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PROCESSAMENTO E RILEVAMENTO DI ESPRESSIONI FACCIALI EMOTIVE SPONTANEE E SIMULATE
No full textLe espressioni facciali sono gli indicatori emozionali più efficaci e affidabili di cui siamo dotati. Tuttavia, è ben noto come gli esseri umani siano abili nel modulare e falsificare le proprie espressioni facciali a seconda dei loro bisogni e situazioni sociali, influenzando implicitamente la percezione e reazione dell’osservatore. Nella seguente ricerca, un nuovo dataset di espressioni facciali ritraenti emozioni è stato creato con il duplice obiettivo di: cercare di discriminare automaticamente la genuinità delle emozioni in accordo ai movimenti facciali esibiti (sezione del “rivelamento della menzogna”), e investigare come il cervello percepisce la visione di espressioni facciali emotive genuine e simulate (sezione del “processamento della genuinità emotiva”). Nella sezione del rivelamento della menzogna, modelli di apprendimenti automatico sono stati implementati e applicati ai video ritraenti emozioni facciali, con il fine di classificare quando una persona stava esprimendo l’emozione in modo sincero o simulato. I risultati confermano un’alta accuratezza (fino all 84%) nella classificazione della genuinità. Inoltre, accurate analisi cinematica sono state svolte per lo studio del sorriso genuino e simulato, investigando le più minime differenze sia in termini di spazio e tempo dei movimenti facciali. I risultati rivelano che l’apertura degli angoli della bocca, così come la loro velocità di movimento, sia più elevata nel sorriso simulato. Nella sezione del “processamento della genuinità emotiva”, sono state utilizzate analisi EEG Tempo Frequenza per comparare la percezione di tre emozioni genuine e simulate: felicità, disgusto e paura. Nel complesso, sono state osservate forti differenze sia nella tempistica che nella topografia delle canoniche bande EEG, suggerendo come le emozioni spontanee e simulate vengano elaborate in modo diverso nel nostro cervello. In particolare, rispetto alla felicità genuina, la felicità simulata ha rivelato un aumento della banda delta e theta all'inizio e alla fine delle espressioni facciali sui siti frontali. Per quanto riguarda la paura, la paura genuina, rispetto alla controparte simulata, provoca un aumento delle bande alfa e beta seguito da un aumento dell'attività theta. Infine, per le espressioni facciali di disgusto, è stato riscontrato un aumento precoce dell'attività theta, alfa e beta per le espressioni simulate, seguita da una maggiore attività nelle bande alfa e beta durante la percezione del disgusto genuino. Le implicazioni e le applicazioni di questi studi sono discusse alla luce dello stato dell'arte della rilevazione della menzogna, della psicologia delle emozioni e del campo dell'intelligenza artificiale.Facial expressions are the most effective and reliable indicator of emotional states. However, people are adept at modulating and falsifying their emotional expressions according to their needs, completely changing the observer’s perception and reaction. A new validated dataset displaying more than 1450 clips of both spontaneous and posed emotional facial expressions was created for a dual purpose: discriminate spontaneous and posed emotions according to the facial movements (detection section) and investigate how the brain extracts the genuineness of emotional expressions (perception section). In the detection part, Machine Learning models were applied to the clips in order to discriminate spontaneous from posed emotion automatically. Results yielded high accuracies in genuineness discrimination (up to 84.4% accuracy). Moreover, for the first time, the 3-D motion analysis was applied to the study of spontaneous and posed dynamic facial expressions of happiness to detect subtle movements in terms of space, time, and speed. Results revealed that the mouth widening and the speed of smiles are greater in posed than spontaneous happiness. In the perception section, time-frequency EEG analysis was used to compare the perception of three spontaneous and posed emotional facial expressions: happiness, disgust, and fear. Overall, strong differences in both the timing and the topography of the canonical EEG bands were observed, revealing how spontaneous and posed emotions are processed differently in our brains. In particular, compared to genuine happiness, posed happiness revealed increased delta and theta power at the onset and offset of the facial expressions over frontal sites. Compared to posed fear, genuine fear elicits an increase in alpha and beta bands followed by an increase in theta activity. Finally, for facial expressions of disgust, we found an early increased theta, alpha, and beta activity for the posed expressions, followed by increased activity in alpha and beta bands during the perception of genuine disgust. The implications and applications of these studies are discussed in light of the state of art of lie detection, psychology of emotions, and the AI field
The charm of structural neuroimaging in insanity evaluations. guidelines to avoid misinterpretation of the findings
Full text linkDespite the popularity of structural neuroimaging techniques in twenty-first-century research, its results have had limited translational impact in real-world settings, where inferences need to be made at the individual level. Structural neuroimaging methods are now introduced frequently to aid in assessing defendants for insanity in criminal forensic evaluations, with the aim of providing “convergence” of evidence on the mens rea of the defendant. This approach may provide pivotal support for judges’ decisions. Although neuroimaging aims to reduce uncertainty and controversies in legal settings and to increase the objectivity of criminal rulings, the application of structural neuroimaging in forensic settings is hampered by cognitive biases in the evaluation of evidence that lead to misinterpretation of the imaging results. It is thus increasingly important to have clear guidelines on the correct ways to apply and interpret neuroimaging evidence. In the current paper, we review the literature concerning structural neuroimaging in court settings with the aim of identifying rules for its correct application and interpretation. These rules, which aim to decrease the risk of biases, focus on the importance of (i) descriptive diagnoses, (ii) anatomo-clinical correlation, (iii) brain plasticity and (iv) avoiding logical fallacies, such as reverse inference. In addition, through the analysis of real forensic cases, we describe errors frequently observed due to incorrect interpretations of imaging. Clear guidelines for both the correct circumstances for introducing neuroimaging and its eventual interpretation are defined
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
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