Extinction of the context and latent inhibition

The hypothesis that latent inhibition could be reduced by extinguishing the experimental context, that is, exposing the rats to the context between exposure to the conditional stimulus (CS) and conditioning, was tested. All experiments used the conditioned emotional response procedure. In Experiment 1, extinction was not effective when the animals were exposed to the clicker 40 times off the baseline of responding for food and when the clicker CS was partially reinforced with shocks during the test phase. In Experiments 2 and 3, latent inhibition could be reduced by extinction if the animals were exposed to the CS 24 or 16 times on-baseline, and if continuous reinforcement was used during the test. In Experiments 4, 5, and 6, we attempted to determine which variable was responsible for the discrepant results. In Experiment 4, extinction was effective with 20 or 40 on-baseline exposures to the CS, using continuous reinforcement during the test. In Experiment 5, extinction was not effective with exposure on- or off-baseline, using 24 exposures and partial reinforcement. Finally, in Experiment 6, extinction reduced latent inhibition using continuous, but not partial, reinforcement with 40 exposures off-baseline. From these results, we concluded that Wagner's model of habituation was not sufficient to account for latent inhibition and that a hybrid model, using both associative and cognitive representational processes, was necessary.     

Extinction of conditioned flavor preferences

In a series of 4 experiments, the effects of extinction on flavor preferences conditioned by mixing flavor cues with a nutrient were examined. In each experiment it was observed that rats preferred a flavor cue that had not undergone extinction to one that had. In addition, this preference was reversed in subjects trained thirsty (Experiments 1 and 2) if the associated nutrient had been devalued prior to the test or the preference for the nonextinguished cue was attenuated by nutrient devaluation in subjects trained hungry (Experiments 3 and 4). The results suggest that extinction may weaken associations between the flavor and the specific sensory properties of the nutrient and, for subjects trained hungry, between the flavor and the motivational components of the nutrient as well.     

Reducing Human Numbers and the Size of our Economies is Necessary to Avoid a Mass Extinction and Share Earth Justly with Other Species

Philosophia - Conservation biologists agree that humanity is on the verge of causing a mass extinction and that its primary driver is our immense and rapidly expanding global economy. We are...     

Extinction of Sidman avoidance behavior

Extinction of Sidman avoidance behavior by eliminating the noxious stimulus was studied in Sprague-Dawley rats with bar-pressing as the response. Each of three subjects was trained and extinguished on each of the following schedules in a different order: nondiscriminated, response-shock interval = 20 sec, shock-shock interval = 5 sec; nondiscriminated, response-shock interval = 40 sec, shock-shock interval = 5 sec; discriminated, response-white noise interval = 15 sec, noise-shock interval = 5 sec, shock-shock interval = 5 sec. Less than one 4-hr session was required for extinction for all procedures. When a warning stimulus was present, resistance to extinction increased. Subjects did not, however, respond to avoid the signal. Only small differences in extinction were found after training on different schedules with no warning signal.     

Extinction of morphine analgesic tolerance

It has been suggested that the analgesic effect of morphine becomes attenuated over the course of successive administrations by a conditional, compensatory, hyperalgesic response elicited by the administration procedure, thus accounting (in part) for analgesic tolerance. On the basis of this associative model of tolerance, it would be predicted that established tolerance would be extinguished by placebo sessions. In experiments of apparently similar design (but conducted by different experimenters in different laboratories), data both confirming and refuting this prediction have previously been published. The present experiment, conducted jointly by the experimenters who reported the divergent findings, was designed to determine the reasons for the different results. It was found that placebo sessions do consistently attenuate morphine analgesic tolerance. Such extinction is not limited to the experimenter, drug preparation, rat strain, or apparatus used in the original, successful demonstration of the phenomenon, but rather is also demonstrable under conditions similar to those used in subsequent experiments which failed to demonstrate extinction of tolerance. Results of the present experiment suggest that the failures to demonstrate extinction of tolerance were attributable to insufficient extinction training.     

Response inhibition in Extinction

In three experiments, rats were given a nonreinforced choice between two instrumental responses, in the presence of stimuli that had separately signalled the various outcomes those responses had earned. Whether those stimuli had been trained in a Pavlovian or instrumental procedure, they selectively enhanced the transfer response with which they shared an outcome. However, a subsequent test showed that this greater responding to a stimulus during extinction produced a reduced ability of that stimulus to augment its transfer response. These results are consistent with the development of an inhibitory S-R association during extinction.     

试论摩尼教消亡的时间

塔里木盆地周缘的喀什噶尔、叶尔羌和阿克苏等地区是摩尼教坚守的最后一块阵地,摩尼教消亡的时间约为18世纪末或19世纪初。此前,有关维吾尔族15世纪末便已实现了全民伊斯兰化的观点应予以纠正。     

Extinction effects during the assessment of multiple problem behaviors

Extinction effects were evaluated in a multiple baseline across behaviors design with 2 boys after just one of several target problem behaviors was observed during a functional analysis. Other target behaviors emerged as extinction was introduced sequentially across all problem behaviors. Results demonstrated an efficient strategy for simultaneously assessing multiple problem behaviors maintained by the same consequence.     

消亡抑或复兴：人本心理学的未来

人本心理学在20世纪末遭遇了内外两方面的危机。但其形成的社会文化与心理学基础依然存在。主流心理学,特别是积极心理学的发展还为她提供了复兴机遇。在未来,人本心理学家需要重审自身使命,明晰研究主题,完善研究方法,保持开放态度,强化组织管理,以推动人本心理学走上复兴之路。     

Preservation of Pavlovian Associations through Extinction

Rats received Pavlovian pairings of conditioned stimuli (CSs) with discriminably different unconditioned stimuli (USs). The resulting CS-US associations, indexed by magazine entry, were subjected to extinction and to interference by pairing the CSs with other USs. Subsequent differential devaluation of the USs by pairing with LiCl revealed the continued presence of the CS-US associations despite these treatments.     

Extinction of avoidance behavior and the problem of residual fear

According to two-factor theory, avoidance responding is predicated on a conjoint relationship between Pavlovian and instrumental conditioning. Recently a variety of evidence has indicated that these processes are independently subject to experimental manipulations, both during acquisition and extinction. The latter finding is paralleled in the clinicial literature by the observation that the elimination of an avoidance response does not adequately reflect concurrent changes in autonomic and verbal behavior. These findings suggest the need for multiple measures of anxiety in assessing the effect of experimental and therapeutic operations on avoidance behavior. This paper also calls attention to the discriminative and reinforcing properties of the CS in an attempt to account for these findings.     

Extinction of conditioned inhibition through nonreinforced presentation of the inhibitor

In previous studies that have tried to extinguish conditioned inhibition through nonreinforced presentations of the inhibitor, researchers have repeatedly failed to find evidence for such extinction. The present study revealed that extinction can be achieved through nonreinforcement of the inhibitor, depending on properties of the reinforcer. In a human causal learning experiment, we found complete extinction in a scenario in which the reinforcer could take on negative values. Thereby, this scenario reflected the assumed symmetrical continuum on which associative strength can vary, according to the Rescorla-Wagner theory of associative learning. In contrast to this, the inhibitory cue retained its inhibitory potential in another condition, in which the scenario did not allow negative values of the reinforcer. nt]mis|Klaus G. Melchers has previously published under the surname “Lober.” Susann Wolff is now working at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany