1,720,958 research outputs found
I Cebi dai cornetti (Cebus Apella) si fanno prendere per la gola? Compromesso tra qualità e quantità del cibo in un compito di scelta differita
No full textIn un compito di scelta intertemporale, in cui gli individui si trovano di fronte alla scelta tra una ricompensa minore e immediata (SS) e una maggiore ma posticipata nel tempo (LL), i soggetti umani svalutano le opzioni maggiormente preferite meno rapidamente rispetto a quelle meno preferite (effetto magnitudine). Tale effetto non è ancora stato osservato in animali non umani, sia manipolando la quantità sia la qualità della ricompensa. Lo scopo di questo studio è valutare se in un compito di scelta intertemporale i cebi dai cornetti mostrino un effetto magnitudine e in che modo la qualità della ricompensa influenzi le loro preferenze temporali. Dieci cebi sono stati testati in quattro condizioni: (i) 2 pezzi di cibo poco preferito vs. 6 pezzi di cibo molto preferito (2 low-6 high); (ii) 2 pezzi di cibo molto preferito vs. 6 pezzi di cibo poco preferito (2 high-6 low); (iii) 2 pezzi di cibo poco preferito vs. 6 pezzi di cibo poco preferito (2 low-6 low); e (iv) 2 pezzi di cibo molto preferito vs. 6 pezzi di cibo molto preferito (2 high-6 high). Come in studi precedenti, non è stato riscontrato l’effetto magnitudine poiché i cebi non scontano l’opzione maggiore di meno quando questa è costituita da un cibo molto preferito rispetto a quando è costituita da un cibo poco preferito (% LL: 2 low-6 high ≈ 2 low-6 low). Tuttavia, quando quantità e qualità della ricompensa entrano in conflitto, i cebi preferiscono quest’ultima. Scelgono infatti l’opzione LL meno nella condizione 2 high-6 low rispetto a tutte le altre condizioni. Questo risultato è in accordo con ciò che emerge da un recente studio sui corvidi testati in un diverso compito di autocontrollo.In the delay choice task, in which individuals face choices between smaller immediate rewards (SS) and larger delayed rewards (LL), humans discount larger rewards less steeply than smaller ones (magnitude effect). However, this effect has not yet been observed in animals when manipulating either the quantity or the quality of the reward. We aimed to assess whether in a delay choice task capuchins (i) show a magnitude effect, and (ii) how the quality of the reward affects their temporal preferences. Ten subjects were presented with four conditions: (i) 2 pieces of low-preferred food vs. 6 pieces of high-preferred food (2 low-6 high), (ii) 2 pieces of high-preferred food vs. 6 pieces of low-preferred food (2 high-6 low), (iii) 2 pieces of low-preferred food vs. 6 pieces of low-preferred food (2 low-6 low), and (iv) 2 pieces of high-preferred food vs. 6 pieces of high-preferred food (2 high-6 high). As in previous studies, we failed to observe a magnitude effect since capuchins did not choose the larger delayed reward significantly more in condition 2 low-6 high than in condition 2 low-6 low (% LL: 2 low-6 high ≈ 2 low-6 low). However, when there is a conflict between quantity and quality, capuchins prefer the quality of the reward, in that they chose the LL option less in condition 2 high-6 low than in the other conditions. Our findings are in agreement with recent results obtained in corvids in a delayed exchange task
Delay choice versus delay maintenance: different measures of delayed gratification in capuchin monkeys (Cebus apella)
No full text
Are capuchin monkeys (Cebus apella) tempted with delicacies? Trade-off between food quality and quantity in a delay choice task
No full textIn the delay choice task, in which individuals face choices between smaller immediate rewards and larger delayed rewards, humans discount larger/more preferred delayed rewards less steeply than smaller/less preferred ones (magnitude effect). However, this effect has not yet been observed in animals either for quantity or quality of the reward. We aimed to assess whether in a delay choice task capuchins (i) show a magnitude effect, and (ii) value more the quality or the quantity of the reward. Six subjects were presented with four conditions: (i) 2 pieces of low-preferred food vs. 6 pieces of high-preferred food (2 low-6 high); (ii) 2 pieces of high-preferred food vs. 6 pieces of low-preferred food (2 high-6 low); (iii) 2 pieces of low-preferred food vs. 6 pieces of low-preferred food (2 low-6 low); and (iv) 2 pieces of high-preferred food vs. 6 pieces of high-preferred food (2 high-6 high). Overall, we failed to observe a magnitude effect since capuchins did not choose the larger delayed reward significantly more in condition 2 low-6 high than in condition 2 low-6 low. Interestingly, capuchins valued the quality of the reward more than its quantity when the delay was implicated, in that they chose the larger delayed reward less in condition 2 high-6 low than in condition 2 low-6 low. Our findings are in agreement with recent results obtained in corvids in a delayed exchange task
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
Misurare l’autocontrollo: studi sperimentali nel cebo dai cornetti (Sapajus spp.), una scimmia sudamericana
No full textVariations 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
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