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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Analysis and evaluation of the pilot attentional model

Ghaderi, Maryam 08 1900 (has links)
Pendant les opérations de vol, les pilotes sont exposés à une variété de conditions émotionnelles, mentales et physiques qui peuvent affecter leurs performances et leur attention. Par conséquent, il est crucial de surveiller leur charge de travail et leurs niveaux d'attention pour maintenir la sécurité et l'efficacité de l'aviation, notamment dans les situations d'urgence. La charge de travail fait référence aux exigences cognitives et physiques imposées aux pilotes lors d'un vol. Des niveaux élevés de charge de travail peuvent entraîner une fatigue mentale, une attention réduite et une surcharge cognitive, ce qui peut entraver leur capacité à effectuer leurs tâches de manière efficace et efficiente. L'attention est un processus cognitif complexe qui limite la capacité de se concentrer et de comprendre tout en même temps. Dans les tâches de traitement de l'information visuelle, la vision humaine est la principale source du mécanisme d'attention visuelle. Le mode de distribution de l'attention d'un pilote a un impact significatif sur la quantité d'informations qu'il acquiert, car la vision est le canal le plus critique pour l'acquisition d'informations. Une mauvaise allocation des ressources attentionnelles peut amener les pilotes à négliger ou à oublier des paramètres spécifiques, ce qui entraîne des risques graves pour la sécurité des aéronefs. Ainsi, cette étude vise à étudier les niveaux d'attention des pilotes lors d'une procédure de décollage simulée, en mettant l'accent particulièrement sur les périodes critiques telles que les pannes de moteur. Pour ce faire, l'étude examine s'il existe une corrélation entre la dilatation de la pupille, mesurée à l'aide de la technologie de suivi oculaire, et les niveaux d'engagement, mesurés à l'aide de l'EEG. Les résultats indiquent que les changements de taille de la pupille sont effectivement corrélés aux changements d'activité de l'EEG, suggérant que la dilatation de la pupille peut être utilisée comme un indicateur fiable de l'engagement et de l'attention. Sur la base de ces résultats, la dilatation de la pupille et l'EEG peuvent être utilisés en combinaison pour examiner de manière globale le comportement des pilotes, car les deux mesures sont des indicateurs valides de l'engagement et de la charge cognitive. De plus, l'utilisation de ces mesures peut aider à identifier les périodes critiques où les niveaux d'attention des pilotes nécessitent une surveillance étroite pour garantir la sécurité et l'efficacité de l'aviation. Cette étude met en évidence l'importance de surveiller la charge de travail et les niveaux d'attention des pilotes et recommande d'utiliser les mesures de dilatation de la pupille et d'EEG pour évaluer la charge cognitive et l'engagement d'un pilote pendant les opérations de vol, améliorant ainsi la sécurité et l'efficacité de l'aviation. / During flight operations, pilots are exposed to a variety of emotional, mental, and physical conditions that can affect their performance and attention. Therefore, it is crucial to monitor their workload and attention levels to maintain aviation safety and efficiency, particularly in emergency situations. Workload refers to the cognitive and physical demands placed on pilots during a flight. High levels of workload can lead to mental fatigue, reduced attention, and cognitive overload, which can hinder their ability to perform their tasks effectively and efficiently. Attention is a complex cognitive process that limits the ability to focus and comprehend everything simultaneously. In visual information processing tasks, human vision is the primary source of the visual attention mechanism. A pilot's attention distribution mode significantly impacts the amount of information they acquire, as vision is the most critical channel for information acquisition. Improper allocation of attention resources can cause pilots to overlook or forget specific parameters, resulting in severe risks to aircraft safety. Thus, this study aims to investigate pilots' attention levels during a simulated takeoff procedure, with a specific focus on critical periods such as engine failures. To achieve this, the study examines whether there is a correlation between pupil dilation, measured using eye-tracking technology, and engagement levels, measured using EEG. The results indicate that changes in pupil size are indeed correlated with changes in EEG activity, suggesting that pupil dilation can be used as a reliable indicator of engagement and attention. Based on these findings, pupil dilation and EEG can be used in combination to comprehensively examine pilot behavior since both measures are valid indicators of engagement and cognitive workload. Furthermore, using these measures can help identify critical periods where pilots' attention levels require close monitoring to ensure aviation safety and efficiency. This study emphasizes the significance of monitoring pilots' workload and attention levels and recommends using pupil dilation and EEG measures to assess a pilot's cognitive workload and engagement during flight operations, ultimately enhancing aviation safety and efficiency.
12

About time

Nowack, Kati 09 June 2016 (has links)
Zeit ist ein fundamentaler Aspekt menschlichen Verhaltens. Während Untersuchungen bislang meist nur auf einem der drei Hauptaspekte der Zeit: Dauer, Zeitfolge und individuelle zeitliche Orientierung fokussierten, untersucht diese Dissertation Zusammenhänge zwischen der individuellen zeitlichen Orientierung und der Zeitfolge. Zeit ist nicht direkt wahrnehmbar, sondern an kognitive Abstraktionsprozesse gebunden. Diese benötigen kognitive Ressourcen und werden kognitiven Fähigkeiten beeinflusst. Daher wurden Zusammenhänge zwischen individueller zeitlicher Orientierung und allgemeinen kognitiven Fähigkeiten ebenfalls untersucht. Studie 1 analysiert, wie verschiedene Aspekte individueller zeitlicher Orientierung korreliert sind, und diese Korrelationen von Alter und Geschlecht beeinflusst sind. Studien 2 und 3a analysieren Zusammenhänge zwischen individueller zeitlicher Orientierung und der Zeitfolge. Studie 3b untersucht mittels einer geometrischen Analogieanforderung Korrelationen zwischen individueller zeitlicher Orientierung und höheren fluiden Intelligenzleistungen. Befunde zu Zeitperspektive-Chronotyp- Relationen sowie Zeithorizont-Chronotyp-Relationen werden berichtet, ebenso Zusammenhänge zwischen Zeitperspektive, Zeithorizont und der Zeitfolge. Ausgehend von diesen und früheren Befunden wird ein kognitives Modell vorgestellt, welches alle drei Aspekte psychologischer Zeit (Zeitdauer; Zeitfolge; individuelle zeitliche Orientierung) integriert. Ferner werden als Ergebnis der Studien Zusammenhänge zwischen der Zukunftsperspektive und fluider Intelligenz sowie Chronotyp und verbaler Intelligenz berichtet. Verhaltensdaten und psychophysiologische Daten (Pupillendilation) zeigen ferner Zusammenhänge zwischen individueller zeitlicher Orientierung, analogem Denken, exekutiven Funktionen und Konfliktverarbeitung. So scheinen Zukunftsperspektive und Morgentyp eng mit Konfliktverarbeitung verbunden, der Zeithorizont hingegen eng mit inhibierenden Kontrollprozessen. / Time is a fundamental aspect of human experience. Whilst most research investigated major aspects of psychological time - time duration, time succession, individual temporal orientation - in isolation, this dissertation investigates interrelations between individual temporal orientation and time succession. Since psychological time is bound to cognitive abstraction processes that rely on cognitive resources and functions, interrelations between individual temporal orientation and cognitive capacities were also investigated. Study 1 explored how different levels of individuals’ temporal orientation may be interrelated, and how interrelations may be influenced by age and sex. Interrelations between individual temporal orientation and time succession were explored in a task predominantly requiring crystallized intelligence (Study 2) and in a semantic analogy task requiring crystallized and fluid intelligence (Study 3a). Study 3b investigated interrelations between individual temporal orientation and higher-level fluid intelligence measures by applying a geometric analogy task. Interrelations between time perspective and chronotype as well as between chronotype and temporal depth are reported. Further, both future time perspective and temporal depth are interrelated with time succession. A testable global working memory model of time perception integrating all three aspects of psychological time is proposed. Further, interrelations between individual temporal orientation and cognitive capacities are reported. Future time perspective was related to fluid intelligence, chronotype to verbal intelligence. Behavioral as well as pupillary data suggest that individual temporal orientation is related to analogical reasoning, executive functions and goal management. Whereas future time perspective and morningness appear interrelated with conflict detection, temporal depth appears interrelated with inhibitory control.
13

Cross-modal mechanisms: perceptual multistability in audition and vision

Grenzebach, Jan 25 May 2021 (has links)
Perceptual multistability is a phenomenon that is mostly studied in all modalities separately. The phenomenon reveals fundamental principles of the perceptual system in the formation of an emerging cognitive representation in the consciousness. The momentary perceptual organizations evoked during the stimulation with ambiguous stimuli switches between several perceptual organizations or percepts: The auditory streaming stimulus in audition and the moving plaids stimulus in vision, elicit different at least two percepts that dominate awareness exclusively for a random phase or dominance duration before an inevitable switch to another percept occurs. The similarity in the perceptual experience has led to propose a global mechanism contributing to the perceptual multistability phenomena crossmodally. Contrary, the difference in the perceptual experience has led to propose a distributed mechanism that is modality-specific. The development of a hybrid model has synergized both approaches. We accumulate empirical evidence for the contribution of a global mechanism, albeit distributed mechanisms play an indispensable role in this cross-modal interplay. The overt report of the perceptual experience in our experiments is accompanied by the recording of objective, cognitive markers of the consciousness: Reflexive movements of the eyes, namely the dilation of the pupil and the optokinetic nystagmus, correlate with the unobservable perceptual switches and perceptual states respectively and have their neuronal rooting in the brainstem. We complement earlier findings on the sensitivity of the pupil to visual multistability: It was shown in two independent experiments that the pupil dilates at the time of reported perceptual switches in auditory multistability. A control condition on confounding effects from the reporting process confines the results. Endogenous, evoked internally by the unchanged stimulus ambiguity, and exogenous, evoked externally by the changes in the physical properties of the stimulus, perceptual switches could be discriminated based on the maximal amplitude of the dilation. The effect of exogenous perceptual has on the pupil were captured in a report and no-report task to detect confounding perceptual effects. In two additional studies, the moment-by-moment coupling and coupling properties of percepts between concurrent multistable processes in audition, evoked by auditory streaming, and in vision, evoked by moving plaids, were found crossmodally. In the last study, the externally induced percept in the visual multistable process was not relayed to the simultaneous auditory multistable process: Still, the observed general coupling is fragile but existent. The requirement for the investigation of a moment-by-moment coupling of the multistable perceptual processes was the application of a no-report paradigm in vision: The visual stimulus evokes an optokinetic nystagmus that has machine learnable different properties when following either of the two percepts. In combination with the manually reported auditory percept, attentional bottlenecks due to a parallel report were circumvented. The two main findings, the dilation of the pupil along reported auditory perceptual switches and the crossmodal coupling of percepts in bimodal audiovisual multistability, speak in favor of a partly global mechanism being involved in control of perceptual multistability; the global mechanism is incarcerated by the, partly independent, distributed competition of percepts on modality level. Potentially, supramodal attention-related modulations consolidate the outcome of locally distributed perceptual competition in all modalities.:COVER 1 BIBLIOGRAPHISCHE BESCHREIBUNG 2 ACKNOWLEDGEMENTS 3 CONTENTS 4 CHAPTER 1: Introduction 6 C1.1: Stability and uncertainty in perception 6 C1.2: Auditory, visual and audio-visual multistability 14 C1.3: Capturing the subjective perceptual experience 25 C1.4: Limitations of preceding studies, objectives, and outline of the Thesis 33 CHAPTER 2: Study 1 “Pupillometry in auditory multistability” 36 C2.1.1 Experiment 1: Introduction 36 C2.1.2 Experiment 1: Material and Methods 38 C2.1.3 Experiment 1: Data analysis 44 C2.1.4 Experiment 1: Results 48 C2.1.5 Experiment 1: Discussion 52 C2.2.1 Experiment 2: Introduction 54 C2.2.2 Experiment 2: Material and Methods 54 C2.2.3 Experiment 2: Data analysis 56 C2.2.4 Experiment 2: Results 57 C2.3 Experiment 1 & 2: Discussion 61 C2.4 Supplement Study 1 65 CHAPTER 3: Study 2 “Multimodal moment-by-moment coupling in perceptual bistability” 71 C3.1.1 Experiment 1: Introduction 71 C3.1.2 Experiment 1: Results 74 C3.1.3 Experiment 1: Discussion 80 C3.1.4 Experiment 1: Material and Methods 84 C3.1.5 Experiment 1: Data analysis 87 C3.2 Supplement Study 2 92 CHAPTER 4: Study 3 “Boundaries of bimodal coupling in perceptual bistability” 93 C4.1.1 Experiment 1: Introduction 93 C4.1.2 Experiment 1: Material and Methods 98 C4.1.3 Experiment 1: Data analysis 102 C4.1.4 Experiment 1: Results 108 C4.1.5 Experiment 1: Discussion 114 C4.2.1 Experiment 2: Introduction 116 C4.2.2 Experiment 2: Material and Methods 119 C4.2.3 Experiment 2: Data analysis 125 C4.2.4 Experiment 2: Results 133 C4.3 Experiment 1 & 2: Discussion 144 C4.4 Supplement Study 3 151 CHAPTER 5: General Discussion 154 C5.1 Significance for models of multistability and implications for the perceptual architecture 162 C5.2 Recommendations for future research 166 C5.3 Conclusion 168 REFERENCES 170 APPENDIX 186 A1: List of Figures 186 A2: List of Tables 188 A3: List of Abbreviations and Symbols 189
14

Interaktionskvalitet - hur mäts det?

Friberg, Annika January 2009 (has links)
Den tekniska utvecklingen har lett till att massiva mängder av information sänds, i högahastigheter. Detta flöde måste vi lära oss att hantera. För att maximera nyttan av de nyateknikerna och undkomma de problem som detta enorma informationsflöde bär med sig, börinteraktionskvalitet studeras. Vi måste anpassa gränssnitt efter användaren eftersom denneinte har möjlighet att anpassa sig till, och sortera i för stora informationsmängder. Vi måsteutveckla system som gör människan mer effektiv vid användande av gränssnitt.För att anpassa gränssnitten efter användarens behov och begränsningar krävs kunskaperom den mänskliga kognitionen. När kognitiv belastning studeras är det viktigt att en såflexibel, lättillgänglig och icke-påträngande teknik som möjligt används för att få objektivamätresultat, samtidigt som pålitligheten är av största vikt. För att kunna designa gränssnittmed hög interaktionskvalitet krävs en teknik att utvärdera dessa. Målet med uppsatsen är attfastställa en mätmetod väl lämpad för mätning av interaktionskvalitet.För mätning av interaktionskvalitet rekommenderas en kombinering av subjektiva ochfysiologiska mätmetoder, detta innefattar en kombination av Functional near-infraredspecroscopy; en fysiologisk mätmetod som mäter hjärnaktiviteten med hjälp av ljuskällor ochdetektorer som fästs på frontalloben, Electrodermal activity; en fysiologisk mätmetod sommäter hjärnaktiviteten med hjälp av elektroder som fästs över skalpen och NASA task loadindex; en subjektiv, multidimensionell mätmetod som bygger på kortsortering och mäteruppfattad kognitiv belastning i en sammanhängande skala. Mätning med hjälp av dessametoder kan resultera i en ökad interaktionskvalitet i interaktiva, fysiska och digitalagränssnitt. En uppskattning av interaktionskvalitet kan bidra till att fel vid interaktionminimeras, vilket innebär en förbättring av användares upplevelse vid interaktion. / Technical developments have led to the broadcasting of massive amounts of information, athigh velocities. We must learn to handle this flow. To maximize the benefits of newtechnologies and avoid the problems that this immense information flow brings, interactionquality should be studied. We must adjust interfaces to the user because the user does nothave the ability to adapt and sort overly large amounts of information. We must developsystems that make the human more efficient when using interfaces.To adjust the interfaces to the user needs and limitations, knowledge about humancognitive processes is required. When cognitive workload is studied it is important that aflexible, easily accessed and non assertive technique is used to get unbiased results. At thesame time reliability is of great importance. To design interfaces with high interaction quality,a technique to evaluate these is required. The aim of this paper is to establish a method that iswell suited for measurement of interaction quality.When measuring interaction quality, a combination of subjective and physiologicalmethods is recommended. This comprises a combination of Functional near-infraredspectroscopy; a physiological measurement which measures brain activity using light sourcesand detectors placed on the frontal lobe, Electrodermal activity; a physiological measurementwhich measures brain activity using electrodes placed over the scalp and NASA task loadindex; a subjective, multidimensional measurement based on card sorting and measures theindividual perceived cognitive workload on a continuum scale. Measuring with these methodscan result in an increase in interaction quality in interactive, physical and digital interfaces.An estimation of interaction quality can contribute to eliminate interaction errors, thusimproving the user’s interaction experience.

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