177,328 research outputs found
L'effetto placebo
No full textThe recent publication of meta-analytic studies that both deny virtually any effectiveness to placebo effect, and attribute to it till 75% of therapeutic efficacy of medical treatments shows the need for a new assessment of this problem. In our study, after a short definition of the effect and a review of the explanations that were given to the effect, we focus our attention on methodological problems, regarding both previous research and meta-analysis, that are published in increasing number in the last few years. Unfortunately, a far exceeding number of clinical research appear subject to many methodological doubts, and meta-analytic studies must discard from 85 to 98% of them; but meta-analysis too appear a mean to obtain any result that one wants to obtain. However, also in reference to alternative medicine, the problem of the placebo deserves a very careful attention, also from the ethical point of view
Do You Hear More Piano or Drum Sounds? An Auditory Version of the Solitaire Illusion
No full textThe file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI linkThe solitaire illusion is an illusion of numerosity proposed by Frith and Frith. In the original version, an apparent number of elements was determined by the spatial arrangement of two kinds of elements (black and white marbles). In our study, an auditory version of the solitaire illusion was demonstrated. Participants were asked to judge if they perceived more drum or piano sounds. When half of the piano tones were perceived as lower in pitch than a drum sound and the other half higher, piano tones appeared to be arranged in small units, leading to numerosity underestimation. Conversely, when all piano tones were perceived to be higher in pitch than the drum sounds, they appeared to be arranged in a single large unit, leading to numerosity
overestimation. Comparable to the visual version of the solitaire illusion, the clustering seems to be determined by Gestalt principles. In our auditory version, a clear reversal of the illusion (numerosity overestimation or underestimation) was observed when piano tones appeared to be arranged in a single large cluster or in several small clusters, respectively
The alliterations have fat tails
No full textSeveral quite different phenomena distribute according to few different functions, which share in a gross sense a particular shape that has induced to call them “fat (heavy, long) tail distributions”. Well-known examples are the so-called Benford’s law, Bradford’s law, Heap’s law, Lotka’s law, and so on. In economics are well known Lorenz’s law and Pareto’s law (on inequality of incoming). In psycholinguistics the most celebrated is undoubtedly Zipf’s law. In this study, we have investigated in this light the alliterations, that is, the relationship between the number of words interposed between two words sharing the same letter at the beginning (x) and number of occurrences of each given x, that is n(x). Analysing different excerpts of texts of XIX Century of different authors (Italian, French and American novelists like D’Annunzio, France and James, or essayists like Leopardi), we found invariably an excellent fit to Lorenz’s law, with an always above .97, and a remarkable stability of parameters within each author, but not between them. However, the mechanisms, which generate such distributions, are far to be clearly understood
Teorie della Personalità: Gli Sviluppi (Personality Theories: the Developments). Vol.2.
No full text
Per una storia della psicometria delle emozioni
No full textViene qui analizzato il tentativo di di misurare le emozioni tra gli ultimi decenni del XIX secolo e la Prima guerra Mondiale.Questo periodo è stato scelto in quanto demarcato all’inizio dalla teoria di Darwin sull’espressione delle emozioni, dalla teoria tridimensionale di Wundt e dalla teoria “periferica” di James-Lange, e alla fine dalla teoria di Canon, che darà un colpo mortale alla teoria di James-Lange, alla fine dello strutturalismo, alla nascita del comportamentismo negli USA e del Gestaltismo in Europa, che porranno in secondo piano le teorie fisiognomiche.
Il focus non è sulle teorie, quanto sui metodi di misura, peraltro costituenti fondamentali su cui costruire gli impianti teorici. Verranno così analizzati metodi fisiognomici, introspettivi, psicofisici e psicofisiologici, che l’attenzione rivolta soprattutto ai primi e agli ultimi.
E interessante notare che il crollo delle vecchie teorie ha portato all’abbandono di pressoché tutti questi metodi, salvo i fisiognomici.
Ancora più interessante notare il relativo abbandono dello studio delle emozioni da parte degli psicologi generalisti, in parallelo con l’affermarsi della psicologia come scienza della “mente”
Dynamic Interval Routing on Asynchronous Rings.
No full textWe consider the problem of routing in an asynchronous dynamically changing ring of processors using schemes that minimize the storage space for the routing information. In general, applying static techniques to a dynamic network would require significant re-computation. Moreover, the known dynamic techniques applied to the ring lead to inefficient schemes. In this paper we introduce a new technique, Dynamic Interval Routing, and we show trade offs between the stretch, the adaptation cost and the size of the update messages used by routing schemes based upon it. We give three algorithms for rings of maximum size N: the first two are deterministic, one with adaptation cost zero but stretch N/2, the other with adaptation cost O(N) messages of O (log N) bits and stretch 1. The third algorithm is randomized, uses update messages of size O(k log N), has adaptation cost O(k) and expected stretch 1+1/k, for any k>=1. All schemes require O(log N) bits per node for the routing information and all messages headers are of O(log N) bits
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