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International audience; The present study examined the evolution of the behavioral performance, subjectively perceived difficulty, and hemodynamic activity of the prefrontal cortex as a function of cognitive load during two different cognitive tasks tapping executive functions. Additionally, it investigated therelationships between these behavioral, subjective, and neuroimaging data. Nineteen right-handed young adults (18–22 years) were scanned using continuous-wave functional near-infrared spectroscopy during the performance of n-back and random number generation tasks in three cognitiveload conditions. Four emitter and four receptor optodes were fixed bilaterally over the ventrolateral and dorsolateral prefrontal cortices to record the hemodynamic changes. A self-reported scale measured the perceived difficulty. The findings of this study showed that an increasing cognitive loaddeteriorated the behavioral performance and increased the perceived difficulty. The hemodynamic activity increased parametrically for the three cognitive loads of the random number generation task and in a two-back and three-back compared to a one-back condition. In addition, the hemodynamic activity was specifically greater in the ventrolateral prefrontal cortex than in the dorsolateral prefrontal cortex for both cognitive tasks (random number generation and n-back tasks). Finally, the results highlighted some links between cerebral oxygenation and the behavioral performance, but not the subjectively perceived difficulty. Our results suggest that cognitive load affects the executive performance and perceived difficulty and that fNIRS can be used to specify the prefrontal cortex’s implications for executive tasks involving inhibition and working memory updating.

International audience; There has been a considerable amount of research to conceptualize how cognition handle multitasking situations. Despite these efforts, it is still not clear how task parameters shape attentionnal resources allocation. For instance, many research have suggested that difficulty levels could explain these conflicting observations and very few have considered other factors such as task importance. In the present study, twenty participants had to carry out two N-Back tasks simultaneously, each subtask having distinct difficulty (0,1 or 2-Back) and importance (1 or 3 points) levels. Participants's cumulative dwell time were collected to assess their attentional strategies. Results showed that depending on the global level of difficulty (combination of the two levels of difficulty), attentional resources of people were driven either by the subtask difficulty (under low-global-difficulty) or the subtask importance (under high-global-difficulty), in a non-compensatory way. We discussed these results in terms of decision-making heuristics and metacognition.

International audience; Cette étude a pour but d’étudier la supervision de système lors de l’utilisation de deux types de systèmesautomatisés : statique ou adaptatif. Notre objectif est d’étudier ces derniers dans des situations où la fiabilitén’est pas parfaite. Nous avons confronté 80 participants à trois tâches du Multi Attribute Task Battery (MATB).Nous avons manipulé quatre niveaux de fiabilité différentes et deux types de systèmes automatisés. Un systèmeadaptatif avec des sessions de contrôle manuel planifiées, ainsi qu’un système statique, où le contrôle nechangeait jamais. Nos résultats ont montré que les participants ne mettaient pas en place les mêmes stratégiesd’allocations visuelles d’attention selon les niveaux de fiabilité du système. Sous un système statique, lesparticipants passaient plus de temps sur la tâche avec le niveau 0% de fiabilité, que dans le niveau 100% où lasurveillance était réduite. Sous un système adaptatif, le comportement visuel était le même mais moins prononcé.Nos données ont également montré des résultats intéressants dans les sessions manuelles où les différentsniveaux de fiabilité n’entrainent pas le même comportement visuel des participants lorsqu’ils retournent ensupervision de système. Le niveau de fiabilité 56.25% a entrainé plus d’implication visuelle des participantsdurant les sessions automatisées, suivant une session de contrôle manuelle.

International audience; The concepts of robustness and resilience are used with increasing frequency from different sectors. The literature review reveals several meanings for each of these terms due probably to specific use in each of the sectors and a progressive adjustment of the definitions across the time. The aims of this article are to identify these definitions and the main similarities and difference between the concepts of resilience and robustness and to propose a classification of them in order to avoid confusions, bad meaning and to provide a better understanding of the subtleties under these concepts. Based on a structured analysis of the literature published in journals of different sectors this paper conceptualizes and comprehensively presents a systematic review of the recent literature on robustness and resilience definitions. Decision-makers and researchers can benefit from our survey since it introduces a structured analysis and recommendations as to which definitions can be used.

International audience; OpenMATB is an open-source variant of the Multi-Attribute Task Battery (MATB) and is available under a free software license. MATB consists of a set of tasks representative of those performed in aircraft piloting. It is used, in particular, to study the effect of automation on decision-making, mental workload, and vigilance. Since the publication of MATB 20 years ago, the subject of automation has grown considerably in importance. After introducing the task battery, this article highlights three main requirements for an up-to-date implementation of MATB. First, there is a need for task customization, to make it possible to change the values, appearance or integrated components (such as rating scales) of the tasks. Second, researchers need software extensibility to enable them to integrate specific features, such as synchronization with psychophysiological devices. Third, to achieve experiment replicability, it is necessary that the source code and the scenario files are easily available and auditable. In the present paper, we explain how these aspects are implemented in OpenMATB by presenting the software architecture and features, while placing special emphasis on the crucial role of the plugin system and the simplicity of the format used in the script files. Finally, we present a number of general trends for the future study of automation in human factors research and ergonomics.

The present study investigated the role of executive functions in the development of two aspects of timing: temporal reproduction and comparison. Children aged 7 and 10 years and young adults were asked to either reproduce target durations (i.e., reproduction task) or judge the similarity of two target durations (i.e., comparison task). These temporal tasks were performed in isolation (single-task condition) or in conjunction (dual-task condition) with an executive task tapping inhibitory control (i.e., Stroop-like interference in animals size task). The results showed that the concurrent executive task degraded temporal performance to a greater extent at the age of 7 years than in older children and adults, and that it had much less influence on temporal comparison than on temporal reproduction. Conversely, regardless of age group, the concurrent timing of stimuli decreased response accuracy in the inhibitory control task in both temporal tasks, but to a greater extent in the comparison than the reproduction task. Furthermore, the dual task condition reduced response time in the executive task, but only in children aged 7 years -and not in older children and adults. Thus, both duration reproduction and comparison relate to executive functions, although the relation is stronger for reproduction. Importantly, timing progress during childhood stems at least partly from more efficient executive functions (more specifically inhibitory control).

International audience; In the present study, participants played a modified ultimatum game simulating a situation of inclusion/exclusion, in which either the participant or a rival could be selected to play as the responder. This selection was made either randomly by a computer (i.e. random pairing mode) or by the proposer (i.e. choice mode), based on physical appearance. Being chosen by the proposer triggered positive reciprocal behavior in participants, who accepted unfair offers more frequently than when they had been selected by the computer. Independently of selection mode, greater P200 amplitudes were found when participants received fair offers than when they received unfair offers and when unfair shares were offered to their rivals rather than to them, suggesting that receiving fair offers or observing a rival's misfortune was rewarding for participants. While participants generally showed more interest in the offers they themselves received (i.e. greater P300 responses to these offers), observing their rivals receive fair shares after the latter had been chosen by the proposer triggered an increase in P300 amplitude likely to ref lect a feeling of envy. This study provides new insights into both the cognitive and affective processes underpinning economic decision making in a context of social inclusion/exclusion.

International audience; We examined the effects of time pressure on duration estimation in a verbal estimation task and a production task. In both temporal tasks, participants had to solve mazes in two conditions of time pressure (with or without), and with three different target durations (30 s, 60 s, and 90 s). In each trial of the verbal estimation task, participants had to estimate in conventional time units (minutes and seconds) the amount of time that had elapsed since they started to solve the maze. In the production task, they had to press a key while solving the maze when they thought that the trial's duration had reached a target value. Results showed that in both tasks, durations were judged longer with time pressure than without it. However, this temporal overestimation under time pressure did not increase with the length of the target duration. These results are discussed within the framework of scalar expectancy theory.

International audience; Automated systems are becoming increasingly prevalent in our societies. Several authors have identified the existence of the complacency phenomenon in supervision tasks, which imply automation execution or industrial computer support. The purpose of this study was to investigate failures of cooperation between human operator and automation. In this paper, we focused on the complacency as a low degree of suspicion towards the proposals of automation, leading to a monitoring deterioration. The main objective was to compare two types of automation, action automation vs information automation, in complacency. We recruited 96 participants to complete three tasks from the Multi-Attribute Task Battery. We found an effect of two types of automation on performance. Detection rate and reaction time were better when failures were reported by information automation than when it was not reported. Eye movements data showed that the automated task was less monitored when the reliability of information was high. We did not find an effect of reliability on NASA TLX score. Finally, we found that information automation can lead to complacency phenomenon. CCS CONCEPTS Human-centered computing-Human computer interaction (HCI)-HCI design and evaluation methods-Laboratory experiments Human-centered computing-Interaction design-Empirical studies in interaction design

ISBN des actes : 979-10-92329-04-9; International audience; Le phénomène de contentement est une conséquence négative pouvant apparaître lorsque nous utilisons un système automatisé. Afin de vérifier si ce phénomène peut également intervenir avec des automates de l'information (i.e interfaces) qui sont de plus en plus présents dans notre quotidien (Smartphone, logiciels d'aide à la décision, etc.), nous avons confronté 96 participants à trois tâches du Multi Attribute Task Battery (MATB). Une tâche de détection de pannes était automatisée selon 2 types d'automate : action (répare automatiquement les pannes) vs. Information (signale les pannes) et selon 4 niveaux de fiabilité (0 ; 56,25; 87,5; 100%). Un effet de la fiabilité de l'automate sur la performance quel que soit le type d'automate a été trouvé. Le taux de détection et le temps de réaction étaient meilleurs lorsque les pannes étaient signalées par l'automate de l'information que lorsqu'elles ne l'étaient pas. Les données eye-tracker ont montré que la tâche automatisée était surveillée moins longtemps lorsque la fiabilité de l'automate de l'information était élevée. Cependant, aucun effet n'a été trouvé pour le score NASA TLX. Ainsi, un automate de l'information peut également engendrer un phénomène de contentement.

International audience

The present study aimed to examine the effects of chronological age and cardiorespiratory fitness (CRF) on cognitive performance and prefrontal cortex activity, and to test the compensation-related utilization of neural circuits hypothesis (CRUNCH). A total of 19 young adults (18&ndash, 22 years) and 37 older ones (60&ndash, 77 years) with a high or low CRF level were recruited to perform a working memory updating task under three different cognitive load conditions. Prefrontal cortex hemodynamic responses were continuously recorded using functional near-infrared spectroscopy, and behavioral performances and perceived difficulty were measured. Results showed that chronological age had deleterious effects on both cognitive performance and prefrontal cortex activation under a higher cognitive load. In older adults, however, higher levels of CRF were related to increased bilateral prefrontal cortex activation patterns that allowed them to sustain better cognitive performances, especially under the highest cognitive load. These results are discussed in the light of the neurocognitive CRUNCH model.

ObjectiveThe objective was to characterize multitask resource reallocation strategies when managing subtasks with various assigned values.BackgroundWhen solving a resource conflict in multitasking, Salvucci and Taatgen predict a globally rational strategy will be followed that favors the most urgent subtask and optimizes global performance. However, Katidioti and Taatgen identified a locally rational strategy that optimizes only a subcomponent of the whole task, leading to detrimental consequences on global performance. Moreover, the question remains open whether expertise would have an impact on the choice of the strategy.MethodWe adopted a multitask environment used for pilot selection with a change in emphasis on two out of four subtasks while all subtasks had to be maintained over a minimum performance. A laboratory eye-tracking study contrasted 20 recently selected pilot students considered as experienced with this task and 15 university students considered as novices.ResultsWhen two subtasks were emphasized, novices focused their resources particularly on one high-value subtask and failed to prevent both low-value subtasks falling below minimum performance. On the contrary, experienced people delayed the processing of one low-value subtask but managed to optimize global performance.ConclusionIn a multitasking environment where some subtasks are emphasized, novices follow a locally rational strategy whereas experienced participants follow a globally rational strategy.ApplicationDuring complex training, trainees are only able to adjust their resource allocation strategy to subtask emphasis changes once they are familiar with the multitasking environment.

Background While the ability to measure time correctly is crucial for adaptation to the external physical and social environment, to date, research on timing ability and its development in individuals with intellectual disability (ID) is unfortunately remarkably scarce. Aims In the present study, we investigated the ability of individuals with mild ID to estimate durations and the development of this ability from 11 to 19 years, in comparison to typically developing (TD) individuals. Methods and procedures Participants with mild ID and TD participants matched on chronological age completed two temporal tasks: (1) a temporal bisection of auditory stimuli, in which they had to decide whether arbitrary stimulus duration was more similar to the short (200 ms) or the long (800 ms) standard previously learned, and (2) a temporal categorization of familiar actions, in which short, medium or long target durations had to be paired with one of three comparison action durations. Outcomes and results Temporal performance was systematically impaired in participants with mild ID. Moreover, the temporal impairment increased with age in the bisection task but not in the categorization task. Conclusions and implications These findings suggest that the ability to estimate durations develops at a slower pace in individuals with mild ID compared to TD individuals., Psychology; Timing; Time estimation; Familiar duration; Mild intellectual disability; Development

Faced with a growing technological evolution-oriented design and automation, studying the effects of mental workload on human efficiency and adaptability arouses genuine interest. The objective of this manuscript is to evaluate the mental workload and to highlight its effects on efficiency, resulting in a behavioral and physiological adaptability of the operator. More precisely, it is a matter of varying the task demand (for example, the difficulty, the temporal pressure, the complexity) to evaluate and identify the effects on the behavioral and physiological adaptability of operator. Behavioral and physiological adaptability was indexed by performance and pre-ejection period reactivity related to effort mobilization. The first article allowed us to highlight a curvilinear effect of mental workload on behavioral and physiological adaptability, as postulated by Hancock and Szalma (2006). The second article has showed that the temporal pressure could to a certain extent promote behavioral adaptability, especially the implementation of strategy. The third article has demonstrated that the air traffic control complex tasks are likely to activate a performance-effort trade-off resulting both behavioral and physiological adaptability of the operator.The applicative purpose of this thesis is to highlight the importance of human factors in the environments design loop, in order to rethink them and/or to bring in tools of help if necessary, at the most opportune moment and in its form the most convincing, in order to promote an optimal mental workload., Face à une évolution technologique croissante centrée sur la conception et l’automatisation pour plus de performance, étudier les effets de la charge mentale de travail sur l’efficience et l’adaptabilité humaine présente un réel intérêt.L’objectif de ce manuscrit est d’évaluer la charge mentale de travail et de mettre en évidence ses effets sur l’efficience, se traduisant par une adaptabilité comportementale et physiologique de l’opérateur. Plus précisément, il s’agit de faire varier les exigences de la tâche (par exemple, la difficulté, la pression temporelle, la complexité) pour évaluer et identifier les effets engendrés sur l’adaptabilité de l’opérateur. L’adaptabilité comportementale était indexée à la performance avec la mise en place de stratégie et l’adaptabilité physiologique à la mobilisation de l’effort mental avec le score de réactivité de la période de pré-éjection. Le premier chapitre démontre un effet curvilinéaire de la charge mentale de travail sur l’adaptabilité comportementale et physiologique, comme postulé par Hancock et Szalma (2006). Le second chapitre met en évidence que la pression temporelle pouvait dans une certaine mesure favoriser l’adaptabilité comportementale, notamment la mise en place de stratégie. Le troisième chapitre montre que les tâches complexes de contrôle du trafic aérien permettent l’activation du compromis performance-effort se traduisant par une adaptabilité comportementale et physiologique de l’opérateur. Ce manuscrit met en lumière l’importance des facteurs humains dans la boucle de conception des environnements de travail, afin de les repenser et/ou de faire intervenir des outils d’aide si nécessaire, au moment le plus opportun et sous sa forme la plus probante, afin de favoriser une charge mentale optimale.

International audience; Road Freight Transport (RFT) companies represent 37,200 companies and roughly 420,000 employees. This sector is confronted by strong competition and growing pressure from customers and suppliers, tight delivery times, exacerbated flexibility, etc. In parallel, they are required to fulfill performance duties in terms of preventing risks of occupational accidents and diseases. In 2016, CNAM statistics reports 70 deaths per year, 3,000,000 work days lost, an average 6 work days lost per employee, an index of frequency (73‰). The planner builds the transport rounds by integrating at best all dimensions (regulation, economic, environmental and prevention of health and safety of their employees). In this context, the Smart Planning project aims to develop a computer system to help create more balanced planning. The purpose of this paper is to present the first results. It proposes, with an ergonomic analysis, to identify the prescribed and tacit constraints manipulated by the planners in two companies. A questionnaire is drawn up to validate and enrich the data on the health and safety dimension.This study is not a business case; it is ergonomic analysis to validate different determinants identified (health and safety) and investigates the assessment of these determinants and their possible consideration during planning.

International audience; In order to implement the human-centric manufacturing and sustainability concepts in industry, an important effort should be done in order to model working conditions for human operators and improve them. Several studies have been conducted for mass production assembly lines where short cycle times make the work content highly repetitive. However, the case of low-volume production with long cycle times and different impacts on human operators has been rarely considered in the literature. In this paper, we develop a model to take into account the associated ergonomic risks in assembly lines with long cycle times. An optimization method is also developed in order to schedule tasks and assign the required tasks to a set of human operators taking into account the existing ergonomic risks.

International audience; BACKGROUND:Although a number of studies have examined sociodemographic, psychosocial, and environmental determinants of the level of physical activity (PA) for older people, little attention has been paid to the predictive power of cognitive strategies for independently living older adults. However, cognitive strategies have recently been considered to be critical in the management of day-to-day living.METHODS:Data were collected from 243 men and women aged 55 years and older living in France using face-to-face interviews between 2011 and 2013.RESULTS:A stepwise discriminant analysis selected five predictor variables (age, perceived health status, barriers' self-efficacy, internal memory, and attentional control strategies) of the level of PA. The function showed that the rate of correct prediction was 73% for the level of PA. The calculated discriminant function based on the five predictor variables is useful for detecting individuals at high risk of lapses once engaged in regular PA.CONCLUSIONS:This study highlighted the need to consider cognitive functions as a determinant of the level of PA and, more specifically, those cognitive functions related to executive functions (internal memory and attentional control), to facilitate the maintenance of regular PA. These results are discussed in relation to successful aging.

International audience; Executive control can be driven by conscious and unconscious monetary cues. This has raised the exciting question regarding the role of conscious and unconscious reward in the regulation of executive control. Similarities and differences have been uncovered between unconscious and conscious processing of monetary rewards. In the present study, we explored whether individual differences associated with reward sensitivity foster these variations on memory-updating—a core component process of executive control. Participants (N = 60) with low, medium, and high reward sensitivity were selected and performed a numerical memory-updating task. At the beginning of each trial, a high (1 euro) or a low (5 cents) reward was presented subliminally (24 ms) or supraliminally (300 ms). Participants earned the reward by responding correctly. Participants with low reward sensitivity performed better for the high reward only in the subliminal condition. For participants with medium reward sensitivity, performance improved with high reward in both subliminal and supraliminal conditions. When participants had high reward sensitivity scores, the effect of reward was stronger in the supraliminal condition than the subliminal condition. These results show that the distinctive effects of conscious and unconscious rewards on executive performance are modulated by individual differences in reward sensitivity. We discuss this finding with reference to models of conscious/unconscious processing of reward stimuli.

International audience; The assembly process is extremely complex for aircraft and its management requires to address numerous optimization problems related to the assignment of tasks to workstations, staffing problem for each workstation and finally the assignment of tasks to operators at each workstation. This paper treats the latter problem dealing with the assignment of tasks to operators under ergonomic constraints. The problem of optimal tasks scheduling in aircraft assembly line is modelled as Resource-Constrained Project Scheduling Problem (RCPSP). The objective of this research is to assign tasks to operators and to find an optimal schedule of task processing under economic and ergonomic constraints. Two different models to solve this problem are presented and evaluated on an industrial case study.

ISBN 978-3-319-92284-3 (print), 978-3-319-92285-0 (online); International audience; Automated systems are becoming increasingly prevalent in our environment. This leads to a new tasks repartition between the human operator and automation. Understanding human-machine cooperation including potential failures has become a hot topic. In this study we focus on a possible negative consequence of automation: the complacency phenomenon. This phenomenon has been repeatedly observed in dynamic situations in which automation execute an action in order to relieve the human operator from his/her activity. In static task, automation often serves to simplify/pre-process the data and not to directly make a decision. The goal of automation in a static task (like planning) is to optimize an external representation and allow the human operator to make his choices more easily. The Eye Tracker is used to understand human behaviors and their strategies in these static situations. The purpose of this study is therefore to compare complacency to "action execution" from complacency to "data simplifica-tion". We confronted 96 participants to these two automation types on the Multi Attribute Task Battery. We also manipulated four levels of automation reliability (0%; 56.25%; 87.5%, 100%). In all these conditions we assessed complacency through the detection rate of automation failure. In addition, we used an eye tracker to assess a potential low level of suspicion regarding automation failure.

International audience; The aim of the present study was to provide descriptive dietary patterns of home-living older adults, and to examine their association with sociodemographic and ‘diet-related’ variables, and health and psychological factors. Dietary patterns were analyzed using separately cluster analysis for men (N = 151, Mage = 72.72, SD = 8.80, range = 56-97) and women (N = 251, Mage = 76.74, SD = 9.95, range = 55-97) in 402 older adults aged 55 years and over. Cluster analyses showed four distinct dietary profiles for each gender. In older men, the four distinct dietary clusters were associated with any differences in sociodemographic and ‘diet-related’ variables, cognitive function, and health and psychological factors. Likewise, in older women, the four distinct dietary clusters were associated with any differences in sociodemographic and ‘diet-related' variables’. However in older women, results showed that the cluster 1 “high fish-fruit-vegetable” was associated with a better cognitive function, a better self-rated health and no depressive symptoms, whereas cluster 3 “moderate ready meals” was associated with cognitive decline, slight depression, and poor perceived health. Results emphasize the interest to take into consideration health and psychological factors associated with dietary patterns to better target the vulnerability of individuals and enable an effective prevention.

International audience; Background: In the elderly, physical activity (PA) enhances cognitive performances, increases brain plasticity and improves brain health. The neurotrophic hypothesis is that the release of brain-derived neurotrophic factor (BDNF), which is implicated in brain plasticity and cognition, is triggered by PA because motoneurons secrete BDNF into the bloodstream during exercise. Individual differences in cognitive performance may be explained by individual differences in genetic predisposition. A single nucleotide polymorphism on the BDNF gene, BDNFVal66Met, affects activity-dependent BDNF secretion. This study investigated the influence of the BDNFVal66Met polymorphism on the relationship between PA and controlled inhibition performance in older adults.Methods: A total of 114 healthy elderly volunteers (mean age = 71.53 years old) were evaluated. Participants were genotyped for the BDNFVal66Met polymorphism. We evaluated inhibitory performance using choice reaction times (RT) and error rates from a Simon-like task and estimated their PA using two self-reported questionnaires. We established four groups according to PA level (active vs. inactive) and BDNFVal66Met genotype (Met carriers vs. Val-homozygous). The results were analyzed using ANOVA and ANCOVA, including age, gender and body mass index as covariates.Results: The BDNFVal66Met polymorphism interacted with PA on controlled inhibition performance. More specifically, inactive Val-homozygous participants exhibited a lower inhibition performance than active Val homozygotes and inactive Met carriers; the former had a higher error rate without differences in RT.Conclusion: Differences between individuals on inhibitory performance may be partially understood by the interaction between genetic influence in BDNF secretion and PA level. The results of this study clearly support the neurotrophic hypothesis that BDNF synthesis is an important mechanism underlying the influence of physical activity on brain structure and functions.

ISBN : 979-10-92329-03-2; International audience

International audience; The resource constrained project scheduling problem (RCPSP) is a well-known combinatorialoptimisation problem. It was shown by reduction from the 3-partition problem that the decisionvariant of the RCPSP isNP-complete in the strong sense even without precedence constraintsand only one resource [1]. A library of instances PSPLIB was created to compare solutionalgorithms and lower bounds, the most known approaches were presented in parts [2], [3] and [4].

One hypothesis that could explain the beneficial effects of physical exercise on cognitive function is the cardiorespiratory hypothesis. This hypothesis proposes that improved cognitive functioning may be in part a result of the physiological processes that occur after physical exercise such as: Increased cerebral perfusion and regional cerebral blood flow. These processes ensure increased oxygenation and glucose transportation to the brain, which together can improve cognitive function. The objective of this narrative review is to examine the contribution of this hypothesis in the care of African older adults with neurodegenerative conditions (i.e., dementia (Alzheimer’s disease)) or with mild cognitive impairments. Although studies in developed countries have examined people of African descent (i.e., with African Americans), only the limited findings presented in this review reflect how these conditions are also important for the African continent. This review revealed that no studies have examined the effects of cardiorespiratory fitness on neurodegenerative disease in Africa. African nations, like many other developing countries, have an aging population that is growing and will face an increased risk of neurodegenerative declines. It is therefore imperative that new research projects be developed to explore the role of the cardiorespiratory fitness in neurodegenerative disease prevention in African nations.

International audience; Lors d’une interaction économique, il est fréquent que deux potentiels acteurs soient mis en concurrence (Rigoni et al., 2010). Au final, un seul sera choisi et pourra prendre part à l’interaction économique. L’issue de cette dernière étant variable, il est probable que le fait d’avoir été choisi ou non modifie la manière dont l’interaction économique est perçue dans son ensemble. Il est donc intéressant d’étudier cette question. L’ultimatum game est le jeu économique le plus fréquemment utilisé pour évaluer la sensibilité à l’inégalité (Guth et al., 1982) et les corrélats électrophysiologiques qui y sont associés (Fabre et al., 2015). Dans ce jeu, le proposeur reçoit une certaine somme d’argent qu’il doit ensuite répartir entre lui et le répondeur. Dans le cas où le répondeur accepte l’offre, la somme sera alors divisée comme proposé par le proposeur, alors que si le répondeur la refuse, les deux joueurs ne recevront rien. Dans cette expérience, les participants jouent à l’ultimatum game en tant que répondeur et sont mis en compétition avec un répondeur ”rival” fictif. Dans la condition contrôle, l’ordinateur décide aléatoirement de qui entre le participant et l’autre répondeur interagira avec le proposeur, alors que dans la condition d’intérêt le participant pense que c’est le proposeur qui sélectionne le répondeur avec lequel il souhaite interagir en se basant sur leurs photos. Nous présentons ici les résultats préliminaires de cette expérience, et plus précisément les potentiels évoqués associés au fait d’être sélectionné ou non par un humain ou un ordinateur.

International audience; The Ultimatum Game (Guth et al., 1982) has been widely used to investigate fairness consideration during economic interactions in social context (e.g., Alexopoulos et al., 2012; Fabre et al., 2015). In this paradigm, the proposer receives a fix amount of money (e.g., 10€) and s/he was required to share a given sum of money with the responder. If the responder accepts the share, the sum will be divided as chosen by the proposer, however if the responder refuses, none of them will receive anything. Usually, proposers and responders are randomly paired in this paradigm. However, the impact of being chosen by the proposer for an economic interaction (i.e., social reward) on the responder's fairness consideration of an offer has never been investigated. Aim: In the present study, we investigated to what extent being chosen for an economic interaction over a rival modifies the fairness consideration of an economic offer and the associated neural correlates. Participants played a modified Ultimatum game as responders. They were in competition with a "rival" responder, in that only one of them was selected to interact economically with the proposer. The pairing between the proposer and one of the responders could be randomly done by a computer (i.e., random pairing) or chosen by the proposer (i.e., proposer choice) based on the responders' photos. Participants were unaware that both the proposer and the rival responder were fictitious. Here we present the preliminary electrophysiological results associated with the selection feedback (i.e. being selected or not for the economic interaction) depending on the selection mode (i.e., random pairing vs. proposer's choice).

International audience; The objective of this study was to examine age-related effects on behavioral performance and metabolic activity of the prefrontal cortex (PFC) in a dual-task paradigm involving fine-motor control and executive-function control. Thirty-one adults (20 ± 1.1 years) and 33 older adults (70.7 ± 5.1 years) performed, separately and then concurrently, a modified Fitts task on targets of different sizes (Index of Difficulty: ID = 3; 4; 5 bits) and the random number generation task (RNG). Movement time (MT) and count score (CS) were the dependent variables for the modified Fitts task and the RNG task, respectively. Relative changes in concentrations of oxyhemoglobin [HbO2] and deoxyhemoglobin [HHb] were recorded continuously on the left and right PFCs, with near-infrared spectroscopy (Oxymon MkIII-Artinis) with an acquisition rate of 10 Hz. Our results showed large motor dual-task cost in seniors compared to young adults. Regarding hemodynamic activity, we have observed a prominent activation of the PFC in the young adults compared to the seniors during the dual-task condition.

International audience; In response to the challenges related to the integration of human considerations in the system engineering process, the Human-System Integration (HSI) approach has been proposed. Although relevant in many aspects, this approach provides limited formalisms. This shortcoming complicates the representations of the system and human aspects within a single model, reducing thereby the means of collaboration among the system engineers and the human factors practitioners. This paper proposes to combine the formalisms of SysML and the Cognitive Work Analysis in order to develop the necessary means of expression to support the HSI approach.

Cet article a pour objectif d’analyser l’activite cognitive d’un des principaux acteurs du secteur de la construction : le conducteur de travaux, operateur charge de preparer, suivre et cloturer les chantiers. En resituant le chantier dans le processus de conception-realisation de l’ouvrage, nous montrons tout d’abord que le chantier est une situation complexe et dynamique. Ce point de vue nous amene ensuite a caracteriser l’activite cognitive du conducteur de travaux comme etant de la supervision de situation dynamique lors de la phase de realisation du chantier et de l’ordonnancement et du reordonnancement lors de la preparation et du suivi du chantier. Les apports de cette perspective sont, d’une part, l’enrichissement des situations dynamiques et, d’autre part, l’ouverture a d’autres facons de questionner l’activite du conducteur de travaux.

Mental workload is a concept central to a range of disciplines (including cognitive psychology and ergonomics) that has given rise to various theoretical and methodological debates. As a result, researchers have used a number of techniques for measuring mental workload. Traditionally, three categories of measurement technique have been recognized: performance measures (e.g., the dual-task paradigm), subjective measures (e.g., rating scales), and physiological measures (e.g., heart, respiration, and blink rates). Each technique has advantages and limitations; however, some limitations may prevent an accurate evaluation of the mental workload. In this article, we focus on the benefits of combining multiple measures of mental workload. However, because combining several techniques is a very complex process, we have developed the Tholos software in an attempt to reduce this complexity. This software package uses measures from each of the three categories: a dual-task paradigm with auditory signals; the National Aeronautics and Space Administration task load index (NASA-TLX) scale and its simplified version, the "raw" task load index (RTLX); and physiological (such as pupil-dilation) measurements with which our software can merge results from the dual-task paradigm. To illustrate the benefits of using Tholos, we describe a puzzle-solving experiment in which we combined multiple measures of mental workload. The results indicate the importance of combining multiple measures to build upon the theoretical and methodological foundations of mental workload.

RESUME Ce texte propose une synthese des travaux conduits sur la notion de contrainte en psychologie cognitive et ergonomique, en s’appuyant egalement sur des recherches issues de l’intelligence artificielle (IA). La notion de contrainte se retrouve frequemment dans la litterature scientifique au sein de ces deux disciplines, sans pour autant qu’un travail de synthese n’ait ete realise. C’est dans l’objectif de remedier a cette limite que ce travail s’inscrit, en nous focalisant plus particulierement sur les situations individuelles de resolution de problemes. La premiere partie de ce travail est consacree a la presentation des differentes definitions et typologies de contraintes que l’on retrouve dans la litterature, en proposant des mises en relation entre les typologies. La seconde partie expose les operations qui sont effectuees sur les contraintes (notamment, la formulation, la propagation et la satisfaction), en proposant egalement des mises en relation entre les differentes approches presentees. Nous concluons ce travail par la proposition de pistes de recherche et de reflexion a approfondir que suggere l’etat d’avancement de la recherche s’interessant aux contraintes.

RESUME Ce texte presente d’abord les differentes situations d’ordonnancement et les questions qu’elles posent, tant aux machines qu’aux humains. Il fait ensuite le point sur les travaux menes depuis la derniere revue de question exhaustive de P. Sanderson (1989) sur les facteurs humains dans l’ordonnancement. Il rappelle l’etat de la question en 1989 et decrit quelques avancees dans le renouvellement des approches formelles, dans l’analyse des strategies humaines et dans l’emergence d’une conception plus cooperative des relations homme-machine dans ce domaine. Il se conclut par quelques directions de recherche qui pourraient etre prometteuses.