Sacha Altay, Anne-Sophie Hacquin, Hugo Mercier (2020). Why do so few people share fake news? It hurts their reputation. New Media and Society, https://doi.org/10.1177/1461444820969893

Résumé : In spite of the attractiveness of fake news stories, most people are reluctant to share them. Why? Four pre-registered experiments (N = 3,656) suggest that sharing fake news hurt one’s reputation in a way that is difficult to fix, even for politically congruent fake news. The decrease in trust a source (media outlet or individual) suffers when sharing one fake news story against a background of real news is larger than the increase in trust a source enjoys when sharing one real news story against a background of fake news. A comparison with real-world media outlets showed that only sources sharing no fake news at all had similar trust ratings to mainstream media. Finally, we found that the majority of people declare they would have to be paid to share fake news, even when the news is politically congruent, and more so when their reputation is at stake.

Sacha Bourgeois-Gironde (2020). Le sourire de ma boulangère : sur le rôle des expressions faciales dans les transactions monétaires. Dans : Claudia Senik éd., Crises de confiance (pp. 213-230). Paris: La Découverte.

Résumé : Pendant toute une période, tous les matins, j’achetais un petit pain au chocolat. La boulangère me souriait. Et je ne me privais pas de la regarder. Les clients ne voyaient qu’elle, mais pas ce qu’elle faisait en sous-main. Je le voyais bien, mais je laissais faire : elle ne rendait pas exactement la monnaie. Ça arrivait de temps en temps : 5 centimes, 10 centimes… Ce n’était pas si cher payé pour son joli sourire. Elle a fini par comprendre que je savais. Et elle a continué un temps, jusqu’au jour où elle a arrêté de me sourire et de ne pas rendre la monnaie exacte. Elle ne voulait pas « vendre » son sourire, même de manière implicite, surtout que, sans paroles certes, cela devenait explicite, de connaissance commune entre nous.

Alex de Carvalho, Isabelle Dautriche, Anne-Caroline Fiévet & Anne Christophe (2020). Toddlers exploit referential and syntactic cues to flexibly adapt their interpretation of novel verb meanings. Journal of Experimental Child Psychology, 203(105017). doi:10.1016/j.jecp.2020.105017

Résumé : Because linguistic communication is often noisy and uncertain, adults flexibly rely on different information sources during sentence processing. We tested whether toddlers engage in a similar process and how that process interacts with verb learning. Across two experiments, we presented French 28-month-olds with right-dislocated sentences featuring a novel verb (“Hei is VERBing, the boyi”), where a clear prosodic boundary after the verb indicates that the sentence is intransitive (such that the NP “the boy” is coreferential with the pronoun “he” and the sentence means “The boy is VERBing”). By default, toddlers incorrectly interpreted the sentence based on the number of NPs (assuming, e.g., that someone is VERBing the boy). Yet, when children were provided with additional information about the syntactic contexts (Experiment 1, N = 81) or the referential/semantic content (Experiment 2, N = 72) of the novel verb, they successfully used the prosodic information as a cue to reach the correct syntactic structure of the sentence and infer the probable meaning of the novel verb. These results suggest that toddlers can flexibly adjust their interpretations of sentences depending on the reliability of the linguistic cues available. Thus, failure to parse a sentence in an adult-like fashion might not necessarily reflect the immaturity of children’s parsing system but rather might be indicative of what cues children consider reliable in that context.

Gerda Melnik & Sharon Peperkamp (2020). High-variability phonetic training enhances L2 lexical processing: evidence from online training of late French-English bilinguals. Bilingualism: Language and Cognition. doi.org/10.1017/S1366728920000644.


Résumé : High-Variability Phonetic Training (HVPT) has been shown to be effective in improving the perception of the hardest non-native sounds. However, it remains unclear whether such training can enhance phonological processing at the lexical level. The present study tested whether HVPT also improves word recognition. Late French learners of English completed eight online sessions of HVPT on the perception of English word-initial /h/. This sound does not exist in French and has been shown to cause difficulty both at the prelexical (Mah, Goad & Steinhauer, 2016) and the lexical level of processing (Melnik & Peperkamp, 2019). In pretest and posttest participants were administered a prelexical identification task and a lexical decision task. Results demonstrate that after training the learners’ accuracy improved in both tasks. Moreover, these improvements were retained four months after posttest. This is the first evidence that short training can enhance not only prelexical perception, but also word recognition.

Anis Najar, Emmanuelle Bonnet, Bahador Bahrami, Stefano Palminteri (2020). The actions of others act as a pseudo-reward to drive imitation in the context of social reinforcement learning. PLoS Biol, 18 (12): e3001028. https://doi.org/10.1371/journal.pbio.3001028

Résumé : While there is no doubt that social signals affect human reinforcement learning, there is still no consensus about how this process is computationally implemented. To address this issue, we compared three psychologically plausible hypotheses about the algorithmic implementation of imitation in reinforcement learning. The first hypothesis, decision biasing (DB), postulates that imitation consists in transiently biasing the learner’s action selection without affecting their value function. According to the second hypothesis, model-based imitation (MB), the learner infers the demonstrator’s value function through inverse reinforcement learning and uses it to bias action selection. Finally, according to the third hypothesis, value shaping (VS), the demonstrator’s actions directly affect the learner’s value function. We tested these three hypotheses in 2 experiments (N = 24 and N = 44) featuring a new variant of a social reinforcement learning task. We show through model comparison and model simulation that VS provides the best explanation of learner’s behavior. Results replicated in a third independent experiment featuring a larger cohort and a different design (N = 302). In our experiments, we also manipulated the quality of the demonstrators’ choices and found that learners were able to adapt their imitation rate, so that only skilled demonstrators were imitated. We proposed and tested an efficient meta-learning process to account for this effect, where imitation is regulated by the agreement between the learner and the demonstrator. In sum, our findings provide new insights and perspectives on the computational mechanisms underlying adaptive imitation in human reinforcement learning.

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