Institut Jean Nicod

We often effortlessly take the perceptual perspective of others: we represent some aspect of the environment that others currently perceive. However, taking someone's perspective can interfere with one's perceptual processing: another person's gaze can spontaneously affect our ability to detect stimuli in a scene. But it is still unclear whether our cognitive evaluation of those judgements is also affected. In this study, we investigated whether social perspective-taking can influence participants' metacognitive judgements about their perceptual responses. Participants performed a contrast detection task with a task-irrelevant avatar oriented either congruently or incongruently to the stimulus location. By “blindfolding” the avatar, we tested the influence of social perspective-taking versus domain-general directional orienting. Participants had higher accuracy and perceptual sensitivity with a congruent avatar regardless of the blindfold, suggesting a directional cueing effect. However, their metacognitive efficiency was modulated only by the congruency of a seeing avatar. These results suggest that perceptual metacognitive ability can be socially enhanced by sharing perception of the same objects with others.

Indoor air pollution is one of the leading causes of morbidity and mortality worldwide, but its sources and impacts are largely misunderstood by the public. In a randomised controlled trial including 281 households in France, we test two interventions aimed at changing indoor polluting behaviour by raising households’ awareness of health risks associated with indoor air pollution. While both generic and personalised information increased knowledge, only personalised information including social comparison feedback changed behaviour, leading to a reduction of indoor PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 µm) emissions by 20% on average. Heterogeneous treatment effects show that this effect is concentrated on the most polluted households at baseline, for whom the reduction reaches 40%.

We investigate the articulation between domain‐general reasoning and interpretive processes in failures of deductive reasoning. We focus on illusory inferences from disjunction‐like elements, a broad class of deductive fallacies studied in some detail over the past 15 years. These fallacies have received accounts grounded in reasoning processes, holding that human reasoning diverges from normative standards. A subset of these fallacies, however, can be analyzed differently: human reasoning is not to blame, instead the premises were interpreted in a nonobvious, yet perfectly predictable and reasonable way. Once we consider these interpretations, the apparent fallacious conclusion is no mistake at all. We give a two‐factor account of these fallacies that incorporates both reasoning‐based elements and interpretive elements, showing that they are not in real competition. We present novel experimental evidence in favor of our theory. Cognitive load such as induced by a dual‐task design is known to hinder the interpretive mechanisms at the core of interpretation‐based accounts of the fallacies of interest. In the first experiment of its kind using this paradigm with an inferential task instead of a simpler truth‐value‐judgment task, we found that the manipulation affected more strongly those illusions where our theory predicts that interpretive processes are at play. We conclude that the best way forward for the field to investigate the elusive line between reasoning and interpretation requires combining theories and methodologies from linguistic semantics and the psychology of reasoning.

We investigate the degree to which mispronounced signs can be accommodated by signers of French Sign Language (LSF). Using an offline judgment task, we examine both the individual contributions of three parameters – handshape, movement, and location – to sign recognition, and the impact of the individual features that were manipulated to obtain the mispronounced signs. Results indicate that signers judge mispronounced handshapes to be less damaging for well-formedness than mispronounced locations or movements. In addition to this macro-effect of parameter, individual features are found to carry different weights during sign recognition, mirroring what has been reported for phonological features in spoken languages. Together, these results thus further support an underlying a-modal phonological architecture for human language, including feature-based phonological representations.

The set of $\textsf{ST}$ ST -valid inferences is neither the intersection, nor the union of the sets of $\textsf{K}_3$ K 3 -valid and $\textsf{LP}$ LP -valid inferences, but despite the proximity to both systems, an extensional characterization of $\textsf{ST}$ ST in terms of a natural set-theoretic operation on the sets of $\textsf{K}_3$ K 3 -valid and $\textsf{LP}$ LP -valid inferences is still wanting. In this paper, we show that it is their relational product . Similarly, we prove that the set of $\textsf{TS}$ TS -valid inferences can be identified using a dual notion, namely as the relational sum of the sets of $\textsf{LP}$ LP -valid and $\textsf{K}_3$ K 3 -valid inferences. We discuss links between these results and the interpolation property of classical logic. We also use those results to revisit the duality between $\textsf{ST}$ ST and $\textsf{TS}$ TS . We present a notion of duality on which $\textsf{ST}$ ST and $\textsf{TS}$ TS are dual in exactly the same sense in which $\textsf{LP}$ LP and $\textsf{K}_3$ K 3 are dual to each other.

Sharing emotions with other individuals is a widespread phenomenon. Previous research proposed that experiencing intense and similar emotions with other individuals reinforces social bonds. However, several aspects of this phenomenon remain unclear, notably whether social bonding requires the convergence and synchronization of emotions in the group, and whether these effects generalize across positively valenced and negatively valenced emotional contexts. To address these questions, we measured subjective emotional experiences, physiological activity (cardiac, respiratory, electrodermal) and social attitudes in dyads of unacquainted individuals who watched videos in the presence of each other. We manipulated the emotional content of the videos and the type of shared attention between participants, to test for the contribution of interpersonal influence. The results revealed that intense emotions indexed by physiological arousal were associated with the emergence of reciprocal prosocial attitudes within dyads, and that this effect depended on joint attention. We did not observe the convergence and synchronization of emotions within dyads, which suggests that experiencing similar emotions was not necessary for social bonding. We discuss implications of this study for research on collective effervescence and the social consequences of shared experiences.

This paper introduces Matraversian skepticism from aesthetics (i.e., there is no cognitively interesting difference between our engagement with fiction versus our engagement with non-fiction) to debates in psychology and cognitive science on memory processing. I argue that the concept of ‘fiction’ has no place in our cognitive models of memory, neither in a specific category of memory, nor as a fact/fiction dimension. I propose a two-stage model of memory processing and explore the skeptical challenge that it poses to existing accounts of the role of the concept of ‘fiction’ in models of memory. An important element of this challenge is the realization that remembering agents typically recognize a range of different kinds of non-fictional, non-believed memories, e.g., memories originating in lies, trickery, dreams, hallucinations, illusions, etc.

In this paper, we show that native speakers spontaneously divide the complex meaning of a new word into a presuppositional component and an assertive component. These results argue for the existence of a productive triggering algorithm for presuppositions, one that is not based on alternative lexical items nor on contextual salience. On a methodological level, the proposed learning paradigm can be used to test further theories concerned with the interaction of lexical properties and conceptual biases.

Feature-based models of sign language use distinctive features to describe the phonological structure of signs. We use near-minimal pairs and phonological phenomena like productivity and neutralisation in French Sign Language to show that the feature [web], which refers to the webbing part of the fingers, should be (re)introduced into the list of phonologically active features. In discussing potential cases of [web] in other sign languages and the impact on the shape of phonological inventories, we first offer an account of [web] in terms of a location feature in line with most traditional feature-geometry models. We then offer some speculations on why a more uniform characterisation of [web] and the features in the same subclass in terms of the orientation type results in more economical models.

Female crested gibbons (genus Nomascus) perform conspicuous sequences of twitching movements involving the rump and extremities. However, these dances have attracted little scientific attention and their structure and meaning remain largely obscure. Here we analyse close-range video recordings of captive crested gibbons, extracting descriptions of dance in four species (N. annamensis, N. gabriellae, N. leucogenys and N. siki). In addition, we report results from a survey amongst relevant professionals clarifying behavioural contexts of dance in captive and wild crested gibbons. Our results demonstrate that dances in Nomascus represent a common and intentional form of visual communication restricted to sexually mature females. Whilst primarily used as a proceptive signal to solicit copulation, dances occur in a wide range of contexts related to arousal and/or frustration in captivity. A linguistically informed view of this sequential behaviour demonstrates that movement within dances is organized in groups and follows an isochronous rhythm — patterns not described for visual displays in other non-human primates. We argue that applying the concept of dance to gibbons allows us to expand our understanding of communication in non-human primates and to develop hypotheses on the rules and regularities characterising it. We propose that crested gibbon dances likely evolved from less elaborate rhythmic proceptive signals, similar to those found in siamangs. Although dance displays in humans and crested gibbons share a number of key characteristics, they cannot be assumed to be homologous. Nevertheless, gibbon dances represent a striking model behaviour to investigate the use of complex gestural signals in hominoid primates.

This study aims to provide a phenomenological description of the sense of volume in sighted people. Especially developed by non-sighted people, the sense of volume is an ability to perceive solids and voids by analysing sound reflection. Our recent works have brought it closer to the human echolocation's ability, but also to a form of spatial hearing based on the analysis of variations in the ambient sound field. In many studies, blindfolded participants were able to detect a surface positioned in front of them. However, there are no studies reporting on the experience of the sense of volume in sighted people under conditions of ecological perception. Consequently, we carried out commented walks, combined with a micro-phenomenological interview method in an urban environment. By cross-referencing participants' perceptions (wall detection at one metre, typologies' discrimination of) with feelings they share (acoustic feelings combined with synesthetic tactile feelings), we demonstrated the ability of sighted people to rapidly unveil a functional sense of volume. Several researchers have hypothesized that sighted people may use a form of automated passive echolocation. In the light of our results, we wonder whether the sense of volume might be a non-conscious factor in an urban atmosphere.

Climate change is currently one of humanity’s greatest threats. To help scholars understand the psychology of climate change, we conducted an online quasi-experimental survey on 59,508 participants from 63 countries (collected between July 2022 and July 2023). In a between-subjects design, we tested 11 interventions designed to promote climate change mitigation across four outcomes: climate change belief, support for climate policies, willingness to share information on social media, and performance on an effortful pro-environmental behavioural task. Participants also reported their demographic information (e.g., age, gender) and several other independent variables (e.g., political orientation, perceptions about the scientific consensus). In the no-intervention control group, we also measured important additional variables, such as environmentalist identity and trust in climate science. We report the collaboration procedure, study design, raw and cleaned data, all survey materials, relevant analysis scripts, and data visualisations. This dataset can be used to further the understanding of psychological, demographic, and national-level factors related to individual-level climate action and how these differ across countries.

We argue that sign language requires a radical extension of formal semantics. It has long been accepted that sign language employs the same logical machinery as spoken language (occasionally making its abstract components overt), and simultaneously makes extensive use of iconicity. But the articulation between these two modules has only been discussed piecemeal. To capture it, we propose an ‘iconological semantics’ that combines standard logical semantics with a pictorial semantics in the Greenberg/Abusch tradition. We start by reanalyzing from this perspective earlier data on iconic loci, which are simultaneously variables and simplified depictions of their denotations. We then analyze new data on ASL classifier predicates, constructions that are lexically specified as being iconic. Their behavior argues for a very expressive system, possibly one in which the object language contains viewpoint variables. These can be left free or they may depend on quantifiers, and distinct viewpoint variables can co-occur in a given sentence; this gives rise to an extraordinary interaction between depictions and logical operators. We then sketch an adaptation of pictorial semantics to the dynamic 3D representations used in sign language. Finally, we suggest that iconological semantics might also illuminate the interaction between logical operators and pro-speech gestures in spoken language. In the end, the standard view of language as a discrete compositional system must be revised: it also has a tightly integrated depictive component, and ‘textbook semantics’ should be revised to capture this fact.

Expressions like two novels are traditionally taken to convey information about cardinality and are analyzed using a cardinality function. Salmon (Philosop Perspect 11:1–15, 1997), Liebesman (Australasian J Philos 93:21–42, 2015; Philos’ Impr 16:1–25, 2016; In D. W. Zimmerman (ed.), Oxford studies in metaphysics, Oxford University Press, Oxford, forthcoming), and Haida and Trinh (in: Dočekal, Wagiel (eds) Formal approaches to number in Slavic and beyond, Language Science Press, Berlin, 2001) argue against this traditional account, claiming that it can’t explain our use of expressions like two and a half novels. According to them, the proper analysis of such expressions requires a partiality measure, which maps entities to rational numbers such as 2.5. In this paper, we set out to defend the traditional account. To do so, we demonstrate that an analysis based on a partiality measure is inconsistent with the truth conditions of plural comparatives and equatives. We also show that such an account doesn’t provide an adequate analysis for expressions like two novels and a half, nor for their French counterparts (e.g., deux romans et demi). Critically, such expressions contain no constituent that could refer to the number 2.5. We provide an alternative analysis for all these expressions, based on cardinality and an operation of non-overlapping summation.

Purpose Food acquisition is an adaptive problem resolved via both physiological and psychological processes. Hunger could serve as a coordinating mechanism for these processes. When hunger increases, it may be beneficial to shift cognitive resources away from other adaptive problems and towards functions that increase the chances of acquiring food, such as memory for food information. However, there is limited research exploring the impacts of hunger on food-related memory, and the results are mixed. We conducted two studies investigating whether increased hunger levels improve memory for food images and prices – but not non-food images and prices – in image recognition and price recall tasks, respectively. Methods Study 1 was an online, observational study (N = 91) using self-reported hunger as a continuous measure. Study 2 was an in-person, between-subjects interventional study (N = 102) where participants were randomly allocated to a hungry or sated condition. We predicted that higher levels of hunger would improve participants’ ability to discriminate between food images they have and have not seen before and correctly recall food prices. Results We found no evidence of a hunger-related memory enhancement for food stimuli in either study in image recognition or price recall tasks. Conclusion Our findings contrast with older research but support more recent work, suggesting that the effect of hunger on food memory may be sensitive to study design and not as broadly generalisable as first thought.

Traditional philosophical inquiry, and more recently neuroscientific studies, have investigated the sources of artworks' aesthetic appeal. A substantial effort has been made to isolate the objective features contributing to aesthetic appreciation. While variables such as contrast or symmetry have been shown to robustly impact aesthetic judgment, they only account for a small portion of the intersubjective variability in aesthetic ratings. Recent multiprocess model of aesthetic appreciation could accommodate this finding by proposing that evaluative processes based on self-reference underpin the idiosyncrasy of aesthetic judgment. We tested this hypothesis in two behavioral studies, that were basically conceptual replications of our previous work, in which we took advantage of the self-reference effect on memory. We also tried to disentangle the role of self-reference and emotional reaction to artworks in guiding aesthetic judgments, by comparing an aesthetic judgment encoding condition to a self-reference condition (Study 1), and an emotional evaluation condition (Study 2). We show that artworks encoded in an aesthetic judgment condition exhibit a similar mnesic advantage compared to both the self-reference and the emotional evaluation encoding conditions. Moreover, retrospective emotional judgment correlates with both self-reference and aesthetic judgments ratings. These results suggest that a basic mechanism, appraisal of self-relevance, could ground aesthetic judgments.

Understanding of the hot corrosion behavior of each constitutive phase of the new Pt-enriched γ/γ′ nickel-based single-crystal TROPEA superalloy is of significant interest for further optimization. Therefore, single-phase γ and γ′ materials containing a low content of Pt (0.13% at.) were manufactured by inductive melting and their behavior was investigated at 900°C with 1 mg/cm² of Na2SO4 deposit using thermogravimetry in air and air + 400 ppm of SO2. After 24 h in air, the scale grown on the γ′ model alloy consisted of an outer heterogeneous NiO layer and of an internal porous α-Al2O3 layer. The addition of 400 ppm of SO2 to air did not really change the nature and morphology of the oxides formed for γ′, but the measured linear rate was tenfold higher than that recorded in air. The γ alloy underwent an incubation period during which the corrosion rate was limited, followed by a propagation stage. In air, the alloy developed an external continuous NiCr2O4 spinel layer and a thin internal Cr2O3 subscale. The γ alloy was able to efficiently re-passivate after the propagation period. With 400 ppm SO2, only a thin protective layer Cr2O3 formed on the surface of γ, with large Cr2O3 crystals growing within the residual Na2SO4. The occurrence of Cr-rich sulfides was also greater in the γ′ model alloy compared to the γ counterpart both in air and in air + 400 ppm of SO2. Therefore, the results clearly evidenced the effect of SO2 on the type I hot corrosion.