Explaining the neural activity distribution associated with discrete movement sequences:Evidence for parallel functional systems

To explore the effects of practice we scanned participants with fMRI while they were performing four-key unfamiliar and familiar sequences, and compared the associated activities relative to simple control sequences. On the basis of a recent cognitive model of sequential motor behavior (C-SMB), we propose that the observed neural activity would be associated with three functional networks that can operate in parallel and that allow (a) responding to stimuli in a reaction mode, (b) sequence execution using spatial sequence representations in a central-symbolic mode, and (c) sequence execution using motor chunk representations in a chunking mode. On the basis of this model and findings in the literature, we predicted which neural areas would be active during execution of the unfamiliar and familiar keying sequences. The observed neural activities were largely in line with our predictions, and allowed functions to be attributed to the active brain areas that fit the three above functional systems. The results corroborate C-SMB’s assumption that at advanced skill levels the systems executing motor chunks and translating key-specific stimuli are racing to trigger individual responses. They further support recent behavioral indications that spatial sequence representations continue to be used

GOLIAH (Gaming Open Library for Intervention in Autism at Home): a 6-month single blind matched controlled exploratory study

BackgroundTo meet the required hours of intensive intervention for treating children with autism spectrum disorder (ASD), we developed an automated serious gaming platform (11 games) to deliver intervention at home (GOLIAH) by mapping the imitation and joint attention (JA) subset of age-adapted stimuli from the Early Start Denver Model (ESDM) intervention. Here, we report the results of a 6-month matched controlled exploratory study.MethodsFrom two specialized clinics, we included 14 children (age range 5–8 years) with ASD and 10 controls matched for gender, age, sites, and treatment as usual (TAU). Participants from the experimental group received in addition to TAU four 30-min sessions with GOLIAH per week at home and one at hospital for 6 months. Statistics were performed using Linear Mixed Models.ResultsChildren and parents participated in 40% of the planned sessions. They were able to use the 11 games, and participants trained with GOLIAH improved time to perform the task in most JA games and imitation scores in most imitation games. GOLIAH intervention did not affect Parental Stress Index scores. At end-point, we found in both groups a significant improvement for Autism Diagnostic Observation Schedule scores, Vineland socialization score, Parental Stress Index total score, and Child Behavior Checklist internalizing, externalizing and total problems. However, we found no significant change for by time × group interaction.ConclusionsDespite the lack of superiority of TAU + GOLIAH versus TAU, the results are interesting both in terms of changes by using the gaming platform and lack of parental stress increase. A large randomized controlled trial with younger participants (who are the core target of ESDM model) is now discussed. This should be facilitated by computing GOLIAH for a web platform.Trial registration Clinicaltrials.gov NCT0256041

Beyond words and images, neurophysiological basis of a common semantic system for sentences and visual scenes understanding

Certaines théories du fonctionnement cognitif postulent l'existence d'un système cérébral impliqué dans la compréhension sémantique indépendamment de la modalité d'entrée des stimuli. L'objectif de ce travail de thèse était d'étudier le fonctionnement d'un tel réseau, impliqué à la fois dans la compréhension de phrases et de scènes visuelles, en lien avec la théorie de la cognition incarnée. Dans la littérature, un ensemble d'aires frontotemporo- pariétales sensorimotrices et associatives sont décrites comme intervenant dans ces processus sémantiques, mais il existe un manque de consensus concernant la nature amodale de ce système et la plupart des travaux existants se sont concentrés sur l'identification de réseaux corticaux impliqués dans les représentations sémantiques, séparément pour l'une ou l'autre des modalités. De plus, les stimuli utilisés dans les protocoles expérimentaux sont généralement moins complexes que les situations interactives auxquelles nous sommes confrontés dans la vie de tous les jours. Une part importante de l'activité mentale humaine réside dans notre capacité à construire des représentations internes riches : ces modèles mentaux, impliqués dans une grande variété de processus cognitifs, nous permettent d'explorer certains souvenirs du passé, de planifier le futur ou encore de comprendre et de s'adapter à une situation en temps réel. Bien que les progrès des techniques d'Imagerie du Tenseur de Diffusion aient rendu possible la visualisation in vivo de fibres de matière blanche dans le cerveau humain, la connectivité du système sémantique amodal a très peu été étudiée jusque-là. Dans ce travail, nous avons utilisé différentes techniques (principalement de neuro-imagerie IRMf, DTI, EEG) pour mettre en évidence les bases neurophysiologiques d'un système sémantique commun impliqué dans la représentation et la compréhension de stimuli complexes verbaux et non-verbaux. Avec notre premier protocole combinant IRMf et DTI, nous nous sommes intéressés aux activations et à la connectivité cérébrales chez 19 sujets sains en train de lire des phrases ou d'observer des images représentant des événements quotidiens. Une analyse de l'activité cérébrale conjointe associée à la compréhension de ces deux types de stimuli a révélé un réseau fronto-temporo-pariétal commun, impliquant le gyrus frontal inférieur, le gyrus précentral, le cortex rétrosplénial, le gyrus temporal moyen avec une activité s'étendant jusqu'à la jonction temporo-pariétale (TPJ) et au lobe pariétal inférieur. La tractographie DTI a révélé une architecture spécifique de fibres de matière blanche, soutenant ce réseau sémantique et qui fait appel principalement aux faisceaux décrits comme la voie ventrale sémantique (IFOF, UF, ILF, MdLF). Notre seconde expérience (protocole comportemental) nous a permis d'étudier les différences interindividuelles dans la capacité à se représenter des phrases présentées visuellement ou auditivement. Nous avons démontré que les individus ne sont pas égaux quant à cette capacité de représentation et que ces différences se reflètent dans des marqueurs comportementaux tels que la facilité de représentation (évaluée par le COR, coefficient de représentabilité) et la vitesse de réponse (TR) ; mais aussi que ces différences interindividuelles trouvent une correspondance avec le nombre de fibres qui composent le MdLF, laissant supposer une implication de ce faisceau dans ces capacités de représentation. Les résultats de ce protocole comportemental, ainsi que ceux de notre troisième protocole en EEG, ont permis de mettre en évidence un effet contextuel particulièrement important pour la création d'une représentation dans les deux modalités : le contexte induit par la présentation d'un premier stimulus (phrase ou image) influence la représentation d'un second stimulus selon que celui-ci est sémantiquement cohérent ou non avec le premier stimulus présenté... [etc]Certain theories of cognitive function postulate a neural system for processing meaning, independent of the stimulus input modality. The objective of this thesis work, in line with the embodied cognition domain, was to study functionalities of such a network involved in both sentence and visual scene comprehension. In the literature, a wide network of fronto-temporo-parietal sensorimotor and associative areas are described as being involved in this process, and while there’s a lack of consensus on the amodal nature of this system, extensive research has focused on identifying distributed cortical systems that participate in meaning representations separately in the visual and language modalities. Moreover, the stimuli used are generally less complex than everyday life situations we meet. However, a significant portion of human mental life is built upon the construction of perceptually and socially rich internal scene representations and these mental models are involved in a large variety of processes for exploring specific memories of the past, planning the future, or understanding current situations. Although diffusion-tensor imagery based techniques makes feasible the visualization of white matter tracts in the human brain, the connectivity of the semantic network has been little studied. Through different experimental protocols involving mainly neuroimaging techniques (fMRI, DTI, EEG), we were able to reveal the neurophysiological basis of this common semantic network involved in the building of representation and comprehension of rich verbal and non-verbal stimuli. With our first experiment, we examined brain activation and connectivity in 19 subjects who read sentences and viewed pictures corresponding to everyday events, in a combined fMRI and DTI study. Conjunction of activity in understanding sentences and pictures revealed a common fronto temporo-parietal network that included inferior frontal gyrus, precentral gyrus, the retrosplenial complex, and medial temporal gyrus extending into the temporo-parietal junction (TPJ) and inferior parietal lobe. DTI tractography revealed a specific architecture of white matter fibers supporting this network which involves principally the pathways described as the ventral semantic route (IFOF, UF, ILF, MdLF). Our second experiment, which is a behavioral protocol, explored interindividual differences in the ability to represent sentences presented in auditory or visual modality. We demonstrated that individuals are not equal in this capacity to represent sentences, these differences were reflected in the effects on behavioral markers including scores of ease of representation (COR) and speed of responses (TR); they are also related to the number of fibers of the MdLF which supposes a role for this fasciculus in capacities of representation. Both the results of this behavioral protocol and results from our third EEG experiment also showed that the contextual effect was significant: the context induced by the presentation of a first stimulus has the ability to influence the representation of a second stimulus when is the second is semantically consistent or not with the first presented stimulus. Our EEG results (ERPs) revealed components influenced by the available semantic information: early attentional effects which could be modality-specific and later semantic integration process common for verbal and non-verbal stimuli... [etc

Au-delà des mots et des images, bases neurophysiologiques d'un système sémantique commun à la compréhension des phrases et des scènes visuelles

Certain theories of cognitive function postulate a neural system for processing meaning, independent of the stimulus input modality. The objective of this thesis work, in line with the embodied cognition domain, was to study functionalities of such a network involved in both sentence and visual scene comprehension. In the literature, a wide network of fronto-temporo-parietal sensorimotor and associative areas are described as being involved in this process, and while there’s a lack of consensus on the amodal nature of this system, extensive research has focused on identifying distributed cortical systems that participate in meaning representations separately in the visual and language modalities. Moreover, the stimuli used are generally less complex than everyday life situations we meet. However, a significant portion of human mental life is built upon the construction of perceptually and socially rich internal scene representations and these mental models are involved in a large variety of processes for exploring specific memories of the past, planning the future, or understanding current situations. Although diffusion-tensor imagery based techniques makes feasible the visualization of white matter tracts in the human brain, the connectivity of the semantic network has been little studied. Through different experimental protocols involving mainly neuroimaging techniques (fMRI, DTI, EEG), we were able to reveal the neurophysiological basis of this common semantic network involved in the building of representation and comprehension of rich verbal and non-verbal stimuli. With our first experiment, we examined brain activation and connectivity in 19 subjects who read sentences and viewed pictures corresponding to everyday events, in a combined fMRI and DTI study. Conjunction of activity in understanding sentences and pictures revealed a common fronto temporo-parietal network that included inferior frontal gyrus, precentral gyrus, the retrosplenial complex, and medial temporal gyrus extending into the temporo-parietal junction (TPJ) and inferior parietal lobe. DTI tractography revealed a specific architecture of white matter fibers supporting this network which involves principally the pathways described as the ventral semantic route (IFOF, UF, ILF, MdLF). Our second experiment, which is a behavioral protocol, explored interindividual differences in the ability to represent sentences presented in auditory or visual modality. We demonstrated that individuals are not equal in this capacity to represent sentences, these differences were reflected in the effects on behavioral markers including scores of ease of representation (COR) and speed of responses (TR); they are also related to the number of fibers of the MdLF which supposes a role for this fasciculus in capacities of representation. Both the results of this behavioral protocol and results from our third EEG experiment also showed that the contextual effect was significant: the context induced by the presentation of a first stimulus has the ability to influence the representation of a second stimulus when is the second is semantically consistent or not with the first presented stimulus. Our EEG results (ERPs) revealed components influenced by the available semantic information: early attentional effects which could be modality-specific and later semantic integration process common for verbal and non-verbal stimuli... [etc]Certaines théories du fonctionnement cognitif postulent l'existence d'un système cérébral impliqué dans la compréhension sémantique indépendamment de la modalité d'entrée des stimuli. L'objectif de ce travail de thèse était d'étudier le fonctionnement d'un tel réseau, impliqué à la fois dans la compréhension de phrases et de scènes visuelles, en lien avec la théorie de la cognition incarnée. Dans la littérature, un ensemble d'aires frontotemporo- pariétales sensorimotrices et associatives sont décrites comme intervenant dans ces processus sémantiques, mais il existe un manque de consensus concernant la nature amodale de ce système et la plupart des travaux existants se sont concentrés sur l'identification de réseaux corticaux impliqués dans les représentations sémantiques, séparément pour l'une ou l'autre des modalités. De plus, les stimuli utilisés dans les protocoles expérimentaux sont généralement moins complexes que les situations interactives auxquelles nous sommes confrontés dans la vie de tous les jours. Une part importante de l'activité mentale humaine réside dans notre capacité à construire des représentations internes riches : ces modèles mentaux, impliqués dans une grande variété de processus cognitifs, nous permettent d'explorer certains souvenirs du passé, de planifier le futur ou encore de comprendre et de s'adapter à une situation en temps réel. Bien que les progrès des techniques d'Imagerie du Tenseur de Diffusion aient rendu possible la visualisation in vivo de fibres de matière blanche dans le cerveau humain, la connectivité du système sémantique amodal a très peu été étudiée jusque-là. Dans ce travail, nous avons utilisé différentes techniques (principalement de neuro-imagerie IRMf, DTI, EEG) pour mettre en évidence les bases neurophysiologiques d'un système sémantique commun impliqué dans la représentation et la compréhension de stimuli complexes verbaux et non-verbaux. Avec notre premier protocole combinant IRMf et DTI, nous nous sommes intéressés aux activations et à la connectivité cérébrales chez 19 sujets sains en train de lire des phrases ou d'observer des images représentant des événements quotidiens. Une analyse de l'activité cérébrale conjointe associée à la compréhension de ces deux types de stimuli a révélé un réseau fronto-temporo-pariétal commun, impliquant le gyrus frontal inférieur, le gyrus précentral, le cortex rétrosplénial, le gyrus temporal moyen avec une activité s'étendant jusqu'à la jonction temporo-pariétale (TPJ) et au lobe pariétal inférieur. La tractographie DTI a révélé une architecture spécifique de fibres de matière blanche, soutenant ce réseau sémantique et qui fait appel principalement aux faisceaux décrits comme la voie ventrale sémantique (IFOF, UF, ILF, MdLF). Notre seconde expérience (protocole comportemental) nous a permis d'étudier les différences interindividuelles dans la capacité à se représenter des phrases présentées visuellement ou auditivement. Nous avons démontré que les individus ne sont pas égaux quant à cette capacité de représentation et que ces différences se reflètent dans des marqueurs comportementaux tels que la facilité de représentation (évaluée par le COR, coefficient de représentabilité) et la vitesse de réponse (TR) ; mais aussi que ces différences interindividuelles trouvent une correspondance avec le nombre de fibres qui composent le MdLF, laissant supposer une implication de ce faisceau dans ces capacités de représentation. Les résultats de ce protocole comportemental, ainsi que ceux de notre troisième protocole en EEG, ont permis de mettre en évidence un effet contextuel particulièrement important pour la création d'une représentation dans les deux modalités : le contexte induit par la présentation d'un premier stimulus (phrase ou image) influence la représentation d'un second stimulus selon que celui-ci est sémantiquement cohérent ou non avec le premier stimulus présenté... [etc

Serious games to teach social interactions and emotions to individuals with autism spectrum disorders (ASD)

International audienceThe use of information communication technologies (ICTs) in therapy offers new perspectives for treating many domains in individuals with autism spectrum disorders (ASD) because they can be used in many different ways and settings and they are attractive to the patients. We reviewed the available literature on serious games that are used to teach social interactions to individuals with ASD. After screening the Medline, Science Direct and ACM Digital Library databases, we found a total of 31 serious games: 16 that targeted emotion recognition or production and 15 that targeted social skills. There was a significant correlation between the number of reports per year and the year of publication. Serious games appeared promising because they can support training on many different skills and they favour interactions in diverse contexts and situations, some of which may resemble real life. However, the currently available serious games exhibit some limitations: (i) most of them are developed for High-Functioning individuals; (ii) their clinical validation has rarely met the evidence-based medicine standards; (iii) the game design is not usually described; and, (iv) in many cases, the clinical validation and playability/game design are not compatible

Common ERP responses to narrative incoherence in sentence and picture pair comprehension

International audienceUnderstanding the neural processes underlying the comprehension of visual images and sentences remains a major open challenge in cognitive neuroscience. We previously demonstrated with fMRI and DTI that compre-hension of visual images and sentences describing human activities recruits a common extended parietal- temporal-frontal semantic system. The current research tests the hypothesis that this common semantic sys-tem will display similar ERP profiles during processing in these two modalities, providing further support for the common comprehension system. We recorded EEG from naïve subjects as they saw simple narratives made up of a first visual image depicting a human event, followed by a second image that was either a sequentially coherent narrative follow-up, or not, of the first. Incoherent second stimuli depict the same agents but shifted into a different situation. In separate blocks of trials the same protocol was presented using narrative sentence stimuli. Part of the novelty is the comparison of sentence and visual narrative responses. ERPs revealed common neural profiles for narrative processing across image and sentence modalities in the form of early and late central and frontal positivities in response to narrative incoherence. There was an additional posterior positivity only for sentences in a very late window. These results are discussed in the context of ERP signatures of narrative pro-cessing and meaning, and a current model of narrative comprehension

Mean imageability ratings for sequentially coherent and incoherent sentence pairs in the visual and auditory conditions.

<p>Bars: Standard deviations (*** p< 0.001, ** p< 0.01).</p