Discrimination of color-odor compounds by honeybees: Tests of a continuity model

In experiments previously reported, individual honeybees were trained in a variety of problems to choose between two visually identical but differently scented targets, one or the other of which contained sucrose solution. The results could be simulated accurately with simple equations for computing changes in associative strength produced by reinforcement or nonreinforcement and for predicting choice on the basis of relative strength. In the present experiments, the targets used differed in color as well as in odor, and the animals were trained in a variety of problems with color-odor compounds. Contrary to expectation, the new results could be simulated accurately with the same equations as before on the further assumption that the components of a compound gain and lose associative strength independently (independence rule) and that the associative strength of a compound is equal to the sum of the strengths of its components (summation rule).     

Analysis of choice in honeybees

Free-flying honeybees were trained in a set of four problems to choose between two differently scented targets, one or the other of which contained sucrose solution. The training was simulated quantitatively, always with the same simple linear equations for computing changes produced by reinforcement and nonreinforcement in the strength of association between each target and the sucrose, but with a diverse array of functions for predicting choice on the basis of relative strength. Accuracy of prediction was indexed by the root-mean-square (RMS) deviation of simulated data from real data. The results provide some good approximations of what is tentatively assumed to be the true choice function, setting the stage for further development of the associative features of the model to encompass more complex phenomena of honeybee learning in choice situations.     

Learning in honeybees as a function of amount of reward: Tests of the equal-asymptote assumption

In Experiments 1 and 2, honeybee foragers visiting the laboratory were fed on targets of two different colors, one containing 5 μl and the other containing 20 μl of 50% sucrose solution. The targets were presented singly in quasi-random sequences on the training visits, after which preference was measured in an unrewarded choice test. In Experiment 1, 16 differentially rewarded training trials with each color were followed by the same number of trials with the color-amount relation reversed; no preference for either color was found in the subsequent choice test. In Experiment 2, 20 differentially rewarded training trials with each color—enough to produce a clear preference for the 20-μl color when given directly after pretraining—were given after 10 feedings to repletion on each color that were calculated to generate near-asymptotic associative strength; no preference for either color was found in the subsequent choice test. In Experiment 3, there were 12 feedings to repletion on one color and, on the other, 12 feedings to repletion followed by 15 trials with a small (5 μl) reward; no preference was found in a subsequent choice test. The results of all three experiments support a nonrepresentational interpretation of the role of amount of reward in the learning of honeybees.     

Matching behavior of honeybees in a multiple-choice situation: The differential effect of environmental stimuli on the choice process

The matching behavior of honeybees in a patch of four artificial feeders was studied under two different environmental conditions in order to examine the involvement of different stimuli in the choice process. Matching fails if all nearby landmarks are removed but can, under certain conditions, be restored by subsequently introducing odors, colors, or landmarks showing that there is no unique stimulus modality that provides matching. We propose two fundamentally different memory processes, both of which affect feeding behavior and support matching. We suggest that in one case, the probability of choice is determined by the strength of direct associations between locally perceived odor stimuli and reward rates. In the second case, simultaneously perceived color stimuli predict the relative reward rates indirectly by the spatial representation of the four feeders. Both memory processes are likely to interact and lead to efficient feeding behavior during foraging under natural conditions.     

An investigation of ambiguous-cue learning in pigeons

Two experiments demonstrated that pigeons can solve a simultaneous discrimination in which on half the trials the positive and an ambiguous cue (A) are presented and on half the trials choice is between A and the negative stimulus. In Experiment 1, where a relatively nondistinctive A cue was used, performance on the former type of trial was superior to that shown on the latter. In Experiment 2, where a distinctive A cue was provided, this pattern of results was reversed. These findings are interpreted in terms of an approach-avoidance explanation first proposed by Leary (1958). Experiment 3 tested and confirmed a central prediction of this explanation by showing that in an orthodox simultaneous discrimination, occasional reinforcements of the negative stimulus produce less accurate performance than do nonreinforcements of the positive.     

Performance of honeybees in analogues of the rodent radial maze

The performance of individual honeybees pretrained to forage at a laboratory window was studied in three rudimentary analogues of the radial maze designed for the study of short-term spatial memory in rats. A linear arrangement of three targets was used in Experiment 1, a triangular arrangement of three targets in Experiment 2, and a rectangular arrangement of four targets in Experiment 3, with reward only for the first response to each of the targets presented on any given trial. Several systematic patterns of responding were observed, with no indication that the choices made by the animals were influenced by memory of targets recently visited.     

Compound-component and conditional discrimination of colors and odors by honeybees: Further tests of a continuity model

In experiments previously reported, individual honeybees were trained in a variety of problems to discriminate color-odor compounds. The results could be modeled accurately on the assumption that the associative strength of each component of a compound stimulus changes independently with reinforcement or nonreinforcement of the compound (independence rule) and that the associative strength of a compound is equal to the sum of the strengths of its components (summation rule). In the present experiments, which were designed to challenge the model, honeybees were trained in compound-component problems (choosing between compounds and their separate components) and in conditional problems (choosing between colors on the basis of a common odor or between odors on the basis of a common color). The new data, together with all of the previous data, could be modeled accurately on the further assumption that interaction among the components of a compound generates a new, compound-unique component that gains and loses associative strength in the same way as other components and contributes in the same way to the strength of the compound; the independence and summation rules continue to apply.     

Reciprocal overshadowing in the discrimination of color-odor compounds by honeybees: Further tests of a continuity model

Honeybees were trained to discriminate between simultaneously presented color-odor compounds, one group with color and odor confounded and a control group with color relevant and odor irrelevant; in subsequent differentially reinforced training with the colors in the absence of the odors, the performance of the two groups was the same (Experiment 1). When, however, response to the colors was measured in a 10-min extinction test, discrimination was found to be poorer after confounded training (Experiment 2), and like results were obtained in an extinction test with the odors after control animals had been trained with odor relevant and color irrelevant, the confounded animals showing poorer discrimination of the odors than the controls (Experiment 3). The results of the first two experiments, in which overshadowing of color by odor was found only with an extinction test, require us to take seriously the possibility that our previous modeling experiments (with probability of correct choice in differentially reinforced training as the measure of performance) may have been insufficiently sensitive to noncontinuity effects. Our first efforts to model extinction suggest, however, that all the results of the present experiments can be understood without sacrifice of the parsimonious independence principle.     

Cognitive diagnostic model of best choice: a study of reading comprehension

Abstract

The present study compared the performance of six cognitive diagnostic models (CDMs) to explore inter skill relationship in a reading comprehension test. To this end, item responses of about 21,642 test-takers to a high-stakes reading comprehension test were analyzed. The models were compared in terms of model fit at both test and item levels, classification consistency and accuracy, and proportion of skill mastery profiles. The results showed that the G-DINA performed the best and the C-RUM, NC-RUM, and ACDM showed the closest affinity to the G-DINA. In terms of some criteria, the DINA showed comparable performance to the G-DINA. The test-level results were corroborated by the item-level model comparison, where DINA, DINO, and ACDM variously fit some of the items. The results of the study suggested that relationships among the subskills of reading comprehension might be a combination of compensatory and non-compensatory. Therefore, it is suggested that the choice of the CDM be carried out at item level rather than test level.     

How honeybees find a place: Lessons from a simple mind

Foraging honeybees find their way from their hive to their food in a stereotypical manner using up to four place-finding servomechanisms in sequence: (1) They first fly a vector (straight-line distance and direction) from their home to the vicinity of the target. Direction is determined by the sun compass and by distant landmarks, while distance is estimated by visual flow. (2) They then beacon in on a landmark near the target location. (3) En route toward the landmark, they may adopt a sensorimotor trajectory that takes them toward the target. (4) Near the expected target location, they attempt image matching, which involves trying to put surrounding landmarks at the correct positions on their eyes. In doing image matching, they fly facing a stereotypical direction, a strategy that makes it unnecessary to translate retinal coordinates into another coordinate system.     

氧化锌压敏电阻静电放电防护性能的测试

研究常用静电放电防护器件氧化锌压敏电阻的静电放电防护性能,设计了一套静电放电防护器性能测试方法,搭建相关测试平台。研究了该保护器件及其组合网络对静电放电脉冲的响应规律及特点,分析了动态导通电阻、箝位电压、响应峰值电流等参数与其静电放电防护能力的关系,并给出了最佳防护方案。该研究为电路设计时选取氧化锌压敏电阻作为静电放电防护器件提供了参考。     

How Well Performance in Curriculum-based Tests Predicts that in Life-based Tests: A Study of 12th-grade Students Learning Chinese Language

A sample of 209 secondary (12th grade) students were tested for their knowledge of Chinese characters, words, and idioms as specified in a Chinese Language syllabus. The students also took comprehension tests in the form of cloze tests based on passages selected from Chinese newspapers and literary works, covering occupations, social events, sports, leisure pursuits and international news. Although performance in curriculum-based tests was satisfactory, the students were found to have difficulty comprehending life-based reading materials. Probable causes for the lack of consistency between performances in the tests using different reading materials are discussed.     

交通方式划分的非集计模型——以蚌埠为例

为研究影响城市交通结构的主要因素,建立出行者属性与个体出行方式选择的合理关系模型.所有的出行者相关属性数据均由统计资料获得,方式选择数据由蚌埠市居民出行调查的数据获得.应用非集计模型来建立个人属性、家庭属性和出行属性与方式选择间的函数关系.建模结果表明：居民出行交通方式选择与个人属性、家庭属性和出行属性之间有较稳定的关系,其随着时间的推移变化甚微.非集计模型所推算的交通方式结构较为精确,可用于交通方式结构的预测.此外,所建模型亦能识别方式分担的主要影响因素,从而实现交通方式结构优化.     

Three dimensions of reflective thinking in solving design problems: a conceptual model

Design tasks are omnipresent in our everyday lives. Previous research shows that reflective thinking is one of the critical factors in solving design problems. Related research has attempted to capture designers’ reflective thinking process. Yet a close inspection of designers’ reflective thinking taking place during their design process demands further effort. To understand designer’s reflective practice and to find better ways to promote novices’ reflective thinking in solving real-world design problems, a comprehensive model was developed. This model identified three dimensions to guide the understanding of designers’ reflective thinking during a design process: (1) the timing of reflection, indicating the points in the process where reflective thinking occurs, (2) the objects of reflection, showing the different types of objects that designers may reflect upon, and (3) the levels of reflection, referring to the different levels of designers’ reflection. This model provides for meaningful aspects of reflective thinking to be situated in a design process, which can guide educators and instructional designers in developing appropriate learning environments for facilitating novice and practicing designers’ reflective thinking. Moreover, the model can serve as a stepping stone for further research.     

Learning in honeybees as a function of amount of reward: Control of delay

Six experiments on learning in honeybees were prompted by the possibility that results previously attributed to a difference in amount of reward (20- versus 5-μl drops of sucrose solution presented on colored targets) might be due at least in part to a difference in delay of reward attendant on greater difficulty in locating the 5-μ1 drops. Substantial reduction in the diameter of the targets, which was designed to facilitate location of the drops, impaired discrimination of the colors, perhaps because their salience was reduced in the process (Experiment 3). White dots used to mark the location of the drops on larger targets also impaired discrimination of the colors, which presumably were overshadowed by the dots (Experiments 1, 2, and 4). That the dots did not serve merely to equate delay but were themselves discriminated was demonstrated in Experiment 5, which produced as well the first indication of an effect of amount of reward uncontaminated by the possibility of differential delay: Animals trained with a 5-μl drop on a dotted target of one color and a drop of the same size on an undotted target of a second color preferred the dotted target, but animals trained with a 5-μl drop on a dotted target of one color and a 20-μl drop on an undotted target of a second color preferred the undotted target. In Experiment 6, with odors substituted for the colors on the assumption that they were less likely to be overshadowed by the dots, what could be interpreted as a pure amount effect was found again. Aside from their relevance to questions about the role of amount of reward, the results have some interesting implications for the theory of discriminative learning in honeybees.     

Comparison of a behavioral model of physicians' drug product choice decision with pharmacists' product choice recommendations: A study of the choice for the treatment of panic disorder

The purpose of this study was to examine and compare the decision process for physicians and pharmacists when considering medications to treat patients with panic disorder. A second‐order confirmatory factor analysis modeling physicians' prescribing influences revealed high factor loadings for efficacy considerations and side effects in conjunction with patient characteristics. A multisample analysis using the physician model revealed that pharmacists also consider the same factors important. Both health care professionals were concerned about the patient's quality of care, recovery, and medication efficacy.     

Reward and learning in honeybees: analysis of an overshadowing effect

Previous experiments have shown that honeybees trained with colored targets baited with 5- versus 20-µl drops of sucrose solution fail to develop a preference for the 20-µl color when the location of the drop on each target is marked by a white dot (dot-color overshadowing) but that discrimination is not impaired by dots when the targets differ in odor rather than in color. In Experiments 1–3, dot-color overshadowing failed to appear with differences in concentration rather than amount of sucrose (50% vs. 20% or 0%), but it did appear in Experiments 4 and 5 with a difference in probability of reward (consistent vs. partial). Experiment 6 showed no dot-odor overshadowing with a difference in probability of reward. The results are not generally predictable from the Rescorla-Wagner principle of shared associative strength, but point instead (in conjunction with those of earlier experiments) to competition for visual attention.     

Learning in honeybees as a function of amount and frequency of reward

In a series of four experiments with free-flying honeybees, individual foragers were trained with targets of two different colors that contained 5 or 20 μl of 50% sucrose solution. The two targets were singly presented in quasi-random sequences on each visit, with the amount of reward to be found on each target perfectly predictable from its color. The number of training visits (4–32) was varied both within and between experiments, and so also was the relative frequency of trials with the 5- and 20-μl targets (1:1, 2:1, 3:1, and 9:1). At the conclusion of training under each condition, unrewarded responses to the targets were measured in a 10-min extinction test, with the targets presented either separately to two different groups of animals (Experiment 1) or as a pair (Experiments 2–4). When the number of training trials with each target was the same (Experiments 1 and 2), the animals responded more in extinction to the 20-μl target than to the 5-μl target, although there was a decline in the overall level of responding to both targets (an overlearning-extinction effect) as the number of training trials increased. After nine times as many, or only three times as many, training trials with the5- μl target as with the 20-μl target, the animals responded more in extinction to the 5-μl target (Experiment 3); after twice as many training trials with the 5-μl target as with the 20-μl target, there was equal responding to both (Experiment 4). The preferences shown in the choice tests of Experiments 2–4 could be simulated rather accurately on the assumptions of a model previously developed to deal with the discrete-trials choice behavior of honeybees and the further assumption that associative strength grows at a rate increasing with amount of reward to an asymptote independent of amount of reward.