Effects of reinforcer delays on choice as a function of income level

Three rats earned their daily food ration by responding during individual trials either on a lever that delivered one food pellet immediately or on a second lever that delivered three pellets after a delay that was continuously adjusted to ensure substantial responding to both alternatives. Choice of the delayed reinforcer increased when the number of trials per session was reduced. This result suggests that models seeking closure on choice effects must include a parameter reflecting how preference changes with sessionwide income. Moreover, models positing that reinforcer probability and immediacy (1/delay) function equivalently in choice are called into question by the finding that probability and immediacy produce opposing effects when income level is changed.     

Simultaneous auditory discrimination.

Stimuli in many visual stimulus control studies typically are presented simultaneously; in contrast the stimuli in auditory discrimination studies are presented successively. Many everyday auditory stimuli that control responding occur simultaneously. This suggests that simultaneous auditory discriminations should be readily acquired. The purpose of the present experiment was to train rats in a simultaneous auditory discrimination. The apparatus consisted of a cage with two response levers mounted on one wall and a speaker mounted adjacent to each lever. A feeder was mounted on the opposite wall. In a go-right/go-left procedure, two stimuli were presented on each trial, a wide-band noise burst through one speaker and a 2-kHz complex signal through the other. The stimuli alternated randomly from side to side across trials, and the stimulus correlated with reinforcement for presses varied across subjects. The rats acquired the discrimination in 400 to 700 trials, and no response position preference developed during acquisition. The ease with which the simultaneous discrimination was acquired suggests that procedures, such as matching to sample, that require simultaneous presentation of stimuli can be used with auditory stimuli in animals having poor vision.     

Facial reactions to auditory stimuli: Sex differences

This study explored whether males and females differ in facial muscle activity when exposed to tone stimuli with different intensity. Males and females were repeatedly exposed to 95 dB and 75 dB 1000 Hz tones while their facial electromyographic (EMG) activity from corrugator and zygomatic muscle regions were measured. Skin conductance responses were also measured. It was found that 95 dB but not 75 dB tones evoked increased corrugator activity. This effect differed significantly between males and females. Thus, it was only females that reacted with a significant increased corrugator response to the high intensity tone. While facial responses differed between the sexes, the skin conductance response patterns did not. Consistent with previous research it is concluded that females are more facially expressive than are males.     

多点触觉定位

在左手食指第一节腹侧分别进行1个点、2个点和3个点的定位实验,探讨了多点定位的特点。实验发现,按单个点的定位误差来计算．1个点和3个点的定位误差无显著差异,且二者均显著地低于2个点的定位误差;在2个点的定位中,一个点的定位误差是此2个点的空间距离的函数．定位误差有随距离加大而增加的趋势;在3个点的定位中．同一个点在不同的3点组台中的定位误差无显著差异。结果指示,多点触觉定位除以受刺激的躯体部位框架为参照（基本参照）外,还受到诸刺激点构成的刺激模式（次级参照）的影响。     

幼儿从电视中学单词──项伴随学习的研究

对幼儿从电视中伴随学习单词的可能性及其影响因素进行了初步的探讨。４０名小班幼儿和４６名大班幼儿参加了实验,他们在接近自然的状态下观看有字幕的动画片。结果发现：幼儿在无任何指导的情况下观看有字幕的动画片,能伴随学习到汉字,这表明,电视对幼儿的词汇发展有着积极的影响;不同性别的儿童都能同等程度地从电视中伴随学习到单词;词义的伴随学习受幼儿原有的词汇水平和幼儿对目标词熟悉程度的影响;词音的伴随学习只发生在词汇水平较高的幼儿当中,并且随着幼儿对目标词熟悉程度的增加而增加;词音和词义的伴随学习存在频度效应。     

The transfer of respondent eliciting and extinction functions through stimulus equivalence classes

Two studies investigated the transfer of respondent elicitation through equivalence classes. In Experiment 1, match-to-sample procedures were used to teach 8 subjects two four-member equivalence classes. One member of one class was then paired with electric shock, and one member of the other class was presented without shock. All remaining stimuli were then presented. Using skin conductance as the measure of conditioning, transfer of conditioning was demonstrated in 6 of the 8 subjects. In Experiment 2, similar procedures were used to replicate the results of Experiment 1 and investigate the transfer of extinction. Following equivalence training and conditioning to all members of one class, one member was then presented in extinction. When the remaining stimuli from this class were then presented, they failed to elicit skin conductance. In the final phase of the experiment, the stimulus that was previously presented in extinction was reconditioned. Test trials with other members of the class revealed that they regained elicitation function. These results demonstrate that both respondent elicitation and extinction can transfer through stimulus classes. The clinical and applied significance of the results is discussed.     

A spanish translation and validation of the daily stress inventory and a comparison of the level of stress experienced by three culturally distinct hispanic groups

Two studies were conducted, the first to establish a valid Spanish version of the Daily Stress Inventory (DSI). A second study was conducted using the bilingual version of the DSI to assess differences in the level of stress experienced by three selected Hispanic groups: (a) very Hispanic/Hispanic-oriented bicultural, (b) true bicultural, and (c) Anglo-oriented bicultural/very Anglicized as determined by the adapted version of the Acculturation Rating Scale for Mexican Americans (ARSMA). It was expected that stress levels would be highest for the least acculturated group. The results of the first study indicate that the Bilingual DSI scores are highly correlated with the scores of the original DSI when both instruments are responded to simultaneously by fully bilingual individuals. In Study 2, the initial data analyses showed no difference in the level of stress reported by Hispanics at different levels of acculturation as measured by the ARSMA. When a median-split method was employed, differences in the DSI I/E measures between the two groups were significant, suggesting that acculturation level may be related to stress level.     

THE UNIT PLAY MANAGER AS FACILITATOR OF PURPOSEFUL ACTIVITIES AMONG INSTITUTIONALIZED PROFOUNDLY AND SEVERELY RETARDED BOYS

Child care workers were trained in specified techniques (play manager routines) in an effort to increase purposeful activity among a group of profoundly and severely retarded institutionalized boys. A system of prompts, increasing the availability of toys and regular staff monitoring, were alternated with normal institutional routines in an ABA reversal design. On the average, activity level increased from 10% to a mean of 70% during treatment conditions. Correspondingly, stereotyped or harmful behaviors decreased from an average of 20% to 70% during treatment.     

Kindergarten attendance in relation to educational level and intelligence in adulthood: A geographical analysis

Level of school education and performance on an intelligence test were analysed for 32 557 Danish young adult males as a function of the geographical region in which they were reared. Positive associations were found between both educational levels and test scores on the one hand, and the proportion of infants attending kindergartens in the given regions (according to official statistics) on the other. Adults who were reared in regions where kindergarten attendance had been high tended to have higher educational levels and test scores, although the data do not permit a precise estimate of the magnitude of this effect. The relationship between kindergarten attendance and intelligence test score appears to have been mediated by educational level. Kindergarten attendance was more common in regions with high population density and high average incomes but the relationship of kindergarten attendance to educational level was significantly independent of these associations. These findings are consistent with the hypothesis that kindergarten attendance can have long-term educational benefits, and might therefore partially explain the upward trend in intelligence test scores over the last few decades.