Graceful Forgetting II. Data as a Process

Data are rapidly growing in size and importance for society, a trend motivated by their enabling power. The accumulation of new data, sustained by progress in technology, leads to a boundless expansion of stored data, in some cases with an exponential increase in the accrual rate itself. Massive data are hard to process, transmit, store, and exploit, and it is particularly hard to keep abreast of the data store as a whole. This paper distinguishes three phases in the life of data: acquisition, curation, and exploitation. Each involves a distinct process, that may be separated from the others in time, with a different set of priorities. The function of the second phase, curation, is to maximize the future value of the data given limited storage. I argue that this requires that (a) the data take the form of summary statistics and (b) these statistics follow an endless process of rescaling. The summary may be more compact than the original data, but its data structure is more complex and it requires an on-going computational process that is much more sophisticated than mere storage. Rescaling results in dimensionality reduction that may be beneficial for learning, but that must be carefully controlled to preserve relevance. Rescaling may be tuned based on feedback from usage, with the proviso that our memory of the past serves the future, the needs of which are not fully known.Comment: 30 pages, 17 figure

Biotechnology policy : Can France move from centralized decision-making to citizen's gouvernance ?

International audienceIn a traditionally technocratic country such as France, the development of the life sciences has provoked a number of new questions both about the consequences of scientific research and about the ways of regulating it. Risks are no longer only material, they are perceived as ethical and social, and citizens are no longer ready to had over their control to technical experts. In the present paper we shall discuss this evolution, based on interview and focus group material collected over the past six years in France

Human Auditory cortical processing of changes in interaural correlation

Sensitivity to the similarity of the acoustic waveforms at the two ears, and specifically to changes in similarity, is crucial to auditory scene analysis and extraction of objects from background. Here, we use the high temporal resolution of magnetoencephalography to investigate the dynamics of cortical processing of changes in interaural correlation, a measure of interaural similarity, and compare them with behavior. Stimuli are interaurally correlated or uncorrelated wideband noise, immediately followed by the same noise with intermediate degrees of interaural correlation. Behaviorally, listeners' sensitivity to changes in interaural correlation is asymmetrical. Listeners are faster and better at detecting transitions from correlated noise than transitions from uncorrelated noise. The cortical response to the change in correlation is characterized by an activation sequence starting from ∼50 ms after change. The strength of this response parallels behavioral performance: auditory cortical mechanisms are much less sensitive to transitions from uncorrelated noise than from correlated noise. In each case, sensitivity increases with interaural correlation difference. Brain responses to transitions from uncorrelated noise lag those from correlated noise by ∼80 ms, which may be the neural correlate of the observed behavioral response time differences. Importantly, we demonstrate differences in location and time course of neural processing: transitions from correlated noise are processed by a distinct neural population, and with greater speed, than transitions from uncorrelated noise

Scanning for oscillations

Objective. Oscillations are an important aspect of brain activity, but they often have a low signal- to-noise ratio (SNR) due to source-to-electrode mixing with competing brain activity and noise. Filtering can improve the SNR of narrowband signals, but it introduces ringing effects that may masquerade as genuine oscillations, leading to uncertainty as to the true oscillatory nature of the phenomena. Likewise, time–frequency analysis kernels have a temporal extent that blurs the time course of narrowband activity, introducing uncertainty as to timing and causal relations between events and/or frequency bands. Approach. Here, we propose a methodology that reveals narrowband activity within multichannel data such as electroencephalography, magnetoencephalography, electrocorticography or local field potential. The method exploits the between-channel correlation structure of the data to suppress competing sources by joint diagonalization of the covariance matrices of narrowband filtered and unfiltered data. Main results. Applied to synthetic and real data, the method effectively extracts narrowband components at unfavorable SNR. Significance. Oscillatory components of brain activity, including weak sources that are hard or impossible to observe using standard methods, can be detected and their time course plotted accurately. The method avoids the temporal artifacts of standard filtering and time–frequency analysis methods with which it remains complementary

Evaluer les pratiques interdisciplinaires

National audienceCet article rend compte de sept journées de séminaire consacrées à un problème crucial tant pour la communauté des scientifiques que pour le reste de la société, celui de l'évaluation des acteurs et des productions de la science, plus particulièrement lorsqu'ils tentent de s'affranchir des limites disciplinaires. Organisées au Collège de France au cours des mois de mars et d'avril 2004 dans le cadre des enseignements de l'EHESS, ces journées faisaient suite à une série de rencontres interdisciplinaires organisée par le Groupe de recherches “Comportement, représentation, culture” depuis 1998. L'objectif de ce groupe est de confronter des chercheurs et expériences disciplinaires des plus variées autour d'objets ou de thématiques de recherche similaires (sur les " Pratiques et Représentations de la Technique " en 2000 ou sur " La Naturalisation de l'Homme et des Animaux " en 2002, par exemple). Si à chaque fois cet objectif de croisement et d'enrichissement des perspectives de recherches fût rempli, la conjonction de points de vue souleva un certain nombre de problèmes liés à la confrontation disciplinaire, et en particulier à un aspect peu envisagé, voire écarté jusqu'à présent par les institutions, celui de l'évaluation. C'est pourquoi nous avions consacré l'ensemble du séminaire à cette question en 2004 – au plus fort du mouvement des chercheurs

Récit d'une traversée

Le récit d'un changement de discipline entre la physique des solides et la sociologie de la communication est l'occasion d'une réflexion sur l'interdisciplinarité, l'épistémologie comparée et sur les difficultés matérielles rencontrées dans une telle traversée de frontières. Seront ainsi abordés le débat empirique/théorique, le caractère collectif de l’activité de recherche, les liens entre objectivation, quantification et modélisation, mais aussi les relations entre le CNRS et l’université dans le domaine des sciences de l’information et de la communication.This is the story of a change of academic discipline, from solid state physics to sociology of communication, which allows us to think about interdisciplinarity, compared epistemology, as well as the material difficulties met when crossing such borders. We shall touch on the debate between empirical and theoretical approaches, collective research activity, the ties between objectifying, quantifying and modelling, as well as the relations between the CNRS and the University in the field of Communication studies

Lire le grand livre de la vie

Le 26 juin 2000, le décryptage quasi complet du génome humain a été annoncé lors d’une conférence de presse à grand spectacle, conjointement par un consortium public international, le Projet Génome Humain, et par une compagnie privée fondée en 1998 par le généticien Craig Venter, Celera Genomics. En février 2001, l’annonce a été répétée, avec tout autant d’éclat, à l’occasion de la publication des résultats dans les revues Science et Nature. Tous les principaux médias ont rapporté et largement commenté ces événements. L’analyse comparative des discours de la presse quotidienne française révèle différents modèles interprétatifs de leur portée : trente mille gènes font-ils un homme ? Les réponses diffèrent et leur analyse permet de cerner la manière dont la société française pense l’apport de la génétique à la compréhension de la vie humaine. Dans cet article, nous analysons de façon comparative les articles parus dans les principaux quotidiens français (La Croix, Le Figaro, L’ Humanité, Libération, Le Monde, Le Parisien) lors de ces deux annonces du décryptage du génome, en abordant tant les métaphores mobilisées autour du projet, l’infographie, les explications du contenu scientifique que les analyses de la portée de la découverte. Peu de journaux rappellent en effet à leurs lecteurs que l’homme n’est pas tout entier inscrit dans ses gènes, que son histoire et son environnement le marquent autant que son code génétique. Toujours d’actualité, la vieille querelle de l’inné et de l’acquis resurgit. Le sens même de ce qu’est l’ADN, support matériel d’une part plus ou moins grande de ce qui est transmis de génération en génération, diffère donc selon les journaux et selon les lectorats. La vision des chercheurs et la confiance qui peut ou doit leur être accordée, l’importance de l’aventure intellectuelle ou des applications concrètes et les risques potentiels entrent dans la composition de représentations différentes de cette « avancée » de la science. On trouve, dans les comptes rendus de ces annonces du décryptage, différentes philosophies de l’être humain. Les journaux populaires restent préoccupés par les perspectives eugénistes. Les journaux ayant de fortes références morales (quelles qu’elles soient, de L’Humanité à La Croix ou au Figaro) rappellent avec énergie le rôle de l’histoire et de l’environnement dans la formation de l’homme, là où d’autres, Libération en particulier, sont prêts à le voir inscrit dans ses gènes. Une grande diversité des discours médiatiques émerge donc, exprimant également des visions différentes de la science. Les quotidiens populaires ont systématiquement pris une certaine distance avec le monde scientifique, rappelant les interrogations d’ordre éthique que soulèvent leurs travaux. Cependant, ils ne constituent pas un bloc monolithique, Le Parisien étant en général plus complet et plus pondéré que son concurrent, France Soir. Les journaux dits d’élite se sont montrés plus proches des institutions, politiques ou scientifiques, plus prompts à accorder leur confiance aux chercheurs, avec là encore des nuances, le Figaro étant plus réservé que ses proches concurrents. Tous ces discours médiatiques portent les traces des interrogations et des hésitations d’une société face à des sciences du vivant qui interrogent et déplacent les limites de l’humanité.Deciphering the Great Book of Life  On 26 June 2000, in a spectacular press conference, the Human Genome Project, an international public consortium, and Celera Genomics, a private company founded in 1998 by the genetician Craig Venter jointly announced the nearly complete decoding of the human genome. The following year, in February 2001, the announcement was reiterated when the the results were published in the journals Science and Nature. All the main media reported and commented these events. The comparative analysis of the discourse of the French daily press reveals different interpretation of the meaning of the discovery. The variety of answers and their analysis throw light on how French society thinks the way genetics contribute to understanding human life. This article makes a comparative analysis of articles published in the major French daily newspapers (La Croix, Le Figaro, L’Humanité, Libération, Le Monde, Le Parisien) on these two announcements, of the metaphors mobilised around the project, the graphics, the scientific explanations as well as the analysis of the discovery’s implications. Few journals recalled that humans are not exclusively inscribed in their genes and that they are as marked by their history and their environment as by their genetic code. The old quarrel between the nature and nurture arises again : do 30000 genes really make a human being ? The very meaning of DNA, a transmission device from one generation to another, changes from one newspaper to another, from one readership to another. The vision of researchers and the trust they can or should be given, the importance of the intellectual adventure or the perspectives of applications or potential risks are part and parcel of the different representations of the “progress” of science. Reports of these announcements of the decoding contain different visions of the human being. Popular newspapers are preoccupied by eugenic perspectives. Papers with strong moral references (whether L’Humanité, La Croix or Le Figaro) energetically recall the role of history and environment in the genesis of man. Others Libération in particular, were more inclined to see humans inscribed in their genes. In summary, we have found a large diversity among the press discourse, also expressing different views of sciences. Popular newspapers have systematically taken a certain distance from the scientific world, recalling the ethical questions often raised by their work. However, they do not constitute a monolithic bloc, Le Parisien being generally more thorough and more balanced than its rival France Soir. The so called elite newspapers have shown themselves to be closer to the political and scientific institutions, quicker in showing trust in researchers, though with some nuances, Le Figaro being more reserved than its close rivals. All these media discourse carry traces of a society’s questions and hesitations when faced with the evolutions of life sciences that probe and shift the boundaries of humanity

O itinerário intelectual de Eliseo Verón na França

Eliseo Verón (1935-2014) foi um dos pesquisadores em ciência da informação e da comunicação dos mais respeitados na França, um dos mais ecléticos - e, sem dúvida, um dos mais exigentes. Ele manteve-se paradoxalmente marginal no meio acadêmico francês - e sua morte, vinte anos após o retorno à Argentina, só deu lugar na França a pequenas manifestações. Foi agora portanto aproveitar a ocasião para traçar algumas linhas de seu itinerário intelectual na França. Tratar-se de uma seleção pessoal, de um testemunho, longe de um real trabalho de história das ideias que permanece a ser feito.Eliseo Verón (1935-2014) was a major Latin-American but also French sociologist and semiotician who was the author of essential contributions to the feld of media research. Although his work has had a high impact in the French and Spanish-speaking areas, it is less well known to the Anglo-Saxon world

Cortical responses to natural speech reflect probabilistic phonotactics

Humans comprehend speech despite the various challenges of real-world environments, such as loud noise and mispronunciation. Our auditory system is robust to these thanks to the integration of the upcoming sensory input with prior knowledge and expectations built on language-specific regularities. One such regularity regards the permissible phoneme sequences, which determine the likelihood that a word belongs to a given language (phonotactic probability; “blick” is more likely to be an English word than “bnick”). Previous research suggested that violations of these rules modulate brain evoked responses such as the N400 and the late positive complex. Yet several fundamental questions remain unresolved, especially regarding the neural encoding and integration strategy of phonotactic information. Here, we used linear modelling approaches to assess the influence of phonotactic probabilities on the brain responses to narrative speech measured with non-invasive EEG. We found that the relationship between continuous speech and EEG responses is best described when the speech descriptor includes phonotactic probabilities. This provides us with a methodology to isolate and measure the brain responses to phonotactics using natural speech at the individual subject-level. Furthermore, such low-frequency signals showed the strongest speech-EEG interactions at latencies of 100-400 ms, supporting a pre-lexical role of phonotactic information