Survival of the partial reinforcement extinction effect after contextual shifts

The effects of contextual shifts on the partial reinforcement extinction effect (PREE) were studied in autoshaping with rats. Experiment 1 established that the two contexts used subsequently were easily discriminable and equally salient. In Experiment 2, independent groups of rats received acquisition training under partial reinforcement (PRF) or continuous reinforcement (CRF). Significant PREEs were observed whether extinction occurred in the same or in a different context. In Experiment 3, after PRF or CRF acquisition training, each group received extinction of the same conditioned stimulus in both the same and different contexts. PREEs were observed under both conditions, although extinction was accelerated after a contextual shift. These results were discussed in relation to the role of mediational states in the PREE.     

Factor analysis and validation of a self-report measure of impaired fear inhibition

Difficulties with inhibiting fear have been associated with the emergence of anxiety problems and poor response to cognitive–behavioural treatment. Fear inhibition problems measured using experimental paradigms involving aversive stimuli may be inappropriate for vulnerable samples and may not capture fear inhibition problems evident in everyday life. We present the Fear Inhibition Questionnaire (FIQ), a self-report measure of fear inhibition abilities. We assess the FIQ’s factor structure across two cultures and how well it correlates with fear inhibition indices derived experimentally. Adolescent participants from Hong Kong and England completed the FIQ, with the English participants also completing a conditioning and extinction task to assess fear inhibition problems. Across both cultures, the FIQ showed a single factor structure and low FIQ scores, or worse fear inhibition problems, were associated with self-reports of heightened anxiety. Correlation of FIQ scores with experimental indices, whilst controlling for anxious symptoms, suggests that the FIQ represents a valid and unique measure of fear inhibition abilities. The FIQ might be used to assess more ecologically valid fear inhibition problems particularly amongst people who have or who are at risk of anxiety diagnoses.     

Utility of extinction-induced response variability for the selection of mands

Functional communication training (FCT; Carr & Durand, 1985) is a commonly used differential reinforcement procedure for replacing problem behavior with socially acceptable alternative responses. Most studies in the FCT literature consist of demonstrations of the maintenance of responding when various treatment components (e.g., extinction, punishment) are present and absent (e.g., Fisher et al., 1993; Wacker et al., 1990). Relatively little research on FCT has (a) evaluated the conditions under which alternative responses are acquired or (b) described procedures with technological precision. Thus, additional research on a cogent technology for response acquisition appears to be warranted. In the current study, we evaluated the efficacy of exposing problem behavior to extinction for inducing response variability as a tool for selecting an alternative response during FCT. Once participants engaged in appropriate alternative responses, the reinforcer identified in the functional analysis as maintaining problem behavior was delivered contingent on the alternative behavior. Results showed that exposing problem behavior to extinction was a useful method for producing alternative behaviors during FCT.     

条件化恐惧复发的动物模型及相关神经机制

创伤后应激障碍(PTSD)受到国内外普遍关注, 临床上常用的暴露疗法就是基于消退原理, 但经过治疗的患者复发率仍然很高, 这提示抑制复发可能是治疗创伤后应激障碍的关键问题。条件性恐惧复发的动物模型主要包括重建、续新和自发恢复, 但是对续新的研究最多。前人的研究结果表明, 恐惧复发具有异质性, 但海马、前额叶与杏仁核三大脑区或许构成了共同的神经基础。文章从脑区机制及药理干预方面进行了综述, 以期对基础研究和临床诊治提供参考。     

阻碍条件性恐惧记忆消退的原因分析

创伤后应激障碍是个体经历严重应激后形成的一种焦虑障碍,对其治疗的关键是消退由创伤应激导致的条件性恐惧记忆,但目前最有效的暴露疗法并不能真正有效地抑制患者恐惧记忆的表达.对条件性恐惧的动物模型研究发现情绪性增强效应、恐惧记忆二级条件化与再巩固、内侧前额叶皮层功能不足等均能够阻碍条件性恐惧记忆的消退.针对这几个方面可以探索治疗创伤后应激障碍的相应方法.     

Nondirective prompting and noncontingent reinforcement in the treatment of destructive behavior during hygiene routines.

The escape-maintained destructive behavior of a girl with mental retardation persisted during hygiene routines with directive prompting, differential reinforcement for compliance, and extinction as treatment. Using nondirective prompting and noncontingent reinforcement, destructive behavior was reduced to near-zero levels during the hygiene routine.     

NONCONTINGENT REINFORCEMENT AS TREATMENT FOR SEVERE PROBLEM BEHAVIOR: SOME PROCEDURAL VARIATIONS

Noncontingent reinforcement (NCR) as a treatment for problem behavior has typically included (a) continuous access to reinforcers at the onset of treatment and (b) extinction. We extended research on NCR by conducting a three-phase preliminary investigation of these components. In Phase 1, a functional analysis showed that the problem behavior of 3 participants with developmental disabilities was maintained by tangible positive reinforcement. In Phase 2, treatment started with the initial NCR interval based on the latency to the first problem behavior during baseline. In Phase 3, treatment consisted of NCR without extinction to determine whether extinction was an essential treatment component. Results showed that the initial NCR schedule based on latency (Phase 2) and NCR without extinction (Phase 3) were effective for reducing rates of problem behavior compared with baseline. Findings are discussed regarding the initial schedule of reinforcement and extinction as components of NCR.     

Reductions in shock frequency and response effort as factors in reinforcement by timeout from avoidance

Rats' presses on one lever canceled shocks programmed after variable cycles, while presses on a second lever occasionally produced a 2-min timout during which the shock-delection schedule was suspended and its correlated stimuli removed. These concurrent schedules of avoidance and timeout were embedded in a multiple schedule whose components differed, within and across conditions, in terms of the programmed shock rate associated with the shock-deletion schedule. Analyses based on the generalized matching law suggest that the reduction in the response requirement correlated with termination of the avoidance schedule was a more important factor in the reinforcing effectiveness of timeout than was shock-frequency reduction, at least in 2 of 3 rats. After training in each condition, responding on the timeout lever was extinguished by withholding timeouts in both components over seven sessions. Resistance to extinction varied directly with the rates of both shock-frequency reduction and avoidance-response reduction experienced during training. Although reduction in response effort appeared to dominate shock-frequency reduction in the maintenance of responding, neither factor had a clear advantage in predicting the course of extinction.     

Reinforcement of inhibition

A differential-reinforcement-of-other-behavior (DRO) schedule with trials and delayed reinforcement was investigated. Periodically a wheel was briefly available to rats, followed six seconds later by brief availability of a bar. Variable-ratio food reinforcement of wheel turns was adjusted to give 95% turns. After variable-ratio-five reinforcement of bar presses produced 100% pressing, then separate ratio schedules were used for presses following turns (turn presses) and presses following nonturns (nonturn presses). Increasing nonturn-press reinforcements decreased turns, even though total reinforcements increased. Reversal by decreasing nonturn-press reinforcements raised turns, though with hysteresis. Thus food reinforcement increased nonturns even though delayed six to ten seconds after nonturns, a delay that greatly reduces response reinforcement. Those and other results indicate that the turn decrease was not due to reinforcement of competing responses. Evidence against other alternatives, and the reduction of responding by increased reinforcement, indicate that the term inhibition is appropriate for the phenomenon reinforced. Response-specific inhibition appears appropriate for this particular kind, since its effects are more specific to particular responses than Pavlovian conditioned-inhibition. Response-specific inhibition seems best considered a behavioral output comparable to responses (e.g., both reinforcible) but with important properties different from responses (e.g., different reinforcement-delay gradients).     

Reinforcement by an imprinting stimulus versus water on simple schedules in ducklings

Ducklings (5 to 28 days old) were trained to peck a pole on fixed-ratio, fixed-interval, and multiple schedules using brief presentation of an imprinting stimulus as the response-contingent event. Other ducklings of the same age were trained similarly except that reinforcement consisted of access to water. With water reinforcement the typical fixed-ratio (“break-run”), fixed-interval (“scallop”), and multiple schedule response patterns were readily established and consistently maintained. With the imprinting stimulus these schedule effects were inconsistent in some subjects and virtually nonexistent in others, despite extended training. Schedule control with the imprinting stimulus was not improved by the use of a reinforcement signaling procedure which enhances responding reinforced by electrical brain stimulation on intermittent schedules. However, the overall rates of responding and the extinction functions generated after reinforcement with water versus the imprinting stimulus were comparable. These findings imply that control by temporal and discriminative stimuli may be relatively weak when a young organism's behavior is reinforced by presentation of an imprinting stimulus.