Comment réagit notre cerveau quand nous explorons quelque chose de nouveau ?
Dans un monde en perpétuel changement, prendre de bonnes décisions requiert de pouvoir explorer différentes stratégies et d’être capable d’identifier celle qui sera la plus adaptée.
Des travaux menés par une équipe de neuroscientifiques de l’Inserm et du CNRS à l’ENS, en collaboration avec l’Université d’Harvard, ont permis de caractériser ce processus cognitif en enregistrant les minuscules champs magnétiques émis par le cerveau humain. Selon les résultats de cette étude, l’exploration de notre environnement, ou le fait de se diriger vers de la nouveauté, s’accompagne d’une élévation soutenue de l’attention qui se manifeste jusque dans le système nerveux périphérique. Ces travaux viennent d'être publiés dans la revue eLife.
Le projet "Emergence of Invariant Speech Representations" a reçu un financement de la fondation pour l'Audition.
Ce projet porté par Yves Boubenec, chercheur au Laboratoire des Systèmes perceptifs, propose une approche unique pour aborder la question fondamentale de savoir comment des représentations robustes des sons dans le cortex auditif émergent au cours du développement précoce du cerveau, et évoluent tout au long de la vie, de la naissance à l'âge adulte.
Labos en fête à l'ENS-PSL !
Samedi 15 et dimanche 16 octobre, à l'occasion de la Fête de la science, les départements de physique, chimie, géosciences, mathématiques, biologie et sciences cognitives de l'ENS-PSL ouvriront leurs portes.
Au programme : mini cours, activités scientifiques, ateliers, expositions, visites de laboratoires. Le programme sera dévoilée très prochainement sur le site internet de La fête de la Science.
Événement gratuit et ouvert à toutes et à tous !
Le bon choix : nous apprenons plus en faisant confiance qu'en ne faisant pas confiance
Hugo Mercier, chercheur à l'Institut Jean Nicod, parle des avantages de la confiance en termes d'apprentissage dans les carnets de l'EHESS.
Google a-t-il développé une IA consciente ?
Aïda Elamrani est doctorante à l'Institut Jean Nicod et chargée d'étude en philosophie de l'IA à l'ENS. Elle revient, dans The Conversation, sur l'histoire de Blake Lemoine, l’ingénieur de Google convaincu que le robot LaMDA a une âme.
L’empreinte carbone de la recherche
Doctorante au sein de l’Institut Jean-Nicod, Eva Wanek s’intéresse aux avancées conceptuelles et méthodologiques récentes en matière de compensation des dommages environnementaux. Maude Gallimard est doctorante au Laboratoire Aménagement, Économie, Transports. Elle s’intéresse aux adaptations et transformations possibles des pratiques académiques en cohérence avec les enjeux environnementaux mis en exergue par la communauté scientifique.
Les deux jeunes femmes mènent, pour le CNRS, une réflexion sur l’impact environnemental de la recherche académique.
Entretien publié dans la lettre de l’institut des sciences humaines et sociales (InSHS) du CNRS.
Une simple allusion verbale peut modifier la perception visuelle d'une personne, surtout si elle est très influençable
Une nouvelle étude montre à quel point il est facile d'influencer les jugements perceptifs d'une personne, en l'amenant à penser qu'elle voit quelque chose qui n'est pas là. Selon les résultats, une courte déclaration verbale peut modifier la perception visuelle d'une personne, surtout si elle est plus sensible à l'influence sociale. Ces résultats ont été récemment publiés dans le Journal of Experimental Psychology : Human Perception and Performance.
Entretien pour Psypost avec Hernan Anllo, postdoctorant au Laboratoire de Neurosciences Cognitives et Computationnelles au sein de l'équipe Human Reinforcemenr Learning, et premier auteur de cette publication.
« L’impact environnemental des jets privés est largement sous-estimé »
Nicolas Baumard et Coralie Chevallier, chercheur et chercheuse en sciences cognitives expliquent dans une tribune publiée dans le « Monde », que l’absence de régulation forte envers l’aviation privée décrédibilise le discours public visant à promouvoir la sobriété énergétique.
Intéroception, le sens de la vie
L'intéroception est la capacité que nous avons à percevoir l'état de notre corps, du battement de notre cœur au mouvement de nos intestins. On découvre un peu plus chaque jour l'étendue de son rôle, de la régulation de notre température corporelle à la perception de nos émotions. Qu'en sait-on ?
Catherine Tallon-Baudry, chercheuse en neurosciences au LNC2 était invitée dans l'émission "La science CQFD" sur France Culture aux côtés de Henry Evrard, directeur de laboratoire au Max Planck Institute for Biological Cybernetics & Center for Integrative Neuroscience.
L'incertitude du point de vue des sciences cognitives
A l'occasion du festival de l’ENS qui a eu lieu le 9 septembre, les chercheur.se.s du DEC ont été invité.e.s à s'exprimer dans les médias.
- Face aux fake news, créons des "hommes de fer" : Sacha Altay et Hugo Mercier expliquent dans une tribune dans Libération qu’il est crucial de «rendre les sources d’information fiables plus dignes de confiance, et ne pas rejeter trop rapidement les points de vue différent du nôtre». Lire l'article
- Comment nous adapter à un temps d'incertitudes ? : Stéphanie Ruphy, professeure de philosophie des sciences à l’ENS, et Charlotte Jacquemot, chercheuse dans l'équipe de NeuroPsychologie Interventionelle du DEC étaient invitées de "L'invité(e) des matins" sur France Culture. Ecouter l'émission
- "L’incertitude n’empêche pas de rechercher la vérité” : entretien avec Jean-Baptise André, chercheur à l'Institut Jean Nicod et Stéphanie Ruphy, responsables scientifiques de la Nuit de l'ENS 2022, sur philomag.com, suivi de l'article de Charlotte Jacquemot intitulé "Quand le cerveau nous joue des tours".
- "Etre sûr du pire est moins stressant que de ne pas savoir" : Charlotte Jacquemot explique dans un article publié sur liberation.com que l’incertitude et le stress qu’elle génère peuvent être gérés grâce aux prédictions en continu du cerveau. Lire l'article
Cyril Atkinson-Clement, Mael Lebreton, Laïla Patsalides, Astride De Liege, Yanica Klein, Emmanuel Roze, Emmanuelle Deniau, Andreas Hartmann, Stefano Palminteri and Yulia Worbe (2022). Decision-making under risk and ambiguity in adults with Tourette syndrome. Psychological Medicine, 1-11. doi:10.1017/S0033291722002318
Tourette syndrome (TS) as well as its most common comorbidities are associated with a higher propensity for risky behaviour in everyday life. However, it is unclear whether this increased risk propensity in real-life contexts translates into a generally increased attitude towards risk. We aimed to assess decision-making under risk and ambiguity based on prospect theory by considering the effects of comorbidities and medication.
Fifty-four individuals with TS and 32 healthy controls performed risk and ambiguity decision-making tasks under both gains and losses conditions. Behavioural and computational parameters were evaluated using (i) univariate analysis to determine parameters difference taking independently; (ii) supervised multivariate analysis to evaluate whether our parameters could jointly account for between-group differences (iii) unsupervised multivariate analysis to explore the potential presence of sub-groups.
Except for general ‘noisier’ (less consistent) decisions in TS, we showed no specific risk-taking behaviour in TS or any relation with tics severity or antipsychotic medication. However, the presence of comorbidities was associated with distortion of decision-making. Specifically, TS with obsessive–compulsive disorder comorbidity was associated with a higher risk-taking profile to increase gain and a higher risk-averse profile to decrease loss. TS with attention-deficit hyperactivity disorder comorbidity was associated with risk-seeking in the ambiguity context to reduce a potential loss.
Impaired valuation of risk and ambiguity was not related to TS per se. Our findings are important for clinical practice: the involvement of individuals with TS in real-life risky situations may actually rather result from other factors such as psychiatric comorbidities.
Axel Baptista, Pierre Jacquet, Nura Sidarus, David Cohen & Valerian Chambon (2022). Susceptibility of Agency Judgments to Social Influence. Cognition, 226, 105173. doi:10.1016/j.cognition.2022.105173
Self-disturbance is recognized as a key symptom of Borderline Personality Disorder (BPD). Although it is the source of significant distress and significant costs to society, it is still poorly specified. In addition, current research and models on the etiology of BPD do not provide sufficient evidence or predictions about who is at risk of developing BPD and self-disturbance, and why. The aim of this review is to lay the foundations of a new model inspired by recent developments at the intersection of social cognition, behavioral ecology, and developmental biology. We argue that the sense of agency is an important dimension to consider when characterizing self-disturbances in BPD. Second, we address the poorly characterized relation between self-disturbances and adverse life conditions encountered early in life. We highlight the potential relevance of Life-History Theory—a major framework in evolutionary developmental biology—to make sense of this association. We put forward the idea that the effect of early life adversity on BPD symptomatology depends on the way individuals trade their limited resources between competing biological functions during development.
Vincent Bouttier, Suhrit Duttagupta, Sophie Denève, Renaud Jardri (2022). Circular inference predicts nonuniform overactivation and dysconnectivity in brain-wide connectomes. Schizophrenia Research, 245, 59-67, ISSN 0920-9964.
Schizophrenia is a severe mental disorder whose neural basis remains difficult to ascertain. Among the available pathophysiological theories, recent work has pointed towards subtle perturbations in the excitation-inhibition (E/I) balance within different neural circuits. Computational approaches have suggested interesting mechanisms that can account for both E/I imbalances and psychotic symptoms. Based on hierarchical neural networks propagating information through a message-passing algorithm, it was hypothesized that changes in the E/I ratio could cause a “circular belief propagation” in which bottom-up and top-down information reverberate. This circular inference (CI) was proposed to account for the clinical features of schizophrenia. Under this assumption, this paper examined the impact of CI on network dynamics in light of brain imaging findings related to psychosis. Using brain-inspired graphical models, we show that CI causes overconfidence and overactivation most specifically at the level of connector hubs (e.g., nodes with many connections allowing integration across networks). By also measuring functional connectivity in these graphs, we provide evidence that CI is able to predict specific changes in modularity known to be associated with schizophrenia. Altogether, these findings suggest that the CI framework may facilitate behavioral and neural research on the multifaceted nature of psychosis.
Grégory Dumont, Alberto Pérez-Cervera, Boris Gutkin (2022). A framework for macroscopic phase-resetting curves for generalised spiking neural networks. Plos Computational Biology. 10.1371/journal.pcbi.1010363
Brain rhythms emerge from synchronization among interconnected spiking neurons. Key properties of such rhythms can be gleaned from the phase-resetting curve (PRC). Inferring the PRC and developing a systematic phase reduction theory for large-scale brain rhythms remains an outstanding challenge. Here we present a theoretical framework and methodology to compute the PRC of generic spiking networks with emergent collective oscillations. We adopt a renewal approach where neurons are described by the time since their last action potential, a description that can reproduce the dynamical feature of many cell types. For a sufficiently large number of neurons, the network dynamics are well captured by a continuity equation known as the refractory density equation. We develop an adjoint method for this equation giving a semi-analytical expression of the infinitesimal PRC. We confirm the validity of our framework for specific examples of neural networks. Our theoretical framework can link key biological properties at the individual neuron scale and the macroscopic oscillatory network properties. Beyond spiking networks, the approach is applicable to a broad class of systems that can be described by renewal processes.
Else Eising, Nazanin Mirza-Schreiber, Eveline L. de Zeeuw, ..., .., Franck Ramus, ... Et Al(2022). Genome-wide analyses of individual differences in quantitatively assessed reading- and language-related skills in up to 34,000 people. PNAS, 19(35), e2202764119. doi:10.1073/pnas.2202764119
The use of spoken and written language is a fundamental human capacity. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30 to 80% depending on the trait. The genetic architecture is complex, heterogeneous, and multifactorial, but investigations of contributions of single-nucleotide polymorphisms (SNPs) were thus far underpowered. We present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures (word reading, nonword reading, spelling, phoneme awareness, and nonword repetition) in samples of 13,633 to 33,959 participants aged 5 to 26 y. We identified genome-wide significant association with word reading (rs11208009, P = 1.098 × 10−8) at a locus that has not been associated with intelligence or educational attainment. All five reading-/language-related traits showed robust SNP heritability, accounting for 13 to 26% of trait variability. Genomic structural equation modeling revealed a shared genetic factor explaining most of the variation in word/nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence, and educational attainment. A multivariate GWAS of word/nonword reading, spelling, and phoneme awareness maximized power for follow-up investigation. Genetic correlation analysis with neuroimaging traits identified an association with the surface area of the banks of the left superior temporal sulcus, a brain region linked to the processing of spoken and written language. Heritability was enriched for genomic elements regulating gene expression in the fetal brain and in chromosomal regions that are depleted of Neanderthal variants. Together, these results provide avenues for deciphering the biological underpinnings of uniquely human traits.
Henry Farrell, Hugo Mercier & Melissa Schwartzberg (2022). Analytical Democratic Theory: A Microfoundational Approach. American Political Science Review, 1-6. doi:10.1017/S0003055422000715
A prominent and publicly influential literature challenges the quality of democratic decision making, drawing on political science findings with specific claims about the ubiquity of cognitive bias to lament citizens’ incompetence. A competing literature in democratic theory defends the wisdom of crowds, drawing on a cluster of models in support of the capacity of ordinary citizens to produce correct outcomes. In this Letter, we draw on recent findings in psychology to demonstrate that the former literature is based on outdated and erroneous claims and that the latter is overly sanguine about the circumstances that yield reliable collective decision making. By contrast, “interactionist” scholarship shows how individual-level biases are not devastating for group problem solving, given appropriate conditions. This provides possible microfoundations for a broader research agenda similar to that implemented by Elinor Ostrom and her colleagues on common-good provision, investigating how different group structures are associated with both success and failure in democratic decision making. This agenda would have implications for both democratic theory and democratic practice.
Víctor Fernández‐Castro, Elisabeth Pacherie (2022). Commitments and the sense of joint agency. Mind & Language. doi:10.1111/mila.12433
The purpose of this article is to explore the role commitments may play in shaping our sense of joint agency. First, we propose that commitments may contribute to the generation of the sense of joint agency by stabilizing expectations and improving predictability. Second, we argue that commitments have a normative element that may bolster an agent's sense of control over the joint action and help counterbalance the potentially disruptive effects of asymmetries among agents. Finally, we discuss how commitments may contribute to make acting jointly emotionally rewarding, both by improving coordination and by inducing or reinforcing the circumstances under which shared emotions emerge among co‐agents.
Charlotte Gallezot, Rachid Riad, Hadrien Titeux, Laurie Lemoine, Justine Montillot, Agnes Sliwinski, Jennifer Hamet Bagnou, Xuan Nga Cao, Katia Youssov, Emmanuel Dupoux, Anne-Catherine Bachoud Levi (2022). Emotion expression through spoken language in Huntington Disease. Cortex. ISSN 0010-9452. doi:10.1016/j.cortex.2022.05.024.
Patients with Huntington’s disease suffer from disturbances in the perception of emotions; they do not correctly read the body, vocal and facial expressions of others. With regard to the expression of emotions, it has been shown that they are impaired in expressing emotions through face but up until now, little research has been conducted about their ability to express emotions through spoken language. To better understand emotion production in both voice and language in Huntington’s Disease (HD), we tested 115 individuals: 68 patients (HD), 22 participants carrying the mutant HD gene without any motor symptoms (pre-manifest HD), and 25 controls in a single-centre prospective observational follow-up study. Participants were recorded in interviews in which they were asked to recall sad, angry, happy, and neutral stories. Emotion expression through voice and language was investigated by comparing the identifiability of emotions expressed by controls, preHD and HD patients in these interviews. To assess separately vocal and linguistic expression of emotions in a blind design, we used machine learning models instead of a human jury performing a forced-choice recognition test. Results from this study showed that patients with HD had difficulty expressing emotions through both voice and language compared to preHD participants and controls, who behaved similarly and above chance. In addition, we did not find any differences in expression of emotions between preHD and healthy controls. We further validated our newly proposed methodology with a human jury on the speech produced by the controls. These results are consistent with the hypothesis that emotional deficits in HD are caused by impaired sensori-motor representations of emotions, in line with embodied cognition theories. This study also shows how machine learning models can be leveraged to assess emotion expression in a blind and reproducible way.
Inês Completo Guerreiro, Zhenglin Gu, Jerrel L. Yakel, & Boris Gutkin (2022). Recurring Cholinergic Inputs Induce Local Hippocampal Plasticity through Feedforward Disinhibition. eNeuro. doi:10.1523/ENEURO.0389-21.2022
The CA1 pyramidal neurons are embedded in an intricate local circuitry that contains a variety of interneurons. The roles these interneurons play in the regulation of the excitatory synaptic plasticity remains largely understudied. Recent experiments showed that recurring cholinergic activation of α7 nACh receptors expressed in oriens-lacunosum-moleculare (OLMα2) interneurons can directly induce LTP in Schaffer collateral (SC)–CA1 synapses. Here, we pair in vitro studies with biophysically based modeling to uncover the underlying mechanisms. According to our model, α7 nAChR activation increases OLM GABAergic activity. This results in the inhibition of the fast-spiking interneurons that provide feedforward inhibition onto CA1 pyramidal neurons. This disinhibition, paired with tightly timed SC stimulation, can induce potentiation at the excitatory synapses of CA1 pyramidal neurons. Our work details the role of cholinergic modulation in disinhibition-induced hippocampal plasticity. It relates the timing of cholinergic pairing found experimentally in previous studies with the timing between disinhibition and hippocampal stimulation necessary to induce potentiation and suggests the dynamics of the involved interneurons play a crucial role in determining this timing.
We use a combination of experiments and mechanistic modeling to uncover the key role for cholinergic neuromodulation of feedforward disinhibitory circuits in regulating hippocampal plasticity. We found that cholinergic activation of α7 nAChR on α7 nACh receptors expressed in oriens-lacunosum-moleculare interneurons, when tightly paired with stimulation of the Schaffer collaterals, can cancel feedforward inhibition onto CA1 pyramidal cells, enabling the potentiation of the SC–CA1 synapse. Our work details how cholinergic action on GABAergic interneurons can tightly regulate the excitability and plasticity of the hippocampal network, unraveling the intricate interplay of the hierarchal inhibitory circuitry and cholinergic neuromodulation as a mechanism for hippocampal plasticity.
Ava Guez, Manuela Piazza, Pedro Pinheiro-Chagas, Hugo Peyre, Barbara Heude & Franck Ramus (2022). Preschool language and visuospatial skills respectively predict multiplication and addition/subtraction skills in middle school children. Developmental science, e13316. doi:10.1111/desc.13316
A converging body of evidence from neuroimaging, behavioral and neuropsychology studies suggests that different arithmetic operations rely on distinct neuro-cognitive processes: while addition and subtraction may rely more on visuospatial reasoning, multiplication would depend more on verbal abilities. In this paper, we tested this hypothesis in a longitudinal study measuring language and visuospatial skills in 358 preschoolers, and testing their mental calculation skills at the beginning of middle school. Language skills at 5.5 years significantly predicted multiplication, but not addition nor subtraction scores at 11.5 years. Conversely, early visuospatial skills predicted addition and subtraction, but not multiplication scores. These results provide strong support for the existence of a double dissociation in mental arithmetic operations, and demonstrate the existence of long-lasting links between language/visuospatial skills and specific calculation abilities.
1. Using structural equation modelling, we analyzed longitudinal data from 358 children.
2. Language skills in preschool significantly predicted multiplication, but not addition nor subtraction scores in middle school. The reverse was true for preschool visuo-spatial skills.
3. Importantly, this pattern remained unchanged when we controlled addition and multiplication operations for overall difficulty and for the magnitude of the operands.
4. These results provide strong support for the existence of a double dissociation in mental arithmetic operations.
Pierre-Carl Langlais, Jean-Baptiste Camps, Nicolas Baumard, Olivier Morin. From Roland to Conan: First results on the corpus of French literary fictions (1050-1920). Digital Humanities 2022 (DH2022), Jul 2022, Tokyo, Japan. halshs-03715836
Tianqiang Liu, Michel Thiebaut de Schotten, Irene Altarelli, Franck Ramus, Jingjing Zhao (2022). Neural dissociation of visual attention span and phonological deficits in developmental dyslexia: A hub-based white matter network analysis. Hum Brain Mapp. doi: 10.1002/hbm.25997. PMID: 35808916.
It has been suggested that developmental dyslexia may have two dissociable causes— a phonological deficit and a visual attention span (VAS) deficit. Yet, neural evidence for such a dissociation is still lacking. This study adopted a data-driven approach to white matter network analysis to explore hubs and hub-related networks correspond- ing to VAS and phonological accuracy in a group of French dyslexic children aged from 9 to 14 years. A double dissociation in brain-behavior relations was observed. Structural connectivity of the occipital-parietal network surrounding the left superior occipital gyrus hub accounted for individual differences in dyslexic children's VAS, but not in phonological processing accuracy. In contrast, structural connectivity of two networks: the temporal–parietal-occipital network surrounding the left middle temporal gyrus hub and the frontal network surrounding the left medial orbital supe- rior frontal gyrus hub, accounted for individual differences in dyslexic children's pho- nological processing accuracy, but not in VAS. Our findings provide evidence in favor of distinct neural circuits corresponding to VAS and phonological deficits in develop- mental dyslexia. The study points to connectivity-constrained white matter subnet- work dysfunction as a key principle for understanding individual differences of cognitive deficits in developmental dyslexia.
Shannon M. Locke, Michael S. Landy, Pascal Mamassian (2022). Suprathreshold perceptual decisions constrain models of confidence. PLoS Comput Biol. 18(7):e1010318. doi: 10.1371/journal.pcbi.1010318. Epub ahead of print. PMID: 35895747.
Perceptual confidence is an important internal signal about the certainty of our decisions and there is a substantial debate on how it is computed. We highlight three confidence metric types from the literature: observers either use 1) the full probability distribution to compute probability correct (Probability metrics), 2) point estimates from the perceptual decision process to estimate uncertainty (Evidence-Strength metrics), or 3) heuristic confidence from stimulus-based cues to uncertainty (Heuristic metrics). These metrics are rarely tested against one another, so we examined models of all three types on a suprathreshold spatial discrimination task. Observers were shown a cloud of dots sampled from a dot generating distribution and judged if the mean of the distribution was left or right of centre. In addition to varying the horizontal position of the mean, there were two sensory uncertainty manipulations: the number of dots sampled and the spread of the generating distribution. After every two perceptual decisions, observers made a confidence forced-choice judgement whether they were more confident in the first or second decision. Model results showed that the majority of observers were best-fit by either: 1) the Heuristic model, which used dot cloud position, spread, and number of dots as cues; or 2) an Evidence-Strength model, which computed the distance between the sensory measurement and discrimination criterion, scaled according to sensory uncertainty. An accidental repetition of some sessions also allowed for the measurement of confidence agreement for identical pairs of stimuli. This N-pass analysis revealed that human observers were more consistent than their best-fitting model would predict, indicating there are still aspects of confidence that are not captured by our modelling. As such, we propose confidence agreement as a useful technique for computational studies of confidence. Taken together, these findings highlight the idiosyncratic nature of confidence computations for complex decision contexts and the need to consider different potential metrics and transformations in the confidence computation.
Manuel Mello, Lennie Dupont, Tahnée Engelen, Adriano Acciarino, Aline W. de Borst & Béatrice de Gelder (2022). The influence of body expression, group affiliation and threat proximity on interactions in virtual reality. Current Research in Behavioral Sciences, 3, 100075. doi:10.1016/j.crbeha.2022.100075
Social threat requires fast adaptive reactions. One prominent threat-coping behavior present in both humans and other species is freezing, of which heart rate deceleration and reduced postural mobility are two key components. Previous studies mostly focused on freezing reactions in rodents, but now virtual reality offers unique possibilities for controlled and ecologically valid lab-based experiments in humans. This immersive virtual reality study examined how several understudied aspects of social threat, i.e., emotional body expressions, group affiliation, and physical distance from the potential threat, affect freezing behavior in humans. We hypothesized that freezing would be observed for approaching aggressive-looking virtual characters and for virtual characters situated in close proximity. Furthermore, we predicted an enhanced freezing response for approaching, aggressive outgroup members. As expected, reduced heart rate and postural mobility were observed in participants when they faced aggressive-looking and proximal virtual characters. Freezing was also observed for ingroup aggression, specifically when participants were embodied in a black-skinned virtual body and faced black-skinned aggressive and proximal virtual characters. Our results provide novel evidence on the social factors that elicit freezing behavior in humans. Importantly, this evidence is based on a highly ecological virtual reality paradigm that enables people to experience a threatening scenario “as if” it was actually happening to them.
Marion Rouault, Aurélien Weiss, Junseok K Lee, Jan Drugowitsch, Valerian Chambon, Valentin Wyart (2022). Controllability boosts neural and cognitive signatures of changes-of-mind in uncertain environments. eLife. 11:e75038. doi:10.7554/eLife.75038
In uncertain environments, seeking information about alternative choice options is essential for adaptive learning and decision-making. However, information seeking is usually confounded with changes-of-mind about the reliability of the preferred option. Here, we exploited the fact that information seeking requires control over which option to sample to isolate its behavioral and neurophysiological signatures. We found that changes-of-mind occurring with control require more evidence against the current option, are associated with reduced confidence, but are nevertheless more likely to be confirmed on the next decision. Multimodal neurophysiological recordings showed that these changes-of-mind are preceded by stronger activation of the dorsal attention network in magnetoencephalography, and followed by increased pupil-linked arousal during the presentation of decision outcomes. Together, these findings indicate that information seeking increases the saliency of evidence perceived as the direct consequence of one’s own actions.
Adrian Valente, Srdjan Ostojic, Jonathan Pillowb(2022). Probing the Relationship Between Latent Linear Dynamical Systems and Low-Rank Recurrent Neural Network Models. Neural Comput; 34 (9): 1871–1892 ; doi:10.1162/neco_a_01522
A large body of work has suggested that neural populations exhibit low-dimensional dynamics during behavior. However, there are a variety of different approaches for modeling low-dimensional neural population activity. One approach involves latent linear dynamical system (LDS) models, in which population activity is described by a projection of low-dimensional latent variables with linear dynamics. A second approach involves low-rank recurrent neural networks (RNNs), in which population activity arises directly from a low-dimensional projection of past activity. Although these two modeling approaches have strong similarities, they arise in different contexts and tend to have different domains of application. Here we examine the precise relationship between latent LDS models and linear low-rank RNNs. When can one model class be converted to the other, and vice versa? We show that latent LDS models can only be converted to RNNs in specific limit cases, due to the non-Markovian property of latent LDS models. Conversely, we show that linear RNNs can be mapped onto LDS models, with latent dimensionality at most twice the rank of the RNN. A surprising consequence of our results is that a partially observed RNN is better represented by an LDS model than by an RNN consisting of only observed units.
Evénements grand public à venir à l'ENS-PSL
Samedi 15 et dimanche 16 octobre : l'ENS fête la science !
Les départements scientifiques de l'ENS-PSL ouvriront leurs portes les 15 et 16 octobre. Au programme : mini conférences, activités scientifiques, ateliers, expositions, visites de laboratoires. Le programme sera dévoilé à la rentrée 2022. Restez connecté.e.s !
Du 12 au 15 octobre, PSL fête la science !
Cette année le thème de la fête de la science est la transition climatique. Du 12 au 15 octobre, PSL - Partage des Savoirs proposera aux chercheurs·es de l’Université de s’installer à l’Académie du Climat où auront lieu conférences et ateliers de médiation scientifique à destination du grand public. Infos à venir sur le site internet de l'Université-PSL. Programme à venir.
Ces événements sont gratuits et ouverts à toutes et à tous.
Agenda des événements du DEC
Retrouvez tous les événements organisés par le DEC sur l'agenda du département.
Un grand nombre de séminaires et de conférences données par les chercheur.ses du DEC ou par nos invité.e.s sont accessibles sur :
- notre chaîne youtube,
- le site des Savoirs de l'ENS,
- la chaîne youtube de l'école