1,720,961 research outputs found
Pigeons’ memory for event duration
No full textPigeon's working memory for event duration was investigated
using variations of the delayed matching to sample procedure. When a retention interval of variable length was interposed between the sample and comparison stimuli, pigeons responded as though a long-duration sample had been short after retention intervals of 10 sec or greater. This "choose short" effect occurred reliably in each subject, regardless of whether the subject was naive or experienced, whether the sample durations were represented by food-access or light, or whether a two- or three-choice procedure was used.
In order to account for these findings, a "subjective shortening" model of memory for event duration was proposed. According to the model, the choose short effect is produced by a discrepancy between a relatively static reference memory of the sample durations and a dynamic working memory of the sample durations that "shortens" over the retention interval. This discrepancy produces the tendency to respond as though the long sample was short,
A number of predictions, derived from the subjective shortening model, were confirmed in subsequent experiments. First, after a long retention interval, the point of subjective
equality between the short and long samples shifted to
a longer duration. Second, stepwise increases in the retention
interval produced a temporary choose short effect, whereas stepwise decreases in the retention interval produced a temporary choose long effect. Third, with extended training at a given retention interval, the choose short and choose long effects diminished and overall accuracy improved. These results provided strong support for the subjective shortening model, whereas they could not be interpreted readily within the context of other conceptualizations
of working memory processes.Arts, Faculty ofPsychology, Department ofGraduat
Pigeons discriminate durations of food access better than durations of light
No full textIn the present experiments stimulus control of pigeons' keypecking by the duration of food access was compared with control by the duration of light. These experiments were designed to extend previous research on three topics within the stimulus control literature: 1) stimulus control by food, 2) comparisons between the effectiveness of different stimuli in controlling behavior, and 3) control by stimulus duration. In Experiment 1, a go/no-go procedure was used to compare control of pigeons' keypecking by food-access duration with control by light duration. Pecks to an illuminated key were reinforced with grain following 10-sec presentations of food access or houselight, but not after 5-sec presentations of either stimulus. Each of the five subjects discriminated food-access duration faster and to a consistently greater degree than light duration. In four between-subject systematic replications, pigeons discriminated food-access duration better than the duration of a localized light, the feeder light, and a keylight, and with either water or food as reinforcement. Experiment 2 demonstrated the generality of these results across discrimination procedures. In this experiment, control by food-access duration was compared with control by light duration under a conditional right-left choice procedure (two pigeons), and a delayed symbolic matching-to-sample procedure (six pigeons). Under both, accuracy was greater on food-access trials than on light trials. In Experiment 3, two pigeons received generalization tests with durations of food access and light that were intermediate to the training values. The results showed that responding was controlled by the duration dimension for both stimuli. The excellent control by food access in these experiments is consistent with previous evidence that food is an effective and memorable stimulus for animals, and the difference in control by the duration of food and light provides empirical support for the common assumption that stimuli differ in their effectiveness of control. Several advantages of using a duration paradigm to compare control by different stimuli are discussed. This research, which demonstrates that the stimulus can play an important role in the accuracy of duration discriminations, also has implications for the study of control by stimulus duration, and for theories of timing processes in animals.Arts, Faculty ofPsychology, Department ofGraduat
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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