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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.
171

An investigation of the role of cognitive style as a mediator of eyewitness memorial performance

Emmett, David William January 2003 (has links)
Six separate experiments were conducted to investigate the role of Field Dependency (FDI) in determining the susceptibility of eyewitnesses to context reinstatement (CR); their performance in free, cued, and multi-choice recall, and facial identification accuracy; and finally the confidence expressed before and after performing these tasks, and the confidence accuracy relationship (C/AR). Questions were also addressed in relation to the measurement scale status of confidence ratings and the validity and utility of the Calibration / Resolution techniques for analysing the C/AR. Experiments I & II focussed on FDI and CR susceptibility, together with accuracy in free recall, cued recall, and recognition. Experiments III & IV focused on FDI, CR, and recognition. Experiment IV also utilised the Calibration / Resolution technique. Experiment V used a computer presented format to focus on FDI and recognition through simultaneous and sequential line-ups presented upright and inverted. Experiment VI included multi-choice recall testing along with free and cued recall and focussed on FDI, CR, and both correct and incorrect information produced. Experiments I, II, & VI indicated that Field Dependent (FD) participants benefited significantly from CR whilst Field Independent (FI) participants did not. FIs consistently outperformed FDs in cued recall. Experiment VI indicated that for FDs CR in free recall increased correct information and decreased erroneous information, leading to a significant improvement in the 'quality' of the information produced. In cued recall, however, correct information produced by FIs was greater than that produced by FDs and erroneous information lower, leading to a significant difference between FDs and FIs in the 'quality' of cued recall produced. Experiments III and IV indicated a significant superiority in facial recognition for FDs as compared to FIs across time delays of one week and three months in filled line-ups but not in blank. The explicit encoding format and upright and inverted lineups used in experiment V indicated a role for both attentiveness to others and configural processing in the superiority of FDs seen in experiments HI & IV. Results across experiments I, II, and VI indicated that confidence was significantly higher following a free recall test than when assessed at other points during recall testing. In experiment III, IV, & V confidence ratings were higher following exposure to the line-up than confidence ratings given before exposure. Results across all six experiments in relation to the C/AR show a marked level of inconsistency, however the use of the calibration / resolution techniques in experiment IV indicated a level of over-confidence on the part of FIs and underconfidence on the part of FDs that is in keeping with the personality aspects of FDI. In experiment VI the same techniques in relation to cued recall indicate a degree of overconfidence for 'easy' questions and under-confidence for 'hard' questions and point to a new approach to the investigation of the role of 'item difficulty' in determining the C/AR. Overall, the thesis argues that cognitive style is an important factor in predicting when context reinstatement will be beneficial, who will perform better in different recollection and recognition tasks, and how confidence will relate to accuracy.
172

Analyzing and fostering students' self-regulated learning through the use of peripheral data in online learning environments / Analyse und Förderung des selbstgesteuerten Lernens durch die Verwendung von peripheren Daten in Online-Lernumgebungen

Hörmann, Markus January 2020 (has links) (PDF)
Learning with digital media has become a substantial part of formal and informal educational processes and is gaining more and more importance. Technological progress has brought overwhelming opportunities for learners, but challenges them at the same time. Learners have to regulate their learning process to a much greater extent than in traditional learning situations in which teachers support them through external regulation. This means that learners must plan their learning process themselves, apply appropriate learning strategies, monitor, control and evaluate it. These requirements are taken into account in various models of self-regulated learning (SRL). Although the roots of research on SRL go back to the 1980s, the measurement and adequate support of SRL in technology-enhanced learning environments is still not solved in a satisfactory way. An important obstacle are the data sources used to operationalize SRL processes. In order to support SRL in adaptive learning systems and to validate theoretical models, instruments are needed which meet the classical quality criteria and also fulfil additional requirements. Suitable data channels must be measurable "online", i.e., they must be available in real time during learning for analyses or the individual adaptation of interventions. Researchers no longer only have an interest in the final results of questionnaires or tasks, but also need to examine process data from interactions between learners and learning environments in order to advance the development of theories and interventions. In addition, data sources should not be obtrusive so that the learning process is not interrupted or disturbed. Measurements of physiological data, for example, require learners to wear measuring devices. Moreover, measurements should not be reactive. This means that other variables such as learning outcomes should not be influenced by the measurement. Different data sources that are already used to study and support SRL processes, such as protocols on thinking aloud, screen recording, eye tracking, log files, video observations or physiological sensors, meet these criteria to varying degrees. One data channel that has received little attention in research on educational psychology, but is non-obtrusive, non-reactive, objective and available online, is the detailed, timely high-resolution data on observable interactions of learners in online learning environments. This data channel is introduced in this thesis as "peripheral data". It records both the content of learning environments as context, and related actions of learners triggered by mouse and keyboard, as well as the reactions of learning environments, such as structural or content changes. Although the above criteria for the use of the data are met, it is unclear whether this data can be interpreted reliably and validly with regard to relevant variables and behavior. Therefore, the aim of this dissertation is to examine this data channel from the perspective of SRL and thus further close the existing research gap. One development project and four research projects were carried out and documented in this thesis. / Lernen mit digitalen Medien ist ein substantieller Bestandteil formeller und informeller Bildungsprozesse geworden und gewinnt noch immer an Bedeutung. Technologischer Fortschritt hat überwältigende Möglichkeiten für Lernende geschaffen, stellt aber gleichzeitig auch große Anforderungen an sie. Lernende müssen ihren Lernprozess sehr viel stärker selbst regulieren als in traditionellen Lernsituationen, in denen Lehrende durch externe Regulation unterstützen. Das heißt, Lernende müssen ihren Lernprozess selbst planen, geeignete Lernstrategien anwenden, ihn überwachen, steuern und evaluieren. Diesen Anforderungen wird in verschiedenen Modellen des selbst-regulierten Lernens (SRL) Rechnung getragen. Obwohl die Wurzeln der Forschung zu SRL bis in die 1980er Jahren zurück reichen, ist die Messung und adäquate Unterstützung von SRL in technologie-gestützten Lernumgebungen noch immer nicht zufriedenstellend gelöst. Eine wichtige Hürde sind dabei die Datenquellen, die zur Operationalisierung von SRL-Prozessen herangezogen werden. Um SRL in adaptiven Lernsystemen zu unterstützen und theoretische Modelle zu validieren, werden Instrumente benötigt, die klassischen Gütekriterien genügen und darüber hinaus weitere Anforderungen erfüllen. Geeignete Datenkanäle müssen „online“ messbar sein, das heißt bereits während des Lernens in Echtzeit für Analysen oder die individuelle Anpassung von Interventionen zur Verfügung stehen. Forschende interessieren sich nicht mehr nur für die Endergebnisse von Fragebögen oder Aufgaben, sondern müssen auch Prozessdaten von Interaktionen zwischen Lernenden und Lernumgebungen untersuchen, um die Entwicklung von Theorien und Interventionen voranzutreiben. Zudem sollten Datenquellen nicht intrusiv sein, sodass der Lernprozess nicht unterbrochen oder gestört wird. Dies ist zum Beispiel bei Messungen physiologischer Daten der Fall, zu deren Erfassung die Lernenden Messgeräte tragen müssen. Außerdem sollten Messungen nicht reaktiv sein – andere Variablen (z.B. der Lernerfolg) sollten also nicht von der Messung beeinflusst werden. Unterschiedliche Datenquellen die zur Untersuchung und Unterstützung von SRL-Prozessen bereits verwendet werden, wie z.B. Protokolle über lautes Denken, Screen-Recording, Eye Tracking, Log-Files, Videobeobachtungen oder physiologische Sensoren erfüllen diese Kriterien in jeweils unterschiedlichem Ausmaß. Ein Datenkanal, dem in der pädagogische-psychologischen Forschung bislang kaum Beachtung geschenkt wurde, der aber nicht-intrusiv, nicht-reaktiv, objektiv und online verfügbar ist, sind detaillierte, zeitlich hochauflösende Daten über die beobachtbare Interkation von Lernenden in online Lernumgebungen. Dieser Datenkanal wird in dieser Arbeit als „peripheral data“ eingeführt. Er zeichnet sowohl den Inhalt von Lernumgebungen als Kontext auf, als auch darauf bezogene Aktionen von Lernenden, ausgelöst durch Maus und Tastatur, sowie die Reaktionen der Lernumgebungen, wie etwa strukturelle oder inhaltliche Veränderungen. Zwar sind die oben genannten Kriterien zur Nutzung der Daten erfüllt, allerdings ist unklar, ob diese Daten auch reliabel und valide hinsichtlich relevanten Variablen und Verhaltens interpretiert werden können. Ziel dieser Dissertation ist es daher, diesen Datenkanal aus Perspektive des SRL zu untersuchen und damit die bestehende Forschungslücke weiter zu schließen. Dafür wurden eine Entwicklungs- sowie vier Forschungsarbeiten durchgeführt und in dieser Arbeit dokumentiert.
173

Virtually Valid? On the Importance of Ecological Validity and Virtual Reality for Social Attention Research / Praktischerweise Valide? Über die Bedeutung von ökologischer Validität und virtueller Realität in der sozialen Aufmerksamkeitsforschung

Großekathöfer, Jonas David January 2022 (has links) (PDF)
Gazes are of central relevance for people. They are crucial for navigating the world and communicating with others. Nevertheless, research in recent years shows that many findings from experimental research on gaze behavior cannot be transferred from the laboratory to everyday behavior. For example, the frequency with which conspecifics are looked at is considerably higher in experimental contexts than what can be observed in daily behavior. In short: findings from laboratories cannot be generalized into general statements. This thesis is dedicated to this matter. The dissertation describes and documents the current state of research on social attention through a literature review, including a meta-analysis on the /gaze cueing/ paradigm and an empirical study on the robustness of gaze following behavior. In addition, virtual reality was used in one of the first studies in this research field. Virtual reality has the potential to significantly improve the transferability of experimental laboratory studies to everyday behavior. This is because the technology enables a high degree of experimental control in naturalistic research designs. As such, it has the potential to transform empirical research in the same way that the introduction of computers to psychological research did some 50 years ago. The general literature review on social attention is extended to the classic /gaze cueing/ paradigm through a systematic review of publications and a meta-analytic evaluation (Study 1). The cumulative evidence supported the findings of primary studies: Covert spatial attention is directed by faces. However, the experimental factors included do not explain the surprisingly large variance in the published results. Thus, there seem to be further, not well-understood variables influencing these social processes. Moreover, classic /gaze cueing/ studies have limited ecological validity. This is discussed as a central reason for the lack of generalisability. Ecological validity describes the correspondence between experimental factors and realistic situations. A stimulus or an experimental design can have high and low ecological validity on different dimensions and have different influences on behavior. Empirical research on gaze following behavior showed that the /gaze cueing/ effect also occurs with contextually embedded stimuli (Study 2). The contextual integration of the directional cue contrasted classical /gaze cueing/ studies, which usually show heads in isolation. The research results can thus be transferred /within/ laboratory studies to higher ecologically valid research paradigms. However, research shows that the lack of ecological validity in experimental designs significantly limits the transferability of experimental findings to complex situations /outside/ the laboratory. This seems to be particularly the case when social interactions and norms are investigated. However, ecological validity is also often limited in these studies for other factors, such as contextual embedding /of participants/, free exploration behavior (and, thus, attentional control), or multimodality. In a first study, such high ecological validity was achieved for these factors with virtual reality, which could not be achieved in the laboratory so far (Study 3). Notably, the observed fixation patterns showed differences even under /most similar/ conditions in the laboratory and natural environments. Interestingly, these were similar to findings also derived from comparisons of eye movement in the laboratory and field investigations. These findings, which previously came from hardly comparable groups, were thus confirmed by the present Study 3 (which did not have this limitation). Overall, /virtual reality/ is a new technical approach to contemporary social attention research that pushes the boundaries of previous experimental research. The traditional trade-off between ecological validity and experimental control thus becomes obsolete, and laboratory studies can closely inherit an excellent approximation of reality. Finally, the present work describes and discusses the possibilities of this technology and its practical implementation. Within this context, the extent to which this development can still guarantee a constructive classification of different laboratory tests in the future is examined. / Blicke sind für Menschen von zentraler Relevanz. Sie sind entscheidend für die Navigation in der Welt und für die Kommunikation mit Mitmenschen. Dennoch zeigt die Forschung der letzten Jahre, dass sich Erkenntnisse aus der experimentellen Forschung zu Blickverhalten vom Labor nicht in alltägliches Verhalten übertragen lassen. So ist beispielsweise die Häufigkeit, mit der Mitmenschen angeschaut werden, erheblich höher in experimentellen Kontexten als das beobachtbare alltägliche Verhalten. Kurz: Erkenntnisse aus Laboren lassen sich nicht zu allgemeinen Aussagen generalisieren. Diesem Spannungsfeld ist die hier vorliegende Arbeit gewidmet. Diese Doktorarbeit beschreibt und dokumentiert den aktuellen Forschungsstand zur sozialen Aufmerksamkeit anhand einer Literaturübersicht inklusive einer Metaanalyse zum /gaze cueing/ Paradigma sowie einer empirischen Untersuchung zur Robustheit des Blickfolgeverhaltens. Zudem wird in einer der ersten Studien in diesem Forschungsfeld virtuelle Realität eingesetzt. Virtuelle Realität hat das Potenzial, die Übertragbarkeit zwischen experimentellen Laboruntersuchungen auf alltägliches Verhalten deutlich zu verbessern. Denn die Technologie ermöglicht eine hohe experimentelle Kontrolle in naturalistischen Forschungdesigns. Damit kann sie die empirische Forschung ebenso stark verändern wie die Einführung des Computers für psychologische Forschung vor rund 50 Jahren. Die Literaturübersicht über soziale Aufmerksamkeit wurde durch eine systematische Begutachtung der Publikationen und einer meta-analystische Auswertung zum klassischen /gaze cueing/ Paradigma erweitert (Studie 1). Die kumulierte Evidenz unterstützt die Befunde primärer Studien: Verdeckte räumliche Aufmerksamkeit wird durch Gesichter gelenkt. Allerdings zeigte sich eine überraschend große Varianz in den publizierten Ergebnissen, die durch die untersuchten experimentellen Faktoren nicht erklärt werden konnte. Es scheint also noch Weitere, nicht gut verstandene Einflussgrößen auf diesen sozial-kognitiven Prozess zugeben. Klassische /gaze cueing/ Studien besitzen zudem eine eingeschränkte ökologische Validität. Diese wird als ein zentraler Grund für die fehlende Generalisierbarkeit diskutiert. Ökologische Validität beschreibt die Übereinstimmung von experimentellen Faktoren mit realistischen Situationen. Ein Stimulus oder ein experimentelles Design kann auf verschiedenen Dimensionen hohe und niedrige ökologische Validität aufweisen. Dies kann auf verschiedene Verhaltensbereiche unterschiedlichen Einfluss haben. Die empirischen Untersuchungen zum Blickfolgeverhalten zeigten, dass der /gaze cueing/ Effekt auch bei kontextuell eingebundenen Stimuli auftritt (Studie 2). Die kontextuelle Einbindung des Richtungscues stellte dabei einen Kontrast zu klassichen /gaze cueing/ Studien dar, die in der Regel Köpfe in Isolation zeigen. Die Forschungsergebnisse lassen sich also /innerhalb/ von kontrollierten Laboruntersuchungen auch auf ökologisch validere Forschungsparadigmen übertragen. Forschungsarbeiten zeigen allerdings, dass die mangelnde ökologische Validität in experimentellen Designs die Übertragbarkeit von experimentellen Befunden auf komplexe Situationen /außerhalb/ des Labors erheblich einschränken. Dies scheint insbesondere der Fall zu sein, wenn soziale Interaktionen und Normen untersucht werden. Die ökologische Validität ist in diesen Studien aber auch für weitere Faktoren häufig eingeschränkt, wie beispielsweise die kontextuelle Einbettung /von Versuchspersonen/, freies Explorationsverhalten (und damit Aufmerksamkeitssteuerung) oder Multimodalität. In einer ersten Arbeit in diesem Forschungsfeld wurde für diese Faktoren mit virtueller Realität eine hohe ökologische Validität erreicht, die so bisher nicht im Labor zu erreichen war (Studie 3). Spannenderweise zeigten sich selbst unter /ähnlichsten/ Bedingungen im Labor und in der natürlichen Umgebung Unterschiede in den beobachteten Fixationsmustern. Interessanterweise sind diese ähnlich zu Befunden, die ebenfalls aus Vergleichen von Augenbewegung im Labor und Felduntersuchung stammten. Diese Befunde, die bisher auf wenig vergleichbare Untersuchungsgruppen beruhen, wurden durch die vorliegende Studie 3 (die diese Einschränkung nicht besitzt) bestätigt. Insgesamt steht der heutigen sozialen Aufmerksamkeitsforschung mit /virtueller Realität/ ein neuer technischer Ansatz zur Verfügung, der die Grenzen bisheriger experimenteller Forschung verschiebt. Die traditionelle Abwägung zwischen ökologische Validität und experimenteller Kontrolle wird damit hinfällig und in Laboruntersuchungen kann die Realität extrem nah nachgebildet werden. Abschließend werden in dieser Arbeit die Möglichkeiten und die praktische Umsetzung dieser Technologie beschrieben und diskutiert. Dabei wird auch kritisch beleuchtet, inwiefern mit dieser Entwicklung auch in Zukunft noch eine konstruktive Einordnung von verschiedenen Laboruntersuchungen gewährleistet werden kann.
174

I control it, but does it mean it is part of me? How the relationship between body movements and controlled object movements influences the sense of agency and the sense of ownership / Ich kontrolliere es, aber ist es deshalb ein Teil von mir? Wie die Umsetzung von Körperbewegungen in Bewegungen von kontrollierten Objekten Sense of agency und Sense of ownership beeinflusst

Liesner, Marvin Paul January 2022 (has links) (PDF)
The “active self” approach suggests that any object we manipulate voluntarily and foreseeably becomes part of our “self” in the sense that we feel control over this object (sense of agency) and experience it as belonging to our own body (sense of ownership). While there is considerable evidence that we can indeed experience both a sense of agency and a sense of ownership over a broad variety of objects when we control these through our actions, the approach has also been criticized for exaggerating the flexibility of the human self. In this thesis, I investigate the influence that the relationship between the body movements controlling an object and the movements of the object itself has on the process of integrating an object into the self. I demonstrate that fully controlling an object is not sufficient for it to be integrated into the self since both explicit and implicit measures of the sense of agency and the sense of ownership indicate less or no integration when body movements are transformed into inverted object movements. Furthermore, I show that such inversions lead to the downregulation of sensory signals either from the body or from the controlled object in order to deal with the conflicting multisensory information when performing such actions. I argue that this downregulation is the underlying factor behind the diminished or eliminated integration of inverted body and object movements and I discuss further pathways for possible future studies building up on these findings. / Der “Active Self”-Ansatz sagt aus, dass jedes Objekt, welches wir willentlich und vorhersehbar manipulieren, Teil unseres „Selbst“ wird in dem Sinne, dass wir Kontrolle über dieses Objekt empfinden (Sense of agency) und es als zu unserem eigenen Körper zugehörig erleben (Sense of ownership). Während es eine beträchtliche Menge an Evidenz dafür gibt, dass wir tatsächlich sowohl Sense of agency als auch Sense of ownership für eine breite Vielfalt an Objekten empfinden können, wenn wir diese durch unsere Handlungen kontrollieren, wurde der Ansatz auch dafür kritisiert die Flexibilität des menschlichen Selbst über zu strapazieren. In dieser Arbeit untersuche ich den Einfluss, den die Beziehung zwischen den Körperbewegungen, welche ein Objekt kontrollieren, und den Bewegungen des Objekts selbst auf den Integrationsprozess eines Objekts in das Selbst hat. Ich demonstriere, dass ein Objekt vollständig zu kontrollieren nicht ausreichend ist, damit es in das Selbst integriert wird, da sowohl explizite als auch implizite Maße für Sense of agency und Sense of ownership weniger oder keine Integration zeigen, wenn Körperbewegungen in invertierte Objektbewegungen transformiert werden. Darüber hinaus zeige ich, dass solche Invertierungen zur Herunterregulierung sensorischer Signale entweder vom Körper oder vom kontrollierten Objekt führen, um mit der konfligierenden multisensorischen Information umzugehen, wenn solche Handlungen ausgeführt werden. Ich argumentiere, dass diese Herunterregulierung der zugrundeliegende Faktor ist für die verringerte oder eliminierte Integration invertierter Körper- und Objektbewegungen und ich diskutiere weitere Richtungen für mögliche zukünftige Studien, die auf diesen Befunden aufbauen.
175

Interactivity as Dynamic Demand: A Conceptual, Methodological, and Empirical Foundation for an Innovative Approach to Study Video Games

Koban, Kevin 09 December 2019 (has links)
Video games are anything but a marginalized subject among communication scholars and media psychologists for quite some time now. Nevertheless, a certain lack of empirically valid theoretical conceptualizations that truly respect the unique nature of the medium is still an important issue, even concerning basic concepts such as interactivity. Drawing from a recently introduced multidimensional conceptualization of video game interactivity as continuously required player effort to meet game demands and to exercise in-situ authorial control over the game experience, this dissertation consists of four manuscripts (covering seven individual studies) that aim for empirical evidence for a rather general but extremely vital question: How do players process video games? In my understanding of the field, this question exemplifies a substantial shift in how researchers examine games to explain not only the medium’s worldwide appeal but also the psychological consequences that may result from playing it. Just as psychophysiological and neurophysiological perspectives have gained significant momentum within game scholarship these days, an experiential approach that focuses on the (dynamic) interplay between demand and effort promises to serve as a valuable theoretical basis to develop an advanced understanding of video gaming beyond what we as game scholars currently know. My work is inspired by this vision and the four manuscripts that are included in this thesis contribute little pieces to it by examining interpersonal competition (manuscript 1) and game streaming (manuscript 3) as well as by developing and validating a German scale to assess different game demands (manuscript 2) and a methodology to explore demand dynamics (manuscript 4). In doing so, it intends to provide conceptual and empirical groundwork necessary not only to ask bigger questions about video games but also to answer them.
176

Tracking the temporal dynamics of cultural perceptual diversity in visual information processing

Lao, Junpeng January 2014 (has links)
Human perception and cognition processing are not universal. Culture and experience markedly modulate visual information sampling in humans. Cross-cultural studies comparing between Western Caucasians (WCs) and East Asians (EAs) have shown cultural differences in behaviour and neural activities in regarding to perception and cognition. Particularly, a number of studies suggest a local perceptual bias for Westerners (WCs) and a global bias for Easterners (EAs): WCs perceive most efficiently the salient information in the focal object; as a contrast EAs are biased toward the information in the background. Such visual processing bias has been observed in a wide range of tasks and stimuli. However, the underlying neural mechanisms of such perceptual tunings, especially the temporal dynamic of different information coding, have yet to be clarified. Here, in the first two experiments I focus on the perceptual function of the diverse eye movement strategies between WCs and EAs. Human observers engage in different eye movement strategies to gather facial information: WCs preferentially fixate on the eyes and mouth, whereas EAs allocate their gaze relatively more on the center of the face. By employing a fixational eye movement paradigm in Study 1 and electroencephalographic (EEG) recording in study 2, the results confirm the cultural differences in spatial-frequency information tuning and suggest the different perceptual functions of preferred eye movement pattern as a function of culture. The third study makes use of EEG adaptation and hierarchical visual stimulus to access the cultural tuning in global/local processing. Culture diversity driven by selective attention is revealed in the early sensory stage. The results here together showed the temporal dynamic of cultural perceptual diversity. Cultural distinctions in the early time course are driven by selective attention to global information in EAs, whereas late effects are modulated by detail processing of local information in WC observers.
177

Neural correlates of prospective memory : an EEG and ICA approach

Cruz San Martin, Gabriela Paz January 2014 (has links)
Have you ever entered a room and wondered ‘What am I supposed to do here?’ or have you ever forgotten to turn off the oven, hang your clothes to dry or make a phone call. These examples illustrate the relevance of ‘prospective memory’ or ‘delayed intentions’ in our daily life activities. Prospective memory is the ability to remember to do something after a delay. This thesis addresses three questions relevant to understand maintenance and execution of intentions: Is attention required to retrieve delayed intentions? What does monitoring mean in the context of prospective memory? Is prospective memory a discrete memory system or it is based on already known attentional and memory mechanisms? To answer these questions, we used electroencephalography (EEG), in (traditional) non-movement and free-movement experimental paradigms. We explored the neural substrate of prospective memory across its different stages: (1) holding intentions during a delay, (2) detecting the right context to perform the delayed intention, and (3) retrieving the content of the intention (the action to be performed). Two types of prospective memory tasks were used: Event-based prospective memory (performing a delayed intention in response to an external cue) and time-based prospective memory (performing the intention at a particular time). Results indicate that: prospective memory always requires attention, at least in experimental contexts; monitoring involves different mechanisms depending on the particular features of the prospective memory task and; prospective memory is not a discrete memory system, but relies on well-established mechanisms for attention and executive control.
178

Perception of self and others in healthy ageing

Girardi, Alessandra January 2013 (has links)
Processing information related to the self and inferring the mental state of another person is known to involve the ventromedial prefrontal cortex (VMPFC) in both younger and older adults (Stone et al., 2008; Kelley et al., 2002; Hynes et al., 2006; Ruby et al., 2009). According to the dorsolateral prefrontal (DLPF) theory of cognitive ageing, processing of the self should not be affected by healthy adult ageing as functions related to the VMPFC remain relatively preserved compared to functions related to the DLPF cortex (MacPherson et al., 2002). Similarly, no age difference should emerge in those tasks thought to tap functions of the VMPFC. The aim of this PhD is to investigate the effect of healthy adult ageing on the ability to process information related to the self and others. A series of experiments was designed to compare the performance of younger and older adults on tasks that investigate processing and retrieval of self-related information (e.g. behaviour prediction, personality judgement, mental state inferences, self-referential). The tasks differ in the extent to which they rely on cognitive effort. The results show that ageing does not affect self-related judgements. A further series of experiments designed to investigate affective and cognitive Theory of Mind (ToM) show that the affective performance, thought to rely on VMPFC activity, is not affected by age. In contrast, the performance of older participants differs from that of younger adults on cognitive ToM task, thought to involve DLPFC brain areas. A final experiment investigated the ability to make self versus other related judgments in a confabulating patient. The results show that the ability to reflect on the self but not on others was intact. In summary, the findings demonstrate that processing self-information and making ToM inferences remains intact in older individuals and is not overtly impaired by confabulation.
179

The relationship between usual alcohol consumption and the content of association memory in young and mature social drinkers

Gadon, Lisa Alexandre January 2002 (has links)
The results from this study indicated that the accessibility of negative alcohol memory associations was higher in alcohol contexts as participants generated more alcohol-related responses to the negative alcohol-related behavioural outcomes. As no effect of context was observed for positive alcohol memory associations, it was postulated that this type of memory association might become activated prior to or during decisions to consume alcohol. In addition, the results indicated that activated negative memory associations might not exert an influential role over decisions to consume alcohol. The results form this study provided further support for the Alcohol-Related Association Memory model of alcohol use. The findings from the series of studies provided support for the Alcohol-Related Association Memory model of alcohol use. In addition to replicating previous research findings, concerning the relationship between alcohol use and positive outcomes of this behaviour, the research findings showed that a relationship between alcohol use and negative outcomes of this behaviour is evident when an appropriate assessment tool is used. In addition to demonstrating that alcohol memory associations are strengthened in relation to current alcohol consumption level, the results from Study 3 showed that the length of an alcohol consumption history relates to the strength and subsequent accessibility of positive and negative alcohol memory associations. It was also indicated that activated negative alcohol memory associations might not exert an influential role over behavioural decisions. Alcohol association memory research, conducted thus far, has shown that there is a relationship between alcohol consumption experience and strength of alcohol memory associations. However, the effect that activated memory associations have on actual alcohol consumption, has not yet been established. Therefore, future research suggestions address this issue.
180

Perceptual errors in predicting vehicle approach in typical and atypical populations

Purcell, Catherine January 2012 (has links)
As a pedestrian at the roadside, the two most informative cues as to the distance and rate of closure of a vehicle are its optical size and the rate of expansion of the optical image. In addition, the time to arrival of an approaching vehicle can be perceptually estimated by the ratio of these two variables, referred to as tau (Lee, 1976). Sensitivity to optic expansion is critical for collision avoidance and was measured in populations of adults, typically developing children, and in children with Developmental Coordination Disorder (DCD), an idiopathic condition characterised by marked impairments in motor coordination that negatively impact on activities of daily living. A central tendency was found in adults (n = 193) between 18 to 59 years of age to make significant errors in judging the approach rates of two vehicles. Inflated errors were observed in children (n = 136) between 6 to 17 years of age, with decreased sensitivity in the youngest age group (6 to 11 years). Furthermore, a significant decrement was found in children (n = 9) with DCD between 6 to 11 years of age. Across all groups, a systematic vehicle size bias was found, whereby faster small vehicles were perceived as travelling slower than larger vehicles. This pattern of results suggest that in general, observers are not utilising tau in judgments of relative approach rates for speeds typically encountered at the roadside, but instead rely on optical expansion that does not compensate for image size. Errors due to a reliance on optic size were inflated in children with DCD, potentially placing them at significantly greater risk at the roadside. To examine the decreased sensitivity observed in DCD, thresholds for detecting visual looming were measured in children (n = 11) with DCD between 6 to 11 years of age. A significant deficit was found when vehicles were presented in perifoveal vision, whereby children with DCD may perceive vehicles that are 5 seconds away as stationary if they are travelling any faster than ~14 mph. This demonstration of a low-level visual processing deficit could suggest an immaturity in the dorsal stream network and explain some of the difficulties that characterise DCD. Critically, perceptual judgments at the roadside are inextricably linked to the motoric capability of the observer. If a pedestrians crossing time is greater than the time available, collision will occur. Crossing gap thresholds were measured and compared to walking times for a single vehicle approaching at varying speeds. Children (n = 9) with DCD between 6 to 11 years of age left considerably longer temporal crossing gaps than their action capabilities necessitated. However, when children with DCD were presented with multiple vehicles in a virtual reality environment, they accepted crossing gaps at all approach speeds that were shorter than the time it would take them to cross. This suggests that children with DCD may not have the perceptual accuracy to predict their required action gaps in a road crossing situation. One explanation for these findings could be a difference in DCD in how vision is dynamically allocated to facilitate the preparation of goal-directed actions. Dynamic allocation of visual attention was assessed in a series of experiments that measured eye movement latencies and hand movement accuracy in children (n = 5) with DCD between 6 to 11 years of age. Both measures were found to be comparable in DCD with their typically developing peers regardless of task complexity, indicating that the allocation of visual attention is not deficient in children with DCD. The prospective control of movement in our everyday lives is critically depended on estimating the immediacy of approaching objects. Combined, these results indicate that children with DCD may be particularly vulnerable at the roadside due to a visual motion processing deficit, consistent with atypical function across broad neural structures such as the dorsal stream.

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