Institute des science Cognitives
Institute des science Cognitives
Jensen K.B.,Karolinska Institutet |
Kirsch I.,Harvard University |
Ponten M.,Karolinska Institutet |
Rosen A.,Karolinska Institutet |
And 8 more authors.
Neurology | Year: 2017
Objective: To determine the placebo component of treatment responses in patients with intellectual disability (ID). Methods: A statistical meta-analysis comparing bias-corrected effect sizes (Hedges g) of drug responses in open-label vs placebo-controlled clinical trials was performed, as these trial types represent different certainty of receiving genuine treatment (100% vs 50%). Studies in fragile X, Down, Prader-Willi, and Williams syndrome published before June 2015 were considered. Results: Seventeen open-label trials (n = 261, 65% male; mean age 23.6 years; mean trial duration 38 weeks) and 22 placebo-controlled trials (n = 721, 62% male; mean age 17.1 years; mean trial duration 35 weeks) were included. The overall effect size from pre to post treatment in open-label studies was g = 0.602 (p = 0.001). The effect of trial type was statistically significant (p = 0.001), and revealed higher effect sizes in studies with 100% likelihood of getting active drug, compared to both the drug and placebo arm of placebo-controlled trials. We thus provide evidence for genuine placebo effects, not explainable by natural history or regression toward the mean, among patients with ID. Conclusions: Our data suggest that clinical trials in patients with severe cognitive deficits are influenced by the certainty of receiving genuine medication, and open-label design should thus not be used to evaluate the effect of pharmacologic treatments in ID, as the results will be biased by an enhanced placebo component. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.
Allami N.,Institute des science Cognitives |
Brovelli A.,Aix - Marseille University |
Hamzaoui E.M.,Mohammed V University |
Regragui F.,Mohammed V University |
And 2 more authors.
Neuropsychologia | Year: 2014
We have previously shown that mental rehearsal can replace up to 75% of physical practice for learning a visuomotor task (Allami, Paulignan, Brovelli, & Boussaoud, (2008). Experimental Brain Research, 184, 105-113). Presumably, mental rehearsal must induce brain changes that facilitate motor learning. We tested this hypothesis by recording scalp electroencephalographic activity (EEG) in two groups of subjects. In one group, subjects executed a reach to grasp task for 240 trials. In the second group, subjects learned the task through a combination of mental rehearsal for the initial 180 trials followed by the execution of 60 trials. Thus, one group physically executed the task for 240 trials, the other only for 60 trials. Amplitudes and latencies of event-related potentials (ERPs) were compared across groups at different stages during learning. We found that ERP activity increases dramatically with training and reaches the same amplitude over the premotor regions in the two groups, despite large differences in physically executed trials. These findings suggest that during mental rehearsal, neuronal changes occur in the motor networks that make physical practice after mental rehearsal more effective in configuring functional networks for skilful behaviour. © 2013 Elsevier Ltd.
Zalla T.,Ecole Normale Superieure de Paris |
Labruyere N.,Institute des science Cognitives |
Labruyere N.,Center Hospitalier le Vinatier |
Clement A.,Hospice Civil de Lyon |
And 2 more authors.
Experimental Brain Research | Year: 2010
This study investigated the ability to predict others' action in a group of children and adolescents with autism spectrum disorders (ASD) (n = 18). Their performance was compared with a group of children with mental retardation (n = 13) and a group of children with typical development (n = 19). Participants were presented with short incomplete videotaped movies showing an actor executing familiar and non-familiar actions. When asked to predict the outcome, participants with ASD produced fewer correct responses and their performance did not improve for familiar actions, as compared to both comparison groups. In addition, they committed a greater number of errors of temporal inversion. These results provide new evidence that an impaired means-end analysis process, leading to a diminished sensitivity to the sequence structure of goal-directed actions, would disrupt the ability to understand and predict others' actions. The comprehension of abnormalities in event knowledge provides a better insight of some of the problems that individuals with ASD encounter in spontaneously understanding real-life social situations. © 2009 Springer-Verlag.
Morisseau T.,Institute des science Cognitives |
Davies C.,University of Leeds |
Matthews D.,University of Sheffield
Journal of Pragmatics | Year: 2013
As children learn their native languages, they come to have detailed expectations about how to refer to things. These expectations and the detection of their violations are key to inference-making processes. But what do children do when their expectations are not met? Using reaction-time measures and gaze-direction monitoring in a referential communication task, we investigated whether 3- and 5-year-olds notice the infelicity of under- and over-informative utterances and then seek out further information in order to recover the speaker's intended meaning. We tested how children resolve under-informative instructions such as "Find the orange" when there is more than one orange in view. We also tested whether instructions such as "Find the cat with a tail", in a context where there is only one, normal-looking cat, would lead them to question why the speaker was over-informative and to seek out further information. Both age groups were sensitive to the ambiguous instructions. Only 5-year-olds were significantly delayed and more likely to check their interlocutor's gaze when responding to over-informative expressions. We discuss how children's spontaneous motivation to resolve violations of expectation, coupled with increased speed of linguistic processing, drives language learning. © 2013 Elsevier B.V.
Christel M.I.,Free University of Berlin |
Jeannerod M.,Institute des science Cognitives |
Weiss P.H.,Kognitive Neurologie |
Weiss P.H.,Jülich Research Center
Experimental Brain Research | Year: 2012
To examine the mechanisms of functional bimanual synchronization in goal-directed movements, we studied the movement kinematics of motorically unimpaired subjects while they performed repetitive prehension movements (either unimanually or bimanually) to small food items. Compared to unimanual conditions, bimanual movement execution yielded a significantly prolonged mouth contact phase. We hypothesized that this threefold prolongation led to a proper functional synchronization of the movement onsets of both hands at the beginning of each new movement cycle. That these temporal adjustments occurred in the movement phase with maximal haptic input points to the importance of sensory feedback for bimanual coordination. These results are discussed with respectto the important role of sensory feedback in the timing of coordinated bimanual movements. Furthermore, we propose that timebased coordinating schemas, which are implemented by the cerebellum and the posterior parietal cortex using sensory feedback, underlie functional inter-limb coordination. © Springer-Verlag 2011.
Dezecache G.,French Institute of Health and Medical Research |
Dezecache G.,Ecole Normale Superieure de Paris |
Mercier H.,French National Center for Scientific Research |
Mercier H.,Institute des science Cognitives |
Scott-Phillips T.C.,University of Edinburgh
Journal of Pragmatics | Year: 2013
The study of pragmatics is typically concerned with ostensive communication (especially through language), in which we not only provide evidence for our intended speaker meaning, but also make manifest our intention to do so. This is not, however, the only way in which humans communicate. We also communicate in many non-ostensive ways, and these expressions often interplay with and complement ostensive communication. For example, fear, embarrassment, surprise and other emotions are often expressed with linguistic expressions, which they complement through changes in prosodic cues, facial and bodily muscular configuration, pupil dilatation and skin colouration, among others. However, some basic but important questions about non-ostensive communication, in particular those concerned with evolutionary stability, are unaddressed. Our objective is to address, albeit tentatively, this issue, focusing our discussion on one particular class of non-ostensive communication: emotional expressions. We argue that existing solutions to the problem of stability of emotional communication are problematic and we suggest introducing a new class of mechanisms-mechanisms of emotional vigilance-that, we think, more adequately accounts for the stability of emotional communication. © 2013 Elsevier B.V.
Silva S.,French Institute of Health and Medical Research |
Silva S.,Toulouse 1 University Capitole |
Loubinoux I.,French Institute of Health and Medical Research |
Olivier M.,Toulouse 1 University Capitole |
And 6 more authors.
Anesthesiology | Year: 2011
Background: Perceptual illusions described in healthy subjects undergoing regional anesthesia (RA) are probably related to short-term plastic brain changes. We addressed whether performance on an implicit mental rotation task reflects these RA-induced changes in body schema brain representations. Studying these changes in healthy volunteers may shed light on normal function and the central mechanisms of pain. Methods: Performance pattern was studied in upper limb-anesthetized subjects on a left/right hand judgment task, which is known to involve motor imagery processes relating to hand posture. Three conditions were used: control (i.e., absence of deafferentation), RA (i.e., deafferentation), and vision (i.e., deafferentated limb exposed to view). To limit potential bias such as order effect, the control state was recorded in a randomized manner. Results: All subjects described perceptual illusions of their anesthetized limb. They were slower and less accurate on the task during RA compared with control. Response patterns were similar in all conditions, suggesting sensitivity of performance to arm/hand biomechanical constraints. Vision was associated with an increase in the proportion of correct responses and a reduction of the response times in hand judgment and was accompanied by disappearance of the lateralization of the underlying mental representations, which was identified during RA. Conclusions: These results suggest the following: (1) the right/left judgment task involves mental simulation of hand movements, (2) underlying mental representations and their neural substrates are subject to acute alterations after RA, and (3) the proprioceptive deficit induced by RA is influenced by the subject's ability to see the anesthetized limb. © 2010, the American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins.
Gautreau A.,Institute des science Cognitives |
Gautreau A.,University of Lyon |
Hoen M.,French Institute of Health and Medical Research |
Hoen M.,French National Center for Scientific Research |
And 3 more authors.
Speech Communication | Year: 2015
This research examines the nature of the interference that occurs during speech-in-speech processing for late bilingual listeners. Native French-speaking listeners with Italian as their L2 performed a lexical decision task with French target words presented amid background speech (i.e., 4-talker babble) and nonspeech background noise (i.e., speech-shaped fluctuating noise). We compared the masking effects of babble generated in the listeners' L1 (French), their L2 (Italian), or an unknown language (Irish) to the masking effects of corresponding fluctuating noise. The fluctuating noise contained spectro-temporal information similar to babble but lacked linguistic information. This design allowed us to compare lexical decision times obtained with the 2 kinds of background noise in each language and thus to assess the linguistic interference caused by babble. Results revealed that babble spoken in the known languages (French and Italian) produced both linguistic and acoustic interference and that babble spoken in the unknown language (Irish) produced acoustic interference only. Furthermore, the L1-French L2-Italian listeners were more strongly affected by the L2 babble than by the L1 babble. © 2015 Elsevier B.V. All rights reserved.
PubMed | Aix - Marseille University, Mohammed V University and Institute des science Cognitives
Type: | Journal: Neuropsychologia | Year: 2014
We have previously shown that mental rehearsal can replace up to 75% of physical practice for learning a visuomotor task (Allami, Paulignan, Brovelli, & Boussaoud, (2008). Experimental Brain Research, 184, 105-113). Presumably, mental rehearsal must induce brain changes that facilitate motor learning. We tested this hypothesis by recording scalp electroencephalographic activity (EEG) in two groups of subjects. In one group, subjects executed a reach to grasp task for 240 trials. In the second group, subjects learned the task through a combination of mental rehearsal for the initial 180 trials followed by the execution of 60 trials. Thus, one group physically executed the task for 240 trials, the other only for 60 trials. Amplitudes and latencies of event-related potentials (ERPs) were compared across groups at different stages during learning. We found that ERP activity increases dramatically with training and reaches the same amplitude over the premotor regions in the two groups, despite large differences in physically executed trials. These findings suggest that during mental rehearsal, neuronal changes occur in the motor networks that make physical practice after mental rehearsal more effective in configuring functional networks for skilful behaviour.
PubMed | Institute des science Cognitives
Type: Journal Article | Journal: Cognitive neuropsychology | Year: 2010
Introduction Due to structural characteristics of the visual pathways, stimuli that are presented in the right half of the visual field (RVF) are initially projected to the left cerebral hemisphere, while those presented in the left half of the visual field (LVF) are projected to the right cerebral hemisphere. This anatomical feature has frequently been taken to support the notion that the well-documented RVF advantage in recognising printed words is a reflection of functional differences between the two hemispheres; notably that of the dominance of the left hemisphere for processing language. Word stimuli that are sent straight to the left hemisphere are believed to profit from more efficient processing than those sent initially to the right hemisphere, because the latter stimuli must follow a longer and more noisy pathway before reaching the language-dominant hemisphere. In the work by Jordan, Patching, and Thomas (2003) the above notion is further developed to speculate that the point of entry of visual information into the cortex may determine the procedure that will underlie the ensuing word recognition process: ... the left hemisphere can process words by mapping orthographic information in parallel onto lexical entries whereas the right hemisphere has a more rudimentary process, that can only map orthographic information sequentially (p. 50).