<p>Previous human behavioral research has provided support for the existence of different frames of reference utilized during spatial processing that can be dependent or independent of the observer. These are known respectively as egocentric and allocentric frames of reference. However, it has been difficult to dissociate these two different processes under realistic conditions. Importantly, how these frames of reference are influenced by the visual and non-visual information is not well understood. Therefore, the studies of this thesis evaluated spatial processing utilizing realistic and ecologically valid stimuli in environments of different scales, while systematically manipulating the visual and non-visual information available during learning. We demonstrated that non-visual information generated by actively walking through an environment leads to more egocentric processing, whereas the same visual motion information presented passively via a video leads to more allocentric processing (Chapter 2). Further, characteristics of the visual scene can also influence how it is processed, dependent on the strength of the verbal identity of the features in the environment (Chapter 3). Specifically, in a small room environment subject’s representations of corners-to-corners (corners do not have an obvious verbal component) were not as strongly encoded relative to each other in comparison to objects-to-objects (objects with an obvious verbal identity ). Finally, we demonstrated differential influences of non-visual information dependent on whether the features in the visual scene were more allocentrically processed or egocentrically processed (Chapter Four). Specifically, when different features of layouts are made distinguishable by their identity, this lead to more allocentric processing whereas when different features are made distinguishable by their relative position, this lead to more egocentric processing. Further, non-visual information made available during spatial updating when the observer is changing viewpoints benefitted tasks focused on differentiating changes to objects’ identity and less so for differentiating changes in relative object position.</p> / Doctor of Philosophy (PhD)

<p>When an observer detects changes in a scene from a viewpoint that is different from the learned viewpoint, viewpoint change caused by observer’s locomotion would lead to better recognition performance compared to a situation where the viewpoint change is caused by equivalent movement of the scene. While such benefit of observer locomotion could be caused by spatial updating through body-based information (Simons and Wang 1998), or knowledge of change of reference direction gained through locomotion (Mou et al, 2009). The effect of such reference direction information have been demonstrated through the effect of a visual cue (e.g., a chopstick) presented during the testing phase indicating the original learning viewpoint (Mou et al, 2009).</p> <p>In the current study, we re-examined the mechanisms of such benefit of observer locomotion. Six experiments were performed using a similar change detection paradigm. Experiment 1 & 2 adopted the design as that in Mou et al. (2009). The results were inconsistent with the results from Mou et al (2009) in that even with the visual indicator, the performance (accuracy and response time) in the table rotation condition was still significantly worse than that in the observer locomotion condition. In Experiments 3-5, we compared performance in the normal walking condition with conditions where the body-based information may not be reliable (disorientation or walking over a long path). The results again showed a lack of benefit with the visual indicator. Experiment 6 introduced a more salient and intrinsic reference direction: coherent object orientations. Unlike the previous experiments, performance in the scene rotation condition was similar to that in the observer locomotion condition.</p> <p>Overall we showed that the body-based information in observer locomotion may be the most prominent information. The knowledge of the reference direction could be useful but might only be effective in limited scenarios such as a scene with a dominant orientation.</p> / Master of Science (MSc)

La mémoire épisodique donne la capacité de voyager mentalement dans son propre passé. En cela,elle permet de faire fi du temps qui passe pour pouvoir revivre des événements passés. Ce travail dethèse évalue l’hypothèse selon laquelle la mémoire épisodique et la sensation de revivre un événementpassé (i.e., conscience autonoëtique) sont basées sur une fluence dans la reconstruction de l’épisode,reconstruction impliquant une mise à jour égocentrée. Cette proposition est développée dans le modèlede Gomez et collaborateurs (Gomez, Rousset & Baciu, 2009) qui propose que la mise à jourégocentrée permette de ré-instancier un point de vue spatialisé égocentré sur l’évènement remémoré.Ce travail de thèse a amené de nouveaux arguments en faveur de ce modèle, en évaluant à la foisl’approche attributionnelle de la mémoire épisodique et le lien fonctionnel entre la mise à jourégocentrée en ligne et la mémoire épisodique. Une première série d’études met en évidence uneinfluence de la fluence du processus de mise à jour égocentrée sur la conscience autonoëtique.L’augmentation artificielle de la fluence de mise à jour égocentrée, lors de la reconnaissance,augmente le sentiment de conscience autonoëtique et ce uniquement lorsque la reconnaissanceimplique une reconstruction. Une seconde série d’études permet de mettre en évidence un effetd’interférence du processus de mise à jour égocentrée en ligne sur la récupération épisodique.Actualiser sa position dans l’espace lors d’un déplacement a beau être un processus automatique, celaralentit spécifiquement le rappel de source. Enfin, une étude impliquant des patients atteints de lamaladie d’Alzheimer, met en évidence une dissociation entre les compétences en mise à jourégocentrée chez ces patients. Ces résultats sont discutés dans le cadre du modèle de Gomez etcollaborateurs et en regard d’une conception incarnée et située de la cognition. / Episodic memory makes it possible to mentally travel back in our own past; it breaks the law of theunidirectionality of time, and allows us to mentally relive past events. The main goal of this work wasto investigate whether episodic memory and the subjective feeling of reliving a past event (i.e.,autonoetic consciousness) arise from the fluency of the reconstruction process of the event. Thisreconstruction would involve the process of egocentric spatial updating with self-motion. Thishypothesis was first developed in Gomez and colleagues' model (Gomez, Rousset, & Baciu, 2009) thatsuggests that egocentric updating re-instances an egocentric spatial point of view on the rememberedevent. The present work brings additional behavioral evidences to this model by assessing both theconception of attributional episodic memory and the functional link between online egocentricupdating with self-motion and episodic memory. A first set of studies showed that enhancingartificially the fluency of the egocentric updating process, during the recognition phase, increasedautonoetic consciousness. Moreover, such phenomenon only happened when recognition involved areconstruction process. A second set of studies showed that performing an online egocentric updatingwith self-motion interfered with remembering. Although the updating of its own position though selfmotionis automatic, it specifically slows down source recall. Finally, a last study showed adissociation between preservations of and deficits of egocentric spatial updating abilities in patientssuffering from Alzheimer's disease. The results of these studies are discussed in the context of Gomezand colleagues' model, and in terms of embodied and situated cognition.

Thesis (Ph. D.)--Miami University, Dept. of Psychology, 2008. / Title from second page of PDF document. Includes bibliographical references (p. 60-67).

La mémoire épisodique donne la capacité de voyager mentalement dans son propre passé. En cela,elle permet de faire fi du temps qui passe pour pouvoir revivre des événements passés. Ce travail dethèse évalue l’hypothèse selon laquelle la mémoire épisodique et la sensation de revivre un événementpassé (i.e., conscience autonoëtique) sont basées sur une fluence dans la reconstruction de l’épisode,reconstruction impliquant une mise à jour égocentrée. Cette proposition est développée dans le modèlede Gomez et collaborateurs (Gomez, Rousset & Baciu, 2009) qui propose que la mise à jourégocentrée permette de ré-instancier un point de vue spatialisé égocentré sur l’évènement remémoré.Ce travail de thèse a amené de nouveaux arguments en faveur de ce modèle, en évaluant à la foisl’approche attributionnelle de la mémoire épisodique et le lien fonctionnel entre la mise à jourégocentrée en ligne et la mémoire épisodique. Une première série d’études met en évidence uneinfluence de la fluence du processus de mise à jour égocentrée sur la conscience autonoëtique.L’augmentation artificielle de la fluence de mise à jour égocentrée, lors de la reconnaissance,augmente le sentiment de conscience autonoëtique et ce uniquement lorsque la reconnaissanceimplique une reconstruction. Une seconde série d’études permet de mettre en évidence un effetd’interférence du processus de mise à jour égocentrée en ligne sur la récupération épisodique.Actualiser sa position dans l’espace lors d’un déplacement a beau être un processus automatique, celaralentit spécifiquement le rappel de source. Enfin, une étude impliquant des patients atteints de lamaladie d’Alzheimer, met en évidence une dissociation entre les compétences en mise à jourégocentrée chez ces patients. Ces résultats sont discutés dans le cadre du modèle de Gomez etcollaborateurs et en regard d’une conception incarnée et située de la cognition. / Episodic memory makes it possible to mentally travel back in our own past; it breaks the law of theunidirectionality of time, and allows us to mentally relive past events. The main goal of this work wasto investigate whether episodic memory and the subjective feeling of reliving a past event (i.e.,autonoetic consciousness) arise from the fluency of the reconstruction process of the event. Thisreconstruction would involve the process of egocentric spatial updating with self-motion. Thishypothesis was first developed in Gomez and colleagues' model (Gomez, Rousset, & Baciu, 2009) thatsuggests that egocentric updating re-instances an egocentric spatial point of view on the rememberedevent. The present work brings additional behavioral evidences to this model by assessing both theconception of attributional episodic memory and the functional link between online egocentricupdating with self-motion and episodic memory. A first set of studies showed that enhancingartificially the fluency of the egocentric updating process, during the recognition phase, increasedautonoetic consciousness. Moreover, such phenomenon only happened when recognition involved areconstruction process. A second set of studies showed that performing an online egocentric updatingwith self-motion interfered with remembering. Although the updating of its own position though selfmotionis automatic, it specifically slows down source recall. Finally, a last study showed adissociation between preservations of and deficits of egocentric spatial updating abilities in patientssuffering from Alzheimer's disease. The results of these studies are discussed in the context of Gomezand colleagues' model, and in terms of embodied and situated cognition.