ILCB

Cartographie des fonctions du Langage par stimulation électrique corticale by Jean-François Demonet
2012-11-23 16:00 - 18:00 (Europe/Paris) | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France

Quantitative models of early language acquisition by Emmanuel Dupoux
2012-12-21 08:00 - 17:00 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
Quantitative models of early language acquisition by Emmanuel Dupoux
The past 40 years of psycholinguistic research has shown that infants learn their first language at an impressive speed. During the first year of life, even before they start to talk, infants converge on the basic building blocks of the phonological structure of their language. Yet, the mechanisms that they use to achieve this early phonological acquisition are still not well known. We show that a modeling approach based on machine learning algorithms and speech technology applied to large speech databases can help to shed light on the early pattern of development. First, we argue that because of acoustic variability, phonemes cannot be acquired directly from the acoustic signal; only highly context dependent and talker dependent phones or phones fragments can be extracted in a bottom-up way. Second, words cannot be acquired directly from the acoustic signal either, but a small number of protowords or sentence fragments can be extracted on the basis of repetition frequency. Third, these two kinds of protolinguistic units can interact with one another in order to converge with more abstract units. The proposal is therefore that the different levels of the phonological system are acquired in parallel, through increasingly more precise approximations. This accounts for the largely overlapping development of lexical and phonological knowledge during the first year of life.

Decomposition makes things worse: A discrimination learning approach to the time course of understanding compounds in reading by Harald Baayen
2013-02-15 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
Decomposition makes things worse: A discrimination learning approach to the time course of understanding compounds in reading by (Eberhard Karls University, Tübingen, Allemagne)
The current literature on morphological processing is dominated by the view that reading a complex word is a two-staged process, with an early blind morphemic decomposition process followed by a late process of semantic recombination (Taft, 2004; Rastle and Davis, 2008a). Various behavioral and magneto- and electroencephalography studies suggest semantic recombination would take place approximately 300-500 ms post onset of the visual stimulus (Lavric et al., 2007). However, eye-tracking studies show that both simple and complex words are read at a rate of 4 to 5 words/second (Rayner, 1998). We report an eye-tracking experiment tracing the reading of English compounds in simple sentences. For about 33% of the trials, a single fixation sufficed for understanding the meaning of the compound. For such trials, the meaning of the compound was available already some 140 ms after the eye first landed on the modifier. All first fixations also revealed an effect of the semantic relatedness of the modifier and head constituents, gauged with a latent
semantic analysis (LSA) similarity measure. These results indicate a much earlier involvement of semantics than predicted by the first-form-then-meaning scenario. Second and subsequent fixation durations revealed that at later processing stages very different semantic processes were involved, gauged by modifier-compound and head-compound LSA similarity measures. Computational modeling of the first fixation with naive discrimination learning (Baayen et al., 2011) indicated that the early (and only the early) semantic effect arises due to the model's connection weights' sensitivity to the collocational co-occurence statistics of orthographic and semantic information carried by word trigrams. We understand the LSA effects arising at later fixations as
reflecting semantic processes seeking to resolve the uncertainty about the targeted meaning that arises as an unintended and time-costly side effect of later fixations causing the head's meaning to be co-activated along with the compound's meaning. Instead of viewing blind morphological decomposition as the gateway through which meaning can be reached, we think that when the meaning of the head becomes available, due to the (non-morphological) nature of visual information uptake when the initial landing position of the eye is non-optimal, understanding comes with greater cognitive costs: Decomposition makes things worse. We speculate that the late semantic effects in the electrophysiological literature, especially those around the N400 time window, reflect late semantic cleaning operations.

Simplicity and Expressivity Compete in Cultural Evolution : Linguistic Structure is the Result by Simon KIRBY
2013-02-15 11:00 - 13:00 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
Simplicity and Expressivity Compete in Cultural Evolution : Linguistic Structure is the Result by Simon KIRBY (University of Edinburgh, UK)
Language, like other human behaviours, exhibits striking systematic structure. For example, two central design features of human language are the way in which sentences are composed of recombinable words, and the way in which those words in turn are created out of combinations of reusable sounds. These properties make language unique among communication systems and enable us to convey an open-ended array of messages.

Recently, researchers have turned to cultural evolution as a possible mechanism to explain systematic structure such as this in language. In this talk, I will briefly present a series of experiments and a computational model that demonstrate why this is a promising avenue for research. Using diffusion chain methods in the laboratory, we can observe how behaviour evolves as it is transmitted through repeated cycles of learning and production (a process known as ""iterated learning""). Across a wide range of experimental contexts, we observe an apparent universal: behaviour transmitted by iterated learning becomes increasingly compressible. When combined with a pressure to also be expressive, this may be sufficient to deliver up the structural design features of language.

Although this work is focussed on human language as a test case, the conclusions are quite general. Cultural transmission by iterated learning is an adaptive process that delivers systematic structure for free.

Speech perception across the adult lifespan with clinically normal hearings by Christian FULLGRABE
2013-04-05 16:00 - 18:00 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
Speech perception across the adult lifespan with clinically normal hearings by Christian FULLGRABE (MRC Institute of Hearing Research, Nottingham, UK)
Subjective reports suggest that older listeners experience increased listening difficulties in noisy environments, and experimental investigations seem to confirm this age-dependent deficit. However, older persons are generally unaware of their peripheral hearing status (i.e., the presence of a hearing loss) and most published studies used lax audiometric inclusion criteria. Hence, lower speech intelligibility could, at least partially, be explained by a reduction in audibility with age. Also, most aging studies limited their age comparison to groups of ""young"" (e.g. ≤ 30 years) and ""older"" listeners (e.g. ≥ 60 years), making it impossible to pinpoint the onset of the putative age effect. This talk will present two cross-sectional investigations of central age effects on speech perception, using participants with clinically normal hearing. Performance on supra-threshold temporal-processing and a battery of cognitive tasks (including tests of processing speed, working memory and attention) was assessed, and compared with speech identification in quiet and in different (steady and fluctuating) background noises. To determine when during adulthood a decline with age in these abilities first becomes apparent, participants were sampled continuously from the entire adult age range (18-91 years). Despite a large individual variability, the results show an age-dependent decline in speech identification, especially above 70 years. Sensitivity to temporal information and cognitive performance deteriorated as early as middle age, and both correlated with speech-in-noise perception.

Runt yak wahoo : baboon speak by Caralyn KEMP
2013-04-12 16:00 - 17:30 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Runt yak wahoo : baboon speak by Caralyn KEMP (BLRI)
Primates vocalise to maintain contact with conspecifics, warn of predators, alert group members to food and to advertise territory, sexual availability and size, but we know surprisingly little about how and why these calls are produced. Can they be varied and is this context dependent? Are these calls vocal responses to emotional states or can they be produced voluntarily? How does the production of these calls compare to human speech? Studying these questions not only helps us to understand what our closest relatives are saying, but also helps us to understand the evolution of our own speech. As part of a larger study considering these questions, I am examining the vocalisations of a captive group of Guinea baboons at the Primate Cognition and Behavior Platform in Rousset. The main goal of this aspect of the project is to produce a large-scale database in order to 1) characterise the vocal repertoire of this baboon species, 2) determine the acoustic features of the vocalisations, and 3) test the descriptive adequacy of existing categories. Determining the precise repertoire of baboon vocalisations will allow us to specify the 'acoustic space' that the vocal track of baboons can produce and how this compares to human vowel production. Taking into consideration the social context in which these vocalisations are produced and how specific situations alter vocal production, we aim to determine whether the baboons are capable of producing these calls voluntarily.

Sonifying handwriting movements for the diagnosis and the rehabilitation of movement disorders by Jérémy DANNA
2013-04-12 16:00 - 18:00 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Sonifying handwriting movements for the diagnosis and the rehabilitation of movement disorders by Jérémy DANNA (BLRI)
Except for the slight scratching of the pen, handwriting is a silent activity. Transforming it into an audible activity might sound curious. However, because audition is particularly appropriate for the perception of fine temporal and dynamical differences, using sounds to gain information about handwriting movements seems judicious. We use the sonification that consists in adding synthetic sounds to silent movements in order to provide support for information processing activities. The idea is to associate a melodious sound, which flows, to a fluent handwriting, and a dissonant sound, which squeaks, to a jerky handwriting. By sonifying the relevant variables of handwriting in dysgraphic children or in Parkinsonian patients, it could be possible to detect their handwritings troubles 'by ear' only.

My talk will be organized in two parts. First, I will expose an experiment showing that adding relevant auditory information is sufficient for discriminating the handwriting of dysgraphic children and the skilled handwriting of proficient children 'by ear' only. I will also present an experiment in progress in which real-time auditory feedback are supplied to help dysgraphic children to improve their handwriting movements. Secondly, I will present the BLRI project that consists in using computerized analysis and sonification of handwriting movements for the early diagnosis of Parkinson Disease.

Prosodic phrasing and ambiguity resolution as revealed by brain potentials by Karsten Steinhauer
2013-05-24 16:00 - 17:30 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Prosodic phrasing and ambiguity resolution as revealed by brain potentials by Karsten Steinhauer (McGill University, School of Communication Sciences & Disorders, Montréal)
Prosodic phrasing has a major impact on our interpretation of utterances. For example, the sentence ""Mary said Peter's brother was the nicest girl at the party"" results in confusion, unless it is presented with prosodic boundaries before and after ""said Peter's brother"". Event-related brain potentials (ERPs) provide an excellent tool to investigate the temporal dynamics of language processing in real-time. In the domain of prosody, distinct ERP components immediately reflect both the processing of prosodic boundaries as well as the subsequent integration of prosody with other types of linguistic information. In my talk, I will give an overview of this research area. After a brief introduction to ERPs, I will review a number of auditory and visual ERP studies and address questions such as: How much time does our brain need to take advantage of prosodic cues? When do children's brains learn to use this information? Does prosodic information play a role during silent reading? Are the brain mechanisms underlying prosodic phrasing in speech comparable to those involved in musical phrasing? How do we integrate multiple (conflicting) boundaries within the same utterance?

Etudes de potentiels évoqués sur le traitement de l'accord en langue orale (or ""ERP studies on oral langage processing of agreement"" (en Français)) by Phaedra Royle
2013-05-29 16:00 - 17:30 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Etudes de potentiels évoqués sur le traitement de l’accord en langue orale (or “”ERP studies on oral langage processing of agreement”” (en Français)) by Phaedra Royle (École d’orthophonie et d’audiologie, Université de Montréal)
Afin d'étudier l'acquisition du traitement de l'accord en genre en français, nous avons développé une étude de potentiels évoqués (PÉs) ayant une interface auditivo-visuelle avec un appariement d'images et de phrases ciblant l'accord intra-nomial. Ce domaine du français est difficile à maîtriser, étant donné la nature irrégulière des marques de l'accord en genre. Les conditions incongruentes présentaient des erreurs du genre pour le déterminant (Det-N « la soulier brun »), et l'adjectif (N-Adj « le soulier « brune »), mais aussi des conditions sémantiquement où le nom et l'image étaient incongruents (par ex. l'enfant voit [un soulier brun] et entend « un POISSON brun ») Deux groupes ont participé à l'étude. Le premier, des jeunes adultes francophones, ont été assignés aléatoirement à deux sous-groupes : avec ou sans tâche. Cette manipulation visait à vérifier si les PÉs obtenus sans tâche étaient similaires à ceux obtenus avec jugement de grammaticalité, étant donné qu'on ne demanderait pas aux enfants de faire de jugement. Les deux groups d'adultes ont montré les PÉs attendus (N400, LAN, P600) en plus d'une onde PMN (Phoneme mismatch negativity) dans les conditions sémantiques et Det-N. L'effet de tâche a été important, en particulier pour l'onde P600 qui montrait une amplitude considérablement plus grande dans le groupe Tâche.

Le second groupe de participants était des enfants âgés de 5 à 9 ans (N=50). Aucune tâche ne leur était demandée mis à part de porter attention à l'histoire racontée (une extraterrestre qui apprend le français au cours de son voyage intergalactique vers le Québec). Nos analyses préliminaires démontrent que ce paradigme induit des composantes chez les enfants qui sont à la fois similaires (N400, P600) et différentes (LAN) de ceux des adultes. Les données des adultes démontrent que les jugements de grammaticalité ne sont pas une précondition à l'apparition de certaines ondes PÉs linguistiques dans des tâches orales. Les différences d?ondes entres les conditions sémantiques et (non)grammaticales appuient une dissociation entre les processus de vérification grammaticale et l'accès lexical dans la vérification de l'accord. Les données préliminaires des enfants démontrent l'utilité de ce paradigme pour l'étude de l'acquisition de processus grammaticaux et lexicaux-sémantiques chez les enfants tout venant qui pourraient maîtriser l'accord mais néanmoins faire des erreurs de production. tâches orales. Les différences d?ondes entres les conditions sémantiques et (non)grammaticales appuient une dissociation entre les processus de vérification grammaticale et l'accès lexical dans la vérification de l'accord. Les données préliminaires des enfants démontrent l'utilité de ce paradigme pour l'étude de l'acquisition de processus grammaticaux et lexicaux-sémantiques chez les enfants tout venant qui pourraient maîtriser l'accord mais néanmoins faire des erreurs de production.

Is lexical selection by competition ? by Robert Hartsuiker
2013-06-07 16:00 - 18:00 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
Is lexical selection by competition ? by Robert Hartsuiker (Ghent University)
There are several contrasting views on the mechanisms of lexical selection in language production. On one view, words compete with each other for selection, so that the time to select one word depends on the activation of competitors. This competitive view is often thought to be supported by semantic interference in picture-word tasks (name the picture, ignore the distractor word). But on another view, the time to select a word depends only on the activation of the highest activated lexical unit. This account is consistent with semantic facilitation in some versions of the picture-word task, but requires an additional mechanism to account for semantic interference effects. Our work of the last few years has tested whether this mechanism is one of self-monitoring and covert error repair. On this view, the distractor sometimes gets ahead of the picture name in production process. To prevent the inadvertent naming of the distractor, it therefore needs to be filtered out covertly, and the more difficult it is to detect and rule out the distractor, the more naming will be delayed. To test this account, we have conducted behavioral experiments and EEG experiments that manipulated parameters we suspect the self-monitoring system to be sensitive to, such as lexical status of the distractor, context (i.e., composition of list of stimuli), and even taboo status of the distractor word. Based on my review of this evidence I will argue that response exclusion by self-monitoring is a viable alternative to lexical selection by competition.

Prosodic Constraints on Children's Variable Production of Grammatical Morphemes by Katherine Demuth
2013-08-29 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Prosodic Constraints on Children’s Variable Production of Grammatical Morphemes by Katherine Demuth (Macquarie University, New South Wales, Australia)
Language acquisition researchers have long observed that children's early use of grammatical morphemes is highly variable. It is generally thought that this is due to incomplete syntactic or semantic representations. However, recent crosslinguistic research has found that the variable production of grammatical morphemes such as articles and verbal inflections is phonologically conditioned. Thus, children are more likely to produce grammatical morphemes in simple phonological contexts than in those that are more complex. This suggests that some of the variability in children's early production (and perception) of grammatical morphemes may be due to phonological context effects, and that some aspects of children's syntactic/semantic representations may be in place earlier than typically assumed. This raises important theoretical and methodological issues for investigating syntactic knowledge in L1 acquisition, but also in bilinguals, L2 children and adults, and those with language impairment (SLI, bilinguals, children with hearing loss). Implications for understanding the mechanisms underlying language processing, the 'perception-production' gap, and a developmental model of speech planning, are discussed.

Synergie in Language Acquisition by Mark Johnson
2013-08-29 10:00 - 12:30 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Synergie in Language Acquisition by Mark Johnson (Macquarie University, New South Wales, Australia)
Each human language contains an unbounded number of different sentences. How can something so large and complex possibly be learnt? Over the past decade and a half we've learned how to define probability distributions over grammars and the linguistic structures they generate, making it possible to define statistical models that learn regularities of complex linguistic structures. Bayesian approaches are particularly attractive because they can exploit ""prior"" (e.g., innate) knowledge as well as learn statistical generalizations from the input.

This talk compares two different Bayesian models of language acquisition. A staged learner learns the components of language independently of each other, while a joint learner learns them simultaneously. A joint learner can take advantages of synergistic dependencies between linguistic components to bootstrap acquisition in ways that a staged learner cannot. We use Bayesian models to show that there are dependencies between word reference, syllable structure and the lexicon that a learner could take advantage of to synergistically improve language acquisition.

What Freud got right about speech errors by Gary S. Dell
2013-09-06 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
What Freud got right about speech errors by Gary S. Dell (University of Illinois, Urbana-Champaign, USA)
Most people associate Sigmund Freud with the assertion that speech errors reveal repressed thoughts, a claim that does not have a great deal of support. I will mention some other things that Freud said about slips, showing that these, in contrast to the repression notion, do fit well with some modern theories of language production. I will illustrate using the interactive two-step theory of lexical access during production, which we have used to understand aspects of aphasic speech error patterns

Social meaning and speech perception by Benjamin Munson
2013-09-06 11:00 - 12:30 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Social meaning and speech perception by Benjamin Munson (University of Minnesota, Etats-Unis)
It is well established that listeners may categorize ambiguous sounds differently when they are led to believe something about the person who produced them, such as their age, social class, gender, or regional background (Hay, Drager & Nolan, 2006 ; McGowan 2011 ; Staum Casasanto 2008 ; Strand & Johnson 1996). This talk will review a set of studies designed to examine two aspects of this phenomenon. First, are the effects different depending on the specific social meaning ascribed to the variation (i.e., what is it about gender that makes listeners change their categorizations when the speaker is suggested to be a man or a woman?). Second, do these effects occur relatively early and automatically in processing, or do they reflect ambiguity resolutions that occur relatively late in processing ?

Vocalisations of Captive Guinea Baboons by Caralyn Kemp
2013-10-25 11:00 - 12:00 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Vocalisations of Captive Guinea Baboons by Caralyn Kemp (Labex BLRI)
As part of a larger study investigating vocal production in Guinea baboons, I have been examining the vocalisations of a captive group at the CNRS primate station in Rousset. The main goal of this aspect of the project was to produce a large-scale database in order to 1) characterise the vocal repertoire of this baboon species, 2) determine the acoustic features of the vocalisations, and 3) test the descriptive adequacy of existing categories. Twelve vocalisations were distinguishable by ear, but not all vocalisations were produced by all age and sex groups. A single vocalisation type could occur in different contexts and some vocalisations had a large degree of variability. This database will be useful for new researchers and care staff who work with Guinea baboons in captivity as well as aiding in our understanding of the evolution of vocal communication between baboon taxa and within the primate genera.

Electrophysiological tools to assess brain activity by Eduardo Martinez-Montes
2013-11-22 08:00 - 17:00
Electrophysiological tools to assess brain activity by Eduardo Martinez-Montes (Head of the Neuroinformatics Department, Cuban Neuroscience Center)
The development of a wide variety of neuroimaging methods based on Magnetic Resonance Imaging has opened new ways for studying brain organization and functioning with high spatial resolution. It is also becoming increasingly clear that the complex functions of the human brain such as cognition, language, attention and several pathologies are not fully explained by only considering the activation of spatially fixed cerebral structures. Rather we need to consider brain functioning as networks of structures that dynamically interact through electrical signals coded by different frequencies. To thoroughly investigate the dynamics of such networks it is important to also use other techniques such as EEG and MEG, which provide direct measurements of the brain electrical activity with high temporal resolution. In this talk, we will present classical and novel strategies for the analysis of EEGMEG data, from statistical measures for detection of the Event Related Brain Dynamics, to methods of dimensionality reduction and the combination of multidimensional analysis with source localization methods. We will describe new approaches for obtaining space-time-frequency characterization of brain electrical activity at the level of neural sources.

Apprentissage par renforcement : de la modélisation des processus neuraux aux applications robotiques by Medhi Khamassi
2013-12-05 08:00 - 17:00 | LIA, chemin des Meinajariès, Avignon, 84911, France
Apprentissage par renforcement : de la modélisation des processus neuraux aux applications robotiques by Medhi Khamassi (l’Institut des Systèmes Intelligents et de Robotique (UPMC))
L'activité phasique des neurones dopaminergiques est considérée depuis une quinzaine d'années comme le substrat neural de signaux d'erreur de prédiction de la récompense (RPE). Ces signaux se sont avérés très proches des signaux d'erreurs générés par les algorithmes d'apprentissage par renforcement (RL). De plus, de nombreuses études ont montré que les algorithmes RL permettaient de bien décrire l'apprentissage animal et humain pendant des tâches de conditionnement pavlovien. Ceci a conduit au développement d'un nombre croissant de modèles computationnels d'apprentissage par renforcement pour décrire les processus neuraux sous-jacents à ces apprentissages. La première partie de l'intervention présentera une introduction à ces modèles, à leur formalisme, et aux données montrant qu'ils permettent de bien décrire certaines activités cérébrales liées à l'apprentissage.
Toutefois, ces modèles d'apprentissage par renforcement commencent à montrer leurs limites, dont l'une est celle du passage à l'échelle, dans le monde réel. Lorsque l'on sort du cadre des simulations parfaites et simplifiées des tâches de laboratoire et que l'on se place dans le cadre de l'interaction réaliste d'un robot avec son environnement, on se rend compte que ces algorithmes ont beaucoup de mal à faire face au bruit, à l'incertitude, aux délais. L'application de ces modèles d'apprentissage au contrôle d'un robot montre que pour réussir à obtenir une bonne performance du robot, il faut faire en plus des hypothèses sur l'interaction de ces modèles avec d'autres systèmes d'apprentissage et avec d'autres processus cognitifs tels que la perception, la cartographie, la navigation. Je montrerai en particulier comment des algorithmes combinant deux types d'apprentissage, dits model-free et model-based, permettent de donner une meilleure performance comportementale au robot et d'expliquer également un plus grand nombre de données expérimentales, en particulier dans des tâches de navigation.

Apprentissage par renforcement (direct et inverse) pour les systèmes interactifs by Olivier Pietquin
2013-12-05 10:00 - 12:00 | LIA, chemin des Meinajariès, Avignon, 84911, France
Apprentissage par renforcement (direct et inverse) pour les systèmes interactifs by Olivier Pietquin (SequeL team, University Lille 1, LIFL CNRS UMR 8022, INRIA Lille)
L'apprentissage par renforcement est une catégorie d'apprentissage automatique qui se différencie des autres par le fait qu'elle a pour objectif l'optimisation d'une séquence de décisions, prenant en compte l'aspect temporel et surtout dirigé par un but du comportement. Cette méthode, d'inspiration biologique, est fondée sur l'accumulation par la machine de récompenses numériques distribuées après chaque décision. Le comportement appris est celui qui maximise, sur le long terme, l'accumulation de récompenses, menant à une séquence de décisions optimale. Ce paradigme d'apprentissage a été introduit dans le domaine des systèmes de dialogue parlé il y a une quinzaine d'année afin d'optimiser les stratégies d'interaction. En effet, ce type de système doit prendre des décisions sur les actes dialogiques à produire à chaque tour d'interaction avec un utilisateur. Ces décisions doivent mener à une interaction la plus naturelle et efficace possible alors que les informations recueillies sont entachées d'erreurs (due à la reconnaissance et la compréhension imparfaites du langage parlé). Il est difficile de définir formellement ce que serait une interaction parfaite, en revanche un utilisateur peut fournir une évaluation a posteriori de cette interaction servant de signal de récompense. Toutefois, un certain nombre de problèmes subsistent encore aujourd'hui pour faire un usage performant de ces méthodes dans le cadre de l'interaction homme-machine. Un de ces problèmes est la définition de la récompense à fournir à la machine pour la voir se comporter de manière naturelle. En effet, l'utilisation de la satisfaction de l'utilisateur a montré quelques limites et est difficile à prédire automatiquement. Dans cet exposé, nous présenterons le paradigme de l'apprentissage par renforcement inverse, visant à estimer la fonction de récompense optimisée par un opérateur humain (supposé optimal) et à la transférer à la machine pour obtenir un comportement similaire dans une tâche d'interaction.

La Poesie des synapses ou comment les mots nous font plaisir ou peur ? by Arthur Jacobs
2013-12-20 14:00 - 17:00 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
La Poesie des synapses ou comment les mots nous font plaisir ou peur ? by Arthur Jacobs (Freie Universität Berlin, Dahlem Institute for Neuroimaging of Emotion (D.I.N.E.))
La lecture n'est pas seulement un processus de traitement d'information, mais elle comporte des réponses affectives et esthétiques qui vont bien au-delà de ce que les modèles actuels de la lecture décrivent. Des mots peuvent nous plaire ou faire mal, des textes nous rendre heureux ou faire pleurer. Mais comment des stimuli ""symboliques"" peuvent-ils évoquer des réponses émotionelles? Quels sont les processus neurocognitifs qui les sous-tendent, et comment les réactions émotionelles à des narrations fictives se distinguent-elles de celles à des narrations factuelles? Dans ce séminaire, j'aborde ces questions dans le cadre d'un modèle neuropoétique de la lecture littéraire qui intègre des éléments de rhétorique, d'esthétique et de poétique cognitive avec des concepts de neurolinguistique et de psychonarrotologie (Jacobs, 2011; 2013). Ces prédictions sont discutées à la lumière des données venant d'études empiriques sur la reconnaissance des mots, la réception de la poésie, et de la compréhension des phrases et textes.

A Vocal Brain: Cerebral Processing of Voice Information by Pascal Belin
2014-01-24 08:00 - 17:00 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
A Vocal Brain: Cerebral Processing of Voice Information (Institut des Neurosciences de La Timone, Marseille, France)
The human voice carries speech but also a wealth of socially-relevant, speaker-related information. Listeners routinely perceive precious information on the speaker's identity (gender, age), affective state (happy, scared), as well as more subtle cues on perceived personality traits (attractiveness, dominance, etc.), strongly influencing social interactions. Using voice psychoacoustics and neuroimaging techniques, we examine the cerebral processing of person-related information in perceptual and neural voice representations. Results indicate a cerebral architecture of voice cognition sharing many similarities with the cerebral organization of face processing, with the main types of information in voices (identity, affect, speech) processed in interacting, but partly dissociable functional pathways.

Sensorimotor processing of speech : brain inspired approaches to automatic speech recognition by Luciano Fadiga, Alessandro D'Ausilio, Leonardo Badino
2014-02-13 11:00 - 17:00 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Sensorimotor processing of speech : brain inspired approaches to automatic speech recognition by Luciano Fadiga, Alessandro D’Ausilio, Leonardo Badino (University of ferrara, Istituto Italiano Di Tecnologia à Gênes)

Prosodic and Social Dimensions of Entrainment in Dialogue by Julia Hirschberg
2014-03-18 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Prosodic and Social Dimensions of Entrainment in Dialogue by (Columbia University)
When people speak together, they often adapt aspects of their speaking style based upon the style of their conversational partner. This phenomena goes by many names, including adaptation, alignment, and entrainment, inter alia. In this talk, I will describe experiments in English and Mandarin prosodic entrainment in the Columbia Games Corpus and in the Tongji Games Corpus, large corpora of speech recorded from subjects playing a series of computer games. I will discuss how prosodic entrainment is related to turn-taking behaviors and to several measures of task and dialogue success. I will also discuss experiments relating entrainment to several social dimensions, including likeability and dominance. This is joint work with Stefan Benus, Agustín Gravano, Ani Nenkova, Rivka Levitan, Laura Willson, and Zhihua Xia.

Neuroanatomical correlates of developmental dyslexia by Irène Altarelli
2014-04-04 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
Neuroanatomical correlates of developmental dyslexia by Irène Altarelli (Brain and Learning Lab., University of Geneva)
Developmental dyslexia is a specific learning disorder that impacts reading abilities, despite normal education, intelligence and perception. The aim of the present work is to determine its neuroanatomical correlates, with the broader goal of identifying associations between genetic variants, brain anatomy and cognitive impairments. To this end, three studies were conducted, comparing magnetic resonance images of dyslexic and control subjects. In a first study, we analysed a variety of cortical measures with both a region of interest and a global vertex-by-vertex approach. In a second study, we focused on the ventral temporo-occipital regions, looking at the structure of functionally defined areas. We defined the subject-by-subject location of cortical regions preferentially responding to written words, faces or houses. A cortical thickness reduction in dyslexic subjects was observed in the left-hemisphere word-responsive region, an effect exclusively driven by dyslexic girls. Finally, in a third study we examined the anatomical asymmetry of the planum temporale, a region which importance in dyslexia has been widely debated. By manually labelling this structure, we observed an abnormal pattern of asymmetry in dyslexic boys only. To conclude, a number of anatomical correlates of dyslexia have emerged from the work presented here, offering a better characterisation of its brain basis.Importantly, our results also stress the importance of gender, a long neglected factor in dyslexia

Fallait-il brûler Verbal Behavior ? by Marc Richelle
2014-04-18 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
Fallait-il brûler Verbal Behavior ? by Marc Richelle (University of Liège, Belgium)
En partant de mon expérience personnelle de ma rencontre avec Verbal Behavior (et avec son auteur) , et des avatars que ce livre a connus, - notamment sa mise à l'écart plus encore dans le monde francophone qu'ailleurs - je tenterai d'en restituer la portée, et aussi de comprendre les raisons, par delà la critique de Chomsky, qui en ont fait un texte largement méconnu.

Fan Cao, Chotiga Pattamadilok, Johannes Ziegler
2014-06-05
Fan Cao (1), Chotiga Pattamadilok (2), Johannes Ziegler (3)
((1)Michigan State University), (2) LPL UMR7309 CNRS AMU, (3) LPC UMR7290 CNRS AMU)
Salle de conférences B011, bât. B 5 avenue Pasteur, Aix-en-Provence
9h30-12h30 Salle de conférences B011, bât. B 5 avenue Pasteur, Aix-en-Provence

Cross-linguistic and neurolinguistic perspectives on reading and speech processing

Neural specialization and reading ability
Fan Cao (Michigan State University)

The brain becomes specialized with exposure to the environment. One piece of evidence comes from how the language system shapes brain function. In a cross-linguistic developmental study, we show growing divergence between Chinese reading and English reading from children to adults. We found that specialization is positively correlated with proficiency. For example, there is reduced specialization in children with reading disability. Another example is proficiency effect in bilinguals, where we found greater specialization with higher proficiency in a group of late Chinese-English bilinguals. We also found that specialization can be facilitated by providing more effective instruction. In a series of training studies, we compared writing and visual-only learning in English learners of Chinese, and we found writing training evoked a more native-like brain network, suggesting greater specialization and accommodation. In summary, the brain becomes specialized with language experience and optimal instruction will promote the process of specialization.

How does learning to read modify speech processing ? Chotiga Pattamadilok (Laboratoire Parole et Langage)

Behavioral and brain imaging studies have demonstrated that learning to read and write changes the way the brain processes spoken language. However, the cognitive and neural mechanisms underlying such modification are still under debate. Two complementary hypotheses have been proposed. According to the ""online"" account, strong connections between spoken and written language result in the automatic co-activation of both codes when one processes language, such that hearing a spoken word activates, in real time, its corresponding written form and vice-versa. According to the ""offline or developmental account"" learning to read induces more profound changes withinthe spoken language system itself, probably by restructuring the nature of the phonological representations. Evidence supporting both hypotheses will be discussed.

A cross-language perspective on reading, reading development and dyslexia Johannes Ziegler (Laboratoire de Psychologie Cognitive)

Many theories assume that different languages or writing systems afford different reading styles. One idea that has been around since the early 70s is that opaque writing systems favor a ""Chinese"" style of reading (a direct route to meaning) whereas transparent writing systems favor a ""Phoenician"" style (an indirect route that is phonologically mediated). However, research on reading development and dyslexia across languages draws a different picture, one in which the core reading processes are very similar across languages. The main differences are related to consistency and orthographic complexity – these variables affect the granularity of the computations rather than the computations themselves.

How do central processes cascade into peripheral processes in written language production? by Sonia Kandel
2014-06-20 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
How do central processes cascade into peripheral processes in written language production? by Sonia Kandel (Univ. Grenoble Alpes, LPNC (CNRS UMR 5105) – Grenoble, France And Univ. Grenoble Alpes, GIPSA-LAB (CNRS UMR 5216), Dept. Parole & Cognition –Grenoble, France)
With the arrival of internet, tablets and smartphones many people spend more time writing than speaking (email, chat, SMS, etc.). Despite the importance of writing in our society, the studies investigating written language production are scarce. In addition, most studies investigated written production either from a central point of view (i.e., spelling processing) or a peripheral approach (i.e., motor production) without questioning their relation. We believe, instead, that central and peripheral processing cannot be investigated independently. There is a functional interaction between spelling and motor processing. Letter production does not merely depend on its shape –and its specifications for stroke order and direction– but also on the way we encode it orthographically. For example, the movements to produce letters PAR in the orthographically irregular word PARFUM (perfume) are different than in the regular word PARDON (pardon). Spelling processes cascade into motor production. The nature of the spelling processes that are activated before movement initiation will determine the way the cascade will operate during movement production. Lexical and sub-lexical processes do not spread into motor execution to the same extent.

The bilingual brain: Plasticity and processing from cradle to grave by Manuel Carreira
2014-07-04 | Salle des voûtes, St Charles, 3 place Victor Hugo, Marseille, 13001, France
The bilingual brain: Plasticity and processing from cradle to grave by Manuel Carreira (Basque Center on Cognition, Brain and Language, Donostia-San Sebastian, Spain IKERBASQUE. Basque Foundation for Science. Bilbao. Spain)
Most people either learn more than one language from birth or invest quite a lot of time and effort learning a second language. Bilingualism and second language learning is an interesting case for investigating cognitive and brain plasticity. In this talk I will describe behavioral and neuroimaging evidence on the cognitive and brain mechanisms adults and infants (monlinguals, bilinguals and second language learners) use for processing language. In particular I will address whether proficient second language learners use similar or different brain mechanisms during processing and what are the neural consequences (structural and functional) of dealing with two languages.

Towards an Online Rhyming Dictionary for Mexican Spanish by Alfonso Medina
2014-07-18 14:00 - 17:00 | LIA, chemin des Meinajariès, Avignon, 84911, France
Towards an Online Rhyming Dictionary for Mexican Spanish by Alfonso Medina
Rhyming dictionaries are a kind of reverse dictionaries. They group words according to rhyming patterns. Rhymes can share exact sequences of vowel and consonant sounds towards the end of a word (consonant rhyme) or just similar vowel sounds (assonant rhyme). Thus, these dictionaries are based on pronunciation, not on writing patterns. Also, since consonance and assonance depend on the stressed syllable, words which end with a stressed syllable are grouped together, those whose stressed syllable is the next to last appear together, and so on.

In addition, word pronunciation may vary with time and across geographical and social dialects. In Spanish, this is particularly clear when word loans (for instance, Anglicisms and Galicisms) are considered. In fact, they tend to keep their original writing, at least in the Mexican variant which is the most spoken one. For example, the following loan words, common in Mexican Spanish, rhyme: flash, collage, garage, cottage, squash. Their last syllable is stressed and they are ordered in reverse according to their sounds and not their letters: (respectively, /fláʃ/, /ko.láʃ/, /ga.ráʃ/, /ko.táʃ/ and /es.kwáʃ/).

The project described takes the current nomenclature of the Diccionario del español de México (http://dem.colmex.mx/) to generate automatically a rhyming dictionary. Also, since the results of an online query to such a dictionary can be quite large, a procedure was developed to rank them semantically. The idea is to measure the similarities of the query definition to each of the definitions of the rhyming words. These words are then ordered from highest to lowest similarity to the query.

The influence of expertise on perception, cognition, and brain connectivity by Stefan Elmer
2014-09-19 11:00 - 13:00 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
The influence of expertise on perception, cognition, and brain connectivity by Stefan Elmer (Universität Zürich)
A better understanding of the perceptual and cognitive neural underpinnings underlying exceptional behavioural skills has important educational, societal, as well as clinical implications (i.e., for example in the context of developmental dyslexia, aphasia, and foreign language learning). Here, I will present recent data collected from professional musicians with and without absolute pitch, as well as from simultaneous language interpreters, to reveal how expertise and training has an influence on the functional-structural malleability of perceptual and cognitive subdivisions of the human brain. In the same context, I will also provide some evidence for transfer effects from musicianship to specific aspects of speech processing. Finally, since currently there is no doubt that perceptual and cognitive functions do not work in isolation but are embedded in neuronal assemblies consisting of networks influencing each other's in a reciprocal manner, I will propose some novel methodological approaches for evaluating functional and structural connectivity within small-scale perceptual-cognitive networks in musicians with and without absolute pitch.

Probabilistic Graphical Models of Dyslexia by Yaïr LAKRETZ
2014-11-28 11:00 - 13:00 | Salle de conférences, 5 avenue Pasteur, Aix-en-Provence, 13100, France
Probabilistic Graphical Models of Dyslexia by Yaïr LAKRETZ (‘Sagol’ school of neuroscience, Tel-Aviv University)
Reading is a complex cognitive faculty, errors in which assume diverse forms. To capture the complex structure of reading errors, we propose a novel way of analyzing these errors using probabilistic graphical models. Our study focuses on three inquiries. (a) We examine which graphical model best captures the hidden structure of reading errors. (b) We draw on the results of (a) to resolve a theoretical debate on whether dyslexia is a monolithic or heterogeneous disorder. (c) We examine whether a graphical model can diagnose dyslexia closely to how experts do. We explore three different models: an LDA-based model and two Naïve Bayes models which differ by their assumptions about the generation process of reading errors. The models are trained on a large corpus of reading errors. Our results show that the LDA-based model best captures patterns of reading errors and may therefore contribute to the understanding of dyslexia and to the diagnostic procedure. We also demonstrate that patterns of reading errors are best described by a model assuming multiple dyslexia subtypes, therefore supporting the heterogeneous approach to dyslexia. Finally, a Naïve Bayes model, which shares assumptions with diagnostic practice, best replicates labels given by clinicians and can be therefore used for automation of the diagnosis process.
