Stimulus intensity affects pigeons’ timing behavior: Implications for an internal clock model

Five pigeons were trained to discriminate between 2- and 10-sec illuminations of a white light; choice of a red pecking key was correct and rewarded after presentation of the short stimulus, whereas choice of a green key was correct and rewarded after presentation of the long stimulus. On half the trials, the light was bright; on the others, it was dim. Durations of 4, 6, and 8 sec of both dim and bright light were also presented; choices on these trials were not rewarded. The probability of the pigeons’ choosing the short alternative decreased in a graded manner as duration of both bright and dim light increased from 2, to 4, to 6, to 8, and to 10 sec. However, the pigeons were more likely to choose the short alternative with longer durations of the dim light than the bright light, a result that implies that the perceived duration of a dim light was shorter than that of a bright light of equal length. One interpretation of this effect is that stimulus intensity affects the rate of the pacemaker in an internal clock mechanism subserving timing of event duration.     

基于EIB总线的图书馆智能照明控制

EIB总线作为楼宇家居自动化控制技术的主流,具有适应性好、功能强大与可靠性高等多方面优点,能很好地满足定时、合成照度、人体检测和手控等不同的照明控制需求。通过智能化的自动控制实现了楼宇的舒适照明和节能照明两大目标,克服传统照明解决不了的问题。     

一种基于视觉的车载照明自动跟踪系统

目前夜间事故勘察车载照明多采用传统自适应灯光,存在照射范围有限且调节照明方向繁琐等问题。因此,基于视觉设计一种车载照明自动跟踪系统。使用视觉处理技术与双步进电机控制对车载照明系统进行改进,以增强车载照明智能化和灵活性。针对传统自适应灯光需人为操纵照射目标的问题,车载照明系统在运行时对红外光源（移动目标）进行图像检测,实时反馈拍摄图像中红外光源位置坐标,再根据位置坐标信息控制双步进电机,带动车载照明灯准确地照射到红外光源坐标位置。实验结果表明,该系统可快速检测到照明目标位置坐标,准确控制步进电机移动,可满足跟踪目标的要求,准确率达 95%。     

Vocalization as an objective measure of shock-elicited social aggression in rats

Intense vocalizations emitted by pairs of shocked rats were compared when physically separated by a transparent partition and when free to engage in social aggression. Greater vocalization occurred in the free-access condition and was positively correlated with visually observed attack scores in pairs that had prior experience with shock. A second experiment determined the influence of repeated fighting exposures upon the correlation between observed attack and vocalization. High positive correlations were obtained after initial sessions within a broad range of intermediate fighting. At high and low extremes of fighting, correlations were nonsignificant. The results are discussed with reference to restriction imposed upon variation of attack scores based upon standard criteria of observation.     

Effects of environmental novelty on filial behavior in imprinted ducklings

Environmental novelty was manipulated in imprinted ducklings by varying the illumination level of the experimental apparatus. Bright illumination disrupted filial behavior in subjects that had received little prior exposure to the imprinting object, with approach being suppressed more when the object was stationary than when it was moving. In subjects with prolonged prior imprinting exposure, bright illumination enhanced filial behavior. These effects can be understood if one assumes that environmental novelty has an energization effect while also eliciting responses that are incompatible with filial behavior.     

The influence of stimulus attributes on duration matching-to-sample in pigeons

A duration matching-to-sample procedure was used to examine the influence of signal properties on temporal estimation and working memory. The results indicated that pigeons responded to durations of a light as if they were longer than equal durations of the absence of the same light, but delay performances did not differ between the two sample types. Similarly, pigeons responded to durations of a bright white light as if they were longer than equal durations of a dim red light, but again, delay performances did not differ between the two sample types. These results are discussed in terms of theoretical issues pertinent to timing, attention, and working memory.     

Simulation experiments on counter beam lighting in highway tunnel

Counter beam lighting was introduced as well as transverse symmetrical lighting and longitudinal symmetrical lighting. Simulation experiments were carried out by using DIAlux lighting software for the above three lighting methods. The results show that counter beam lighting is more reasonable to be adopted in the tunnel entrance zone because its threshold increment of disability glare is greater. Counter beam lighting can improve the background luminance of the obstacles and lighting efficiency compared with transverse symmetrical lighting and longitudinal symmetrical lighting. Therefore, tunnel lighting energy-saving can be achieved by reducing the road luminance demands and luminaries power. Longitudinal symmetrical lighting is conducive to the large luminaries spacing in the tunnel internal zone; so power consumption can be reduced by decreasing the number of luminaries used. Tunnel walls are unsuitable to pave with smooth or bright material. Installation height of the luminaries has less effect on counter beam lighting.     

Blocking as a function of added cue intensity

Twelve rats were initially trained to leverpress for water in the presence of a tone. Responses in the absence of the tone were never reinforced. Following this pretraining, a novel light cue was simultaneously compounded with all presentations of the tone as a relevant but redundant predictor of reinforcement. For three different groups of subjects, the light cue was of either bright, moderate, or dim intensity. After compound training, all subjects experienced nonreinforced presentations of each of the two components of the compound. Results indicated that the relative degree of control exerted by the light over behavior increased with increases in light (added cue) intensity.     

Gender,prior knowledge,interest, and experience in electricity and conceptual change text manipulations in learning about direct current

The present study investigated relationships between gender, interest and experience in electricity, and conceptual change text manipulations on learning fundamental direct current concepts. Conceptual change text has been shown to lead to better conceptual understanding of electrical concepts than traditional didactic text, but previous research suggested that the effect interacted with the gender of the participants. We hypothesized that interest moderated this interaction. In this study, men and women who had higher or lower interest in electricity and greater or lessor experience with electricity read conceptual change or traditional text. When interest level, experience, and prior knowledge were not included in the analysis, both gender and text type produced significant main effects. When interest level, experience, and prior knowledge were included in the analysis, conceptual change text led to better understanding of electricity concepts than did the traditional text, and the effect of gender was eliminated. This finding supports the hypothesis that prior interest level, experience, and knowledge mediate apparent gender differences in learning about electricity. It suggests that conceptual change text manipulations are likely to be effective for both men and women. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 107–123, 1997.     

Light stimulus change evokes an activity response in the rat

Bright light may be a danger signal for rats because they are more vulnerable to predators in bright environments. We examined the fear-evoking properties of bright light with a novel open-field procedure that confronts a rat with the sudden onset or termination of a bright light gradient. The rats did not freeze but exhibited a transient increase in locomotion to light onset and termination, which we call theactivity response (AR). This finding suggests that the AR is an exploratory response geared at investigating stimulus change. The rats also displayed a preference for dark to the lighting differential that was not due to the novelty or slight heating differential supplied by the lamps. These experiments demonstrate that the sudden onset of bright light engages preencounter defensive behavior, as described by the predatory imminence model (Fanselow & Lester, 1988). This task is amenable to studying light-evoked defensive responses.     

白光LED照明通信关键技术及发展趋势研究

与传统照明光源相比,白光LED具有高效节能长寿环保等明显优势,这种绿色固态照明产品将会成为未来人工照明光源的主流产品。而且白光LED相对于传统光源,还有响应快、调制性好和灵敏度高的特点,能够在用作照明光源的同时,传输信号进行通信,实现白光LED照明通信双重功能。本文介绍了白光LED照明通信系统的基本构成,分析其关键技术及发展趋势。     

Dyadic analyses of friendship in a sample of preschool-age children attending Head Start: correspondence between measures and implications for social competence

Friendships among a large sample of preschool-age children (N = 471) attending Head Start were assessed. Based on sociometric data, friendship dyads were identified as reciprocated (mutual choice) or nonreciprocated (unilateral choice). Dyads were further classified with respect to gender composition as either same- or mixed-gender dyads. Older children were more likely to participate in a reciprocated friendship than were younger children and reciprocated dyads were more likely to be same-gender than were nonreciprocated dyads. Analyses of interaction between dyad partners revealed that reciprocated friends interacted more frequently across all categories of interaction coded and looked at each other more frequently than did members of nonreciprocated dyads. For the positive interaction subscore, the friendship status effect was modified by a significant interaction with gender composition such that significant effects of friendship status were obtained only for same-gender dyads. Additional analyses indicated that the average social competence level was greater for reciprocated dyads than for nonreciprocated dyads. The findings suggest that reciprocated friendships are meaningful for preschool-age children and may serve as special socialization contexts in which the repertoire of behavior can be exercised and perhaps improved. They also highlight the salience of same-gender friendships in the preschool classroom.     

教室智能照明控制系统的设计

针对室内不同区域对于光照强度的不同要求,设计了一个利用STM32作为控制器的教室智能照明控制系统,能够依据室内照明强度以及室内人员分布情况对教室内光照强度进行实时,动态的调整。结果表明,该系统既可以保证教室内的光照强度充足,又不会造成电力浪费。     

Play-solicitation behavior in juvenile male and female rats

Play-solicitation and social investigatory behaviors were observed in male and female juvenile rats exposed to playful and nonplayful juvenile social stimuli. A nonplayful state was induced by treatment with scopolamine HBr. In Experiment 1, the play-solicitation behavior of males exposed to nonplayful stimuli was reliably greater than that of females; social investigation did not differ by gender. In Experiment 2, males and females were exposed to nonplayful male and female stimuli. Male subjects engaged in more soliciting than did female subjects, and male social stimuli were subjected to more soliciting than were female social stimuli. Experiment 3 compared the influence of varying social deprivation intervals on play soliciting by male juveniles. Although social investigation did not vary reliably with interval of social deprivation, play soliciting increased reliably with longer intervals of isolation. In Experiment 4, play-soliciting behavior of males exposed to nonplayful males correlated positively and reliably with play fighting behavior upon exposure to normally playful males. The results support the proposal that some specific behaviors functionally provoke interactive play fighting.     

Enhanced facial discrimination: effects of experience with American sign language

On-line comprehension of American Sign Language (ASL) requires rapid discrimination of linguistic facial expressions. We hypothesized that ASL signers' experience discriminating linguistic facial expressions might lead to enhanced performance for discriminating among different faces. Five experiments are reported that investigate signers' and non-signers' ability to discriminate human faces photographed under different conditions of orientation and lighting (the Benton Test of Facial Recognition). The results showed that deaf signers performed significantly better than hearing non-signers. Hearing native signers (born to deaf parents) also performed better than hearing nonsigners, suggesting that the enhanced performance of deaf signers is linked to experience with ASL rather than to auditory deprivation. Deaf signers who acquired ASL in early adulthood did not differ from native signers, which suggests that there is no 'critical period' during which signers must be exposed to ASL in order to exhibit enhanced face discrimination abilities. When the faces were inverted, signing and nonsigning groups did not differ in performance. This pattern of results suggests that experience with sign language affects mechanisms specific to face processing and does not produce a general enhancement of visual discrimination. Finally, a similar pattern of results was found with signing and nonsigning children, 6-9 years old. Overall, the results suggest that the brain mechanisms responsible for face processing are somewhat plastic and can be affected by experience. We discuss implications of these results for the relation between language and cognition.     

基于室内照明艺术的几点思考

室内照明绝不仅仅是灯具的选择与堆砌,而是一门光环境艺术.本文主要从照度与效果、光色与气氛、光照角度与心理感受、灯具的构图四个层面对室内照明艺术进行探讨.     

录播教室灯光改造实践研究与应用

综合考虑多种因素,了解光源的特性,选择合适的灯具,结合布光的专业知识,进行反复实践研究,形成了一套录播教室灯光改造的解决方案,能够改善拍摄条件和拍摄质量,展现优质的教学内容与教学水平。     

Stimulus salience and asymmetric forgetting in the pigeon

Pigeons were trained using a symbolic delayed matching-to-sample procedure involving bright versus dim houselight samples. We hypothesized that when sample stimuli differ in salience, increasing the size of the retention interval will affect performance on trials initiated by the more salient sample only. In agreement with this prediction, accuracy following the dim sample did not decline as the retention interval increased, whereas accuracy following the bright sample declined to well below 50% correct. In a second experiment, the less salient (dim) sample from Experiment 1 was arranged as the more salient sample in a sample/no-sample procedure. Accuracy on dim sample trials then declined to well below 50% correct as the retention interval increased, whereas accuracy on no-sample trials remained constant. The results suggest that when sample stimuli differ in salience, pigeons may transform the nominal discrimination task into a detection task in which they respond on the basis of the presence or absence of the more salient sample.     

Contextual generality of roosttime restlessness in captive American robins (Turdus migratorius)

A series of experiments with captive American robins examined factors affecting roosttime restlessness, that is, the burst of locomotor activity that appears at dusk and is thought to be a correlate of the communal roosting habit of this species. First, the restlessness occurred earlier on cloudy days than on sunny ones, suggesting the importance of illumination level in initiating the activity burst. Second, in studies on social effects, the restlessness was greater when robins were totally isolated than when they had visual-auditory access to conspecifics; indeed, when a small flock of robins was housed together, restlessness at dusk was suppressed completely. Third, the birds were more restless when they could see a human observer than when they could not, implying an interaction of tearfulness with the roosting tendency. Finally, restlessness occurred in a large flight cage as well as in small cages, as long as the birds were not maintained in a flock. In sum, roosttime restlessness appears to be a robust phenomenon that occurs under a wide range of laboratory conditions, but which also can be substantially influenced by numerous environmental variables. Further experimental examination of these variables may advance present understanding of the survival value of communal roosting in this species.     

Changes in the Social Skills and Behavior Problems of Homeless and Housed Children During the Preschool Year

This study examined the social competence and mental health of homeless and permanently housed preschool children enrolled in the Head Start program. Mothers and Head Start teachers rated the social skills and behavior problems of 38 homeless and 46 housed preschoolers twice during the school year. The researchers compared the behavior of the homeless and housed preschoolers soon after they entered Head Start, as well as changes in children's behavior six months after their initial assessment. Both parents and teachers reported that homeless children exhibited more behavioral problems than housed children at the beginning of the study, but perceived no significant differences in the two groups' social skills. Mothers reported significant declines in homeless children's compliance relative to their housed peers at the conclusion of the study, while teachers noted significant declines in homeless children's compliance and expressive skills. Both mothers and teachers reported that homeless children exhibited significantly greater increases in behavior problems than their housed peers over the study period. Findings indicate the need for Head Start and other early childhood programs to develop interventions designed to moderate the negative effect of homelessness on young children's social-emotional development.