Thesis (Ph. D.)--Psychology, Georgia Institute of Technology, 2007. / Washburn, David, Committee Member ; Spieler, Dan, Committee Member ; Schumacher, Eric, Committee Member ; Engle, Randall, Committee Chair ; Corballis, Paul, Committee Member.

Designing user-interfaces so that first-time or infrequent users can accomplish their goals by exploration has been an enduring challenge in Human-Computer Interaction. Iterative user-testing is an effective but costly method to develop user-interfaces that support use through exploration. A complementary method is to use modeling tools that can generate predictions of user exploration given a user-interface and a goal description. Recent computational models of goal-directed user exploration have focused on predicting user exploration of websites and demonstrated how predictions can inform user-interface design. These models employ the common concepts of label following and information scent: that the user's choice is partly determined by the semantic relevance between the user's goal and the options presented in the user-interface. However, in addition to information scent, other factors including the layout position and grouping of options in the user-interface also affect user exploration and the likelihood of success. This dissertation contributes a new model of goal-directed user exploration, called CogTool- Explorer, which considers the layout position and the grouping of options in the user-interface in concert with a serial evaluation visual search process and information scent. Tests show that predictions from CogTool-Explorer match participant data better than alternative models that do not consider layout position and grouping. This dissertation work has also integrated the CogTool- Explorer model into an existing modeling tool, called CogTool, making it easier for other researchers and practitioners to setup and generate predictions of likely user exploration paths and task performance using CogTool-Explorer.

The present investigation examined the role of cognitive interference in sport. In Study 1 an instrument to assess intrusive thoughts athletes experience during performance was developed (Thought Occurrence Questionnaire for Sport; TOQS). In the first part of the study, which involved modification of an instrument constructed in educational settings, three types of thoughts were identified. These were 'performance worries', 'situation irrelevant thoughts' and 'thoughts of escape'. In the second part of the study, which involved validation of the modified instrument, support for the psychometric properties of the TOQS was provided through tests of convergent, concurrent and discriminant validity. Study 2 examined situational antecedents of cognitive interference. Discrepancies between expected and actual performance was identified as the best predictor of cognitive interference athletes experience, whereas cognitive anxiety was found moderately related to cognitive interference. Finally, it was found that athletes experiencing their anxiety states as facilitative reported less cognitive interference than athletes experiencing their anxiety states as debilitative. Study 3 investigated possible effects cognitive interference has on aspects of sport performance based on athletes' perceptions. Participants reported cognitive interference to be detrimental to their concentration. Furthermore, it was revealed that different types of thoughts influence effort input in different ways. The relationship between 'performance worries' and subsequent effort depended on goal attainment expectancies. Athletes holding higher expectancies reported that their worries resulted in increased effort, whereas athletes holding lower expectancies reported their worries to result in decreased effort. 'Situation irrelevant thoughts' were reported not to have any effects on subsequent effort, while 'thoughts of escape' were associated with decreases in effort. Finally, Study 4 examined relationships between achievement goal orientations and cognitive interference. A negative relationship between task orientation and thoughts of escape was the only strong and consistent association that emerged. Goal profiles analysis revealed that, in contrast to athletes holding self-referenced goals, for those holding comparative goals outcome is an important determinant of withdrawal thoughts. The results of the present investigation are discussed in relation to findings in educational and sport settings, and a conceptual model regarding the role of cognitive interference in sport is proposed. Overall, cognitive interference is identified as a topic which requires further examination in the sport psychology domain.

Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2016-01-26T11:33:45Z No. of bitstreams: 1 arquivototal.pdf: 4463211 bytes, checksum: 90644c5d39937552b58c0d8121a9da17 (MD5) / Made available in DSpace on 2016-01-26T11:33:45Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4463211 bytes, checksum: 90644c5d39937552b58c0d8121a9da17 (MD5) Previous issue date: 2015-04-24 / The population aging is a universal phenomenon and this causes an increasing concern with this population and the increase in the life expectancy. In regards to the elderly, the physical exercises are essential, therefore they assist in the prevention of the illnesses caused by aging and in the promotion of its independence and quality of life. This research had the general objective to analyze the effect of the Exergames in the cognitive performance (attention and memory) and functionary (balance, marches, daily force of the inferior members and activities) of elderly without dementia. One was about an almost experimental and quantitative research with accomplishment of daily pre-test and after-test, carried through before and after intervention of psychomotor protocol set of rules with Exergames. The final sample of 18 elderly was equally divided between experimental group and control. At an assisted living facility for elderly individuals, located in Joao Pessoa, thirty sessions of exercises utilizing theX-BOX 360 Kinect® and Nitendo Wii® consoles were carried through with a frequency of three times a week and one hour of duration a day. To evaluate the effect of the intervention, functional cognitive instruments were applied to the elderly participants. The data had been analyzed statistically through inferential tests of comparison of averages and the level of significance adopted in this research was of 5%. In the results it was observed in the comparison between the groups (intervention x controlled) that the training with Exergames contributed significantly for the improvement of the functional performance (p = 0.001) and of the activities of daily life (p = 0,015). In the cognitive performance, significant improvement in the general cognition was observed, through the Moca, in the group of intervention (p = 0,007) and in the immediate logical memory (p = 0.001) and delayed (p = 0,038) between the groups. Due to the preliminary results of this research, it is concluded that the Exergames work as a new strategy in health with the purpose to provide improvement and/or cognitive function maintenance in the elderly, promoting a healthy aging and contributing for the satisfaction with the practice of physical exercise. / O envelhecimento populacional é um fenômeno universal e isto ocasiona uma preocupação crescente com esta população e com o aumento na expectativa de vida. Na atenção ao idoso os exercícios físicos são imprescindíveis, pois auxiliam na prevenção das doenças causadas pelo envelhecimento e na promoção da sua independência e qualidade de vida. Esta pesquisa teve o objetivo geral de analisar os efeitos dos exergames no desempenho cognitivo (atenção e memória) e funcional (equilíbrio, marcha, força dos membros inferiores e atividades diárias) de idosos sem demência. Tratou-se de uma pesquisa quase experimental e quantitativa com realização de pré-teste e pós-teste, realizados antes e após intervenção de um protocolo neuropsicomotor com exergames. A amostra final foi de 18 idosas divididas igualmente entre grupo experimental e controle. Foram realizadas 30 sessões de exercícios utilizando os jogos dos consoles X-BOX 360 Kinect® e Nitendo Wii® em um centro de referência para idosos de João Pessoa, com uma frequência de três vezes semanais e uma hora de duração ao dia. Para avaliar os efeitos da intervenção, foram utilizados instrumentos funcionais e cognitivos gerais e específicos com os idosos participantes. Os dados foram analisados estatisticamente através de testes inferenciais de comparação de médias e o nível de significância adotado nesta pesquisa foi de 5%. Nos resultados observou-se na comparação entre os grupos (intervenção x controle) que o treinamento com exergames contribuiu significativamente para a melhora do desempenho funcional (p = 0,001) e das atividades de vida diária (p = 0,015). No desempenho cognitivo, observou-se melhora significativa na cognição geral, através do Moca, no grupo de intervenção (p = 0,007) e na memória lógica imediata (p = 0,001) e tardia (p = 0,038) entre os grupos. Diante dos resultados preliminares desta pesquisa, conclui-se que os exergames funcionam como uma nova estratégia em saúde com a finalidade de proporcionar melhora e/ou manutenção cognitiva e funcional no idoso, promovendo um envelhecimento saudável e contribuindo para a satisfação com a prática de exercício físico.

Ce projet de mémoire s’intéresse à la mise en relation du cognitive enhancement observé dans les universités occidentales contemporaines et de la société dans laquelle il s’insère. Nous avons voulu détacher la perspective du phénomène des analyses principalement orientées vers les programmes de sciences de la santé et de droit, ainsi que de l’approche quantitative, clinique, athéorique et somme toute moralisatrice qui lui est usuellement accordée afin d’explorer la nature des pratiques d’usages de psychotropes des étudiants universitaires en sciences humaines et sociales en vue d’augmenter leurs performances cognitives, d’approfondir la compréhension des raisonnements sous-jacents à ces pratiques, puis de resituer ces derniers dans leur contexte élargi. Nous avons interrogé treize étudiants de divers programmes de sciences humaines et sociales consommant, ou ayant déjà consommé, des psychotropes en vue de rehausser leurs performances cognitives en contexte académique. Les résultats suggèrent un écart dans la nature de leurs pratiques d’usage par rapport aux domaines d’études habituellement préconisés en ce sens qu’une grande variété de substances sont considérées comme supports cognitifs ; ensuite, que le recours aux psychotropes dans une visée de performance cognitive s’éloigne des logiques de la nécessité médicale et de la toxicomanie. En premier lieu, le cognitive enhancement est associé par plusieurs à une souffrance psychique liée à une perte de repères existentiels et les étudiants y ont recours dans une optique de compréhension de soi et de quête de repères dans un monde qu’ils ressentent comme instable. En second lieu, la consommation de psychotropes s’apparente davantage à un désir de satisfaire aux conditions incertaines et menaçantes des demandes externes de performance telles qu’ils les appréhendent qu’à un souci de soigner quelque condition médicale de la cognition. Nous pensons que le rapport au psychotrope qu’entretiennent les étudiants universitaires en sciences humaines et sociales s’insère en toute cohérence dans les discours et injonctions contemporaines de performance, en ce sens que leur souffrance psychique individuelle expose les limites de ce que la société attend d’eux. / This master’s thesis assesses the underlying dynamics in the cognitive enhancement phenomenon observed in Western contemporary universities and the social context in which it emerges. Detaching our perspective from the analysis of healthcare and law fields of study as well as from the usual quantitative, clinical, atheoretical and over all moralizing approach, we aimed to explore the use of psychotropic substances in humanities and social science students, to better understand the rationales behind those behaviours and to situate them in their broader context. Thirteen humanities and social science students were interviewed regarding their past or present use of psychotropics as cognitive enhancers in academia. Results suggest a gap between their practices and those of the healthcare and law students, in that a wider variety of psychotropics are used as enhancers ; it also shows that the use of cognitive enhancers parts from the medical logic as well as that of addiction. First, the students’ practices are often oriented by an existential disorientation and it seems that their resort to psychotropics assists a quest for control, understanding and stability in themselves and in a world perceived as perpetually unstable. Furthermore, those practices serve a wish to satisfy a range of uncertain and threatening conditions related to external demands as apprehended, more than to treat any medical condition regarding cognition. We believe that the underlying rationales behind the humanities and social science university students use of psychotropics fit into the performance oriented contemporary discourse and injunctions in the sense that their individual suffering exposes the limits of what society expects from them.

This dissertation contributes an enhanced understanding of team cognition, in general, and collaborative problem solving (CPS), specifically, through an integration of methods that measure team interaction dynamics and knowledge building as it occurs during a complex CPS task. The need for better understanding CPS has risen in prominence as many organizations have increasingly worked to address complex problems requiring the combination of diverse sets of individual expertise to achieve solutions for novel problems. Towards this end, the present research drew from theoretical and empirical work on Macrocognition in Teams that describes the knowledge coordination arising from team communications during CPS. It built from this by incorporating the study of team interaction during complex collaborative cognition. Interaction between team members in such contexts has proven to be inherently dynamic and exhibiting nonlinear patterns not accounted for by extant research methods. To redress this gap, the present research drew from work in cognitive science designed to study social and team interaction as a nonlinear dynamical system. CPS was examined by studying knowledge building and interaction processes of 43 dyads working on NASA's Moonbase Alpha simulation, a CPS task. Both non-verbal and verbal interaction dynamics were examined. Specifically, frame-differencing, an automated video analysis technique, was used to capture the bodily movements of participants and content coding was applied to the teams' communications to characterize their CPS processes. A combination of linear (i.e., multiple regression, t-test, and time-lagged cross-correlation analysis), as well as nonlinear analytic techniques (i.e., recurrence quantification analysis; RQA) were applied. In terms of the predicted interaction dynamics, it was hypothesized that teams would exhibit synchronization in their bodily movements and complementarity in their communications and further, that teams more strongly exhibiting these forms of coordination will produce better problem solving outcomes. Results showed that teams did exhibit a pattern of bodily movements that could be characterized as synchronized, but higher synchronization was not systematically related to performance. Further, results showed that teams did exhibit communicative interaction that was complementary, but this was not predictive of better problem solving performance. Several exploratory research questions were proposed as a way of refining the application of these techniques to the investigation of CPS. Results showed that semantic code-based communications time-series and %REC and ENTROPY recurrence-based measures were most sensitive to differences in performance. Overall, this dissertation adds to the scientific body of knowledge by advancing theory and empirical knowledge on the forms of verbal and non-verbal team interaction during CPS, but future work remains to be conducted to identify the relationship between interaction dynamics and CPS performance.

Dans de nombreuses activités physiques et sportives, la performance dépend de l’efficacité des processus physiologiques et cognitifs sollicités dans l’action. Plus précisément, il semblerait que celle-ci soit fréquemment influencée par l’efficacité des processus décisionnels qui s’effectuent sous pression temporelle. A ce titre, ce travail de thèse s’intéresse à l’effet de l’administration de trois supplémentations nutritionnelles classiquement consommées par les athlètes (hydrates de carbone, caféine et guarana) sur le fonctionnement cognitif au cours d’un exercice. Nos résultats indiquent que l’ingestion isolée de ces trois composés améliore la vitesse du traitement de l’information lors d'une tâche décisionnelle dès la fin d’un exercice. Par ailleurs, l’utilisation de la caféine en rinçage de bouche semble aussi pertinente, puisque nos résultats suggèrent une amélioration probable de l’efficacité des processus relatifs à la gestion d’un conflit au cours de l’exercice. Enfin, une diminution de la perception de l’effort est aussi rapportée lors de l’ingestion de caféine et de guarana, ou de l’utilisation d’hydrates de carbone en rinçage de bouche. L’ensemble de ces résultats indique une potentialisation de l’effet de l’exercice sur la performance cognitive. Il suggère aussi que la mise en place de supplémentations nutritionnelles lors d’un exercice améliore l’efficacité de processus cognitifs qui s’avèrent être essentiels à la performance sportive. / In sport and exercise activities, successful performances strongly depend on the ability to simultaneously carry out cognitive and physical demands. More precisely, it would seem that performance is frequently influenced by the efficacy of decision-making realized under strong temporal pressure. The aim of this thesis work is to assess the effect of nutritional supplements that is carbohydrate, caffeine and guarana on cognitive functions during an acute exercise. Overall, our results suggest that ingestion of these three supplements enhance speed of information processing during a decision-making task at the end of exercise. Additionally, caffeine mouth rinsing seems worthwhile since a likely enhancement of inhibition processes has been reported after use during exercise. Finally, a decrease of perceived exertion has been reported with caffeine and guarana ingestion along with carbohydrate mouth rinsing. In conclusion, our results indicate the potentiation of exercise effects on cognitive function. Furthermore, they suggest nutritional supplements could enhance cognitive processes during exercise in what may be a predictive factor of performance enhancement.

The objective of this study was to assess low to high levels of Cognitive Workload by measuring heart rate and cortical blood flow in real-time. Four conditions were implemented into a within-subjects experimental design. Two conditions of difficulty and two conditions of trial order were used to illicit different levels of workload which will be analyzed with psychophysiological equipment. Functional Near-Infrared Spectroscopy (fNIRS) has become more prominent for measuring the blood oxygenation levels in the prefrontal cortex of individuals operating in hazardous work environments, students with learning disabilities, and in research for military training. This is due to the fNIR device being highly mobile, inexpensive, and able to produce a high-spatial resolution of the dorsolateral prefrontal cortex during executive functioning. Heart Rate will be measured by an Electrocardiogram, which will be used in concordance with fNIR oxygenation levels to predict if an individual is in a condition that produces low or high mental workload. Successfully utilizing heart rate and blood oxygenation data as predictors of cognitive workload may validate implementing multiple physiological devices together in real-time and may be a more accurate solution for preventing excessive workload.

Cette étude s’intéresse au lien entre les dynamiques cérébrales et les capacités cognitives, cette problématique a déjà été explorée auparavant en imagerie cérébrale, notamment à l’aide de tâches effectuées pendant l’imagerie. Cependant la caractérisation de l’activité spontanée a principalement été faite soit avec une faible précision spatiale (capteur EEG/MEG), soit en IRMf qui a une faible résolution temporelle. L’objectif de cette thèse est de caractériser l’activité spontanée au repos au niveau cortical associée à différents processus cognitifs et leur performance. Le second chapitre cherche à établir les corrélats neuronaux de la performance de la mémoire au repos à l’aide des puissances spectrales localisées au niveau des sources corticales. Le troisième chapitre cherche à répliquer les méthodes utilisées dans l’article 1 avec les mêmes participants, mais dans un autre domaine cognitif afin d’établir les corrélats neuronaux de la fluence verbale ainsi que de discriminer une composante verbale et exécutive. Ces deux composantes ont été mises en évidence en utilisant une factorisation avec un test purement exécutif (Trail making test- condition 4) et un autre purement verbal (richesse du vocabulaire). Dans le quatrième chapitre, nous répliquons encore la méthode de l’article 1 avec les mêmes sujets, mais sur un test d’apprentissage verbal. Lors de l’apprentissage verbal, deux stratégies d’apprentissage (sériel et sémantique) possibles sont utilisées de manière concurrente, nous avons cherché à établir si des différences comportementales se traduisaient par des patrons d’activation différents. Dans le cinquième chapitre, nous avons cherché à établir des différences fonctionnelles entre les survivants de la leucémie et des sujets contrôles, puis à établir un lien entre la neurotoxicité et le déficit cognitif rencontré chez cette population, finalement nous avons établi un modèle intégrant neurotoxicité, performance cognitive et marqueur neurophysiologique fonctionnel cérébral. Cette recherche aura approfondi les connaissances sur l’état de repos et principalement fourni les premiers travaux qui mettent en lien l’activité cérébrale spontanée au repos au niveau des sources corticales avec plusieurs tests neuropsychologiques comportementaux. Les résultats ont amené des patrons d’activation spatio-fréquentielle différents, démontrant des spécificités reliées à certains tests comportementaux ou des traitements de l’information (sériel ou sémantique). Finalement les travaux sur les survivants de la leucémie ont montré que l’état de repos pouvait caractériser le fonctionnement des déficits cognitifs à long terme et être un marqueur de remédiation pour de futurs traitements. / This study is interested in the link between brain dynamics and cognitive abilities. This problem has already been explored before in brain imaging, notably with the help of task performed during imaging. However, the characterization of spontaneous activity has mainly been done either with weak spatial resolution (EEG/MEG sensor) or in fMRI which has a low temporal resolution. The objective of this thesis is to characterize the spontaneous activity at rest at the cortical level associated with different cognitive processes and their performance. The second chapter seeks to establish the neural correlates of resting memory performance using spectral powers localized at cortical sources. The third chapter seeks to replicate the methods used in article 1 with the same participants but in another cognitive domain in order to establish the neural correlates of verbal fluency as well as to discriminate a verbal and an executive component. These two components were highlighted using a factorization with a purely executive test (Trail making test-condition 4) and another purely verbal one (vocabulary richness). In the fourth chapter, we replicate the method of article 1 with the same subjects, but on a verbal learning test. During verbal learning, two possible learning strategies (serial and semantic) are used concurrently, we sought to establish whether behavioural differences translate into different activation patterns. In the fifth chapter, we sought to establish functional differences between leukemia survivors and control subjects, then to search for a link between neurotoxicity and the cognitive deficit encountered in this population; finally we established a model integrating neurotoxicity, cognitive performance and functional neurophysiological brain markers. This research will have deepened the knowledge on the resting state and mainly provided the first works that link the spontaneous brain activity at rest at the level of cortical sources with several behavioural neuropsychological tests. The results led to different spatio-frequential activation patterns, showing specificities related to certain behavioural tests or information processing (serial or semantic). Finally, work on leukemia survivors has shown that resting states could characterize the functioning of long-term cognitive deficits and be a remediation marker for future treatments.

Les athlètes utilisent les suppléments nutritionnels avec pour objectif d'améliorer leur performance sportive. La performance sportive dépend de facteurs physiques, mais également de facteurs cognitifs. Les suppléments nutritionnels riches en flavanols issu du cacao (CF) peuvent stimuler la fonction vasculaire, réduire le stress oxydant et améliorer la fonction cognitive. L'objectif de cette thèse est donc d’analyser les effets d'une consommation aigue, ou pendant une semaine, de CF, sur la performance physique et cognitive chez des athlètes, chez des sujets actifs et chez des personnes ayant un diabète de type 1 (DT1). De plus, l’objectif est d’investiguer les effets des CF en altitude simulé, où l’hypoxie limite la performance cognitive et physique.La consommation aigue de 900 mg CF (dont 196 mg d'épicatéchine) suscite une augmentation de l’oxygénation cérébrale, mais pas de la concentration de BDNF sérique et n'a pas d’effet sur la fonction cognitive chez des sportifs sains. L’effet bénéfique des CF sur l’oxygénation cérébrale au repos est dépassé par l’ampleur de l’augmentation de la perfusion et de l’oxygénation cérébrale à l’exercice physique et n'est donc plus visible en post-exercice.En hypoxie (altitude simulée de 4000 m), la consommation aigue de 530 mg CF (dont 100 mg d'épicatéchine) augmente la réponse hémodynamique du cortex préfrontal durant une tâche cognitive, mais n’affecte pas l’activité neuronale. Les CF améliorent la pensée abstraite en normoxie, mais n’améliorent aucun autre domaine des fonctions cognitives. Seule la précision lors du test de Stroop est diminuée par l’hypoxie. De plus, la réponse hémodynamique du cortex préfrontale et l’activité neuronale ne diffèrent pas en hypoxie vs. en normoxie.Le diabète de type 1 (DT1) est associé avec une dysfonction endothéliale, qui constitue un des facteurs de déclin cognitif lié au diabète. Dans une 3ième étude, la fonction cognitive n’est pas altérée chez les patients DT1, en comparaison des sujets sains, alors que l'activation cérébrale diffère entre ces 2 groupes. Cette différence d'activation cérébrale pourrait alors jouer un rôle compensatoire chez les patients DT1. La consommation aigue de CF peut améliorer les fonctions exécutives chez des patients DT1 et des sujets sains, et peut augmenter le signal BOLD dans les régions du cerveau activées par les tâches cognitives.Ainsi, la consommation aigue de CF augmente la vasoréactivité cérébrale. Ces changements sont associés avec une meilleure fonction cognitive chez des patients DT1, alors que ce n’est pas le cas chez des sujets entraînés, ni au niveau de la mer, ni en hypoxie. Malgré ces effets bénéfiques des CF, l’exercice physique semble rester un moyen beaucoup plus efficace pour stimuler la vasoreactivité cérébrale et les fonctions cognitives.Nous nous sommes aussi intéressés aux effets de CF sur la capacité antioxydante, le stress oxydant et la production de NO pendant l’exercice, ainsi que sur les implications pour la performance physique et la récupération, chez des athlètes. La consommation aigue de 903 mg CF augmente la capacité antioxydante au repos et pendant l’exercice, mais sans réduire le stress oxydant et la production de NO. La consommation pendant une semaine de 530 mg CF (dont 100 mg d'épicatéchine) atténue la peroxydation lipidique induite par l’exercice, mais n’influence pas la capacité antioxydante. Les CF ne modifient pas la production et la biodisponibilité du NO pendant un exercice en normoxie et en hypoxie (altitude simulée de 3000 m). La consommation de CF pendant une semaine peut augmenter la fonction endothéliale de repos, et peut réduire les effets nuisibles de l'hypoxie sur l’oxygénation préfrontale au repos et pendant l’exercice modéré. Par contre, cet effet disparait pendant l’exercice intense. La consommation aigue, et pendant une semaine, de CF n’augmente pas la performance physique, ni en normoxie, ni en hypoxie. / Sports performance depends on physical factors, but also on cognitive functioning. Nutritional supplements as potential ergogenic aids can impact muscle, but also the brain. Cocoa flavanols (CF) have antioxidant capacities, can stimulate vascular function, and potentially enhance cognitive function. CF intake might thus improve exercise performance and recovery by reducing oxidative stress, increasing NO availability and/or boosting cognitive function. It is the purpose of this PhD to identify the effects of CF on physical and cognitive performance in healthy athletes at sea level and altitude, as well as in patients with type 1 diabetes. Our systematic review showed that CF can reduce exercise-induced oxidative stress, but without improving exercise performance. Combining CF intake and exercise training improves cardiovascular risk factors and vascular function in healthy and overweight participants, but evidence on the synergistic effects of CF and exercise training on oxidative stress, inflammation and fat and glucose metabolism is lacking.In a randomized, placebo-controlled, double blind cross-over study, we showed that 900 mg CF intake increased prefrontal oxygenation in athletes, but without affecting executive function. BDNF was not affected by CF intake. The effects of high-intensity exercise largely overruled the effects of CF intake: large beneficial effects of exercise on prefrontal oxygenation and cognitive function were observed and CF supplementation did not enlarge these effects. In a 2nd study, the effect of acute CF intake (530 mg CF) on performance on a demanding cognitive test was assessed in normoxia and hypoxia (simulated altitude 4000 m). Electroencephalogram and fNIRS were used to analyse neuronal activity and hemodynamic changes. Acute CF intake improved the neurovascular response, but did not affect neuronal activity and cognitive performance in normoxia and hypoxia. Most cognitive functions, the cerebrovascular response and neuronal activity, were not altered in hypoxia in healthy subjects. In a 3rd study, we found that acute intake of 900 mg CF enhanced cognitive performance on the Flanker test in patients with type 1 diabetes, and their healthy matched controls. CF intake increased the BOLD response in brain areas activated during this specific task. While cognitive performance was not deteriorated in patients with type 1 diabetes, a different brain activation pattern during the cognitive task was observed, compared to healthy controls and this brain activation pattern was altered by CF intake. To conclude, acute CF intake improves prefrontal oxygenation and cerebrovascular responsiveness. This can be associated with better cognitive function in patients with type 1 diabetes, but does not result in improved executive function in healthy persons. Compared to exercise, the magnitude of the CF-induced neurovascular changes is small.Two studies were conducted examining the effects of CF on exercise-induced oxidative stress, NO availability and its implications for exercise performance, in well-trained cyclists. We found that acute CF (900 mg) improved the exercise-induced increase in total antioxidant capacity, but did not reduce the exercise-induced increase in lipid peroxidation. One week CF intake (530 mg CF) improved vascular function at rest, and prefrontal oxygenation at rest and during low-intensity exercise, but did not influence muscular oxygenation. One week CF intake partially restored the hypoxia-induced decline in prefrontal oxygenation during rest and low-intensity exercise, but not during high-intensity exercise. One week CF intake reduced exercise-induced lipid peroxidation, but did not alter total antioxidant capacity. Both acute and 1-week CF intake did not improve exercise performance and recovery and do not change NO production during exercise (in normoxia and hypoxia) in well-trained athletes.