Title to be Announced

Jean-Marie Besnier
CREA, Ecole Polytechnique

Developing cerebral architecture for multiple acquisitions and adaptations by young children

Yves Burnod
LIF, Faculté de Médecine Pierre et Marie Curie - Site Pitié-Salpétrière

Young children acquire multiple new sensory-motor abilities and cognitive capacities in a complex and uncertain world. The neural basis of such capacities and abilities have been explored by thousands of brain imaging studies. We have performed a systematic analysis of a database collecting these results to reveal a basic set of brain functional networks which control these abilities and capacities. We explore how the developing connectome which controls the maturation of new functional networks can guide the multiple acquisitions and adaptations by young children during the interactions with a large variety of environments. We will discuss how the theory of Viability can help to model this process.

A model of viability for a monetary economy

Jean Cartelier
Université de Paris X-Nanterre

For at least two centuries the main bone of contention among economists was the stability properties of a market economy. Recurrent crisis, business cycles, long-term oscillations of economic activity were as many occasions to elaborate optimistic or pessimistic arguments. The domination of Arrow-Debreu model of competitive general equilibrium during the 1950's and 1960's allowed economists to make their points more precise. Global asymptotic stability was an area of intensive studies and debates. As it is well-known negative results due to Sonnenschein, Debreu, Mantel, Saari and others put an end to that study during the 1970's. Nowadays, academic theoreticians have no longer concern in out-ofequilibrium positions and in global stability. Self-regulation of a market economy (the traditional and most fundamental question of political economy for centuries) has disappeared on the agenda. Even the recent global financial crisis. although present in innumerable public debates, has not changed anything in the methods of academic theory. Viability approach opens new perspectives in the field. But it raises also difficult problems of interpretation. Equilibrium, a central notion in eonomic theory, has probably to be thought anew. The same is true for the idea of self-regulation of a market economy. In order to illustrate what precedes, a model of a pure market economy is presented and discussed.

Antifragility and tinkering in biology (and in economy). Flexibility is an efficient epigenetic solution for risk management

Antoine Danchin
CEA/Génoscope, Evry

The notion of antifragility, an attribute that allows systems to thrive in an unpredictable world, was recently proposed by Nassim Taleb in the context of financial exchanges. Contrasting reproduction (making a similar copy) with replication (make an identical copy), we show that the management of populations of biological objects similar to each other, but sensitive to the state of the environment, can result in an antifragile behaviour. The discussion will be illustrated by the example of natural ageing, as opposed to the inevitable unfolding of senescence and death.

Application of Viability Theory to Macroeconomics Growth Theory and to Financial Modelling

Vladimir Lozève
Natixis, Paris

Applied Mathematical Modelling in Macroeconomics is based and computed following statistical ethodology. For instance the mainstream Growth models are mainly descriptive, there is no in-built feedback loop regulating the system evolution. Therefore the long term dynamics is divergent. Financial modelling is a branch of stochastic calculus mainly designed to compute the mathematical expectation of the value of an asset which is a measure of central tendency. That kind of models offers very little pertinent information about the "borderline" of the system as the ...Krach. In Macroeconomics Viability Theory could enable us to introduce the long term viable dynamics and the long term cyclicity of the macroeconomics growth.

In Financial Theory Viability Theory could enable us to model the contingent uncertainty of the extreme evolution of financial assets.

Viabilist and Tychastic Approaches to Guaranteed ALM Problem

Olivier Dordan¹ and Luxi Chen²
1. U. Bordeaux 22. VIMADES

This study reconsiders the problem of hedging a liability by a portfolio made of a riskless asset and an underlying. Given a process forecasting the lower bounds of the returns of the underlying, the software computes both the Minimum Guaranteed Investment (or Solveny Requirement Capital), and a management rule VPPI, (Viabilist Portfolio Performance and Insurance) ensuring that, at each date, the value of the portfolio is "always": exceeding liabilities. Examples of management during the crisis of the summer 2011 are provided.

"Embryonic development as a viabiity screen for potential evolutionary innovations

Nadine Peyrieras
Institut de Neurobiologie Alfred Fessard, Gif-sur-Yvette

Epistemic viability and the dynamics of acceptances

Joëlle Proust
Institut Jean Nicod, Paris

Intelligent agency requires an ability to control and monitor one's cognitive states, e.g. retrieve memories, check one's perceptions or one's utterances. The aim of cognitive control is to acquire cognitively reliable properties, such as retrieving a correct answer. Intelligent agents in realistic settings, however, need to track other epistemic norms beyond accuracy, such as the comprehensiveness of a list, the intelligibility of a text, the coherence of a story, the relevance of a remark, or the consensuality of a claim. Experimental studies in metacognition suggest that such norms are indeed used by human and some non-human agents to control and monitor their own cognitive performance. Viability theory offers a model of the dynamic constraints that apply to the various forms of self-evaluation, able to explain why sensitivity to epistemic norms differs with ages.

Biodiversity evaluation, modelling and viability

Jean-Philippe Terreaux
Irstea

The biodiversity, if only for the ecosystem services it allows, but not exclusively, is at the source of different values for the present and future generations, values which can be taken into account thanks to the representation of the world which is implicit in our decision models.

So economic considerations in connection with the optimization of the natural resources usage or exploitation can be integrated to estimate the biodiversity value in monetary terms and enable deciding for example between economic development and nature or species conservation.

Another representation of the world and of the decision making, allowed by the theory of the viability, leads to quite another approach, looking for the achievement of objectives which seem to better correspond to the driving of the human affairs, and thereby, which is more acceptable for decision making.