Henri Vandendriessche, nouveau lab manager du DEC

Le DEC a le plaisir d'accueillir son nouveau lab manager, Henri Vandendriessche. Agé de 24 ans, Henri est titulaire d’un diplôme d’ingénieur en électronique et informatique obtenu à Lille. Il a effectué une partie de ses études en Allemagne, notamment à l’université technique de Dortmund.

Ses missions principales sont:

- la gestion des cabines d’expérimentation du deuxième étage au 29 rue d'Ulm et également du système de réservation en ligne GRR.
- la maintenance de la plateforme (ordinateurs, logiciels, matériel expérimental, …).
- la formation à l’utilisation des dispositifs expérimentaux.

Henri Vandendriessche est joignable par email, henri.vandendriessche@ens.fr ou au 01 44 32 27 92.

Barbalat G, Leboyer M, Zalla T. (2014) - A specific impairment in cognitive control in individuals with high-functioning autism. J Psychiatr Res. Jul 23. pii: S0022-3956(14)00210-6. doi: 10.1016/j.jpsychires.2014.07.013.

Abstract:
Although it is largely demonstrated that Autism Spectrum Disorders (ASDs) are characterized by executive dysfunctions, little is known about the fine-grained levels of this impairment. Here, we investigated the hierarchical architecture of control modules in autism using an experimental paradigm based upon a multistage model of executive functions. This model postulates that executive functions are hierarchically organized as a cascade of three different control processes, which are implemented according to information conveyed by sensory signals (sensory control), the immediate perceptual context (contextual control), and the temporal episode in which stimuli occur (episodic control). Sixteen high-functioning adults with autism or Asperger Syndrome (HFA/AS) and sixteen matched comparison participants took part in two distinct visuo-motor association experiments designed to separately vary the demands of sensory and episodic controls (first experiment) and contextual and episodic controls (second experiment). Participants with HFA/AS demonstrated no significant differences in performances with comparison participants when they had to control sensory or contextual information. However, they showed decreased accuracy when having to control information related to episodic signals. Remarkably, performances in episodic control were associated to the autism spectrum quotient in both groups, suggesting that this episodic control impairment might be at the core of ASDs. Those results plead for a specific, rather than generalised, deficit in executive functions in autism. Our study contributes to a better understanding of the impaired cognitive processes that are unique to autism and warrants confirmation using other models of executive functions.

Cabrera, L., Tsao, F-M., Gnansia, D., Bertoncini, J., & Lorenzi C. - The role of spectro-temporal fine structure cues in lexical-tone discrimination for French and Mandarin listeners Journal of the Acoustical Society of America.

Abstract:
The role of spectro-temporal modulation cues in conveying tonal information for lexical tones was assessed in native-Mandarin and native-French adult listeners using a lexical-tone discrimination task. The fundamental frequency (F0) of Thai tones was either degraded using an 8-band vocoder that reduced fine spectral details and frequency-modulation cues, or extracted and used to modulate the F0 of click trains. Mandarin listeners scored lower than French listeners in the discrimination of vocoded lexical tones. For click trains, Mandarin listeners outperformed French listeners. These preliminary results suggest that the perceptual weight of the fine spectro-temporal modulation cues conveying F0 information is enhanced for adults speaking a tonal language.

Cheveigné, A., Parra, L.. (2014) Joint decorrelation: a versatile tool for multichannel data analysis. NeuroImage, 98, 487-505.

Abstract:
We review a simple yet versatile method for the analysis of multichannel data, focusing in particular on brain signals measured with EEG, MEG, ECoG, LFP or optical imaging. Sensors are combined linearly with weights that are chosen to provide optimal signal-to-noise ratio. Signal and noise can be variably defined to match the specific need, e.g. reproducibility over trials, frequency content, or differences between stimulus conditions. We demonstrate how the method can be used to remove power line or cardiac interference, enhance stimulus-evoked or stimulus-induced activity, isolate narrow-band cortical activity, and so on. We trace its origins; offer an easy-to-understand explanation; review a range of applications; and chart failure scenarios that might lead to misleading results. In addition to its flexibility and effectiveness, a major appeal of the method is that it is easy to understand.

Sid Kouider, Thomas Andrillon, Leonardo S. Barbosa, Louise Goupil & Tristan A. Bekinschtein. Current Biology, 11 septembre 2014 - Inducing task-relevant responses to speech in the sleeping brain

Summary:
Falling asleep leads to a loss of sensory awareness and to the inability to interact with the environment [1]. While this was traditionally thought as a consequence of the brain shutting down to external inputs, it is now acknowledged that incoming stimuli can still be processed, at least to some extent, during sleep [2]. For instance, sleeping participants can create novel sensory associations between tones and odors [3] or reactivate existing semantic associations, as evidenced by event-related potentials [4, 5, 6 and 7]. Yet, the extent to which the brain continues to process external stimuli remains largely unknown. In particular, it remains unclear whether sensory information can be processed in a flexible and task-dependent manner by the sleeping brain, all the way up to the preparation of relevant actions. Here, using semantic categorization and lexical decision tasks, we studied task-relevant responses triggered by spoken stimuli in the sleeping brain. Awake participants classified words as either animals or objects (experiment 1) or as either words or pseudowords (experiment 2) by pressing a button with their right or left hand, while transitioning toward sleep. The lateralized readiness potential (LRP), an electrophysiological index of response preparation, revealed that task-specific preparatory responses are preserved during sleep. These findings demonstrate that despite the absence of awareness and behavioral responsiveness, sleepers can still extract task-relevant information from external stimuli and covertly prepare for appropriate motor responses.

Martin JR, Dezecache G, Pressnitzer D, Nuss P, Dokic J, Bruno N, Pacherie E, Franck N.2014 Aug 18 - Perceptual hysteresis as a marker of perceptual inflexibility in schizophrenia. Conscious Cogn.;30C:62-72. doi: 10.1016/j.concog.2014.07.014.

Abstract:
People with schizophrenia are known to exhibit difficulties in the updating of their current belief states even in the light of disconfirmatory evidence. In the present study we tested the hypothesis that people with schizophrenia could also manifest perceptual inflexibility, or difficulties in the updating of their current sensory states. The presence of perceptual inflexibility might contribute both to the patients' altered perception of reality and the formation of some delusions as well as to their social cognition deficits. Here, we addressed this issue with a protocol of auditory hysteresis, a direct measure of sensory persistence, on a population of stabilized antipsychotic-treated schizophrenia patients and a sample of control subjects. Trials consisted of emotional signals (i.e., screams) and neutral signals (i.e., spectrally-rotated versions of the emotional stimuli) progressively emerging from white noise - Ascending Sequences - or progressively fading away in white noise - Descending Sequences. Results showed that patients presented significantly stronger hysteresis effects than control subjects, as evidenced by a higher rate of perceptual reports in Descending Sequences. The present study thus provides direct evidence of perceptual inflexibility in schizophrenia.

Friederike Moltmann (2014) - Propositions, Attitudinal Objects, and the Distinction Between Actions and Products Canadian Journal of Philosophy, Special Issue: Essays on the Nature of Propositionson Propositions, Edited by G. Rattan and D. Hunter 43 (5-6):679-701

Abstract
Propositions as mind-independent abstract objects raise serious problems such as their cognitive accessibility and their ability to carry essential truth conditions, as a number of philosophers have recently pointed out. This paper argues that ‘attitudinal objects’ or kinds of them should replace propositions as truth bearers and as the (shared) objects of propositional attitudes. Attitudinal objects, entities like judgments, beliefs, and claims, are not states or actions, but rather their (spatio-temporally coincident) products, following the distinction between actions and products introduced by Twardowski (1912). The paper argues that the action–product distinction is not tied to particular terms in a particular language, but is to be understood as the more general distinction between an action and the (abstract or physically realized) artifact that it creates. It thus includes the distinction between the passing of a law and the law itself and an act of artistic creation and the created work of art.

Moon, Il J., Won, J-H., Park, M.-H., Ives, D. T., Nie, K., Heinz, M. G., Lorenzi, C. & Rubinstein, J. T., (2014, in press) Optimal combination of neural temporal envelope and fine structure cues to explain speech identification in background noise - Journal of Neuroscience.

Abstract:
The dichotomy between acoustic temporal envelope (ENV) and fine structure (TFS) cues has stimulated numerous studies over the past decade to understand the relative role of acoustic ENV and TFS in human speech perception. Such acoustic temporal speech cues produce distinct neural discharge patterns at the level of the auditory nerve, yet little is known about the central neural mechanisms underlying the dichotomy in speech perception between neural ENV and TFS cues. We explored the question of how the peripheral auditory system encodes neural ENV and TFS cues in steady or fluctuating background noise, and how the central auditory system combines these forms of neural information for speech identification. We sought to address this question by (1) measuring sentence identification in background noise for human subjects as a function of the degree of available acoustic TFS information and (2) examining the optimal combination of neural ENV and TFS cues to explain human speech perception performance using computational models of the peripheral auditory system and central neural observers. Speech-identification performance by human subjects decreased as the acoustic TFS information was degraded in the speech signals. The model predictions best matched human performance when a greater emphasis was placed on neural ENV coding rather than neural TFS. However, neural TFS cues were necessary to account for the full effect of background-noise modulations on human speech-identification performance.

Roux, P., Forgeot d’Arc, B., Passerieux, C., & Ramus, F. (2014) - Is the Theory of Mind deficit observed in visual paradigms in schizophrenia explained by an impaired attention toward gaze orientation? . Schizophrenia Research, 157, 78-83.

Abstract:
Schizophrenia is associated with poor Theory of Mind (ToM), particularly in goal and belief attribution to others. It is also associated with abnormal gaze behaviors toward others: individuals with schizophrenia usually look less to others' face and gaze, which are crucial epistemic cues that contribute to correct mental states inferences. This study tests the hypothesis that impaired ToM in schizophrenia might be related to a deficit in visual attention toward gaze orientation. We adapted a previous non-verbal ToM paradigm consisting of animated cartoons allowing the assessment of goal and belief attribution. In the true and false belief conditions, an object was displaced while an agent was either looking at it or away, respectively. Eye movements were recorded to quantify visual attention to gaze orientation (proportion of time participants spent looking at the head of the agent while the target object changed locations). 29 patients with schizophrenia and 29 matched controls were tested. Compared to controls, patients looked significantly less at the agent's head and had lower performance in belief and goal attribution. Performance in belief and goal attribution significantly increased with the head looking percentage. When the head looking percentage was entered as a covariate, the group effect on belief and goal attribution performance was not significant anymore. Patients' deficit on this visual ToM paradigm is thus entirely explained by a decreased visual attention toward gaze.

Zalla T, Sirigu A, Robic S, Chaste P, Leboyer M, Coricelli G. (2014) - Feelings of regret and disappointment in adults with high-functioning autism. Cortex. Sep;58:112-22. doi: 10.1016/j.cortex.2014.05.008. Epub 2014 Jun 9. PMID: 25010486

Abstract:
Impairments in emotional processing in Autism Spectrum Disorders (ASDs) can be characterised by failure to generate and recognize self-reflective, cognitive-based emotions, such as pride, embarrassment and shame. Among this type of emotions, regret and disappointment, as well as their positive counterparts, result from a counterfactual comparison, that is the comparison between an actual value ("what is") and a fictive value ("what might have been"). However, while disappointment is experienced when the obtained outcome is worse than the expected outcome that might have occurred from the same choice, regret occurs when one experiences an outcome that is worse than the outcome of foregone choices. By manipulating a simple gambling task, we examined subjective reports on the intensity of negative and positive emotions in a group of adults with High-Functioning Autism or Asperger syndrome (HFA/AS), and a control group matched for age, gender and educational level. Participants were asked to choose between two lotteries with different levels of risk under two conditions of outcome feedback: (i) Partial, in which only the outcome of the chosen lottery was visible, (ii) Complete, in which the outcomes of the two lotteries were simultaneously visible. By comparing partial and complete conditions, we aimed to investigate the differential effect between disappointment and regret, as well as between their positive counterparts. Relative to the control participants (CP), the group with HFA/AS reported reduced regret and no difference between regret and disappointment, along with a preserved ability to use counterfactual thinking and similar choice behaviour. Difficulties to distinguish the feeling of regret in participants with HFA/AS can be explained by diminished emotional awareness, likely associated with an abnormal fronto-limbic connectivity.

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