Archive Electronique - Institut Jean Nicod
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1997 research outputs found
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The Pulfrich solidity illusion: a surprising demonstration of the visual system’s tolerance of solidity violations
International audiencePhysical objects behave following the principle of solidity: One solid object cannot pass through another. To what extent does the visual system integrate this physical regularity as a prior constraint? A new variant of the Pulfrich effect demonstrates a surprising degree of tolerance for violations of solidity when pitted against motion and depth cues. When adult participants view a pendulum swinging in the fronto-parallel plane with both eyes (one of which was covered by a light-attenuating filter), they falsely perceive the pendulum as swinging in an elliptical path (known as the "Pulfrich effect"). Here, we show that even when the pendulum's motion takes place entirely behind a solid horizontal bar, observers nevertheless see the pendulum pass through the bar while moving in an ellipse. This illusion suggests that the Pulfrich effect and the underlying stereoscopic depth cues can be robust to object solidity
Certain and Uncertain Inference with Indicative Conditionals
International audienceThis paper develops a trivalent semantics for the truth conditions and the probability of the natural language indicative conditional. Our framework rests on trivalent truth conditions first proposed by W. Cooper and yields two logics of conditional reasoning: (i) a logic C of inference from certain premises; and (ii) a logic U of inference from uncertain premises. But whereas C is monotonic for the conditional, U is not, and whereas C obeys Modus Ponens, U does not without restrictions. We show systematic correspondences between trivalent and probabilistic representations of inferences in either framework, and we use the distinction between the two systems to cast light, in particular, on McGee's puzzle about Modus Ponens. The result is a unified account of the semantics and epistemology of indicative conditionals that can be fruitfully applied to analyzing the validity of conditional inferences
Why do some words have more meanings than others? A true neutral model for the meaning-frequency correlation
International audienceThe lexica of natural languages are ambiguous, but the degree of ambiguity is unequal between words. Some words have more meanings than others. However, the exact properties that favor some words over others when acquiring a new meaning are not very well understood. In recent years, several studies suggested that some words gain more meanings than others based on selection for efficient communication, which could explain the correlation between meaning and frequency discovered by Zipf (Piantadosi, Tily, & Gibson, 2012; Gibson et al., 2019). The object of this study is to assess the role of selection in the meaning-frequency correlation using a neutral model that yields a meaning-frequency correlation without selection pressures. We provide a model where words gain additional meanings through reuse. In the neutral model presented in this paper, words are chosen to be reused at random, independently of their frequency, hence there is no selection mechanism favoring efficient communication. Unlike previous attempts to introduce null models of the meaning-frequency correlation (Caplan, Kodner, & Yang, 2020; Trott & Bergen, 2020), it truly does not rely on selection for frequency. We show that statistical regularities related to ambiguity, such as Zipf's meaning-frequency correlation, can arise in conditions when words are not undergoing any selective pressures. This model has the additional property of matching word frequency distributions of natural languages. It can provide the baseline against which the presence of selection for efficient communication in natural languages can be assessed
Classification de tweets en situation d'urgence pour la gestion de crises
International audienceLe traitement de données provenant de réseaux sociaux en temps réel est devenu une outil attractifdans les situations d'urgence, mais la surcharge d'informations reste un défi à relever. Dans cet article,nous présentons un nouveau jeu de données en français annoté manuellement pour la gestion de crise.Nous testons également plusieurs modèles d'apprentissage automatique pour classer des tweets enfonction de leur pertinence, de l'urgence et de l'intention qu'ils véhiculent afin d'aider au mieux lesservices de secours durant les crises selon des méthodes d'évaluation spécifique à la gestion de crise.Nous évaluons également nos modèles lorsqu'ils sont confrontés à de nouvelles crises ou même denouveaux types de crises, avec des résultats encourageant
Truth and Falsity in Buridan's Bridge
International audienceThis paper revisits Buridan's Bridge paradox (Sophismata, chapter 8, Sophism 17), itself close kin to the Liar paradox, a version of which also appears in Bradwardine's Insolubilia. Prompted by the occurrence of the paradox in Cervantes's Don Quixote, I discuss and compare four distinct solutions to the problem, namely Bradwardine's "just false" conception, Buridan's "contingently true/false" theory, Cervantes's "both true and false" view, and then Jacquette's "neither true simpliciter nor false simpliciter" account. All have in common to accept that the Bridge expresses a truth-apt proposition, but only the latter three endorse the transparency of truth. Against some previous commentaries I first show that Buridan's solution is fully compliant with an account of the paradox within classical logic. I then show that Cervantes's insights, as well as Jacquette's treatment, are both supportive of a dialetheist account, and Jacquette's in particular of the strict-tolerant account of truth. I defend dialetheist intuitions (whether in LP or ST guise) against two objections: one concerning the future, the other concerning the alleged simplicity of the Bridge compared to the Liar
Moralization and extremism robustly amplify myside sharing
International audienceAbstract We explored whether moralization and attitude extremity may amplify a preference to share politically congruent (“myside”) partisan news and what types of targeted interventions may reduce this tendency. Across 12 online experiments (N = 6,989), we examined decisions to share news touching on the divisive issues of gun control, abortion, gender and racial equality, and immigration. Myside sharing was systematically observed and was consistently amplified when participants (i) moralized and (ii) were attitudinally extreme on the issue. The amplification of myside sharing by moralization also frequently occurred above and beyond that of attitude extremity. These effects generalized to both true and fake partisan news. We then examined a number of interventions meant to curb myside sharing by manipulating (i) the audience to which people imagined sharing partisan news (political friends vs. foes), (ii) the anonymity of the account used (anonymous vs. personal), (iii) a message warning against the myside bias, and (iv) a message warning against the reputational costs of sharing “mysided” fake news coupled with an interactive rating task. While some of those manipulations slightly decreased sharing in general and/or the size of myside sharing, the amplification of myside sharing by moral attitudes was consistently robust to these interventions. Our findings regarding the robust exaggeration of selective communication by morality and extremism offer important insights into belief polarization and the spread of partisan and false information online
Zipf’s Law of Abbreviation holds for individual characters across a broad range of writing systems
International audienceZipf's Law of Abbreviation-the idea that more frequent symbols in a code are simpler than less frequent ones-has been shown to hold at the level of words in many languages. We tested whether it holds at the level of individual written characters. Character complexity is similar to word length in that it requires more cognitive and motor effort for producing and processing more complex symbols. We built a dataset of character complexity and frequency measures covering 27 different writing systems. According to our data, Zipf's Law of Abbreviation holds for every writing system in our dataset-the more frequent characters have lower degrees of complexity and vice-versa. This result provides further evidence of optimization mechanisms shaping communication systems
Designing an acceptable and fair carbon tax: The role of mental accounting
International audienceDespite its potential for curbing greenhouse gas emissions, carbon taxation encounters strong public resistance. However, acceptability depends on how tax revenues are used. We test the hypothesis that mental accounting theory can both explain systematic patterns in citizens’ preferences, such as the support for environmental earmarking, and help design a carbon tax scheme that is both acceptable and fair. Across six experiments conducted in the United Kingdom and in France (N total = 7100), we show that: (a) There is an acceptability boost when the use of tax revenues matches the tax domain thematically (e.g., allocating carbon tax revenues to green projects), as demonstrated by an interaction effect between the tax domain and the expenditure domain on the level of tax support. This result is consistent with the use of a mental accounting heuristic, by which people create mental budgets where the origin of revenues is matched thematically with their domain of use. (b) Carbon tax acceptability varies with the proportion of tax revenues earmarked for green projects. (c) A mixed carbon tax scheme, in which most revenues are earmarked for green projects and the rest is redistributed to low-income households to be spent on sustainable expenses, receives most support among the tested options. We also demonstrate the robustness of the mental accounting heuristic in two ways: by showing that the preference for environmental earmarking of carbon taxes is observed across all relevant subsections of the population, and that mental accounting also appears to shape preferences for health-related earmarking of tobacco taxes, and social-related earmarking of inheritance taxes
Super Linguistics: an introduction
International audienceWe argue that formal linguistic theory, properly extended, can provide a unifying framework for diverse phenomena beyond traditional linguistic objects. We display applications to pictorial meanings, visual narratives, music, dance, animal communication, and, more abstractly, to logical and non-logical concepts in the ‘language of thought’ and reasoning. In many of these cases, a careful analysis reveals that classic linguistic notions are pervasive across these domains, such as for instance the constituency (or grouping) core principle of syntax, the use of logical variables (for object tracking), or the variety of inference types investigated in semantics/pragmatics. The aim of this overview is to show how the application of formal linguistic concepts and methodology to non-linguistic objects yields non-trivial insights, thus opening the possibility of a general, precise theory of signs. (An appendix, found in the online supplements to this article, surveys applications of Super Linguistics to animal communication.