Maintien à court terme de l'information chez l'enfant de 2 à 6 ans : oubli temporel et aide au maintien du but

Working memory is an essential component of thought that is highly involved in learning and academic achievement. However, it is rarely studied in preschoolers, mainly because of a lack of suitable paradigms. Therefore, this thesis investigated the functioning of working memory in children between 2 and 6 years. For this purpose, two original paradigms were used. They were designed to be close to game situations which should help young children to focus their attention on the task. Firstly it was shown that the recall performance decreased over time, even in the absence of an interfering task. Children of this age therefore use a passive maintenance, i.e. without spontaneously implementing any strategy of maintenance. Furthermore, the decline of the information was similar through age. For the first time, it has been demonstrated that the rate of information forgetting did not vary between 2 and 6. Finally, none of these two factors, i.e. implementation of a strategy of maintenance and change in the speed of forgetting can explain the increase in memory capacity between 2 and 6 years of age. Secondly, it has been shown that the intrinsic characteristics of the task could lead to improved recall performance, perhaps by inducing a strategy of maintenance. Particularly, the implementation of a motor activity, i.e. walking during the retention period, has enabled these young children to counteract to some extent the temporal decay of information. Then, the implementation of a motor activity, by directing the attention of young children to a visual cue related to the goal of the task, help them to maintain in memory the purpose of the task. Attentional resources could be harnessed to improve performance of recall, perhaps by implementing a retention strategy.La mémoire de travail est un composant essentiel de la pensée qui est fortement impliquée dans les apprentissages et la réussite scolaires. Pourtant, elle est rarement étudiée chez l’enfant d’âge préscolaire, du fait notamment d’un manque de paradigmes adaptés. Cette thèse visait donc à étudier le fonctionnement de la mémoire de travail chez cette population, soit entre 2 et 6 ans. Pour cela, deux paradigmes originaux ont été utilisés. Ils ont été conçus pour être proches de situations de jeux, propices à aider le jeune enfant à focaliser son attention sur la tâche. Ainsi, il a tout d’abord été montré que les performances de rappel diminuaient au fil du temps, et ce, même en l’absence de tâche interférente. Les enfants de cette tranche d’âge opèrent donc un maintien passif de l’information, i.e. sans mise en œuvre spontanée de stratégie de maintien de l’information. De plus, le déclin de l’information était similaire au travers de l’âge. Pour la première fois, il a donc été mis en évidence que la vitesse d’oubli de l’information ne variait pas entre 2 et 6 ans. Finalement, aucun de ces deux facteurs, i.e. mise en œuvre de stratégie de maintien de l’information et modification de la vitesse d’oubli de l’information, ne peut être avancé pour expliquer l’augmentation des capacités mémorielles entre 2 et 6 ans. Ensuite, il a été montré que les caractéristiques intrinsèques de la tâche pouvaient conduire à une amélioration des performances de rappel, peut-être par la mise en œuvre d’une stratégie de maintien. Notamment, la réalisation d’une activité motrice, i.e. marche durant le délai de rétention, a permis à ces jeunes enfants de contrecarrer dans une certaine mesure l’oubli temporel de l’information. La mise en œuvre d’une activité motrice, en dirigeant l’attention du jeune enfant vers un indice visuel du but à atteindre, aiderait celui-ci à maintenir le but de la tâche en mémoire. Les ressources attentionnelles ainsi dégagées pourraient être mises au service d’une amélioration des performances de rappel, peut-être par la mise en œuvre d’une stratégie de maintien

Dynamics of oddball sound processing: Trial-by-trial modeling of ECoG signals

Recent computational models of perception conceptualize auditory oddball responses as signatures of a (Bayesian) learning process, in line with the influential view of the mismatch negativity (MMN) as a prediction error signal. Novel MMN experimental paradigms have put an emphasis on neurophysiological effects of manipulating regularity and predictability in sound sequences. This raises the question of the contextual adaptation of the learning process itself, which on the computational side speaks to the mechanisms of gain-modulated (or precision-weighted) prediction error. In this study using electrocorticographic (ECoG) signals, we manipulated the predictability of oddball sound sequences with two objectives: (i) Uncovering the computational process underlying trial-by-trial variations of the cortical responses. The fluctuations between trials, generally ignored by approaches based on averaged evoked responses, should reflect the learning involved. We used a general linear model (GLM) and Bayesian Model Reduction (BMR) to assess the respective contributions of experimental manipulations and learning mechanisms under probabilistic assumptions. (ii) To validate and expand on previous findings regarding the effect of changes in predictability using simultaneous EEG-MEG recordings. Our trial-by-trial analysis revealed only a few stimulus-responsive sensors but the measured effects appear to be consistent over subjects in both time and space. In time, they occur at the typical latency of the MMN (between 100 and 250 ms post-stimulus). In space, we found a dissociation between time-independent effects in more anterior temporal locations and time-dependent (learning) effects in more posterior locations. However, we could not observe any clear and reliable effect of our manipulation of predictability modulation onto the above learning process. Overall, these findings clearly demonstrate the potential of trial-to-trial modeling to unravel perceptual learning processes and their neurophysiological counterparts

A reproducible open platform for a collective process - Translating CIDOC CRM 7.1.2 in French

he conference present a reproducible open platform supported collective process for the full translation of the CIDOC CRM 7.1.2/3 (future ISO version). The project of translation is conceived and held following FAIR principles and in a fully reproducible way. It also aim at building a CIDOC CRM user community among Digital Humanity research institutions through considering the translation process as a learning experience, a collaboration project and moreover as Digital Humanities research project

Human milk nutritional composition across lactational stages in Central Africa

The African region encompasses the highest undernutrition burden with the highest neonatal and infant mortality rates globally. Under these circumstances, breastfeeding is one of the most effective ways to ensure child health and development. However, evidence on human milk (HM) composition from African women is scarce. This is of special concern, as we have no reference data from HM composition in the context of food insecurity in Africa. Furthermore, data on the evolution of HM across lactational stages in this setting lack as well. In the MITICA study, we conducted a cohort study among 48 Central-African women and their 50 infants to analyze the emergence of gut dysbiosis in infants and describe the mother-infant transmission of microbiota between birth and 6 months of age. In this context, we assessed nutritional components in HM of 48 lactating women in Central Africa through five sampling times from week 1 after birth until week 25. Unexpectedly, HM-type III (Secretor + and Lewis genes -) was predominant in HM from Central African women, and some nutrients differed significantly among HM-types. While lactose concentration increased across lactation periods, fatty acid concentration did not vary significantly. The overall median level of 16 detected individual human milk oligosaccharides (HMOs; core structures as well as fucosylated and sialylated ones) decreased from 7.3 g/l at week 1 to 3.5 g/l at week 25. The median levels of total amino acids in HM dropped from 12.8 mg/ml at week 1 to 7.4 mg/ml at week 25. In contrast, specific free amino acids increased between months 1 and 3 of lactation, e.g., free glutamic acid, glutamine, aspartic acid, and serine. In conclusion, HM-type distribution and certain nutrients differed from Western mother HM

Admission criteria and management of critical care patients in a pandemic context: position of the Ethics Commission of the French Intensive Care Society, update of April 2021.

Intensive care unit professionals have experience in critical care and its proportionality, collegial decision-making, withholding or withdrawal of treatment deemed futile, and communication with patients' relatives. These elements rely on ethical values from which we must not deviate in a pandemic situation. The recommendations made by the Ethics Commission of the French Intensive Care Society reflect an approach of responsibility and solidarity towards our citizens regarding the potential impact of a pandemic on critical care resources in France, with the fundamental requirement of respect for human dignity and equal access to health care for all

Food Insecurity and Maternal Diet Influence Human Milk Composition between the Infant's Birth and 6 Months after Birth in Central-Africa

Although the World Health Organization (WHO) and UNICEF recommend that infants should be exclusively breastfed for the first 6 months of life, evidence is scarce on how the mother’s undernourishment status at delivery and maternal dietary factors influence human milk (HM) composition during the first 6 months of life in regions with high food insecurity. The maternal undernourishment status at delivery, maternal diet, and HM nutrients were assessed among 46 women and their 48 vaginally born infants in Bangui at 1, 4, 11, 18, and 25 weeks after birth through 24-h recalls and food consumption questionnaires from December 2017 to June 2019 in the context of the "Mother-to-Infant TransmIssion of microbiota in Central-Africa" (MITICA) study. High food insecurity indexes during the follow-up were significantly associated with them having lower levels of many of the human milk oligosaccharides (HMOs) that were measured and with lower levels of retinol (aß-coef = −0.2, p value = 0.04), fatty acids (aß-coef = −7.2, p value = 0.03), and amino acids (aß-coef = −2121.0, p value < 0.001). On the contrary, women from food-insecure households displayed significantly higher levels of lactose in their HM (aß-coef = 3.3, p value = 0.02). In parallel, the consumption of meat, poultry, and fish was associated with higher HM levels of many of the HMOs that were measured, total amino acids (aß-coef = 5484.4, p value < 0.001), and with lower HM levels of lactose (aß-coef = −15.6, p value = 0.01). Food insecurity and maternal diet had a meaningful effect on HM composition with a possible impact being an infant undernourishment risk. Our results plead for consistent actions on food security as an effective manner to influence the nutritional content of HM and thereby, potentially improve infant survival and healthy growth

Maintaining information in Short-Term Memory between 2 and 6 years old of age : temporal forgetting and helping in maintaining the goal

La mémoire de travail est un composant essentiel de la pensée qui est fortement impliquée dans les apprentissages et la réussite scolaires. Pourtant, elle est rarement étudiée chez l’enfant d’âge préscolaire, du fait notamment d’un manque de paradigmes adaptés. Cette thèse visait donc à étudier le fonctionnement de la mémoire de travail chez cette population, soit entre 2 et 6 ans. Pour cela, deux paradigmes originaux ont été utilisés. Ils ont été conçus pour être proches de situations de jeux, propices à aider le jeune enfant à focaliser son attention sur la tâche. Ainsi, il a tout d’abord été montré que les performances de rappel diminuaient au fil du temps, et ce, même en l’absence de tâche interférente. Les enfants de cette tranche d’âge opèrent donc un maintien passif de l’information, i.e. sans mise en œuvre spontanée de stratégie de maintien de l’information. De plus, le déclin de l’information était similaire au travers de l’âge. Pour la première fois, il a donc été mis en évidence que la vitesse d’oubli de l’information ne variait pas entre 2 et 6 ans. Finalement, aucun de ces deux facteurs, i.e. mise en œuvre de stratégie de maintien de l’information et modification de la vitesse d’oubli de l’information, ne peut être avancé pour expliquer l’augmentation des capacités mémorielles entre 2 et 6 ans. Ensuite, il a été montré que les caractéristiques intrinsèques de la tâche pouvaient conduire à une amélioration des performances de rappel, peut-être par la mise en œuvre d’une stratégie de maintien. Notamment, la réalisation d’une activité motrice, i.e. marche durant le délai de rétention, a permis à ces jeunes enfants de contrecarrer dans une certaine mesure l’oubli temporel de l’information. La mise en œuvre d’une activité motrice, en dirigeant l’attention du jeune enfant vers un indice visuel du but à atteindre, aiderait celui-ci à maintenir le but de la tâche en mémoire. Les ressources attentionnelles ainsi dégagées pourraient être mises au service d’une amélioration des performances de rappel, peut-être par la mise en œuvre d’une stratégie de maintien.Working memory is an essential component of thought that is highly involved in learning and academic achievement. However, it is rarely studied in preschoolers, mainly because of a lack of suitable paradigms. Therefore, this thesis investigated the functioning of working memory in children between 2 and 6 years. For this purpose, two original paradigms were used. They were designed to be close to game situations which should help young children to focus their attention on the task. Firstly it was shown that the recall performance decreased over time, even in the absence of an interfering task. Children of this age therefore use a passive maintenance, i.e. without spontaneously implementing any strategy of maintenance. Furthermore, the decline of the information was similar through age. For the first time, it has been demonstrated that the rate of information forgetting did not vary between 2 and 6. Finally, none of these two factors, i.e. implementation of a strategy of maintenance and change in the speed of forgetting can explain the increase in memory capacity between 2 and 6 years of age. Secondly, it has been shown that the intrinsic characteristics of the task could lead to improved recall performance, perhaps by inducing a strategy of maintenance. Particularly, the implementation of a motor activity, i.e. walking during the retention period, has enabled these young children to counteract to some extent the temporal decay of information. Then, the implementation of a motor activity, by directing the attention of young children to a visual cue related to the goal of the task, help them to maintain in memory the purpose of the task. Attentional resources could be harnessed to improve performance of recall, perhaps by implementing a retention strategy

Young children's decay of memory traces in short-term memory

International audienc

Maintien de l'information en mémoire de travail chez l'enfant de 4 à 6 ans : impact d'une activité motrice orientée vers un but

National audienc