Percentage reinforcement of fixed-ratio and variable-interval performances

Twenty to seventy per cent of the reinforcements scheduled for pigeons' fixed-ratio 80 performances were replaced by a 4-sec timeout. Pauses after reinforced ratios were unchanged at 80% reinforcement, but were lengthened at lower reinforcement percentages. Pauses after nonreinforced ratios were shorter than post-reinforcement pauses. When 50% of the reinforcements arranged by a variable-interval 60-sec schedule were replaced by a 4-sec timeout, pauses after reinforcement omission increased. Both frustrative nonreward and reinforcement aftereffects notions can explain the fixed-ratio results; neither easily explains the variable-interval data.     

Effects of d-amphetamine and chlordiazepoxide on spaced responding in pigeons

The effects of d-amphetamine and chlordiazepoxide were studied in pigeons on performance (1) under a schedule that reinforced responses on a key (food key) if they were more than 20 sec apart, (2) under the same schedule when responses also were required on a collateral key during the interresponse time on the food key, and (3) under the same schedule when responses were required on a collateral key during the interresponse time on the food key and collateral-key responses could produce a stimulus correlated with the availability of food. Under all three spaced-responding schedules, d-amphetamine and chlordiazepoxide at low dose levels slightly increased the frequency of short interresponse times on the food key for about half the birds, and either did not affect the interresponse time patterns of the other birds, or lengthened the durations slightly. At higher dose levels, d-amphetamine and chlordiazepoxide increased the frequency of long interresponse times or abolished responding in all birds. Changes in the pattern of interresponse times on the food key did not seem to depend on changes in the rate or pattern of collateral-key responses.     

Effects of barbiturates and other sedative hypnotics in pigeons trained to discriminate phencyclidine from saline.

Pigeons were trained to peck the center key (lighted white) of three response keys to turn off the center keylight and to light one of the side keys with a red keylight and the other side key with a green keylight. Five responses (fixed-ratio component) on either side key relighted the center key. Food was delivered following 10 fixed-ratio components on the red key if 1.5 mg/kg phencyclidine had been given before the session. The position of the red and green keylights on the side keys varied randomly each time they were lighted by a peck on the center key. Subsequently, increasing doses of phencyclidine, barbital, amobarbital, phenobarbital, methaqualone, methyprylon, diazepam, oxazepam, and d-amphetamine were substituted for the training dose of phencyclidine, using a cumulative dosing procedure. At low doses of the sedative hypnotics, birds pecked the keylight color associated with saline. At higher doses, birds pecked both key colors. At the highest doses of pentobarbital and amobarbital, some birds responded almost exclusively On he color associated with phencyclidine. When responding on keys of both colors occurred following administration of phencyclidine or other sedative hypnotics, this responding was controlled by key position rather than by key color.     

Experiences that motivate moral development: The role of cognitive dissonance

It has been found in previous research concerning Kohlberg's stages of moral development that engagement in a “real-life” moral dilemma sometimes leads to an advance in an individual's level of moral thought. It is argued in this study that such moral growth is often motivated by the need to reduce cognitive dissonance, which, it is suggested, frequently accompanies choice and commitment in moral contexts. Subjects in the present study delivered counterattitudinal messages that contained arguments that were either 1 stage higher or 1 stage lower than their characteristic level of moral reasoning. Half of the subjects freely chose to deliver these messages, and half did not. Afterwards, subjects' attitudes toward the issues discussed in their messages and their tendency to conceptualize moral issues in terms of the higher or lower levels of reasoning contained in their messages were assessed. The subjects who (a) had freely chosen to deliver the message, and (b) had delivered the message containing higher level arguments used significantly more advanced moral reasoning after their counterattitudinal advocacy than they had before it. These subjects showed greater change in their attitudes regarding the topic discussed in their message than other subject groups. These results suggest that moral behavior will be likely to promote moral growth (a) if it occurs under circumstances that promote cognitive dissonance (e.g., free choice) and (b) if advanced moral ideas are made salient during the dissonance reduction process.     

The effects upon food-reinforced pecking and treadle-pressing of auditory and visual signals for response-independent food

Seven pigeons whose key-pecking was maintained by food reinforcement on a differential-reinforcement-of-low-rates 12-sec limited-hold 4-sec schedule and 12 other pigeons whose treadle-pressing was maintained by the same schedule received appetitive Pavlovian conditioning trials superimposed upon the instrumental baseline. Half the birds in each group received a tone as the CS, and the other half received a stimulus change on the key. Each CS was 20 sec long, and was immediately followed by 10-sec access to grain. The visual CS markedly facilitated the rate of pecking on the key for the birds whose baseline response was pecking. The visual CS produced auto-shaping of the key-peck and tended to produce suppression of treadle-pressing for the birds whose baseline response was treadle-pressing. The auditory CS produced inconsistent effects across birds regardless of the baseline response. In all cases the conditioned effects extinguished when response-independent food was omitted.     

幼儿外倾性与攻击行为的关系:自我控制和母亲温暖教养的调节作用

本研究以上海市某幼儿园的237名3~6岁幼儿为被试,请母亲填写幼儿气质及教养方式问卷,幼儿园教师评定幼儿的攻击行为,探讨幼儿外倾性与攻击行为的关系,以及自我控制和母亲温暖教养方式在其中的保护作用。结果表明,自我控制和母亲温暖可以调节幼儿外倾性与攻击行为的关系。与较低的自我控制和母亲温暖的幼儿相比,幼儿较高的自我控制和母亲温暖,可以弱化外倾性与攻击行为的正向关联。结果揭示了自我控制和母亲温暖对幼儿外倾性具有保护作用,有助于减弱这些个体的攻击行为。     

Bias of phencyclidine discrimination by the schedule of reinforcement.

Pigeons, trained to discriminate phencyclidine from saline under a procedure requiring the bird to track the location of a color, received cumulative doses of phencyclidine, pentobarbital, or d-amphetamine with a variety of schedules of reinforcement in effect (across phases). When the same second-order schedules were used to reinforce responding after either saline or phencyclidine administration, stimulus control by phencyclidine did not depend on the schedule parameter. When different second-order schedules were used that biased responding toward the phencyclidine-correlated key color, pigeons responded on the phencyclidine-correlated key at lower doses of phencyclidine and pentobarbital than when the second-order schedule biased responding toward the saline key color. A similar but less marked effect was obtained with d-amphetamine. Attempts to produce bias by changing reinforcement magnitude (duration of food availability) were less successful. A signal-detection analysis of dose-effect curves for phencyclidine under two of the second-order schedules employed suggested that at low doses of phencyclidine, response bias is a major determinant of responding. As doses were increased, position preferences occurred and response bias decreased; at higher doses both response bias and position preference decreased and discriminability increased. With low doses of pentobarbital, responding again was biased but increasing doses produced position preference with only small increases in discriminability. At low doses of d-amphetamine responding also was biased, but bias did not decrease consistently with dose nor did discriminability increase. These experiments suggest that the schedule of reinforcement can be used to bias responding toward or away from making the drug-correlated response in drug discrimination experiments, and that signal-detection analysis and analysis of responding at a position can be used to separate the discriminability of the drug state from other effects of the drug on responding.     

A comparison of the punishing effects of response-produced shock and response-produced time out

Electric shock and time out were compared as punishers in the squirrel monkey. At the parameters investigated, both suppressed responding to about the same degree. Scheduling punishment intermittently or administering pentobarbital reduced the effectiveness of both punishers. The effects of the punishers were different in that responding suppressed by shock recovered more within a session than responding suppressed by time out. Responding was suppressed after some shock-punishment components, but less often after time-out-punishment components. The similarities of the two punishers were more striking than the differences.     

现实驱动和情节驱动对时间信息表征的影响

采用动窗技术,探讨在记叙文理解中现实驱动和情节驱动对时间信息表征的影响.实验1验证了强印象假设中时间转换的效应,说明读者是根据对现实的期望来建构情境模型的,具体来说,读者采用现实驱动的加工方式表征情境模型中的时间信息.实验2探讨现实驱动和情节驱动对时间信息表征的共同影响,结果表明,读者根据故事情节产生的愿望在一定程度上改变了现实驱动所产生的时间转换的效应,证实了情节驱动在表征情境模型中的时间信息时的作用.     

说明文阅读中因果序列的表征

结合自定步调阅读与句子启动再认范式, 探讨说明文阅读过程中因果序列的表征问题。研究包括3个实验, 实验1的文本提供一个包括4个概念的因果链(如, A－B－C－D), 文本最后设置包含概念A或概念B或概念C的句子, 对概念D进行探测, 结果发现, 对于概念D的再认启动作用, 概念C＞概念B＞概念A; 实验2改变因果链的说明顺序, 使之与因果链本身次序不一致, 结果与实验1一致; 实验3的文本分别介绍两条独立的因果链(如A－B－C; D－E－F), 最后呈现包含概念A或概念D的句子, 对概念C进行探测, 结果发现, 包含概念A的句子理解启动了相关因果链, 使读者对随后呈现的概念C的再认反应加快。基于本研究结果, 结合相关研究, 本文尝试提出说明文文本表征的建构模式。