Application of Optimal Designs to Item Calibration

In computerized adaptive testing (CAT), examinees are presented with various sets of items chosen from a precalibrated item pool. Consequently, the attrition speed of the items is extremely fast, and replenishing the item pool is essential. Therefore, item calibration has become a crucial concern in maintaining item banks. In this study, a two-parameter logistic model is used. We applied optimal designs and adaptive sequential analysis to solve this item calibration problem. The results indicated that the proposed optimal designs are cost effective and time efficient.     

Effects of Initial Values and Convergence Criterion in the Two-Parameter Logistic Model When Estimating the Latent Distribution in BILOG-MG 3

Parameters of the two-parameter logistic model are generally estimated via the expectation-maximization algorithm, which improves initial values for all parameters iteratively until convergence is reached. Effects of initial values are rarely discussed in item response theory (IRT), but initial values were recently found to affect item parameters when estimating the latent distribution with full non-parametric maximum likelihood. However, this method is rarely used in practice. Hence, the present study investigated effects of initial values on item parameter bias and on recovery of item characteristic curves in BILOG-MG 3, a widely used IRT software package. Results showed notable effects of initial values on item parameters. For tighter convergence criteria, effects of initial values decreased, but item parameter bias increased, and the recovery of the latent distribution worsened. For practical application, it is advised to use the BILOG default convergence criterion with appropriate initial values when estimating the latent distribution from data.     

轻度认知损伤患者的联系记忆损伤特征

遗忘型轻度认知损伤患者(aMCI)在项目记忆和联系记忆上都有损伤．本文通过临床记忆量表中的项目记忆和联系记忆测验,研究aMCI的联系记忆是否比项目记忆有更显著的损伤．另外,通过分析配对联想学习测验,进一步研究aMCI联系记忆损伤的特点．25名aMCI和28名健康老人参与了两个联系记忆测验(配对联想学习测验和联想回忆测验)和两个项目记忆测验(图像自由回忆和无意义图形再认),aMCI患者在联系记忆测验上表现出了更显著的损伤,即使控制了项目记忆的损伤,aMCI的联系记忆仍然比健康老人显著降低．另外,ROC分析表明联系记忆测验比项目记忆测验对aMCI病人有更高的区分度．对配对联想学习测验的分析表明,相对于健康老人,aMCI患者在记忆有语言联系的词对要比记忆无语义联系的词对更为困难．本研究进一步表明aMCI患者的联系记忆比项目记忆有更大的损伤．相对于健康老人,aMCI患者不仅难以在两个无关项目间创建记忆连接,而且在有效利用项目间本身的语义联系方面存在更大的损伤．联系记忆测验比项目记忆测验对aMCI患者有更高的区分度．在神经心理评估中增加联系记忆测验,能更加有效地识别aMCI患者．     

De Cognitieve Screening Test (CST) getoetst aan het schaalmodel van Mokken

The Cognitive Screening Test (CST) is a twenty-item orientation questionnaire in Dutch, that is commonly used to evaluate cognitive impairment. This study applied Mokken Scale Analysis, a non-parametric set of techniques derived from item response theory (IRT), to CST-data of 466 consecutive participants in psychogeriatric day care. The full item set and the standard short version of fourteen items both met the assumptions of the monotone homogeneity model, with scalability coefficient H = 0.39, which is considered weak. In order to select items that would fulfil the assumption of invariant item ordering or the double monotonicity model, the subjects were randomly partitioned into a training set (50% of the sample) and a test set (the remaining half). By means of an automated item selection eleven items were found to measure one latent trait, with H = 0.67 and item H coefficients larger than 0.51. Cross-validation of the item analysis in the remaining half of the subjects gave comparable values (H = 0.66; item H coefficients larger than 0.56). The selected items involve year, place of residence, birth date, the monarch's and prime minister's names, and their predecessors. Applying optimal discriminant analysis (ODA) it was found that the full set of twenty CST items performed best in distinguishing two predefined groups of patients of lower or higher cognitive ability, as established by an independent criterion derived from the Amsterdam Dementia Screening Test. The chance corrected predictive value or prognostic utility was 47.5% for the full item set, 45.2% for the fourteen items of the standard short version of the CST, and 46.1% for the homogeneous, unidimensional set of selected eleven items. The results of the item analysis support the application of the CST in cognitive assessment, and revealed a more reliable 'short' version of the CST than the standard short version (CST14).     

Sib‐sib communication and the risk of prey theft in the barn owl Tyto alba

Conflicts among siblings are widespread and their resolution involves complex physical and communication tools. Observations in the barn owl Tyto alba showed that siblings vocally communicate in the absence of parents to negotiate priority of access to the impending food resources that parents will bring. In the present paper, we hypothesize and provide correlative evidence that after a parent brought a food item to their progeny, sibling competition involves vocal sib‐sib communication. A food item takes a long time to be entirely consumed, and hence siblings continue to compete over prey monopolization even after parents gave a food item to a single offspring. When physical competition is pronounced and thereby the risk of prey theft is high, the individual that received a prey item consumes it in a concealed place. Concomitantly, nestlings vocalize intensely probably to indicate their motivation to siblings to not share their food item, since this vocal behaviour was particularly frequent in younger individuals for which the risk of being robbed is higher than in their older siblings. Furthermore, nestlings consumed more rapidly a food item when their siblings vocalized intensely presumably because the intensity of siblings’ vocalizations is associated with a risk of prey theft. Our correlative study suggests that sibling competition favoured the evolution of sib‐sib communication under a wide range of situations.     

Relationship between Item Responses of Negative Affect Items and the Distribution of the Sum of the Item Scores in the General Population

BackgroundSeveral studies have shown that total depressive symptom scores in the general population approximate an exponential pattern, except for the lower end of the distribution. The Center for Epidemiologic Studies Depression Scale (CES-D) consists of 20 items, each of which may take on four scores: “rarely,” “some,” “occasionally,” and “most of the time.” Recently, we reported that the item responses for 16 negative affect items commonly exhibit exponential patterns, except for the level of “rarely,” leading us to hypothesize that the item responses at the level of “rarely” may be related to the non-exponential pattern typical of the lower end of the distribution. To verify this hypothesis, we investigated how the item responses contribute to the distribution of the sum of the item scores.MethodsData collected from 21,040 subjects who had completed the CES-D questionnaire as part of a Japanese national survey were analyzed. To assess the item responses of negative affect items, we used a parameter r, which denotes the ratio of “rarely” to “some” in each item response. The distributions of the sum of negative affect items in various combinations were analyzed using log-normal scales and curve fitting.ResultsThe sum of the item scores approximated an exponential pattern regardless of the combination of items, whereas, at the lower end of the distributions, there was a clear divergence between the actual data and the predicted exponential pattern. At the lower end of the distributions, the sum of the item scores with high values of r exhibited higher scores compared to those predicted from the exponential pattern, whereas the sum of the item scores with low values of r exhibited lower scores compared to those predicted.ConclusionsThe distributional pattern of the sum of the item scores could be predicted from the item responses of such items.     

The formation and execution of sequential plans in pigeons (Columba livia)

The ability to formulate and execute plans is a hallmark of human behaviour. Here we present evidence of planning in pigeons. Subjects were trained to respond to three geometric shapes in a prescribed order. Probe trials were then introduced in which, following a response to the first item, the on screen positions of the second and third item were exchanged. If subjects were planning a sequence of responses at the outset of a trial, we would expect reaction time to the second item to increase, reflecting the updating of a predetermined response plan. This is exactly what was found. Subjects also responded correctly on trials in which, following a response to the first item, stimuli were covered by opaque white squares. Together these results suggest pigeons are able to plan one step ahead on the simultaneous chaining paradigm.     

关于利用伪变量对多点试验进行回归分析的改进

针对文［１］仅考虑了各点回归方程间常数项可能不同，而忽略了其它回归系数也可能不同的情况，本文对伪变量形式进行了修正，通过引入伪变量的相互作用项，使得到的回归模型更合理，可靠性更高．     

A simple model of information use in the exploitation of patchily distributed food

In this paper we consider a simple model of an environment in which prey are distributed in patches. It is assumed that each patch contains at most one item, but items may vary in the ease with which they can be found. The time spent in unsuccessful search on a patch gives information of whether a patch contains an item, and if it does, how difficult that item is to find. We show how this information can be used to find the policy which maximizes the mean rate of reward for the environment. The analysis is illustrated by two examples.     

Dutch translation and cross-cultural adaptation of the PROMIS? physical function item bank and cognitive pre-test in Dutch arthritis patients

Introduction

Patient-reported physical function is an established outcome domain in clinical studies in rheumatology. To overcome the limitations of the current generation of questionnaires, the Patient-Reported Outcomes Measurement Information System (PROMIS^®) project in the USA has developed calibrated item banks for measuring several domains of health status in people with a wide range of chronic diseases. The aim of this study was to translate and cross-culturally adapt the PROMIS physical function item bank to the Dutch language and to pretest it in a sample of patients with arthritis.

Methods

The items of the PROMIS physical function item bank were translated using rigorous forward-backward protocols and the translated version was subsequently cognitively pretested in a sample of Dutch patients with rheumatoid arthritis.

Results

Few issues were encountered in the forward-backward translation. Only 5 of the 124 items to be translated had to be rewritten because of culturally inappropriate content. Subsequent pretesting showed that overall, questions of the Dutch version were understood as they were intended, while only one item required rewriting.

Conclusions

Results suggest that the translated version of the PROMIS physical function item bank is semantically and conceptually equivalent to the original. Future work will be directed at creating a Dutch-Flemish final version of the item bank to be used in research with Dutch speaking populations.     

Specificity of priming: a cognitive neuroscience perspective

Priming is a nonconscious form of memory that involves a change in a person's ability to identify, produce or classify an item as a result of a previous encounter with that item or a related item. One important question relates to the specificity of priming - the extent to which priming reflects the influence of abstract representations or the retention of specific features of a previous episode. Cognitive neuroscience analyses provide evidence for three types of specificity: stimulus, associative and response. We consider empirical, methodological and conceptual issues that relate to each type of specificity, and suggest a theoretical perspective to help in guiding future research.     

Resource Management in the Orb-Weaving Spider Zygiella x-notata II. Ability to Manage a Set of Various Prey

Management of a set of various prey received ‘simultaneously’ by the orb-weaving spider Zygiella x-notata is investigated in relation to prey species, weight, order of arrival in the web, and factors concerning the spider's state of nourishment. When the spiders encountered several different prey ‘simultaneously’, they subdued all of them, took one of them to begin consumption, and stored the others in the web. The first item for consumption was chosen according to the characteristics of the available prey. Factors concerning previous feeding influenced the spiders's choice of the first item to be ingested. Exploitation of the first item, estimated by the quantity of food extracted and the time necessary for this extraction, depended on the type and the quantity of prey at the spider's disposal. When the spiders received several prey, they spent less time feeding on the first cricket compared with spiders receiving only one cricket, while no difference was found when the first prey item exploited was a fly.     

Accepting loss: the temporal limits of reciprocity in brown capuchin monkeys

Delayed reciprocity is a potentially important mechanism for cooperation to occur. It is however rarely reported among animals, possibly because it requires special skills like the ability to plan a loss. We tested six brown capuchin monkeys (Cebus apella) in such skills. Subjects were studied in exchange tasks in which they had to retain a food item for a given time lag before returning it to an experimenter and obtaining a more desirable reward. Experiments showed that the subjects could wait for several minutes when allowed to return only part of the initial item. When required to return the full item intact, however, most subjects could not sustain a time lag longer than 10 s. Although the duration of waiting increased with the amount of return expected by subjects, in most cases it did not extend beyond 20 s even when the eperimenter offered a food amount 40 fold the initial item. The failure of capuchin monkeys to sustain long-lasting waiting periods may be explained by limited self-control abilities. This would prevent them achieving reciprocal altruism.     

A general theory of central place foraging for single-prey loaders

This paper analyses the problem of prey choice for a forager that can collect only one item per foraging trip. In the terminology of Orians and Pearson (1979) this is central-place foraging by single-prey loaders. Our analysis goes beyond that of Orians and Pearson by including a cost of time away from the central place that can be a constant per unit time or can increase. Two new effects emerge: (i) It can be optimal to abandon the foraging trip without having collected an item, (ii) The minimum acceptable item depends on the time spent foraging. We show how our framework encompasses cases not usually thought of as central place foraging, such as diving animals that must surface for air.     

Iconic memory

Investigations of the processing of brief visual displays, and the explanation of such processing in terms of iconic memory, are reviewed. It is concluded that the concept of a pre-categorical sensory memory for visual material remains tenable. The ability to report material from brief visual displays is seen as depending upon parallel (and perhaps unlimited) transfer from iconic memory to a post-categorical memory mode, followed by a limited (and perhaps serial) transfer to an output stage. Decisions about, or responses to, items can only be made when they are in the output stage. Because transfer out of the post-categorical mode can be performed on the basis of pre-categorical stimulus features, pre-categorical information about items in the post-categorical mode must be accessible. One way in which this would be possible is if the transfer of an item into the post-categorical mode takes the form of the creation, to represent the item, of a temporary file of information including both pre-categorical and post-categorical features of the item. Any such feature can be used as the basis for selecting the item for transfer from the post-categorical mode to the output stage, for subsequent decision or report.     

Hurrying Foragers Fail to Choose the Best Prey Item: Prey Choice in Paper Wasps Depredating Conspecific Nests

Animals frequently face situations where they must choose one prey item from a set of options. Animals are often considered to be able to choose the best prey item from multiple alternatives. However, time may be required to make accurate decisions, and under natural conditions, time is usually limited. Here, we examined whether animals fail to choose the most profitable prey item under time‐limited conditions. A queen (foundress) of a paper wasp Polistes chinensis antennalis starts a colony in spring and maintains the nest alone until the emergence of workers. At the stage, the foundress often depredates larvae in other conspecific nests. The intruder needs to finish choosing and extracting a single larva during the absence of the owner from the nest. Intruders preferred the fifth‐instar larvae, which are the largest and the most profitable prey among larvae. When the time spent in choosing was long, intruders were able to choose the fifth‐instar larvae with a higher probability. However, when the time spent in choosing was short, intruders sampled only a small fraction of larvae in a nest, and the probability of choosing the fifth‐instar larvae decreased. Furthermore, we found that intruders decreased the time spent in choosing under higher time constraints. These results suggest that under time‐limited conditions, intruders occasionally failed to choose the most profitable prey item because of incomplete information on the availability of options. These results also suggest a trade‐off between speed and accuracy of choosing the best item from a set of options.     

Anesthesiology: New Muscle Relaxants

The Council on Scientific Affairs of the California Medical Association presents the following epitomes of progress in anesthesiology. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and clinical importance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, and scholars to stay abreast of progress in medicine, whether in their own field of special interest or another.The epitomes included here were selected by the Advisory Panel to the Section on Anesthesiology of the California Medical Association, and the summaries were prepared under the direction of Dr Jackson and the panel.     

Neurology: Use of Antiepileptic Drugs in Pregnancy

The Scientific Board of the California Medical Association presents the following inventory of items of progress in neurology. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, or scholars to stay abreast of these items of progress in neurology that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another.The items of progress listed below were selected by the Advisory Panel to the Section on Neurology of California Medical Association, and the summaries were prepared under its direction.