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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; We compared automation monitoring evolution of static or adaptive automation for four different reliability levels over 90 minutes. Previous studies have demonstrated degraded human performance when monitoring automation and that it is possible to mitigate this monitoring performance drop by using adaptive automation. We used the Open Multi-Attribute Task Battery to manipulate two type of automation (static automation without manual take-over sessions and adaptive automation with planned take-over sessions) and four levels of reliability. Participants performed three simultaneous tasks, one of which was automated. Our results suggest that a perfectly reliable or a totally unreliable automation led to different strategies by the participants in terms of visual allocation policy. Under static automation, the time spent looking at the automated task in the 0% reliability level increased over the duration of the experiment; however, the opposite was observed for the 100% reliability level. Although similar, the magnitude of this pattern of results was largely diminished under adaptive automation. For static automation, the reported data also showed a direct link between trust in automation and visual scanning strategies. The more the trust increased, the less the automated task was looked at.

International audience; Previous research has suggested that information and action automation stages do not imply the same consequences for human performance in the supervision of automated systems. Still, only a few studies have simultaneously investigated these stages. When information and action automation are reliable, both can support performance. However, with unreliable aids, the literature has suggested that action automation tends to be more detrimental than information automation. This study aimed to assess the contributions of imperfect information and action automation on attentional allocation and to investigate a potential monitoring inefficiency in a multitasking environment. Participants (n = 96) completed three Multi-Attribute Task Battery (MATB) tasks. A monitoring task was automated with two types of automation (action or information) of four reliabilities each (0%; 56.25%; 87.5%; 100%). Ocular behaviors and performance were assessed. Results show that reliability of information automation influenced visual resource allocation. When information automation was the most reliable, participants spent the least amount of time sampling the monitoring task. Finally, the reliability of action automation triggered no effect on performance or cumulative dwell times. Our results suggest that in complex multitasking situations where information and action automation occurred simultaneously, participants allocated fewer visual resources to automated task with increased information automation reliability. Similarly, their performance was better only with increased information automation.

International audience; The aging process does not progress at the same speed between individuals (Hertzog, Kramer, Wilson, & Lindenberger,2008). The following two categories of factors moderate the speed of aging and explain a large part of the variance in the cognitive performance of individuals throughout the life span: genetic factors and lifestyle factors. Genetic factors are related to genetic polymorphisms that can influence cognitive phenotypes. Lifestyle factors notably include the amount of physical activity (PA) practiced every week throughout a long period (e.g., 1 year) and the dietary habits. This chapter aimsto specify the relationships among the following four variables: aging, inhibitory control, the genetic polymorphism of the brain-derived neurotrophic factor (BDNF) gene located at codon 66, and PA.In the second and following section, we focus on inhibitory control and show its crucial role in cognition and daily living. In the third section, we discuss on the unity and diversity of inhibitory processes. In the fourth section, we presentthe two main categories of effortful inhibitory control and their brain substrates. In the fifth section, we address the deleterious effect of aging on this important executive function. In the sixth section, we explain the role of neurotrophins, and more particularly the brain-derived neurotrophic factor (BDNF), in brain plasticity and brain health, and present the gene that affects its trafficking and secretion. In the seventh and eighth parts, we review the role of the genetic polymorphism of this gene in cognition during aging. Finally, in the ninth section, we examine the moderating role of physicalactivity and eating behaviors in the relationship between BDNF polymorphism and cognitive aging.

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; A seminal work by Sheridan and Verplank depicted 10 levels of automation, ranging from no automation to an automation that acts completely autonomously without human support. These levels of automation were later complemented with a four-stage model of human information processing. Next, human-machine cooperation centred models and associated cooperation modes were introduced. The objective of the experiment was to test which human-machine theorie describe automation use better. The participants were asked to choose repeatedly between four automation types (i.e. no automation, warning, co-action, function delegation) to complete three multi-attribute task battery tasks. The results showed that the participants favour the selection of automation types offering the best human-machine interactions quality rather that the most effective automation type. Contrary to human-machine cooperation models, technology centred models could not predict accurately automation selection. The most advanced automation was not the most selected.Practitioner Summary: The experiment dealt with how people select different automation types to complete the multi-attribute task battery that emulates recreational aircraft pilot tasks. Automation performance was not the main criteria that explain automation use, as people tend to select an automation type based on the quality of the human-machine cooperation.

International audience; If it can be assumed that positive affect modulates cognitive control, the underlying mechanisms remain unclear. The main aim of this study was to investigate how positive affect influences proactive and reactive modes of control and to explore the temporal dynamic of this influence, in terms of its transient and/or sustained effects. We used the AX-continuous performance task, combined with event-related potentials (ERP) recording. The results showed that positive affect impaired proactive control. More specifically, response preparation was weaker, as highlighted by a decreased contingent negative variation (CNV), prior to the target. As a consequence, conflict detection, as reflected by the N2 component, was decreased under positive affect. The P3a, associated with conflict resolution, remained unaffected by positive emotion, suggesting a lack of reactive control modulation. These effects were diffuse and did not appear on a transient timescale, highlighting the importance of positive emotion's time course for how it influences cognitive control processes.

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; Positive affect strongly modulates goal-directed behaviors and cognitive control mechanisms. It often results from the presence of a pleasant stimulus in the environment, whether that stimulus appears unpredictably or as a consequence of a particular behavior. The influence of positive affect linked to a random pleasant stimulus differs from the influence of positive affect resulting from performance-contingent pleasant stimuli. However, the mechanisms by which the performance contingency of pleasant stimuli modulates the influence of positive affect on cognitive control mechanisms have not been elucidated. Here, we tested the hypothesis that these differentiated effects are the consequence of the activation of the motivational “wanting” component specifically under performance contingency conditions. To that end, we directly compared the effects on cognitive control of pleasant stimuli (a monetary reward) attributed in a performance contingent manner, and of random pleasant stimuli (positive picture) not related to performance, during an AX-CPT task. Both proactive and reactive modes of control were increased specifically by performance contingency, as reflected by faster reaction times and larger amplitude of the CNV and P3a components. Our findings advance our understanding of the respective effects of affect and motivation, which is of special interest regarding alterations of emotion–motivation interaction found in several psychopathological disorders.

International audience; Automated systems changed the role of the human operator from active controller to supervisor of automated system. This new role comes with several human factors issues, as monitoring inefficiency. Some authors showed that it is possible to mitigate this monitoring performance drop using adaptive automation. Here, we assessed the consequences of a return to manual control with four different levels of automation reliability on eighty students. We compared the effect of the introduction of two manual sessions to exclusively automated sessions (total duration 90 min) using the MATB-II (i.e., intermittent vs permanent automation). Results showed that participants spend more time looking at the automated task in the 0% level reliability compared to 100% level of reliability over the time whatever the automation type. Manuals sessions in intermittent automation group had an impact on the time spend looking at the automated monitoring task.

International audience; Two experimental studies were carried out to investigate whether adding multimedia features in a concept mapping task would improve the quality of the map built by students and promote more effective learning with expository hypertexts. Ninety-Nine undergraduates built a concept map to learn about a topic (water cycle or nitrogen cycle) either with a text-based or with a multimedia presentation of concepts (i.e. concepts were presented as textual labels illustrated with relevant pictures). Multimedia presentation of concepts was expected to foster the construction of a more elaborate concept map, to increase information processing and to improve learning outcome. Results of the two experiments were consistent by showing that multimedia presentation led learners to spend more time building the concept map and to build more coherent maps (i.e. text-based inter-connected concepts). In addition, experiment 2 showed that the multimedia presentation of concepts in concept mapping could also foster deeper exploration of the hypertext. However, learning outcomes were not affected by the learning conditions.

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

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.

International audience; Introduction. Cognitive reserve (CR) was proposed to explain how individual differences in brain function help to cope with the effects of normal aging and neurodegenerative diseases. Education, professional solicitations, and engagement in leisure and physical activities across the lifetime are considered as major determinants of this reserve. Method. Using multiple linear regression analyses, we tested separately in healthy elderly and Parkinson’s disease (PD) populations to what extent cognitive performance in several domains was explained by (a) any of these four environmental lifespan variables; (b) demographic and clinical variables (age, gender, depression score, and, for the PD group, duration of disease and dopaminergic drugs). We also tested for an interaction, if any, between these lifespan variables and brain pathology indexed by global atrophy measured from high-resolution anatomical magnetic resonance imaging. Results. Age was negatively associated with cognitive performance in the PD group. In healthy elderly participants, we observed significant positive associations between cognitive performance and (a) education, (b) leisure activities, and (c) professional solicitation (decisional latitude). Furthermore, participants with greater brain atrophy benefited more from CR. In PD patients, education and professional solicitations contributed to cognitive performance but to a lesser extent than in controls. CR factors modulated the relationship between cognition and brain atrophy only in patients with a slight or moderate brain atrophy. Conclusions. Education is the CR factor that contributed the most to late cognitive functioning in both groups, closely followed by leisure activity in normal aging and professional solicitations in PD. Our results also provide evidence suggesting that the effects of CR does not express similarly in normal aging and PD. From a broader perspective, these results seem to indicate that CR factors the most consistently practiced across lifespan (education and professional solicitation) are those that are the more strongly associated to late cognitive efficiency.

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; 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.

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 cognitive neuroscience of aging is a growing and stimulating research area. The development of neuroimaging techniques in the past two decades has considerably increased our understanding of the brain mechanisms that might underlie cognitive performance and resulting changes due to normal aging. Beside traditional metabolic neuroimaging techniques, such as Positron Emission Tomography and functional Magnetic Resonance Imaging, near infrared spectroscopy (NIRS), an optical imaging technique allowing to monitor real-time cerebral blood oxygenation, has gained recent interest in this field. The aim of the present review paper, after briefly presenting the NIRS technique, is to review and to summarize the recent results of neuroimaging studies using this technique in the field of cognitive aging. The reviewed literature shows that, despite low spatial resolution and cerebral depth penetration, this technique provides consistent findings on the reduced hemodynamic activity as a function of chronological age, mainly in the prefrontal cortex. Important moderators of brain hemodynamics, such as cognitive load, subjects’ characteristics and experimental conditions, for which the NIRS technique is sensitive, are discussed. Strengths and weaknesses of functional NIRS in the field of cognitive aging are presented and finally, novel perspectives of research are proposed.

International audience; The Skill, Rule, and Knowledge framework is a highly influential framework in HF/E that led to few empirical validations. In this article, we focused on mental workload predictions suggesting that control modes are supposed to produce gradually higher levels of mental workload. Forty-four participants were given a modified MATB-II task. They had to solve different tasks to illustrate skill-based, rule-based, and knowledge-based control modes. The results showed expected workload levels for skill and rule-based control modes. However, the knowledge-based control mode produced both the lowest mental workload but also the lowest performance of the three modes. We interpreted the results in the light of neurophysiologically plausible studies distinguishing engagement and effort (from overall mental workload). We noticed that participants did not fully engage in the knowledge-based control mode, which then limited their effort and ultimately produced a lower performance compared to the other control modes. We argue that conceptual refinement of mental workload based on neurophysiologically plausible theories illustrates the interest of neurosciences in HF/E.; Rasmussen (1979, 1983, 1986) a proposé le modèle cadre des habiletés, règles et connaissances (SRK). Si ce modèle est particulièrement influant dans la communauté des Facteurs Humains et Ergonomie, peu d’études empiriques ont tenté de le mettre à l’épreuve. Dans cet article, nous nous focalisons sur les prédictions de ce modèle envers la charge mentale. Elles suggèrent que le mode de contrôle produit des niveaux distincts et croissants de charge mentale. Pour tester cette prédiction nous avons réalisé une expérience auprès de quarante-quatre participants ayant à résoudre une version modifiée des tâches du MATB-II. Plus précisément, ils devaient réaliser trois tâches différentes illustrant chacune un niveau de contrôle fondé sur les habiletés, les règles ou les connaissances. Des indices physiologiques (cardiaques), des évaluations subjectives de la charge ainsi que des mesures de performance ont été recueillis. Les résultats sont conformes aux prédictions concernant les modes de contrôles liés aux habiletés et aux règles. Néanmoins, lorsque le mode était basé sur les connaissances, les participants obtenaient les moins bonnes performances et percevaient la charge mentale comme étant la plus faible. Nous interprétons ces résultats à la lumière d’études issues des neurosciences et distinguons l’engagement et l’effort. Nous notons que les participants ne se sont pas pleinement engagés dans la tâche, par un effort réduit et une performance plus faible que dans les autres tâches. Nous considérons alors que ce type de raffinement conceptuel de la charge mentale s’appuyant sur les neurosciences souligne l’intérêt de la neuro­ergonomie pour les Facteurs Humains et l’Ergonomie.

International audience; Although it is very useful in daily life, children have difficulties to estimate durations using conventional time units. The aim of the present study was to examine whether young children aged three, five and eight years and adults are able to categorize familiar actions according to their duration, by using a new task not relying on knowledge of conventional time units. Participants performed a forced-choice categorization task in which short, medium or long target action durations had to be paired with one of three comparison action durations (short, medium or long). Results showed that as age increased so, too, did the percentage of accurate temporal categorizations, while that of temporal categorization errors decreased. Moreover, except at three years, the least frequent error consisted in categorizing a short action as a long one. These results are discussed in the light of event representation theory and the role of experience in temporal cognition.

International audience; It is well-known that processing speed and executive functions decline with advancing age. However, physical activity (PA) has a positive impact on cognitive performances in aging, specifically for inhibition. Less is known concerning intraindividual variability (iiV) in reaction times. This study aims to investigate the influence of PA and sex differences on iiV in inhibitory performance during aging. Healthy adults were divided into active and sedentary groups according to PA level. To analyse iiV in reaction times, individual mean, standard deviation and the ex-Gaussian parameters were considered. An interaction between activity level and sex was revealed, sedentary females being slower and more variable than sedentary men. No sex differences were found in the active groups. These results indicate that the negative impact of sedentariness on cognitive performance in older age is stronger for females. The present findings underline the need to consider sex differences in active aging approaches.

International audience; The aims of this study were to examine the effects of aerobic exercise on measures of executive performance and their relationships with changes in cardiorespiratory fitness, cardiac vagal control (heart rate variability) and psychological variables. Thirty-six sedentary seniors aged 60–75 years were randomly assigned to a swimming and aquaerobics program or a stretching program two times a week for 21 weeks. Executive functions (inhibition, updating of working memory and cognitive flexibility) and cardiorespiratory fitness (estimated VO2max) were assessed at the start, after 10 weeks of program and at the end of the program. Resting HRV and measures of psychological outcomes (depression, self-efficacy, decisional balance) were obtained at the start and at the end of the program. Participants of both groups significantly improved their VO2max level, their psychological state and their performance for the 2-back task. Only the participants in the aquaerobics group significantly improved their vagally-mediated HRV and their performance for the Stroop test and the verbal running-span test at the end of the program. Only improvements in cardiac vagal control and in inhibition were shown to be functionally related. These results are discussed in line with the model of neurovisceral integration.

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 L’objectif de cette etude est d’examiner les effets de la pression temporelle sur les estimations de durees. Les participants doivent resoudre des labyrinthes dans deux conditions de pression temporelle (avec/sans). Apres chaque labyrinthe, ils doivent estimer la duree ecoulee depuis le debut de la resolution. Les resultats revelent que sous pression temporelle, les participants 1) surestiment les durees de resolution des labyrinthes et 2) sont moins variables dans leurs estimations temporelles. Ces resultats sont discutes dans le cadre du modele de traitement de l’information temporelle.

Cet article propose d’etudier le concept de charge mentale et ce qu’il implique dans le domaine de l’aeronautique. Les modes de gestion de la charge mentale qui sont employes par les operateurs sont l’objet de cette analyse. L’objectif ici est de definir les indicateurs de la situation qui agissent sur cette gestion, ainsi que la facon dont ils sont traites par l’operateur au cours de l’execution d’une tâche. Pour cela, une etude du concept de charge mentale, basee sur les travaux anterieurs publies sur cette question, est associee aux principales caracteristiques du domaine deduites d’observations menees sur le terrain. Ce travail nous permet de proposer un modele operatif de gestion de la charge mentale. Ce modele illustre le role essentiel joue par la nature de la situation et de ses evolutions au cours du temps sur la gestion des ressources cognitives des operateurs.

Scheduling activities are carried out in the domains of industry (production scheduling), personnel (nurse scheduling) and transportation (train scheduling). Nevertheless, there is little available knowledge on how operators schedule. In general, laboratory studies have been found to be not entirely representative of real situations (i.e. there are problems of ecological validity). Furthermore, it is difficult to make generalizations because field studies are usually conducted with just one scheduler. To overcome these two issues, this paper suggests bringing laboratory and field studies closer together using a cognitive typology. First, typologies that do not explicitly refer to a cognitive point of view are discussed. Second, the properties of a cognitive typology are detailed. A cognitive typology specific to scheduling situations is presented. This typology associates seven dimensions with their related human strategies: complexity; uncertainty; time pressure; cycle synchronicity; process steadiness; ...

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.

International audience; How professional and novice designers manage multiple objectives through constraint satisfaction was studied. An objective is defined as a network of constraints; a constraint is characterized as related to a source (internal or external) and an addressee (e.g., client or user). It has been shown that designers favour objectives related to external constraint (e.g., data from the task) and to the client. Generally, client and external constraints are identical. To study the management of multiple objectives, fifteen web site designers were instructed to design a site according to user's objectives or client's objectives. Our results indicate that the validity status allocated to constraints is more determined by the status of the addressee than by the status of the source, whatever the objective condition that must be satisfied. Possible methodological generalizations are discussed.

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.