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Publications of year 2014
Books
  1. Stanislas DEHAENE. Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts. Viking Press, 2014. [bibtex-entry]


Thesis
  1. Jean-Remi King. Décodage des états mentaux conscients et non-conscients. PhD thesis, Paris VI, 2014. [PDF] [bibtex-entry]


  2. Anne Kösem. Temps objectif et temps perçu en contexte multisensoriel. PhD thesis, Paris VI, 2014. [PDF] [bibtex-entry]


  3. Lynn Uhrig. Cerebral mechanisms of general anesthesia. A hierarchy of responses to auditory regularities in the awake and anesthetized macaque brain. PhD thesis, Paris VI, 2014. [bibtex-entry]


  4. C. Wacongne. Neuronal modeling of conscious and unconscious processing of regularities. PhD thesis, Paris VI, 2014. [bibtex-entry]


  5. Nicolas Zilber. ERF and scale-free analyses of source-reconstructed MEG brain signals during a multisensory learning paradigm. PhD thesis, 2014. [PDF] [bibtex-entry]


Book chapters
  1. Valentina. Borghesani, F. Pedregosa, Evelyn Eger, M. Buiatti, and Manuela Piazza. A perceptual-to-conceptual gradient of word coding along the ventral path. In 4th International Workshop on Pattern Recognition in NeuroImaging. 2014. [PDF] [bibtex-entry]


  2. Manuela Piazza. Comment la culture façonne le cerveau: mécanismes neuronaux de la lecture et du calcul. In Odile Jacob Ed, editor,Cerveau, psyché et développement, pages 109-117. C. Chiland et J.P. Raynaud, 2014. [bibtex-entry]


Articles in journals
  1. K. Amunts, M. J. Hawrylycz, D. C. Van Essen, J. D. Van Horn, N. Harel, J-B. Poline, F. De Martino, J. G. Bjaalie, G. Dehaene-Lambertz, S. Dehaene, P. Valdes-Sosa, B. Thirion, K. Zilles, S. L. Hill, M. B. Abrams, P. A. Tass, W. Vanduffel, A. C. Evans, and S. B. Eickhoff. Interoperable atlases of the human brain. Neuroimage, 99:525--532, October 2014. [WWW] [PDF]
    Abstract: The last two decades have seen an unprecedented development of human brain mapping approaches at various spatial and temporal scales. Together, these have provided a large fundus of information on many different aspects of the human brain including micro- and macrostructural segregation, regional specialization of function, connectivity, and temporal dynamics. Atlases are central in order to integrate such diverse information in a topographically meaningful way. It is noteworthy, that the brain mapping field has been developed along several major lines such as structure vs. function, postmortem vs. in vivo, individual features of the brain vs. population-based aspects, or slow vs. fast dynamics. In order to understand human brain organization, however, it seems inevitable that these different lines are integrated and combined into a multimodal human brain model. To this aim, we held a workshop to determine the constraints of a multi-modal human brain model that are needed to enable (i) an integration of different spatial and temporal scales and data modalities into a common reference system, and (ii) efficient data exchange and analysis. As detailed in this report, to arrive at fully interoperable atlases of the human brain will still require much work at the frontiers of data acquisition, analysis, and representation. Among them, the latter may provide the most challenging task, in particular when it comes to representing features of vastly different scales of space, time and abstraction. The potential benefits of such endeavor, however, clearly outweigh the problems, as only such kind of multi-modal human brain atlas may provide a starting point from which the complex relationships between structure, function, and connectivity may be explored.
    [bibtex-entry]


  2. M. Andres, C. Finocchiaro, M. Buiatti, and M Piazza. Contribution of motor representations to action verb processing. Cognition, 2014. [PDF] [bibtex-entry]


  3. Anahita Basirat, Stanislas Dehaene, and Ghislaine Dehaene-Lambertz. A hierarchy of cortical responses to sequence violations in three-month-old infants. Cognition, 132(2):137--150, August 2014. [WWW] [PDF]
    Abstract: The adult human brain quickly adapts to regular temporal sequences, and emits a sequence of novelty responses when these regularities are violated. These novelty responses have been interpreted as error signals that reflect the difference between the incoming signal and predictions generated at multiple cortical levels. Do infants already possess such a hierarchy of violation-detection mechanisms? Using high-density recordings of event-related potentials during an auditory local-global violation paradigm, we show that three-month-old infants process novelty in temporal sequences at two distinct levels. Violations of local expectancies, such as perceiving a deviant vowel "a" after repeated presentation of another vowel i-i-i, elicited an early auditory mismatch response. Conversely, violations of global expectancies, such as hearing the rare sequence a-a-a-a instead of the frequent sequence a-a-a-i, modulated this early mismatch response and led to a late frontal negative slow wave, whose cortical sources included the left inferior frontal region. These results suggest that the infant brain already possesses two dissociable systems for temporal sequence learning.
    [bibtex-entry]


  4. Manon J. Benders, Kirsi Palmu, Caroline Menache, Cristina Borradori-Tolsa, Francois Lazeyras, Stephane Sizonenko, Jessica Dubois, Sampsa Vanhatalo, and Petra S. Hüppi. Early Brain Activity Relates to Subsequent Brain Growth in Premature Infants. Cereb Cortex, May 2014. [WWW] [PDF]
    Abstract: Recent experimental studies have shown that early brain activity is crucial for neuronal survival and the development of brain networks; however, it has been challenging to assess its role in the developing human brain. We employed serial quantitative magnetic resonance imaging to measure the rate of growth in circumscribed brain tissues from preterm to term age, and compared it with measures of electroencephalographic (EEG) activity during the first postnatal days by 2 different methods. EEG metrics of functional activity were computed: EEG signal peak-to-peak amplitude and the occurrence of developmentally important spontaneous activity transients (SATs). We found that an increased brain activity in the first postnatal days correlates with a faster growth of brain structures during subsequent months until term age. Total brain volume, and in particular subcortical gray matter volume, grew faster in babies with less cortical electrical quiescence and with more SAT events. The present findings are compatible with the idea that (1) early cortical network activity is important for brain growth, and that (2) objective measures may be devised to follow early human brain activity in a biologically reasoned way in future research as well as during intensive care treatment.
    [bibtex-entry]


  5. Florence Bouhali, Michel Thiebaut de Schotten, Philippe Pinel, Cyril Poupon, Jean-François Mangin, Stanislas Dehaene, and Laurent Cohen. Anatomical connections of the visual word form area.. J Neurosci, 34(46):15402--15414, November 2014. [WWW]
    Abstract: The visual word form area (VWFA), a region systematically involved in the identification of written words, occupies a reproducible location in the left occipitotemporal sulcus in expert readers of all cultures. Such a reproducible localization is paradoxical, given that reading is a recent invention that could not have influenced the genetic evolution of the cortex. Here, we test the hypothesis that the VWFA recycles a region of the ventral visual cortex that shows a high degree of anatomical connectivity to perisylvian language areas, thus providing an efficient circuit for both grapheme-phoneme conversion and lexical access. In two distinct experiments, using high-resolution diffusion-weighted data from 75 human subjects, we show that (1) the VWFA, compared with the fusiform face area, shows higher connectivity to left-hemispheric perisylvian superior temporal, anterior temporal and inferior frontal areas; (2) on a posterior-to-anterior axis, its localization within the left occipitotemporal sulcus maps onto a peak of connectivity with language areas, with slightly distinct subregions showing preferential projections to areas respectively involved in grapheme-phoneme conversion and lexical access. In agreement with functional data on the VWFA in blind subjects, the results suggest that connectivity to language areas, over and above visual factors, may be the primary determinant of VWFA localization.
    [bibtex-entry]


  6. Audrey Bénézit, Lucie Hertz-Pannier, Ghislaine Dehaene-Lambertz, Karla Monzalvo, David Germanaud, Delphine Duclap, Pamela Guevara, Jean-François Mangin, Cyril Poupon, Marie-Laure Moutard, and Jessica Dubois. Organising white matter in a brain without corpus callosum fibres.. Cortex, 63C:155--171, September 2014. [WWW] [PDF]
    Abstract: Isolated corpus callosum dysgenesis (CCD) is a congenital malformation which occurs during early development of the brain. In this study, we aimed to identify and describe its consequences beyond the lack of callosal fibres, on the morphology, microstructure and asymmetries of the main white matter bundles with diffusion imaging and fibre tractography. Seven children aged between 9 and 13 years old and seven age- and gender-matched control children were studied. First, we focused on bundles within the mesial region of the cerebral hemispheres: the corpus callosum, Probst bundles and cingulum which were selected using a conventional region-based approach. We demonstrated that the Probst bundles have a wider connectivity than the previously described rostrocaudal direction, and a microstructure rather distinct from the cingulum but relatively close to callosal remnant fibres. A sigmoid bundle was found in two partial ageneses. Second, the corticospinal tract, thalamic radiations and association bundles were extracted automatically via an atlas of adult white matter bundles to overcome bias resulting from a priori knowledge of the bundles' anatomical morphology and trajectory. Despite the lack of callosal fibres and the colpocephaly observed in CCD, all major white matter bundles were identified with a relatively normal morphology, and preserved microstructure (i.e. fractional anisotropy, mean diffusivity) and asymmetries. Consequently the bundles' organisation seems well conserved in brains with CCD. These results await further investigations with functional imaging before apprehending the cognition variability in children with isolated dysgenesis.
    [bibtex-entry]


  7. Lucie Charles, Jean Rémi King, and Stanislas DEHAENE. Decoding the Dynamics of Action, Intention, and Error Detection for Conscious and Subliminal Stimuli. The Journal of Neuroscience, 34(4):1158-1170, 2014. [PDF] [bibtex-entry]


  8. Stanislas Dehaene, Lucie Charles, Jean-Remi King, and Sebastien Marti. Toward a computational theory of conscious processing. Current Opinion in Neurobiology, 25:76-84, 2014. [PDF] [bibtex-entry]


  9. Stanislas Dehaene. Reading in the Brain Revised and Extended: Response to Comments. Mind & Language, 29:320-35, 2014. [PDF] [bibtex-entry]


  10. Dror Dotan, Naam Friedmann, and Stanislas Dehaene. Breaking down number syntax: Spared comprehension of multi-digit numbers in a patient with impaired digit-to-word conversion. Cortex, 59:62-73, 2014. [PDF] [bibtex-entry]


  11. J. Dubois, G. Dehaene-Lambertz, S. Kulikova, C. Poupon, P. S. Hüppi, and L. Hertz-Pannier. The early development of brain white matter: A review of imaging studies in fetuses, newborns and infants. Neuroscience, 276:48-71, December 2014. [WWW] [PDF]
    Abstract: Studying how the healthy human brain develops is important to understand early pathological mechanisms and to assess the influence of fetal or perinatal events on later life. Brain development relies on complex and intermingled mechanisms especially during gestation and first post-natal months, with intense interactions between genetic, epigenetic and environmental factors. Although the baby's brain is organized early on, it is not a miniature adult brain: regional brain changes are asynchronous and protracted, i.e. sensory-motor regions develop early and quickly, whereas associative regions develop later and slowly over decades. Concurrently, the infant/child gradually achieves new performances, but how brain maturation relates to changes in behavior is poorly understood, requiring non-invasive in vivo imaging studies such as magnetic resonance imaging (MRI). Two main processes of early white matter development are reviewed: (1) establishment of connections between brain regions within functional networks, leading to adult-like organization during the last trimester of gestation, (2) maturation (myelination) of these connections during infancy to provide efficient transfers of information. Current knowledge from post-mortem descriptions and in vivo MRI studies is summed up, focusing on T1- and T2-weighted imaging, diffusion tensor imaging, and quantitative mapping of T1/T2 relaxation times, myelin water fraction and magnetization transfer ratio.
    [bibtex-entry]


  12. Jessica Dubois, Sofya Kulikova, Lucie Hertz-Pannier, Jean-François Mangin, Ghislaine Dehaene-Lambertz, and Cyril Poupon. Correction strategy for diffusion-weighted images corrupted with motion: application to the DTI evaluation of infants' white matter.. Magn Reson Imaging, 32(8):981--992, October 2014. [WWW] [PDF]
    Abstract: Diffusion imaging techniques such as DTI and HARDI are difficult to implement in infants because of their sensitivity to subject motion. A short acquisition time is generally preferred, at the expense of spatial resolution and signal-to-noise ratio. Before estimating the local diffusion model, most pre-processing techniques only register diffusion-weighted volumes, without correcting for intra-slice artifacts due to motion or technical problems. Here, we propose a fully automated strategy, which takes advantage of a high orientation number and is based on spherical-harmonics decomposition of the diffusion signal.The correction strategy is based on two successive steps: 1) automated detection and resampling of corrupted slices; 2) correction for eddy current distortions and realignment of misregistered volumes. It was tested on DTI data from adults and non-sedated healthy infants.The methodology was validated through simulated motions applied to an uncorrupted dataset and through comparisons with an unmoved reference. Second, we showed that the correction applied to an infant group enabled to improve DTI maps and to increase the reliability of DTI quantification in the immature cortico-spinal tract.This automated strategy performed reliably on DTI datasets and can be applied to spherical single- and multiple-shell diffusion imaging.
    [bibtex-entry]


  13. Imen El Karoui, Jean-Remi King, Jacobo Sitt, Florent Meyniel, Simon Van Gaal, Dominique Hasboun, Claude Adam, Vincent Navarro, Michel Baulac, Stanislas Dehaene, Laurent Cohen, and Lionel Naccache. Event-Related Potential, Time-frequency, and Functional Connectivity Facets of Local and Global Auditory Novelty Processing: An Intracranial Study in Humans. Cereb Cortex, June 2014. [WWW] [PDF]
    Abstract: Auditory novelty detection has been associated with different cognitive processes. Bekinschtein et al. (2009) developed an experimental paradigm to dissociate these processes, using local and global novelty, which were associated, respectively, with automatic versus strategic perceptual processing. They have mostly been studied using event-related potentials (ERPs), but local spiking activity as indexed by gamma (60-120 Hz) power and interactions between brain regions as indexed by modulations in beta-band (13-25 Hz) power and functional connectivity have not been explored. We thus recorded 9 epileptic patients with intracranial electrodes to compare the precise dynamics of the responses to local and global novelty. Local novelty triggered an early response observed as an intracranial mismatch negativity (MMN) contemporary with a strong power increase in the gamma band and an increase in connectivity in the beta band. Importantly, all these responses were strictly confined to the temporal auditory cortex. In contrast, global novelty gave rise to a late ERP response distributed across brain areas, contemporary with a sustained power decrease in the beta band (13-25 Hz) and an increase in connectivity in the alpha band (8-13 Hz) within the frontal lobe. We discuss these multi-facet signatures in terms of conscious access to perceptual information.
    [bibtex-entry]


  14. C. Kabdebon, F. Leroy, H. Simonnet, M. Perrot, J. Dubois, and G. Dehaene-Lambertz. Anatomical correlations of the international 10-20 sensor placement system in infants. Neuroimage, May 2014. [WWW] [PDF]
    Abstract: Developmental research, as well as paediatric clinical activity crucially depends on non-invasive and painless brain recording techniques, such as electroencephalography (EEG), and near infrared spectroscopy (NIRS). However, both of these techniques measure cortical activity from the scalp without precise knowledge of the recorded cerebral structures. An accurate and reliable mapping between external anatomical landmarks and internal cerebral structures is therefore fundamental to localise brain sources in a non-invasive way. Here, using MRI, we examined the relations between the 10-20 sensor placement system and cerebral structures in 16 infants (3-17 weeks post-term). We provided an infant template parcelled in 94 regions on which we reported the variability of sensors locations, concurrently with the anatomical variability of six main cortical sulci (superior and inferior frontal sulcus, central sulcus, sylvian fissure, superior temporal sulcus, and intraparietal sulcus) and of the distances between the sensors and important cortical landmarks across these infants. The main difference between infants and adults was observed for the channels O1-O2, T5-T6, which projected over lower structures than in adults. We did not find any asymmetry in the distances between the scalp and the brain envelope. However, because of the Yakovlean torque pushing dorsally and frontally the right sylvian fissure, P3-P4 were not at the same distance from the posterior end of this structure. This study should help to refine hypotheses on functional cognitive development by providing an accurate description of the localization of standardised channels relative to infants' brain structures. Template and atlas are publicly available on our Web site (http://www.unicog.org/pm/pmwiki.php/Site/InfantTemplate).
    [bibtex-entry]


  15. J-R. King and S. Dehaene. A model of subjective report and objective discrimination as categorical decisions in a vast representational space. Philos Trans R Soc Lond B Biol Sci, 369(1641):20130204, 2014. [WWW] [PDF]
    Abstract: Subliminal perception studies have shown that one can objectively discriminate a stimulus without subjectively perceiving it. We show how a minimalist framework based on Signal Detection Theory and Bayesian inference can account for this dissociation, by describing subjective and objective tasks with similar decision-theoretic mechanisms. Each of these tasks relies on distinct response classes, and therefore distinct priors and decision boundaries. As a result, they may reach different conclusions. By formalizing, within the same framework, forced-choice discrimination responses, subjective visibility reports and confidence ratings, we show that this decision model suffices to account for several classical characteristics of conscious and unconscious perception. Furthermore, the model provides a set of original predictions on the nonlinear profiles of discrimination performance obtained at various levels of visibility. We successfully test one such prediction in a novel experiment: when varying continuously the degree of perceptual ambiguity between two visual symbols presented at perceptual threshold, identification performance varies quasi-linearly when the stimulus is unseen and in an 'all-or-none' manner when it is seen. The present model highlights how conscious and non-conscious decisions may correspond to distinct categorizations of the same stimulus encoded by a high-dimensional neuronal population vector.
    [bibtex-entry]


  16. J-R. King and S. Dehaene. Characterizing the dynamics of mental representations: the temporal generalization method. Trends Cogn Sci, March 2014. [WWW] [PDF]
    Abstract: Parsing a cognitive task into a sequence of operations is a central problem in cognitive neuroscience. We argue that a major advance is now possible owing to the application of pattern classifiers to time-resolved recordings of brain activity [electroencephalography (EEG), magnetoencephalography (MEG), or intracranial recordings]. By testing at which moment a specific mental content becomes decodable in brain activity, we can characterize the time course of cognitive codes. Most importantly, the manner in which the trained classifiers generalize across time, and from one experimental condition to another, sheds light on the temporal organization of information-processing stages. A repertoire of canonical dynamical patterns is observed across various experiments and brain regions. This method thus provides a novel way to understand how mental representations are manipulated and transformed.
    [bibtex-entry]


  17. Jean-Rémi King, Alexandre Gramfort, Aaron Schurger, Lionel Naccache, and Stanislas Dehaene. Two distinct dynamic modes subtend the detection of unexpected sounds. PLoS One, 9(1):e85791, 2014. [WWW] [PDF]
    Abstract: THE BRAIN RESPONSE TO AUDITORY NOVELTY COMPRISES TWO MAIN EEG COMPONENTS: an early mismatch negativity and a late P300. Whereas the former has been proposed to reflect a prediction error, the latter is often associated with working memory updating. Interestingly, these two proposals predict fundamentally different dynamics: prediction errors are thought to propagate serially through several distinct brain areas, while working memory supposes that activity is sustained over time within a stable set of brain areas. Here we test this temporal dissociation by showing how the generalization of brain activity patterns across time can characterize the dynamics of the underlying neural processes. This method is applied to magnetoencephalography (MEG) recordings acquired from healthy participants who were presented with two types of auditory novelty. Following our predictions, the results show that the mismatch evoked by a local novelty leads to the sequential recruitment of distinct and short-lived patterns of brain activity. In sharp contrast, the global novelty evoked by an unexpected sequence of five sounds elicits a sustained state of brain activity that lasts for several hundreds of milliseconds. The present results highlight how MEG combined with multivariate pattern analyses can characterize the dynamics of human cortical processes.
    [bibtex-entry]


  18. André Knops, Stanislas Dehaene, Ilaria Berteletti, and Marco Zorzi. Can approximate mental calculation account for operational momentum in addition and subtraction?. Q J Exp Psychol (Hove), February 2014. [WWW] [PDF]
    Abstract: The operational momentum (OM) effect describes a cognitive bias whereby we overestimate the results of mental addition problems while underestimating for subtraction. To test whether the OM emerges from psychophysical characteristics of the mental magnitude representation we measured two basic parameters (Weber fraction and numerical estimation accuracy) characterizing the mental magnitude representation and participants' performance in cross-notational addition and subtraction problems. Although participants were able to solve the cross-notational problems, they consistently chose relatively larger results in addition problems than in subtraction problems, thus replicating and extending previous results. Combining the above measures in a psychophysical model allowed us to partially predict the chosen results. Most crucially, however, we were not able to fully model the OM bias on the basis of these psychophysical parameters. Our results speak against the idea that the OM is due to basic characteristics of the mental magnitude representation. In turn, this might be interpreted as evidence for the assumption that the OM effect is better explained by attentional shifts along the mental magnitude representation during mental calculation.
    [bibtex-entry]


  19. André Knops, Manuela Piazza, Rakesh Sengupta, Evelyn Eger, and David Melcher. A shared, flexible neural map architecture reflects capacity limits in both visual short-term memory and enumeration. J Neurosci, 34(30):9857--9866, July 2014. [WWW] [PDF]
    Abstract: Human cognition is characterized by severe capacity limits: we can accurately track, enumerate, or hold in mind only a small number of items at a time. It remains debated whether capacity limitations across tasks are determined by a common system. Here we measure brain activation of adult subjects performing either a visual short-term memory (vSTM) task consisting of holding in mind precise information about the orientation and position of a variable number of items, or an enumeration task consisting of assessing the number of items in those sets. We show that task-specific capacity limits (three to four items in enumeration and two to three in vSTM) are neurally reflected in the activity of the posterior parietal cortex (PPC): an identical set of voxels in this region, commonly activated during the two tasks, changed its overall response profile reflecting task-specific capacity limitations. These results, replicated in a second experiment, were further supported by multivariate pattern analysis in which we could decode the number of items presented over a larger range during enumeration than during vSTM. Finally, we simulated our results with a computational model of PPC using a saliency map architecture in which the level of mutual inhibition between nodes gives rise to capacity limitations and reflects the task-dependent precision with which objects need to be encoded (high precision for vSTM, lower precision for enumeration). Together, our work supports the existence of a common, flexible system underlying capacity limits across tasks in PPC that may take the form of a saliency map.
    [bibtex-entry]


  20. R Kolinsky, J Morais, L Cohen, G Dehaene-Lambertz, and S Dehaene. L influence de l apprentissage du langage ecrit sur les aires du langage / The impact of literacy on the language brain areas. Rev Neuropsy, 6(3):173-81, 2014. [PDF] [bibtex-entry]


  21. S. Kulikova, L. Hertz-Pannier, G. Dehaene-Lambertz, A. Buzmakov, C. Poupon, and J. Dubois. Multi-parametric evaluation of the white matter maturation.. Brain Struct Funct, September 2014. [WWW] [PDF]
    Abstract: In vivo evaluation of the brain white matter maturation is still a challenging task with no existing gold standards. In this article we propose an original approach to evaluate the early maturation of the white matter bundles, which is based on comparison of infant and adult groups using the Mahalanobis distance computed from four complementary MRI parameters: quantitative qT1 and qT2 relaxation times, longitudinal ?? and transverse ?? diffusivities from diffusion tensor imaging. Such multi-parametric approach is expected to better describe maturational asynchrony than conventional univariate approaches because it takes into account complementary dependencies of the parameters on different maturational processes, notably the decrease in water content and the myelination. Our approach was tested on 17 healthy infants (aged 3- to 21-week old) for 18 different bundles. It finely confirmed maturational asynchrony across the bundles: the spino-thalamic tract, the optic radiations, the cortico-spinal tract and the fornix have the most advanced maturation, while the superior longitudinal and arcuate fasciculi, the anterior limb of the internal capsule and the external capsule have the most delayed maturation. Furthermore, this approach was more reliable than univariate approaches as it revealed more maturational relationships between the bundles and did not violate a priori assumptions on the temporal order of the bundle maturation. Mahalanobis distances decreased exponentially with age in all bundles, with the only difference between them explained by different onsets of maturation. Estimation of these relative delays confirmed that the most dramatic changes occur during the first post-natal year.
    [bibtex-entry]


  22. Anne Kösem, Alexandre Gramfort, and Virginie van Wassenhove. Encoding of event timing in the phase of neural oscillations. Neuroimage, 92C:274--284, February 2014. [WWW] [PDF]
    Abstract: Time perception is a critical component of conscious experience. To be in synchrony with the environment, the brain must deal not only with differences in the speed of light and sound but also with its computational and neural transmission delays. Here, we asked whether the brain could actively compensate for temporal delays by changing its processing time. Specifically, can changes in neural timing or in the phase of neural oscillation index perceived timing? For this, a lag-adaptation paradigm was used to manipulate participants' perceived audiovisual (AV) simultaneity of events while they were recorded with magnetoencephalography (MEG). Desynchronized AV stimuli were presented rhythmically to elicit a robust 1Hz frequency-tagging of auditory and visual cortical responses. As participants' perception of AV simultaneity shifted, systematic changes in the phase of entrained neural oscillations were observed. This suggests that neural entrainment is not a passive response and that the entrained neural oscillation shifts in time. Crucially, our results indicate that shifts in neural timing in auditory cortices linearly map participants' perceived AV simultaneity. To our knowledge, these results provide the first mechanistic evidence for active neural compensation in the encoding of sensory event timing in support of the emergence of time awareness.
    [bibtex-entry]


  23. C. Lopez-Escribano and Antonio Moreno. Neuroscience and education:developmental study of a hemispherectomy case / Neurociencia y educación: estudio evolutivo de un caso de hemisferectomía. Infancia y Aprendizaje: Journal for the Study of Education and Development, 08 Oct, 2014. [PDF] [bibtex-entry]


  24. Sébastien Marti, Louis Thibault, and Stanislas Dehaene. How does the extraction of local and global auditory regularities vary with context?. PLoS One, 9(9):e107227, 2014. [WWW] [PDF]
    Abstract: How does the human brain extract regularities from its environment? There is evidence that short range or 'local' regularities (within seconds) are automatically detected by the brain while long range or 'global' regularities (over tens of seconds or more) require conscious awareness. In the present experiment, we asked whether participants' attention was needed to acquire such auditory regularities, to detect their violation or both. We designed a paradigm in which participants listened to predictable sounds. Subjects could be distracted by a visual task at two moments: when they were first exposed to a regularity or when they detected violations of this regularity. MEG recordings revealed that early brain responses (100-130 ms) to violations of short range regularities were unaffected by visual distraction and driven essentially by local transitional probabilities. Based on global workspace theory and prior results, we expected that visual distraction would eliminate the long range global effect, but unexpectedly, we found the contrary, i.e. late brain responses (300-600 ms) to violations of long range regularities on audio-visual trials but not on auditory only trials. Further analyses showed that, in fact, visual distraction was incomplete and that auditory and visual stimuli interfered in both directions. Our results show that conscious, attentive subjects can learn the long range dependencies present in auditory stimuli even while performing a visual task on synchronous visual stimuli. Furthermore, they acquire a complex regularity and end up making different predictions for the very same stimulus depending on the context (i.e. absence or presence of visual stimuli). These results suggest that while short-range regularity detection is driven by local transitional probabilities between stimuli, the human brain detects and stores long-range regularities in a highly flexible, context dependent manner.
    [bibtex-entry]


  25. Felipe Pegado, Enio Comerlato, Fabricio Ventura, Antoinette Jobert, Kimihiro Nakamura, Marco Buiatti, Paulo Ventura, Ghislaine Dehaene-Lambertz, Regine Kolinsky, Jose Morais, Lucia W. Braga, Laurent Cohen, and Stanislas Dehaene. Timing the impact of literacy on visual processing.. Proc Natl Acad Sci U S A, 111(49):E5233--E5242, December 2014. [WWW] [PDF]
    Abstract: Learning to read requires the acquisition of an efficient visual procedure for quickly recognizing fine print. Thus, reading practice could induce a perceptual learning effect in early vision. Using functional magnetic resonance imaging (fMRI) in literate and illiterate adults, we previously demonstrated an impact of reading acquisition on both high- and low-level occipitotemporal visual areas, but could not resolve the time course of these effects. To clarify whether literacy affects early vs. late stages of visual processing, we measured event-related potentials to various categories of visual stimuli in healthy adults with variable levels of literacy, including completely illiterate subjects, early-schooled literate subjects, and subjects who learned to read in adulthood (ex-illiterates). The stimuli included written letter strings forming pseudowords, on which literacy is expected to have a major impact, as well as faces, houses, tools, checkerboards, and false fonts. To evaluate the precision with which these stimuli were encoded, we studied repetition effects by presenting the stimuli in pairs composed of repeated, mirrored, or unrelated pictures from the same category. The results indicate that reading ability is correlated with a broad enhancement of early visual processing, including increased repetition suppression, suggesting better exemplar discrimination, and increased mirror discrimination, as early as ? 100-150 ms in the left occipitotemporal region. These effects were found with letter strings and false fonts, but also were partially generalized to other visual categories. Thus, learning to read affects the magnitude, precision, and invariance of early visual processing.
    [bibtex-entry]


  26. Felipe Pegado, Kimihiro Nakamura, Lucia W. Braga, Paulo Ventura, Gilberto Nunes Filho, Christophe Pallier, Antoinette Jobert, José Morais, Laurent Cohen, Régine Kolinsky, and Stanislas Dehaene. Literacy breaks mirror invariance for visual stimuli: A behavioral study with adult illiterates. J Exp Psychol Gen, 143(2):887--894, April 2014. [WWW] [PDF]
    Abstract: The ability to recognize 2 mirror images as the same picture across left-right inversions exists early on in humans and other primates. In order to learn to read, however, one must discriminate the left-right orientation of letters and distinguish, for instance, b from d. We therefore reasoned that literacy may entail a loss of mirror invariance. To evaluate this hypothesis, we asked adult literates, illiterates, and ex-illiterates to perform a speeded same-different task with letter strings, false fonts, and pictures regardless of their orientation (i.e., they had to respond "same" to mirror pairs such as "iblo oldi"). Literates presented clear difficulties with mirror invariance. This "mirror cost" effect was strongest with letter strings, but crucially, it was also observed with false fonts and even with pictures. In contrast, illiterates did not present any cost for mirror pairs. Interestingly, subjects who learned to read as adults also exhibited a mirror cost, suggesting that modest reading practice, late in life, can suffice to break mirror invariance. (PsycINFO Database Record (c) 2014 APA, all rights reserved).
    [bibtex-entry]


  27. Marcela Peña, Diana Arias, and Ghislaine Dehaene-Lambertz. Gaze Following Is Accelerated in Healthy Preterm Infants.. Psychol Sci, August 14, August 2014. [WWW] [PDF]
    Abstract: Gaze following is an essential human communication cue that orients the attention of two interacting people to the same external object. This capability is robustly observed after 7 months of age in full-term infants. Do healthy preterm infants benefit from their early exposure to face-to-face interactions with other humans to acquire this capacity sooner than full-term infants of the same chronological age, despite their immature brains? In two different experiments, we demonstrated that 7-month-old preterm infants performed like 7-month-old full-term infants (with whom they shared the same chronological age) and not like 4-month-old full-term infants (with whom they shared the same postmenstrual age). The duration of exposure to visual experience thus appears to have a greater impact on the development of early gaze following than does postmenstrual age.
    [bibtex-entry]


  28. Philippe Pinel, Christophe Lalanne, Thomas Bourgeron, Fabien Fauchereau, Cyril Poupon, Eric Artiges, Denis Le Bihan, Ghislaine Dehaene-Lambertz, and Stanislas Dehaene. Genetic and Environmental Influences on the Visual Word Form and Fusiform Face Areas. Cereb Cortex, May 2014. [WWW] [PDF]
    Abstract: Two areas of the occipitotemporal cortex show a remarkable hemispheric lateralization: written words activate the visual word form area (VWFA) in the left fusiform gyrus and faces activate a symmetrical site in the right hemisphere, the fusiform face area (FFA). While the lateralization of the VWFA fits with the leftward asymmetry of the speech processing network, origin of the rightward asymmetry for faces is still unclear. Using fMRI data from 64 subjects (including 16 monozygotic (MZ) and 13 dizygotic (DZ) twin pairs), we investigated how activations evoked by written words, faces, and spoken language are co-lateralized in the temporal lobe, and whether this organization reflects genetic factors or individual reading expertise. We found that the lateralization of the left superior temporal activation for spoken language correlates with the lateralization of occipitotemporal activations for both written words and faces. Behavioral reading scores also modulate the responses to words and faces. Estimation of genetic and environmental contributions shows that activations of the VWFA, the occipital face area, and the temporal speech areas are partially under genetic control whereas activation of the FFA is primarily influenced by individual experience. Our results stress the importance of both genetic factors and acquired expertise in the occipitotemporal organization.
    [bibtex-entry]


  29. Jacobo Diego Sitt, Jean-Remi King, Imen El Karoui, Benjamin Rohaut, Frederic Faugeras, Alexandre Gramfort, Laurent Cohen, Mariano Sigman, Stanislas Dehaene, and Lionel Naccache. Large scale screening of neural signatures of consciousness in patients in a vegetative or minimally conscious state. Brain, June 2014. [WWW] [PDF]
    Abstract: In recent years, numerous electrophysiological signatures of consciousness have been proposed. Here, we perform a systematic analysis of these electroencephalography markers by quantifying their efficiency in differentiating patients in a vegetative state from those in a minimally conscious or conscious state. Capitalizing on a review of previous experiments and current theories, we identify a series of measures that can be organized into four dimensions: (i) event-related potentials versus ongoing electroencephalography activity; (ii) local dynamics versus inter-electrode information exchange; (iii) spectral patterns versus information complexity; and (iv) average versus fluctuations over the recording session. We analysed a large set of 181 high-density electroencephalography recordings acquired in a 30 minutes protocol. We show that low-frequency power, electroencephalography complexity, and information exchange constitute the most reliable signatures of the conscious state. When combined, these measures synergize to allow an automatic classification of patients' state of consciousness.
    [bibtex-entry]


  30. Marcin Szwed, Emilie Qiao, Antoinette Jobert, Stanislas Dehaene, and Laurent Cohen. Effects of Literacy in Early Visual and Occipitotemporal Areas of Chinese and French Readers. J Cogn Neurosci, 6:459-475, March 2014. [WWW] [PDF]
    Abstract: How does reading expertise change the visual system? Here, we explored whether the visual system could develop dedicated perceptual mechanisms in early and intermediate visual cortex under the pressure for fast processing that is particularly strong in reading. We compared fMRI activations in Chinese participants with limited knowledge of French and in French participants with no knowledge of Chinese, exploiting these doubly dissociated reading skills as a tool to study the neural correlates of visual expertise. All participants viewed the same stimuli: words in both languages and matched visual controls, presented at a fast rate comparable with fluent reading. In the Visual Word Form Area, all participants showed enhanced responses to their known scripts. However, group differences were found in occipital cortex. In French readers reading French, activations were enhanced in left-hemisphere visual area V1, with the strongest differences between French words and their controls found at the central and horizontal meridian representations. Chinese participants , who were not expert French readers, did not show these early visual activations. In contrast, Chinese readers reading Chinese showed enhanced activations in intermediate visual areas V3v/hV4, absent in French participants. Together with our previous findings [Szwed, M., Dehaene, S., Kleinschmidt, A., Eger, E., Valabregue, R., Amadon, A., et al. Specialization for written words over objects in the visual cortex. Neuroimage, 56, 330-344, 2011], our results suggest that the effects of extensive practice can be found at the lowest levels of the visual system. They also reveal their cross-script variability: Alphabetic reading involves enhanced engagement of central and right meridian V1 representations that are particularly used in left-to-right reading, whereas Chinese characters put greater emphasis on intermediate visual areas.
    [bibtex-entry]


  31. Lynn Uhrig, Stanislas Dehaene, and Bechir Jarraya. A Hierarchy of Responses to Auditory Regularities in the Macaque Brain. The Journal of Neuroscience, 34:1127-32, 2014. [PDF] [bibtex-entry]


  32. L. Uhrig, S. Dehaene, and B. Jarraya. Cerebral mechanisms of general anesthesia. Ann Fr Anesth Reanim, 33(2):72--82, February 2014. [WWW] [PDF]
    Abstract: How does general anesthesia (GA) work? Anesthetics are pharmacological agents that target specific central nervous system receptors. Once they bind to their brain receptors, anesthetics modulate remote brain areas and end up interfering with global neuronal networks, leading to a controlled and reversible loss of consciousness. This remarkable manipulation of consciousness allows millions of people every year to undergo surgery safely most of the time. However, despite all the progress that has been made, we still lack a clear and comprehensive insight into the specific neurophysiological mechanisms of GA, from the molecular level to the global brain propagation. During the last decade, the exponential progress in neuroscience and neuro-imaging led to a significant step in the understanding of the neural correlates of consciousness, with direct consequences for clinical anesthesia. Far from shutting down all brain activity, anesthetics lead to a shift in the brain state to a distinct, highly specific and complex state, which is being increasingly characterized by modern neuro-imaging techniques. There are several clinical consequences and challenges that are arising from the current efforts to dissect GA mechanisms: the improvement of anesthetic depth monitoring, the characterization and avoidance of intra-operative awareness and post-anesthesia cognitive disorders, and the development of future generations of anesthetics.
    [bibtex-entry]


  33. Simon van Gaal, Lionel Naccache, Julia D I. Meuwese, Anouk M. van Loon, Alexandra H. Leighton, Laurent Cohen, and Stanislas Dehaene. Can the meaning of multiple words be integrated unconsciously?. Philos Trans R Soc Lond B Biol Sci, 369(1641):20130212, May 2014. [WWW] [PDF]
    Abstract: What are the limits of unconscious language processing? Can language circuits process simple grammatical constructions unconsciously and integrate the meaning of several unseen words? Using behavioural priming and electroencephalography (EEG), we studied a specific rule-based linguistic operation traditionally thought to require conscious cognitive control: the negation of valence. In a masked priming paradigm, two masked words were successively (Experiment 1) or simultaneously presented (Experiment 2), a modifier ('not'/'very') and an adjective (e.g. 'good'/'bad'), followed by a visible target noun (e.g. 'peace'/'murder'). Subjects indicated whether the target noun had a positive or negative valence. The combination of these three words could either be contextually consistent (e.g. 'very bad - murder') or inconsistent (e.g. 'not bad - murder'). EEG recordings revealed that grammatical negations could unfold partly unconsciously, as reflected in similar occipito-parietal N400 effects for conscious and unconscious three-word sequences forming inconsistent combinations. However, only conscious word sequences elicited P600 effects, later in time. Overall, these results suggest that multiple unconscious words can be rapidly integrated and that an unconscious negation can automatically 'flip the sign' of an unconscious adjective. These findings not only extend the limits of subliminal combinatorial language processes, but also highlight how consciousness modulates the grammatical integration of multiple words.
    [bibtex-entry]


  34. Virginie van Wassenhove and Lucille Lecoutre. Duration estimation entails predicting when.. Neuroimage, November 2014. [WWW]
    Abstract: The estimation of duration can be affected by context and surprise. Using MagnetoEncephaloGraphy (MEG), we tested whether increased neural activity during surprise and following neural suppression in two different contexts supported subjective time dilation (Eagleman & Pariyadath, 2009; Pariyadath & Eagleman, 2012). Sequences of three 300ms frequency-modulated (FM, control) or pure tones (test) were presented and followed by a fourth FM varying in duration. In test, the last FM was perceived as significantly longer than veridical duration (Tse, Intriligator, Rivest, & Cavanagh, 2004) but did not differ from the perceived duration in control. Several novel and distinct neural signatures were observed in duration estimation: first, neural suppression of standard stimuli was observed for the onset but not for the offset auditory evoked responses. Second, ramping activity increased with veridical duration in control whereas at the same latency in test, the amplitude of the midlatency response increased with the distance of deviant durations. Third, in both conditions, the amplitude of the offset auditory evoked responses accounted well for participants' performance: the longer the perceived duration, the larger the offset response. Fourth, neural duration demarcated by the peak latencies of the onset and ramping evoked activities indexed a systematic time compression that reliably predicted subjective time perception. Our findings suggest that interval timing undergoes time compression by capitalizing on the predicted offset of an auditory event.
    [bibtex-entry]


  35. Arnaud Viarouge, Edward M. Hubbard, and Stanislas Dehaene. The Organization of Spatial Reference Frames Involved in the SNARC Effect. Q J Exp Psychol (Hove), February 2014. [WWW] [PDF]
    Abstract: Abstract The SNARC effect refers to faster reaction times for larger numbers with right-sided responses, and for smaller numbers with left-sided responses (Dehaene et al., 1993), even when numerical magnitude is irrelevant. Although the SNARC is generally thought to reflect a mapping between numbers and space, the question of which spatial reference frame(s) are critical for the effect has not been systematically explored. We propose a dynamic hierarchical organization of the reference frames (from a global left-right frame to body- and object-related frames), where the influence of each frame can be modulated by experimental context. We conducted two experiments based on predictions derived from this organizational system. Experiment 1 compared instructions that differed only in focusing participants' attention on either the response buttons or the hands. Instructions focusing on a hand-based reference frame eliminated the SNARC. Experiment 2 provided the opportunity for an object-centered reference frame to manifest itself in the SNARC. Although we did not observe an effect of an object-centered reference frame, we observed the influence of other reference frames in a context where an object-centered reference frame was emphasized. Altogether, these results support the proposed organization of the reference frames.
    [bibtex-entry]



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Last modified: Thu Dec 14 15:36:12 2017
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