. With long extinction sessions, facilitation by CDP occurred rapidly, indicating that this effect is determined primarily by the number of extinction trials that have occurred (rather than days of extinction or number of CDP administrations). Implications for the role of GABAergic processes in operant extinction are discussed.

EFFECTS OF REINFORCEMENT SCHEDULE ON FACILITATION OF OPERANT EXTINCTION BY CHLORDIAZEPOXIDE

Learning and memory are central topics in behavioral neuroscience, and inbred mice strains are widely investigated. However, operant conditioning techniques are not as extensively used in this field as they should be, given the effectiveness of the methodology of the experimental analysis of behavior. In the present study, male C57B1/6 mice, widely used as background for transgenic studies, were trained to lever press on discrete-trial fixed-ratio 5 or fixed-interval (11 s or 31 s) schedules of food reinforcement and then exposed to 15 extinction sessions following vehicle or chlordiazepoxide injections (15 mg/kg i.p., administered either prior to all extinction sessions, or prior to the final 10 extinction sessions). Extinction of operant behavior was facilitated by drug administration following training on either schedule, but this facilitation only occurred once a number of extinction sessions had taken place. The extinction process proceeded more rapidly following fixed-interval training. Resistance to extinction was equally high following training with either schedule type, and was reduced by drug administration in both cases. These phenomena were evident in individual cumulative records and in analyses of group data. Results are interpreted in terms of phenomena of operant extinction identified in Skinner's (1938) Behavior of Organisms, and by behavioral momentum theory. These procedures could be used to extend the contribution of operant conditioning to contemporary behavioral neuroscience.

Extinction of operant behavior as the test for cognitive disorders induced with kainic acid.

Wistar rats were trained food-procuring task for 5 days and then extinction of the operant behavior was studied for 6 days after injection of an epileptogen (kainic acid, 8 mg/kg, intraperitoneally). Kainic acid induced long-term impairment of inhibitory processes in the brain, which impeded extinction of a conditioned response. This effect was prevented by daily injections of anticonvulsant sodium valproate (300 mg/kg for 4 days).

EFFECTS OF REINFORCEMENT MAGNITUDE ON SPONTANEOUS RECOVERY

Extinction of operant behavior has been associated with a number of undesirable effects. One such effect is the temporary reappearance of behavior after responding appears to be completely extinguished, known as spontaneous recovery. In this report, the occurrence of spontaneous recovery and its attenuation with large amounts of reinforcement were examined during the treatment of disruption.

Developing a technology for the use of operant extinction in clinical settings: an examination of basic and applied research.

Extinction of operant behavior, which involves terminating the reinforcement contingency that maintains a response, is important to the development, generalization, and reduction of behavior in clinical settings. We review basic and applied research findings on variables that influence the direct and indirect effects of extinction and discuss the potential value of a general technology for the use of extinction. We suggest that current research findings are not sufficient for the development of a comprehensive, applied technology of extinction and provide extensive guidelines for further studies on factors that may affect the course of extinction in clinical settings.

Extinction of operant behavior: An analysis based on foraging considerations

In two experiments, the frequency of food reinforcement provided by variable interval (VI) schedules prior to extinction was varied. In the first experiment, two-component multiple schedules resulted in a greater number of responses in extinction in the presence of the stimulus previously associated with the richer of the two component schedules than that previously associated with the leaner schedule. In the second experiment, different groups of animals were trained on different VI schedules. Responding in extinction was analyzed into bouts of responding showing that the number of response bouts increased and the number of responses per bout decreased with decreasing frequency of reinforcement during training. These data are compatible with an analysis of operant behavior based on an analogy to processes that presumably-occur-in naturalistic foraging situations. According to this analogy, behavior associated with search for a food source (i.e., number of response bouts) and that of procurement of food from a source (i.e., responses per bout) represent aspects of behavior that are differentially strengthened by different VI schedules. Extinction serves to reveal this differential strengthening.

Plasma corticosterone increases produced by extinction of operant behavior in rats.

Abstract Male Long-Evans rats were conditioned to lever press for water on a continuous reinforcement schedule. Plasma corticosterone concentrations were determined following reinforced sessions and extinction sessions. All animals were sampled under both conditions, using a balanced repeated measures design. In addition, the pre-session or basal concentration of plasma corticosterone was measured in one subgroup. Plasma corticosterone levels were significantly elevated as a function of extinction, while reinforced responding produced no change compared to the basal level. The results show a major physiological change occurring as a consequence of extinction of an appetitive task; this and other findings suggest that the pituitary-adrenal hormone system plays a role in extinction of appetitive behavior.