Distinct neurocomputational mechanisms support informational and socially normative conformity

A change of mind in response to social influence could be driven by informational conformity to increase accuracy, or by normative conformity to comply with social norms such as reciprocity. Disentangling the behavioural, cognitive, and neurobiological underpinnings of informational and normative conformity have proven elusive. Here, participants underwent fMRI while performing a perceptual task that involved both advice-taking and advice-giving to human and computer partners. The concurrent inclusion of 2 different social roles and 2 different social partners revealed distinct behavioural and neural markers for informational and normative conformity. Dorsal anterior cingulate cortex (dACC) BOLD response tracked informational conformity towards both human and computer but tracked normative conformity only when interacting with humans. A network of brain areas (dorsomedial prefrontal cortex (dmPFC) and temporoparietal junction (TPJ)) that tracked normative conformity increased their functional coupling with the dACC when interacting with humans. These findings enable differentiating the neural mechanisms by which different types of conformity shape social changes of mind

Modeling of Sediment Transport and Turbidity Maximum in the Gironde Estuaries (France) by Single- and Two-Phase Approaches

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Knowing Ourselves Together: The Cultural Origins of Metacognition

Metacognition – the ability to represent, monitor and control ongoing cognitive processes – helps us perform many tasks, both when acting alone and when working with others. While metacognition is adaptive, and found in other animals, we should not assume that all human forms of metacognition are gene-based adaptations. Instead, some forms may have a social origin, including the discrimination, interpretation, and broadcasting of metacognitive representations. There is evidence that each of these abilities depends on cultural learning and therefore that cultural selection might shape human metacognition. The cultural origins hypothesis is a plausible and testable alternative that directs us towards a substantial new programme of research

Together, Slowly but Surely: The Role of Social Interaction and Feedback on the Build-Up of Benefit in Collective Decision-Making

That objective reference is necessary for formation of reliable beliefs about the external world is almost axiomatic. However, Condorcet (1785) suggested that purely subjective information—if shared and combined via social interaction—is enough for accurate understanding of the external world. We asked if social interaction and objective reference contribute differently to the formation and build-up of collective perceptual beliefs. In three experiments, dyads made individual and collective perceptual decisions in a two-interval, forced-choice, visual search task. In Experiment 1, participants negotiated their collective decisions with each other verbally and received feedback about accuracy at the end of each trial. In Experiment 2, feedback was not given. In Experiment 3, communication was not allowed but feedback was provided. Social interaction (Experiments 1 and 2 vs. 3) resulted in a significant collective benefit in perceptual decisions. When feedback was not available a collective benefit was not initially obtained but emerged through practice to the extent that in the second half of the experiments, collective benefits obtained with (Experiment 1) and without (Experiment 2) feedback were robust and statistically indistinguishable. Taken together, this work demonstrates that social interaction was necessary for build-up of reliable collaborative benefit, whereas objective reference only accelerated the process but—given enough opportunity for practice—was not necessary for building up successful cooperation

PREDICTION AND VALIDATION FOR THE AERODYNAMIC NOISE OF HIGH-SPEED TRAIN POWER CAR

The aerodynamic noise of high-speed train power car was investigated in this article. The full-scale power car was first modeled, and the external steady flow field was computed by a realizable k-ε turbulence model. The aerodynamic noise sources of the power car surface and the external transient flow field were then calculated by broadband noise source model and large eddy simulation (LES) model, respectively. The static pressures on the train surface were obtained from the results of the transient model. Considering the transient flow field, the far-field aerodynamic noise generated by the power car was finally derived from Lighthill-Curle theory. It was validated by means of on-line tests that have been performed along a real high-speed railway line. Through comparisons between simulations and measurements, it is shown that the simulation model gives reliable aerodynamic noise predictions. We foresee numerous applications for modeling and control of the aerodynamic noise in high-speed train

A Two Phase Numerical Model For The Water Injection Dredging (WID) Technology: An Unified Formulation For Continuum Mechanic

Accurate simulation of the sediment processes at the vicinity of the sediment bed/water interface is still very difficult because of the multi-physic character of the problem. A soil is a continuum and porous media having solid properties such as elasticity and plasticity. It is usually considered as impermeable boundary which could evolve through erosion and deposition fluxes. Flow characteristics close to the liquid-bed interface are poorly described by soil mechanics and rheological characteristics of the soil are usually neglected by fluid mechanics. In order to account for the flow domain as a whole, extending from the substratum up to the water surface as a continuum body, in which all physical phenomenon such as suspension, hindered settling, consolidation, erosion and re-suspension, could be taken in consideration, a unified approach of continuum mechanic should be applied. This is why we propose herein a more general model, which does not split regions. This unified approach enables the description of the ‘liquid like’ or/and ‘solid like’ behaviour. This paper presents new development of the two phase Eulerian-Eulerian NSMP (Navier-Stokes Multi-Phase) code. The new development consists in computing a solid and elastic stress following the procedure by Greenshield and Weller (2005) and a specific treatment for the liquid-like to solid-like transition. The new model is validated against laboratory experiment reproducing the test of Water injection dredging by Badr et al. (2013). Here we consider the experimental configuration by Badr et al. (2013) which consists in a granular (non-cohesive) bed subjected to a vertical impinging jet in a 2D geometry (Hele Shaw cell, 50cm height, 20cm wide with 3.2cm gap). A comparison between the results obtained by the present model with the previous studies (Hanson and Cook, 2004; Rajaratnam and Mazurek, 2005) is done

Statistical Effects in the Multistream Model for Quantum Plasmas

A statistical multistream description of quantum plasmas is formulated, using the Wigner-Poisson system as dynamical equations. A linear stability analysis of this system is carried out, and it is shown that a Landau-like damping of plane wave perturbations occurs due to the broadening of the background Wigner function that arises as a consequence of statistical variations of the wave function phase. The Landau-like damping is shown to suppress instabilities of the one- and two-stream type.Comment: 5 page