School for Advanced Studies in the Social Sciences

About: School for Advanced Studies in the Social Sciences is a facility organization based out in Villejuif, France. It is known for research contribution in the topics: Politics & Context (language use). The organization has 1230 authors who have published 2084 publications receiving 57740 citations. The organization is also known as: Ecole des Hautes Etudes en Sciences Sociales & EHESS.

A parsimonious approach for spatial transmission and heterogeneity in the COVID-19 propagation

Abstract: Raw data on the number of deaths at a country level generally indicate a spatially variable distribution of COVID-19 incidence. An important issue is whether this pattern is a consequence of environmental heterogeneities, such as the climatic conditions, during the course of the outbreak. Another fundamental issue is to understand the spatial spreading of COVID-19. To address these questions, we consider four candidate epidemiological models with varying complexity in terms of initial conditions, contact rates and non-local transmissions, and we fit them to French mortality data with a mixed probabilistic-ODE approach. Using statistical criteria, we select the model with non-local transmission corresponding to a diffusion on the graph of counties that depends on the geographic proximity, with time-dependent contact rate and spatially constant parameters. This suggests that in a geographically middle size centralized country such as France, once the epidemic is established, the effect of global processes such as restriction policies and sanitary measures overwhelms the effect of local factors. Additionally, this approach reveals the latent epidemiological dynamics including the local level of immunity, and allows us to evaluate the role of non-local interactions on the future spread of the disease.

The mark of bodily ownership

Abstract: Do bodily sensations include a distinctive experience of the body as of one's own? I am aware that this hand is mine. But is the sense of ownership of my hand manifested to me in a more primitive form than beliefs or judgements? Bermudez (2011) and Martin (1995) have recently argued in favour of a deflationary account of the sense of ownership, according to which there is nothing it feels like to experience one's body as of one's own, no felt 'myness' that goes over and above the mere experience of one's bodily properties. Here I present a series of counter-arguments against the deflationary conception of ownership. First, I will argue that there are belief-independent illusions of ownership. Secondly, I will show that one can have bodily sensations with no sense of ownership. I will then conclude that the notion of 'experience of ownership' is a good explanatory tool to account for these borderline situations

Directional performances with moving plaids: component-related and plaid-related processing modes coexist.

Abstract: A moving grating oriented ± 45° to the vertical can be perceived at choice as drifting along a left-right or up-down directional axis. When the drifting stimulus is presented alone, direction discrimination thresholds are independent of the specified response-axis. However, they strongly depend on it when the moving stimulus is superimposed on a vertical or horizontal stationary grating. Facilitation is always obtained when the drift direction of the intersections of the two gratings ('blobs') is collinear with the response-axis (i.e. when the orientations of the stationary grating and of the response-axis coincide), while inhibition is observed in the 'noncollinear' cases (i.e. when the orientations of the stationary grating and of the response-axis are orthogonal). These results are generalized in a series of reaction time (RT) experiments where the stimulus configuration described above was set at suprathreshold contrasts and where the orientation/direction of the drifting grating was variable. RT increased when the angle between the response-axis and the direction of the drifting grating increased (uncertainty effect), whether the test stimulus was presented alone, or superimposed on the stationary grating. The uncertainty effect was, however, significantly decreased under 'collinearity' conditions. The attenuation of the uncertainty effect was proportional with the velocity of the blobs and about equal in amount to the RT decrease obtained through the manipulation of the velocity of the drifting grating when presented alone (velocity effect). This observation strongly suggests that both component- and blob/plaid-related information contribute to the directional perception of a compound stimulus and that they sum algebraically.

The growth equation of cities

Abstract: The science of cities seeks to understand and explain regularities observed in the world's major urban systems. Modelling the population evolution of cities is at the core of this science and of all urban studies. Quantitatively, the most fundamental problem is to understand the hierarchical organization of cities and the statistical occurrence of megacities, first thought to be described by a universal law due to Zipf, but whose validity has been challenged by recent empirical studies. A theoretical model must also be able to explain the relatively frequent rises and falls of cities and civilizations, and despite many attempts these fundamental questions have not been satisfactorily answered yet. Here we fill this gap by introducing a new kind of stochastic equation for modelling population growth in cities, which we construct from an empirical analysis of recent datasets (for Canada, France, UK and USA) that reveals how rare but large interurban migratory shocks dominate city growth. This equation predicts a complex shape for the city distribution and shows that Zipf's law does not hold in general due to finite-time effects, implying a more complex organization of cities. It also predicts the existence of multiple temporal variations in the city hierarchy, in agreement with observations. Our result underlines the importance of rare events in the evolution of complex systems and at a more practical level in urban planning.