Sensorimotor learning in a Bayesian computational model of speech communication

International audienceAlthough sensorimotor exploration is a basic process within child development, clear views on the underlying computational processes remain challenging. We propose to compare eight algorithms for sensorimotor exploration, based on three components: " accommodation " performing a compromise between goal babbling and social guidance by a master, " local extrapolation " simulating local exploration of the sensorimotor space to achieve motor generalizations and " idiosyncratic babbling " which favors already explored motor commands when they are efficient. We will show that a mix of these three components offers a good compromise enabling efficient learning while reducing exploration as much as possible

Modeling the concurrent development of speech perception and production in a Bayesian framework: COSMO, a Bayesian computational model of speech communication: Assessing the role of sensory vs. motor knowledge in speech perception

International audienceIt is now widely accepted that there is a functional relationship between the speech perception and production systems in the human brain. However, the precise mechanisms and role of this relationship still remain debated. The question of invariance and robustness in categorization are set at the center of the debate: how is stable information extracted from the variable sensory input in order to achieve speech comprehension? In this context, auditory (resp. motor, perceptuo-motor) theories propose that speech is categorized thanks to auditory (resp. motor, perceptuo-motor) processes. However, experimental evidence is still scarce and does not allow to clearly distinguish between the current theories and determine whether invariance in speech perception is of an auditory or motor type. This is why we developed COSMO, a Bayesian model comparing sensory and motor processes in the form of probability distributions which enable both theoretical developments and quantitative simulations. A first significant result in COSMO is an indistinguishability theorem: it is only by simulations of adverse conditions or partial learning that the specificity of sensory vs. motor processing can emerge and provide a basis for evaluation of the specific role of each sub-system. We present the COSMO model, and how its sensory and motor sub-systems are learned, then we describe simulations exploring the way these sub-systems differ during speech categorization. We discuss the experimental results in the light of a “narrowband vs. wideband” interpretation: the sensory sub-system is more precisely tuned to the frequently learned sensory input and hence more efficient in recognizing these inputs, providing a “narrowband” system. Conversely, the motor sub-system is less accurate to recognize learned sensory inputs but it has better generalization properties, making it more robust to unexpected variability which would provide it with “wideband” characteristics

Assessing Idiosyncrasies in a Bayesian Model of Speech Communication

International audienceAlthough speakers of one specific language share the same phoneme representations, their productions can differ. We propose to investigate the development of these differences in production , called idiosyncrasies, by using a Bayesian model of communication. Supposing that idiosyncrasies appear during the development of the motor system, we present two versions of the motor learning phase, both based on the guidance of an agent master: " a repetition model " where agents try to imitate the sounds produced by the master and " a communication model " where agents try to replicate the phonemes produced by the master. Our experimental results show that only the " communication model " provides production idiosyncrasies, suggesting that idiosyncrasies are a natural output of a motor learning process based on a communicative goal

Sensorimotor learning in a Bayesian computational model of speech communication

International audienceAlthough sensorimotor exploration is a basic process within child development, clear views on the underlying computational processes remain challenging. We propose to compare eight algorithms for sensorimotor exploration, based on three components: " accommodation " performing a compromise between goal babbling and social guidance by a master, " local extrapolation " simulating local exploration of the sensorimotor space to achieve motor generalizations and " idiosyncratic babbling " which favors already explored motor commands when they are efficient. We will show that a mix of these three components offers a good compromise enabling efficient learning while reducing exploration as much as possible

Phonology in the mirror: Comment on "Towards a Computational Comparative Neuroprimatology: Framing the language-ready brain" by Michael A. Arbib

International audienceThe contribution by M.A. Arbib over the years and as it appears summarized and conceptualized in this paper is admirable, extremely impressive, and very convincing in many aspects. A key value of this work is that it systematically attempts to introduce formal conceptualization and modeling in the reasoning about facts and interpretations

Does the commercialization of sport has a decisive influence on the success of social sporting projects? : shown at the Dortmund fan project

Die Kommerzialisierung des Sports hängt stark von dem Einfluss der Medien, der Politik und vom gesellschaftlichen Interesse ab. Erkannt wurde die Werbewirksamkeit des Fußballsports in den 80er Jahren. Deutlich zeichnet sich eine dynamische Entwicklung in der Vermarktung des Sports ab. Zeitsynchron ergab sich durch die Tendenz zur erhöhten Gewaltbereitschaft in den Fußballstadien die Notwendigkeit von sozialsportiven Projekten. Verbände und Organisationen erkannten in der Entwicklung des Zuschauerverhaltens zunehmend die Gefahr für das positive Image des Fußballs. Dieser Problematik wurde durch die Schaffung von Fanprojekten entgegen gewirkt. Nur durch eine nachhaltige Ausrichtung und einer kontinuierlichen Weiterentwicklung können diese dauerhaft bestehen. Analysiert wird am Beispiel des Dortmunder Fan-Projekts, wie die Kommerzialisierung des Fußballsports dazu beiträgt, sozialsportive Projekte erfolgreich umzusetzen. Durch Literaturanalyse und ein Experteninterview wird die These der Arbeit unterstützt, dass die Kommerzialisierung des Sports direkten Einfluss auf sozialsportive Projekte hat

The fenugreek odor of Lactarius helvus

International audienceThe odor of Lactarius helvus (Fr.: Fr.) Fr. (Russulales, Russulaceae) has been described as a strong spicy smell reminiscent of chicory and fenugreek. Lactarius helvus was investigated for volatile compounds by GC/MS. The volatile components proportion corresponds to 0.04% of dry weight. Thirty-eight components were identified. The major constituents were capric acid (25.6%), 3-amino-4,5-di-methyl-2(5H)-furanone (15.8%, [1]) and 2-methyl-butyric acid (12.9%). 3-Hydroxy-4,5-dimethyl-2(5H)-furanone (=sotolon, [2], 1.4%), the hydroxy furanone derivative molecule with the characteristic aroma of Trigonella foenum graecum seeds, is the key compound responsible for the fenugreek odour of L. helvus. Sotolon is widely used as an aroma component in food and tobacco industries due to its strong reminiscent odour

Volatile aroma constituents of Agarics and Boletes

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Les substances volatiles dans les genres Cantharellus, Craterellus et Hydnum

EID:2-s2.0-1042267757International audienceLe genre Cantharellus comporte des espèces d’intérêt économique (Danell et Camacho, 1997), appréciées des mycophiles pour leur intérêt gustatif. L’arôme fruité des hanterelles est généralement rapproché de celui de la mirabelle ou de l’abricot. Le travail présenté porte sur la détermination des substances volatiles aromatiques de Cantharellus cibarius, Craterellus cornucopioides, C. lutescens et C. tubaeformis. Les composés volatils des champignons frais ont été extraits par de l’éther éthylique. Les extraits organiques, concentrés sous azote, ont été analysés par CG/SM. L’identification des composés volatils a été réalisée grâce à leur spectre de masse et à leur temps de rétention. Quinze composés volatils ont été identifiés pour C. cibarius, dix-neuf pour C. cornucopioides, onze pour C. lutescens et dix-sept pour C. tubaeformis. Les composés en C-8 souvent très représentés chez les champignons et globalement responsables de « l’odeur fongique » sont retrouvés en proportions importantes notamment pour C. cibarius (75 %) et C. lutescens (63 %). Ainsi, le 1-octèn-3-ol, représente à lui seul de 26 % à 38 % des composés volatils pour les quatre espèces. Le (E)-2-octénol est l’un des composés volatils majoritaires pour C. cibarius et C. cornucopioides tandis que le (E)-2-octénal est majoritaire chez C. lutescens. D’autres composés comme le limonène (15 % chez C. cornucopioides) et le 2-phényléthanal (15 % chez C. tubaeformis) ont aussi été identifiés en grande quantité. Le benzaldéhyde, les isomères du 2, 4-décadiénal et le dihydroactinidiolide, composés contribuants à l’arôme de l’abricot ou de la mirabelle (Ismail et al. 1981, Takeoka et al. 1990) ont également été isolés. Cependant, d’autres composés aux notes florales ou fruitées comme le myrcène, bien que détectés en proportions plus faibles, participent aussi à la complexité de l’arôme de ces champignons