Kognitive Kontrolle wird besonders in solchen Momenten deutlich, wenn eine geplante Handlung gestört wird. Weil zwei widerstreitende Verhaltenstendenzen gleichzeitig bestehen oder anlaufen, entsteht ein Konflikt. Experimentell können kognitive Konflikte beispielsweise mit dem Stroop-Paradigma hergestellt und untersucht werden (Stroop, 1935). Es ist dabei eine aktuelle Frage, wie Konflikte zeitlich verarbeitet werden und wo im Gehirn diese Verarbeitung geschieht. Zeitlich können Konflikte beispielsweise dann entstehen, wenn die Informationen des Stimulus abgerufen werden oder auch erst dann, wenn die intendierte Antwort tatsächlich für die Artikulation ausgewählt werden muss. Eine weiterführende Frage ist, ob sich die entsprechenden Ergebnisse für verschiedene Stroop-Varianten unterscheiden. In der vorliegenden Arbeit wurden diese Fragen systematisch für die Verarbeitung von Objekten und Zahlen mit zwei Varianten des Stroop-Paradigmas untersucht. In der vorliegenden Dissertation präsentiere ich Ergebnisse von Reaktionszeitstudien und fMRT-Experimenten zum zeitlichen Ablauf und zu neuronalen Substraten kognitiver Konflikte während der Verarbeitung von Objekten und Zahlen. Um die Konflikte zeitlich und räumlich lokalisieren zu können, wird die Abrufphase und die Antwortphase separat modelliert. Die Ergebnisse deuten darauf hin, dass die Konflikte eher während des Abrufs als bei der Antwortauswahl stattfinden. Außerdem wird geschlussfolgert, dass die Konflikte für Zahl- und Objektrepräsentationen nicht auf gemeinsamen neuronalen Substraten basieren. Die Ergebnisse meiner Reaktionszeitstudien und der MRT-Studien deuten also darauf hin, dass Konflikte bei der Verarbeitung von Objekten und Zahlen zwar einem ähnlichen zeitlichen Verlauf folgen, aber offenbar in unterschiedlichen neuronalen Netzwerken verarbeitet werden. / In daily life, we constantly have to adjust our goals and plans to changing task demands and internal needs. Our ability to balance the initiation and inhibition of our actions, and to solve resulting conflicts between them, is referred to as cognitive control. To study the processes of cognitive control, the Stroop Paradigm has become a popular tool (Stroop,1935). The Stroop Paradigm is frequently used to address central questions of cognitive control. It is, for instance, an open issue, where and when in the processing stream cognitive conflicts arise. Do they arise early, for example, during the retrieval of target and distractor? Or do they occur late, when the response is prepared for execution? Another debate is concerned with the question whether the findings agree for different Stroop variants (Van Maanen et al., 2009). In this dissertation I present research on the temporal characteristics and the neural substrates of cognitive conflicts during the processing of objects and numbers. To better understand the locus of the conflict, the retrieval phase and the response phase are modelled separately. The results from several reaction time studies and from two fMRI experiments speak to the issue that processing costs occur during retrieval, i.e., early in the processing stream, for both, object and number representations. The results further indicate that the processing of the conflict between target and distractor for number and object representations do not rely on common neural substrates. I will thus present the results from behavioural and functional imaging experiments, showing similar temporal patterns for the conflicts in both systems, but distinct underlying neural networks.

Introdução: Concomitante ao processo de envelhecimento populacional, estão ocorrendo mudanças climáticas, sendo a principal delas o aquecimento global. O envelhecimento leva a mudanças tanto nos mecanismos de termorregulação quanto no desempenho cognitivo. Embora inúmeros estudos tenham avaliado o efeito do calor sobre a cognição de adultos jovens, este é um tema praticamente inexplorado na população geriátrica. Objetivos: Avaliar o efeito da exposição ao calor sobre o desempenho cognitivo de idosos saudáveis e identificar fatores que expliquem as variações na susceptibilidade ao estresse térmico nesta população. Casuística e Métodos: 68 idosos com bom desempenho físico e cognitivo realizaram uma bateria de testes neuropsicológicos em duas condições ambientais: 24oC (controle) e 32oC (calor). Através de cinco testes selecionados da Bateria Neuropsicológica Automatizada de Testes de Cambridge (CANTAB), foram avaliados diferentes aspectos do desempenho cognitivo com foco principal em memória, atenção e velocidade de processamento. Um escore composto global de desempenho cognitivo foi criado usando a medida mais representativa de cada um desses testes. Antes e após cada uma das sessões de testes, foram aferidos o peso corporal, a temperatura axilar, a temperatura auricular, a frequência cardíaca e a pressão arterial. Por meio da análise de variância para medidas repetidas (ANOVA), verificou-se a interação entre o efeito da temperatura na cognição (avaliada pelo escore composto global) e características sociodemográficas (idade, sexo, educação, cor), frequência de exercício físico e umidade relativa registrada durante o protocolo de exposição ao calor. Adicionalmente, foi também desenvolvido um modelo de regressão linear multivariada a fim de identificar variáveis independentes que explicariam a susceptibilidade ao estresse pelo calor. Resultados: A idade média da amostra foi de 73,28 anos. 42,9% dos indivíduos relataram praticar atividade física quatro ou mais vezes por semana. As temperaturas auriculares e axilares aumentaram significativamente após a exposição ao calor, sendo que as diferenças médias encontradas foram de 0,55 e 0,43oC respectivamente. Não foram observadas diferenças significativas entre quaisquer medidas individuais de desempenho ou no escore composto global quando comparamos o desempenho cognitivo sob as duas temperaturas experimentais. Na análise de interação, somente os níveis de umidade registrados durante o protocolo de exposição ao calor e a frequência da prática de exercícios modificaram significativamente o efeito da temperatura sobre o desempenho cognitivo. Os sujeitos expostos a maior umidade relativa do ar no protocolo de calor e os voluntários menos ativos apresentaram piora no desempenho cognitivo na sessão a 32oC. Estes achados foram confirmados num modelo de regressão linear totalmente ajustado. Conclusão: A análise principal mostrou que o desempenho cognitivo de idosos com boa funcionalidade não sofreu efeito deletério da exposição ao calor. No entanto, os voluntários expostos ao calor mais úmido e aqueles que relataram menor frequência de exercício físico apresentaram pior desempenho na sessão de calor que na de controle. As variáveis sócio-demográficas como idade, gênero, escolaridade e cor não tiveram influência na susceptibilidade ao estresse térmico / Introduction: Concomitantly to the process of population aging, major climate changes are taking place, among which global warming is regarded as the most important. Aging leads to changes in temperature control mechanisms and is associated with a subtle and progressive decline in cognitive functions. Although a great deal of studies have evaluated the effect of heat on the cognitive performance of young adults, to the best of our knowledge, no studies have directly investigated the effects of warm environments on the cognitive functioning of older adults. Objectives: To evaluate the effect of heat exposure on the cognitive performance of healthy older adults and to identify factors that would explain variations in susceptibility to heat stress in that population. Methods: 68 older adults with both good physical and cognitive performance were requested to take a series of neuropsychological tests under two environmental conditions: at 24oC and 32oC. Five tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered to measure different aspects of cognitive functioning while focusing on memory, attention and processing speed. A global composite score of cognitive performance was created, using the most representative measures of each one of those five tests. Before and after each session, measures of auxiliary temperature, tympanic temperature, blood pressure, heart rate, and body weight were obtained. Interaction analysis was carried out using repeated measures analysis of variance (ANOVA) in order to check whether the effect of temperature on cognition, assessed by the global composite score, was modified by sociodemographic characteristics (age, gender, education, race), frequency of physical activity or relative humidity registered during the heat protocol. In addition, a multiple linear regression model has been fitted to identify independent variables that would explain susceptibility to heat stress Results: The mean age of the sample was 73.28 years and 42.9% of the participants reported performing physical activities at least four times a week. Tympanic and auxiliary temperatures increased significantly after the heat exposure with increases of 0.55 and 0.43oC, respectively. No significant differences were observed among any individual measures or the composite score, when comparing the cognitive performance under the two experimental temperatures. In the interaction analysis, only the humidity levels during the heat exposure protocol and the frequency of physical activities significantly modified the effects of temperature on cognitive performance. Participants exposed to higher relative air humidity during the heat protocol and the less active ones have presented worse cognitive performance in the session at 32oC. Those findings have been confirmed by a totally adjusted linear regression model. Conclusion: The main analysis has shown that the cognitive performance of older healthy adults has not had deleterious effect of heat exposure. Nevertheless, the volunteers exposed to more humid heat and those who have reported lower frequency of physical exercises have shown worse performance during the heat session than in the control session. The sociodemographic variables such as age, gender, education and race have not had any influence over susceptibility to heat stress

OBJETIVO: 1- Avaliar e comparar o tempo de frenagem medido no simulador de direção virtual entre motoristas com e sem paraplegia; 2- Identificar e descrever as variáveis preditoras do tempo de frenagem no simulador de direção para os motoristas com paraplegia. METODOLOGIA: Motoristas do sexo masculino com paraplegia (n = 20 com idade média de 38,1 ± 3,6 anos) e motoristas sem paraplegia (n = 20 com idade média de 38,0 ± 5,8) com carteira de habilitação válida tiveram o tempo de frenagem medido no simulador de direção virtual. Os motoristas sem paraplegia foram avaliados com controles convencionais de pedais de freio e aceleração e os motoristas com paraplegia usaram controles manuais. O teste t de Student comparou os resultados do entre os grupos. A correlação do tempo de frenagem foi realizada com as variáveis selecionadas para o estudo nos motoristas com paraplegia. RESULTADOS: As diferenças do tempo de frenagem do simulador entre os grupos não foram estatisticamente significativas (motoristas sem paraplegia = 0,90 segundos; motoristas com paraplegia 0,92 segundos, p > 0,05). A experiência de dirigir correlaciona-se significativamente com o tempo de frenagem dos motoristas com paraplegia (r = -58, p = 0,009). Análises de regressão linear indicaram que anos de escolaridade, experiência de direção e o teste neuropsicológico MOCA (variáveis explicativas) explicaram 60,2% da resposta do tempo de frenagem do simulador de direção para os motoristas com paraplegia. CONCLUSÃO: A experiência de condução, anos de escolaridade e o teste neuropsicológico MOCA foram identificadas como preditoras do tempo de frenagem do simulador de direção para motoristas com paraplegia / Objective: (1) To identify differences in driving simulator braking time response between paraplegic and able-bodied drivers (2) To determine the contributions of age, driving experience, length of disability, handgrip strength and, neuropsychological tests, as selected factors, to driving simulator braking time response of drivers with paraplegia. Design: Two groups of male able-bodied and paraplegic drivers had their braking time response evaluated in an automatic transmission car simulator. Able-bodied drivers were tested with conventional controls and paraplegic drivers used hand controls. Drivers with paraplegia performed simple, choice and go-no-go reaction time tests as neuropsychological evaluation. Student\'s t test compared results of driving simulator braking time response between groups. Persons\' correlation verified the association between driving simulator braking time responses and selected variables of the drivers with paraplegia. Subjects: Able-bodied drivers (n=20 mean age 38.0±5.8) and paraplegic drivers (n=20 mean age 38.1±3.6) with valid driver license accepted to be part of this study. Results: Differences of simulator braking time response between groups were not statistically significant (able-bodied=0.90 seconds; paraplegic drivers 0.92 seconds, p>0.05). Driving experience significantly correlates with braking time response of the drivers with paraplegia (r= -58, p=0.009). Linear regression analyses indicated that years of education and driving experience (explanatory variables) explained 60.2% of driving simulator braking time response for the drivers with paraplegia. Conclusion: Driving experience, years of education and MOCA neuropsychological test were predictors variables of driving simulator braking time for paraplegic drivers

Existant en tant que pratique sportive, l’apnée est également de plus en plus utilisée dans d’autres activités sportives dont la natation, à l’entraînement et/ou en compétition. Toutefois, les réponses à l‘apnée dynamique ont été peu explorées lors d’efforts physiques intenses, en particulier en natation. L’objectif de ce travail de thèse est donc d’étudier sur le terrain en situation de nage (étude 1 et 2) et en laboratoire (étude 3) lors d’un exercice intermittent de pédalage, les réponses physiologiques, psychologiques et ergogéniques à l’apnée aiguë apparaissant lors d’efforts intenses. Le métabolisme a été notamment évalué à partir de la mesure de l’oxygénation tissulaire, de paramètres sanguins et de marqueurs hormonaux. Les principaux résultats de ces études montrent qu’en apnée la performance dépendrait de la capacité des sujets à maintenir leur fréquence cardiaque et que l’effort est globalement perçu comme plus dur. L’apnée n’induisait pas d’augmentation de la lactatémie, sans doute en lien avec l’absence de modification de l’extraction musculaire de l’oxygène. Au niveau cérébral, le maintien de l’oxygénation expliquerait la non modification du temps de réaction en apnée. Enfin toutes nos études ont révélé une désaturation artérielle significative en apnée, dès la première apnée de 10 secondes (étude 3) mais sans effet de la capacité d’apnée (étude 1) ou de l’intensité de nage (étude 2) suggérant que la durée compenserait l’intensité. Il serait donc intéressant d’étudier ultérieurement les effets respectifs du couple intensité/durée et les effets chroniques d’un entraînement comportant un exercice intermittent intense lors d’apnées dynamiques. / Existing as a sport practice, apnea is also increasingly used in other sports activities including swimming, training and/or competition. However, responses to dynamic apnea have been little explored during intense physical exercise, especially in swimming. The objective of this thesis is to study, in the field in swimming situations (study 1 and 2) and in the laboratory (study 3) during an intermittent cycling exercise, the physiological, psychological and ergogenic responses to acute apnea appearing during intense exercises. Metabolism was especially assessed by measurement of tissue oxygenation, blood parameters and hormonal markers. The main results of these studies show that in apnea the performance would depend on the ability of the subjects to maintain their heart rate and that the exercise is globally perceived as harder. Apnea did not induce an increase in lactatemia, probably related to the lack of modification of the muscle extraction of oxygen. At the cerebral level, the maintenance of the oxygenation would explain that the reaction time is not altered with apnea. Finally, all our studies revealed a significant arterial desaturation in apnea at the first repetition of the 10-second apnea (study 3) but without the effect of apnea capacity (study 1) or swimming intensity (study 2) suggesting that the duration would compensate for the intensity. It would therefore be interesting to study later the respective effects of the intensity/duration pair and the chronic effects of training involving intense intermittent exercise during dynamic apneas.

前言:由於注意力不足過動症（Attention Deficit/ Hyperactivity Disorder, ADHD）患者在不同的認知作業具有一致的反應模式-他們的反應時間慢且變異量大，已有學者們認為這與他們在能量調節缺損有關。 研究目的：一、以ex-Gaussian的估計參數（μ、σ、τ）分析ADHD患者在柯能氏持續表現作業(Conners’ Continuous Performance Test, CCPT) 的反應時間，探討與釐清不同能量調節歷程（事件速度與作業時間長度）可能的影響。二、藉由行為量表以及CCPT的錯誤反應與參數的關係，推論μ、σ、τ可能的心理涵義。三、以能量調節歷程（ISI與Block）與ex-Gaussian的估計參數（μ、σ、τ）的關係，探討不同ADHD亞型患者在能量調節的可能問題。四、由於時間知覺作業與注意力資源分配有密切關連性，因此本研究也想探討不同ADHD亞型患者時間知覺作業（時間再製單一與雙重作業）的表現與能量調節的關係。五、從不同發展階段討論ADHD亞型患者與對照組在ex-Gaussian參數的差異是否會隨著年齡發展而有所改變。 方法:本研究受試包括261位ADHD混合型(ADHD-Combined Type)患者(221位男生，84.7%)，151位ADHD注意力不足型(ADHD-Inattentive Type)患者(128位男生，84.8%) 以及161位對照組受試(124位男生，77.0%)。測量工具包括: 1)中文版K-SADS-E 臨床診斷會談，2) 中文版短式柯能氏家長版/教師版量表，3) 中文版注意力不足過動症 (SNAP-IV)父母/教師量表，4) 柯能氏持續表現作業，5) 時間再製雙重作業，6) 魏氏兒童智力量表中文版第三版。 結果:1) 相較於對照組受試，ADHD患者有較快的μ以及較大的σ與τ，並且τ的效果量最大，與過去的研究相符。2) ISI/Block增加，皆會使得ADHD患者在τ的增加量顯著大於對照組受試；但ISI放慢會使得個體的μ變慢，Block增加卻只會影響ADHD患者的μ加快；ADHD患者與對照組在σ的差異只在ISI的變化，在Block中的σ沒有顯著組別差異。3) 從行為量表與參數的關係，τ與ADHD患者的核心症狀普遍具有關連性；在CCPT的錯誤反應與參數的關係發現μ與誤判錯誤，τ與漏判錯誤的關係最為密切。4) 在ADHD亞型的比較，ADHD-C患者在μ顯著快於ADHD-IA患者，但是兩組在τ沒有顯著的差異。5) ADHD亞型在時間再製作業同樣受到時距與作業複雜度的影響，當時距愈長（17秒）與對照組有顯著差異。再者，τ是解釋時間估計變異量中最重要的參數。6) 在兒童與青少年期的比較，ADHD患者與對照組在τ的差異沒有改變。不過在青少年期ADHD亞型在μ皆顯著比對照組快，但是在σ沒有差異。 討論:本研究不但釐清ADHD患者的反應時間特性，也支持認知能量模式對於ADHD患者病理的描述。再者，研究也發現ADHD不同亞型具有類似的能量調節缺損的歷程，他們在時間知覺作業的結果也支持注意力資源與能量調節具有理論的複核效度，在不同發展時期的比較也再次顯示τ是ADHD患者與對照組受試的主要差異。本研究認為ex-Gaussian參數是估計認知能量模式中的能量庫的適當測量方式，並可藉由認知能量的病理模式建構介入與治療的方向。 / Background: Literature documents that the reaction time (RT) assessed by a variety of neuropsychological tasks is typically both slower and more variable in individuals with attention-deficit hyperactivity disorder (ADHD) than the controls. Some studies further lent evidence to support a relationship between the RT patterns and the difficulty of effort regulation in ADHD. Objectives: 1) To explore the moderating effects from effort regulation (the inter-stimulus intervals (ISI) and Block) on three parameters (μ, σ, τ) of ex-Gaussian distribution of the reaction time of the Conner’s Continuous Performance Test (CCPT) among individuals with ADHD as compared with the controls; 2) To examine the association between the ex-Gaussian parameters and ADHD symptoms and the response errors in the CCPT to infer the psychological meanings of ex-Gaussian parameters (μ, σ, and τ); 3) To understand effort regulation for the ADHD-Combined Type (ADHD-C) and ADHD-Inattentive Type (ADHD-IA) by examining the relationship between effort regulation process (ISI and Block effects) and ex-Gaussian parameters (μ, σ, and τ); 4) To compare the performance in the time reproduction dual tasks and its relationship with ex-Gaussian parameters (μ, σ, and τ) among the ADHD-C, ADHD-IA, and controls; 5) To examine the developmental change of ex-Gaussian parameters (μ, σ, and τ) and to test the difference among the two age groups (adolescent vs. child) with three diagnostic groups (ADHD-C, ADHD-IA, and controls) on ex-Gaussian parameters. Methods: We assessed 261 participants with DSM-IV ADHD-C (221 Boys, 84.7%), 151 participants with ADHD-IA (128 Boys, 84.8%), and 161 typically developing controls (124 Boys, 77.0%). Their age ranged from 6 to 16 years old. All the participants and their parents were interviewed with the Chinese version of the Kiddie Epidemiologic Version of the Schedule for Affective Disorders and Schizophrenia to confirm the psychiatric diagnosis of ADHD and other psychiatric disorders. Participants also received the Chinese versions of the Conners’ Parent Rating Scale-revised: Short Form (CPRS-R: S), the Conners’ Teacher Rating Scale-revised: Short Form (CTRS-R: S), the Swanson, Nolan, and Pelham, version IV scale (SNAP-IV)-Parent/Teacher Forms, the Time Perception Single and Dual Tasks, the CCPT and Intelligence (WISC-Ⅲ). Results: Participants with ADHD had a smaller μ and larger σ and τ with the largest effect sizes from τ. As ISI/Block increased, the magnitude of greater τ in participants with ADHD than controls increased. As the ISI increased, μ became slower in both groups; as the Block increased, μ became smaller only noted in participants with ADHD. There were significant group differences (ADHD/control) in σ estimation across different ISIs rather than in different Block levels. Regarding the association between ADHD symptoms and ex-Gaussian parameters (μ, σ, and τ), only τ was related to ADHD symptoms. Moreover, μ was correlated with commission errors of the CCPT; τ was correlated with omission errors of the CCPT. ADHD subtypes analysis revealed that participants with ADHD-C had smaller μ than participants with ADHD-IA without significant difference in τ; there was no subtype difference in time reproduction but the differences between the ADHD and control groups were magnified with increased time intervals and task complexity. Moreover, the variance of the time reproduction performance can be explained well by τ. As to the developmental comparison (children vs. adolescents), larger τ in participants with ADHD than control participants did not vary between child and adolescent participants. On the other hand, there were development changes in μ and σ estimates. For example, adolescents with ADHD had smaller μ than the controls without group difference in σ. Discussion: This study contributes not only to our understanding about RT in ADHD, but also to provide evidence to support the Cognitive-Energetic Model for ADHD. The findings also demonstrated similar compensation in effort regulation between the ADHD-C and ADHD-IA. Moreover, the findings support the cross-validity between time perception and effort regulation. Among the three ex-Gaussian parameters, τ is the most significant index to differentiate ADHD from non-ADHD. Finally, this study provides strong evidence to support the ex-Gaussian parameter as an appropriate method to assess the energetic pool of the Cognitive-Energetic Model for ADHD. A theoretical model for intervention can be established by taking the pathological model of Cognitive-Energetic Model for ADHD as reference.

Hansen and Hansen (1988) found that angry targets in happy crowds were found more quickly and accurately than happy targets in angry crowds. This finding, they dubbed the Face-in-the-Crowd effect. Gilboa-Schechtman and colleagues (1999) found that high anxious participants show a greater enhancement of detecting angry versus happy targets. The purpose of the current studies was to replicate these findings, and to determine whether Rational and Experiential decision-making styles play a role in target detection (Study One) and crowd searching (Study Two), and if these decision-making styles interact with affective predisposition for both reaction time and galvanic skin response in the face-in-the-crowd task. In Study One, I replicated the anger superiority effect and the Anxiety x Target interaction. I also found that the Rational Group tended to be faster than the Experiential Group overall. I found that the High Trait Anxious group had higher GSR than the Low Trait Anxious group averaged over both target conditions. The Rational group had higher GSR when presented with happy targets than when presented with angry targets whereas the Experiential group did not show this difference. In Study Two, I failed to replicate the anger inferiority effect of crowd searching, but I did find that the Rational group tended to be faster than the Experiential group, especially for angry crowd searching. I also found that the Low-State-Anxious-Rational group had lower galvanic skin responses than all other groups across all analyses. The most exciting finding of these two studies was that he Rational Group demonstrated a facility for the face-in-the-crowd task, validating decision-making style as an important dimension to be considered in future face-in-the-crowd research. The research also provided support for network theories and it is hoped that future studies might endeavor to explore facial processing with this theoretical framework in mind.

En este estudio se analizan los parámetros mecánicos fuerza de impacto (FI), tiempo de reacción (TR), tiempo de movimiento (TM), tiempo total de respuesta (TT) y dominancia, en la patada circular o Bandal Chagui en Taekwondo, basado en la regulación de la distancia de golpeo (ED1, ED2 y ED3). Para ello, se ha utilizado un sistema de nueva creación formado por una plataforma de contacto, una plataforma de fuerzas, un led de luces y un maniqui. La muestra esta compuesta por 51 taekwondistas (22 medallistas y 29 no medallistas; 37 varones y 19 mujeres; 42 diestros y 9 zurdos) de la Comunidad Valenciana con una media de edad de 24.49 años (DT = 5.94), una media de peso de 70.91 kg (DT = 12.95) y una longitud de pierna de 1.03 metros (DT = .06). En cuanto a la fuerza de impacto, los resultados muestran que los medallistas golpean con una mayor fuerza de impacto que los no-medallistas desde la distancia larga (D3) con ambas piernas y, desde la distancia corta (D1) con la pierna izquierda. Asimismo, los varones golpean con una mayor fuerza de impacto que las mujeres desde todas las distancias, excepto desde la distancia media (D2) con la pierna izquierda. Por otra parte, en el género varón, el peso tiene una relación positiva con la fuerza de impacto.En cuanto al tiempo de reacción, existen diferencias entre medallistas y no-medallistas desde la distancia media (D2) y larga (D3) con la pierna izquierda, mientras que el género no influye en el tiempo de reacción. En el tiempo de movimiento, no existen diferencias entre medallistas y no-medallistas ni entre varones y mujeres. Al mismo tiempo, el tiempo de reacción tiene una relación negativa con el tiempo de movimiento. Por su parte, los medallistas muestran un menor tiempo total de respuesta que los no-medallistas desde la distancia larga (D3) con la pierna izquierda, mientras que los varones golpean en un menor tiempo total de respuesta que las mujeres desde la distancia corta (D1). En cuanto a los análisis realizados teniendo en cuenta la dominancia, los medallistas muestran una asimetría en el tiempo de reacción desde la distancia larga (D3), mientras los no-medallistas muestran una asimetría en el tiempo total de respuesta desde las tres distancias planteadas (ED1, ED2 y ED3) y, en la fuerza de impacto desde la distancia corta (D1). El género varón muestra una asimetría en la fuerza de impacto desde la distancia corta (D1), mientras que en el género mujer no existen diferencias entre la pierna dominante y no-dominante. Así pues, la distancia de ejecución es un factor a tener en cuenta en la realización de una patada circular o Bandal Chagui medido con un sistema capaz de obtener datos objetivos del rendimiento mecánico mediante la estandarización de un protocolo, permitiendo diferenciar a los sujetos en función del nivel competitivo y del género, siendo una herramienta útil en el entrenamiento. / We analyzed the mechanical parameters impact force (FI), reaction time (TR), movement time (MT) and total response time (TT) and dominance in a roundhouse kick among three execution distances. To this end, a new system based in a contact platform, force platform, a led and a mannequin was used. The sample was composed by 51 taekwondo players (22 medallist and 29 non medallist; 37 male and 19 female) aged from 16 to 31 years (M = 24.49; S.D. = 5.9), weighing from 46 to 101 kg (M = 70.91; SD = 12.91) were selected to participate in the study. Medallists kicks with a higher FI from the long distance with both legs and from the shortest one with the left leg. Men kick with higher FI than women from all distances, except from the medium distance with the left leg. Significant differences have been found between medallists and non-medallist for RT from medium and large distance with the left leg, without differences among genere. No differences have been fount among movement time. Reaction time and movement time has a negative relation. Medallist had a less TT than non-medallist from the large distance with the left leg, while men kick with less TT than women from the shortest one. Medallist showed an asymmetry in RT from the large distance, while for non-medallist this asymmetry is showed in TT from all distances and in FI from the shortest distance. The execution distance is a parameter to take into account into a roundhouse kick performance.

Hansen and Hansen (1988) found that angry targets in happy crowds were found more quickly and accurately than happy targets in angry crowds. This finding, they dubbed the Face-in-the-Crowd effect. Gilboa-Schechtman and colleagues (1999) found that high anxious participants show a greater enhancement of detecting angry versus happy targets. The purpose of the current studies was to replicate these findings, and to determine whether Rational and Experiential decision-making styles play a role in target detection (Study One) and crowd searching (Study Two), and if these decision-making styles interact with affective predisposition for both reaction time and galvanic skin response in the face-in-the-crowd task. In Study One, I replicated the anger superiority effect and the Anxiety x Target interaction. I also found that the Rational Group tended to be faster than the Experiential Group overall. I found that the High Trait Anxious group had higher GSR than the Low Trait Anxious group averaged over both target conditions. The Rational group had higher GSR when presented with happy targets than when presented with angry targets whereas the Experiential group did not show this difference. In Study Two, I failed to replicate the anger inferiority effect of crowd searching, but I did find that the Rational group tended to be faster than the Experiential group, especially for angry crowd searching. I also found that the Low-State-Anxious-Rational group had lower galvanic skin responses than all other groups across all analyses. The most exciting finding of these two studies was that he Rational Group demonstrated a facility for the face-in-the-crowd task, validating decision-making style as an important dimension to be considered in future face-in-the-crowd research. The research also provided support for network theories and it is hoped that future studies might endeavor to explore facial processing with this theoretical framework in mind.

L’intégration de stimulations provenant de modalités sensorielles différentes nous offre des avantages perceptifs tels qu’une meilleure discrimination et une accélération des temps de réponse (TR) face aux évènements environnementaux. Cette thèse a investigué les effets de la position spatiale de stimulations visuelles et tactiles sur le gain de redondance (GR), qui correspond à une réduction du temps de réaction lorsque deux stimulations sont présentées simultanément plutôt qu’isolément. La première étude a comparé le GR lorsque les mêmes stimulations visuotactiles sont présentées dans une tâche de détection et une tâche de discrimination spatiale. Les stimulations étaient présentées unilatéralement dans le même hémichamp ou bilatéralement dans les hémichamps opposés. Dans la tâche de détection, les participants devaient répondre à toutes les stimulations, peu importe leur localisation. Les résultats de cette tâche démontrent que les stimulations unilatérales et bilatérales produisent un GR et une violation du modèle de course indissociables. Dans la tâche de discrimination spatiale où les participants devaient répondre seulement aux stimulations présentées dans l’hémichamp droit, les TR aux stimulations bilatérales étaient moins rapides. Nous n’avons pas observé de différence entre le GR maximal obtenu dans l’une ou l’autre des tâches de cette étude. Nous concluons que lorsque l’information spatiale n’est pas pertinente pour accomplir la tâche, les stimulations unilatérales et bilatérales sont équivalentes. La manipulation de la pertinence de l’information spatiale permet donc d’induire une altération du GR en fonction de la localisation des stimulations. Lors d’une seconde étude, nous avons investigué si la différence entre les gains comportementaux résultants de l’intégration multimodale et intramodale dépend de la configuration spatiale des stimulations. Les résultats montrent que le GR obtenu pour les conditions multimodales surpasse celui obtenu pour les stimulations intramodales. De plus, le GR des conditions multimodales n’est pas influencé par la configuration spatiale des stimulations. À l’opposé, les stimulations intramodales produisent un GR plus important iii lorsque les stimulations sont présentées bilatéralement. Nos résultats suggèrent que l’intégration multimodale et intramodale se distinguent quant au GR qu’ils produisent et quant aux conditions nécessaires à cette amélioration. La troisième étude examine le rôle du corps calleux (CC) dans l’observation du GR obtenu pour les stimulations multimodales et intramodales lorsque celles-ci sont présentées unilatéralement et bilatéralement. Quatre patients ayant une agénésie congénitale du corps calleux (AgCC) et un patient callosotomisé ont été comparés à des individus normaux dans une tâche de détection. Dans l’ensemble, les résultats suggèrent que le CC n’est pas nécessaire pour l’intégration interhémisphérique de stimulations multimodales. Sur la base d’études précédentes démontrant le rôle des collicules supérieurs (CS) dans l’intégration multimodale, nous concluons qu’en l’absence du CC, les bénéfices comportementaux résultants d’un traitement sous-cortical par les CS ne reflètent pas les règles d’intégration observées dans les études neurophysiologiques chez l’animal. / The integration of stimuli from the same or different modalities offers many benefits such as enhanced discrimination and accelerated reaction to objects. This thesis investigates the effects of stimuli’s spatial location on the redundancy gain (RG) obtained with cross-modal and within-modal stimulations. The RG is a decrease in reaction times (RT) when two or more stimuli are presented simultaneously rather than a single stimulation. The first study investigated cross-modal visuo-tactile integration in a single reaction time task and a choice reaction time task. Each unisensory stimulus was presented to either the left or right hemispace, and multisensory stimuli were presented in a unilateral (e.g. visual right/tactile right) or bilateral configuration (e.g. visual right/tactile left). The first task was a simple reaction time (SRT) paradigm where participants had to responded to all stimulations, irrespective of spatial position. Results showed that multisensory gain and coactivation were the same for spatially aligned and misaligned visuotactile stimulations. In the second task, a choice reaction time (CRT) paradigm where participants responded to rightsided stimuli only, bilateral stimuli yielded slower reaction times. No difference in multisensory gain was found between the SRT and CRT tasks for unilateral stimulations. Overall, the results suggest that when spatial information is task-irrelevant, multisensory integration of unilateral and bilateral stimuli is equivalent. However, manipulating task requirements can alter this effect. In the second study, we investigated if the behavioral enhancements resulting from within-modal and cross-modal integration depend on the spatial congruency of the redundant stimuli. Results show that the redundancy gains (RG) obtained from the cross-modal conditions were far greater than those obtained from combinations of two visual or two tactile targets. Moreover, we found that the spatial alignment of the targets did not influence the RG obtained in cross-modal conditions, whereas within-modal stimuli produced a greater RG when the targets where delivered in separate hemispaces. These results suggest that within-modal and cross-modal integration are not only distinguishable by the amount of facilitation they produce, but also by the spatial configuration under which this facilitation occurs. The third study examines the role of the corpus callosum (CC) in mediating the RG observed for unilateral and bilateral cross-modal integration. Using a simple detection task, we tested four congenitally acallosal and one callosotomized individuals. No significant difference between congenitally acallosal individuals and controls were found for unilateral within-modal conditions or for multisensory conditions. Overall, these results demonstrate that the CC in not required to integrate cross-modal information across hemispheres and that intrahemispheric processing is preserved in acallosal individuals. Based on previous studies demonstrating the role of the superior colliculus in multisensory integration, our results suggest that in the absence of the CC, the behavioral benefit resulting from subcortical processing by the superior colliculus does not reflect the neurophysiological constraints of multisensory integration.

Thesis (Ph. D.)--Uniformed Services University of the Health Sciences, 2005. / Typescript (photocopy).