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161.
162.
R W Foltin 《Journal of the experimental analysis of behavior》1999,72(2):215-234
The effects of the availability of an alternative reinforcer on responding maintained by food pellets or drug solutions were examined in 8 adult male baboons (Papio hamadrayas anubis). During daily 23-hr experimental sessions, baboons had access to both food pellets and fluid under a two-choice procedure, in which the response requirement, under a fixed-ratio schedule, differed for the two commodities. There were no restrictions on access to water, which was continuously available from a spout at the rear of each cage. In Experiment 1, the fixed-ratio requirement, or cost, for fluid delivery remained constant while the fixed-ratio requirement for pellets was changed every 2 or 3 days when (a) no fluid, (b) a dilute dextrose vehicle, (c) 0.008 mg/kg per delivery cocaine, (d) 0.016 mg/kg per delivery cocaine, or (e) 0.032 mg/kg per delivery cocaine was available concurrently. In Experiment 1, progressively increasing the response requirement for pellets decreased pellet intake, but for 4 baboons pellet intake at maximum pellet cost was lower when cocaine, compared to the vehicle, was available. Increasing the response requirement for pellets had variable effects on vehicle intake. However, increasing the response requirement for pellets increased intake of at least one dose of cocaine to a greater extent than vehicle in all 8 baboons. Thus, cocaine could be considered a more effective economic substitute than vehicle for pellets. Experiment 2 systematically varied the order in which the response requirements for a pellet delivery were presented and added a control condition in which cocaine doses, yoked to the amount self-administered, were given three times during the session by the experimenter. Again, pellet intake at maximal pellet cost was lower when cocaine, compared to the vehicle, was available. In contrast, experimenter-given cocaine doses did not alter responding maintained by pellets. Thus, the effects of self-administered cocaine on responding maintained by food pellets differed from the effects of experimenter-given cocaine on responding maintained by food pellets. 相似文献
163.
AGGRESSION AS POSITIVE REINFORCEMENT IN MICE UNDER VARIOUS RATIO‐ AND TIME‐BASED REINFORCEMENT SCHEDULES 下载免费PDF全文
Michael E. May Craig H. Kennedy 《Journal of the experimental analysis of behavior》2009,91(2):185-196
There is evidence suggesting aggression may be a positive reinforcer in many species. However, only a few studies have examined the characteristics of aggression as a positive reinforcer in mice. Four types of reinforcement schedules were examined in the current experiment using male Swiss CFW albino mice in a resident—intruder model of aggression as a positive reinforcer. A nose poke response on an operant conditioning panel was reinforced under fixed‐ratio (FR 8), fixed‐interval (FI 5‐min), progressive ratio (PR 2), or differential reinforcement of low rate behavior reinforcement schedules (DRL 40‐s and DRL 80‐s). In the FR conditions, nose pokes were maintained by aggression and extinguished when the aggression contingency was removed. There were long postreinforcement pauses followed by bursts of responses with short interresponse times (IRTs). In the FI conditions, nose pokes were maintained by aggression, occurred more frequently as the interval elapsed, and extinguished when the contingency was removed. In the PR conditions, nose pokes were maintained by aggression, postreinforcement pauses increased as the ratio requirement increased, and responding was extinguished when the aggression contingency was removed. In the DRL conditions, the nose poke rate decreased, while the proportional distributions of IRTs and postreinforcement pauses shifted toward longer durations as the DRL interval increased. However, most responses occurred before the minimum IRT interval elapsed, suggesting weak temporal control of behavior. Overall, the findings suggest aggression can be a positive reinforcer for nose poke responses in mice on ratio‐ and time‐based reinforcement schedules. 相似文献
164.
J.F. Rickard S. Body Z. Zhang C.M. Bradshaw E. Szabadi 《Journal of the experimental analysis of behavior》2009,91(1):75-87
This experiment examined the relationship between reinforcer magnitude and quantitative measures of performance on progressive‐ratio schedules. Fifteen rats were trained under a progressive‐ratio schedule in seven phases of the experiment in which the volume of a 0.6‐M sucrose solution reinforcer was varied within the range 6–300 μl. Overall response rates in successive ratios conformed to a bitonic equation derived from Killeen's (1994) Mathematical Principles of Reinforcement. The “specific activation” parameter, a, which is presumed to reflect the incentive value of the reinforcer, was a monotonically increasing function of reinforcer volume; the “response time” parameter, δ, which defines the minimum response time, increased as a function of reinforcer volume; the “currency” parameter, b, which is presumed to reflect the coupling of responses to the reinforcer, declined as a function of volume. Running response rate (response rate calculated after exclusion of the postreinforcement pause) decayed monotonically as a function of ratio size; the index of curvature of this function increased as a function of reinforcer volume. Postreinforcement pause increased as a function of ratio size. Estimates of a derived from overall response rates and postreinforcement pauses showed a modest positive correlation across conditions and between animals. Implications of the results for the quantification of reinforcer value and for the use of progressive‐ratio schedules in behavioral neuroscience are discussed. 相似文献
165.
166.
Albert Maydeu-Olivares 《Psychometrika》2006,71(1):57-77
Discretized multivariate normal structural models are often estimated using multistage estimation procedures. The asymptotic
properties of parameter estimates, standard errors, and tests of structural restrictions on thresholds and polychoric correlations
are well known. It was not clear how to assess the overall discrepancy between the contingency table and the model for these
estimators. It is shown that the overall discrepancy can be decomposed into a distributional discrepancy and a structural
discrepancy. A test of the overall model specification is proposed, as well as a test of the distributional specification
(i.e., discretized multivariate normality). Also, the small sample performance of overall, distributional, and structural
tests, as well as of parameter estimates and standard errors is investigated under conditions of correct model specification
and also under mild structural and/or distributional misspecification. It is found that relatively small samples are needed
for parameter estimates, standard errors, and structural tests. Larger samples are needed for the distributional and overall
tests. Furthermore, parameter estimates, standard errors, and structural tests are surprisingly robust to distributional misspecification.
This research was supported by the Department of Universities, Research and Information Society (DURSI) of the Catalan Government,
and by grants BSO2000-0661 and BSO2003-08507 of the Spanish Ministry of Science and Technology. 相似文献
167.
2个实验对PDP的启动型实验程序与Richardson-Klavehn的修正模型进行了比较研究,通过对指示语的操纵,考察提取策略是否完全受意志控制,以及注意水平、刺激材料、测验类型、加工水平对被试作业的影响.结果发现刺激材料对有意识控制记忆的实验结果影响很大,对PDP的无意识自动加工参数无影响;启动型实验程序的结果与PDP理论相当一致;提取策略不一定是受意志精确控制的. 相似文献
168.
考察了4至5岁儿童的现实性监测在延时0天、3天和7天条件下的成绩。结果发现:对真实动作的源混淆更多地发生在延时3-7天,而对想象动作的源混淆更多地发生在0-3天,且对想象动作的现实性监测比对真实动作的现实性监测更早达到随机水平。这表明事件在现实性监测的时间效应中存在不同的特点。 相似文献
169.
讨论了词语使用过程中视觉使用频率和听觉使用频率的区分。通过两个实验对听觉使用频率进行了探讨。实验一通过量表评定法得到了两组视觉使用频率相同,但听觉使用频率不同的双字词,实验二利用实验一得到的两组双字词对被试进行了记忆测验,在单一的听觉条件下,发现在自由回忆,听觉再认和模糊辨听这两类不同的记忆测验中出现了实验性分离现象;反映了听觉使用频率自身的一些特征。 相似文献
170.
Factor analysis is regularly used for analyzing survey data. Missing data, data with outliers and consequently nonnormal data are very common for data obtained through questionnaires. Based on covariance matrix estimates for such nonstandard samples, a unified approach for factor analysis is developed. By generalizing the approach of maximum likelihood under constraints, statistical properties of the estimates for factor loadings and error variances are obtained. A rescaled Bartlett-corrected statistic is proposed for evaluating the number of factors. Equivariance and invariance of parameter estimates and their standard errors for canonical, varimax, and normalized varimax rotations are discussed. Numerical results illustrate the sensitivity of classical methods and advantages of the proposed procedures.This project was supported by a University of North Texas Faculty Research Grant, Grant #R49/CCR610528 for Disease Control and Prevention from the National Center for Injury Prevention and Control, and Grant DA01070 from the National Institute on Drug Abuse. The results do not necessarily represent the official view of the funding agencies. The authors are grateful to three reviewers for suggestions that improved the presentation of this paper. 相似文献