The understanding of the subjective experience of a visually stable world despite the occurrence of an observer's eye movements has been the focus of extensive research for over 20 years. These studies have revealed fundamental mechanisms such as anticipatory receptive field (RF) shifts and the saccadic suppression of stimulus displacements, yet there currently exists no single explanatory framework for these observations. We show that a previously presented neuro-computational model of peri-saccadic mislocalization accounts for the phenomenon of predictive remapping and for the observation of saccadic suppression of displacement (SSD). This converging evidence allows us to identify the potential ingredients of perceptual stability that generalize beyond different data sets in a formal physiology-based model. In particular we propose that predictive remapping stabilizes the visual world across saccades by introducing a feedback loop and, as an emergent result, small displacements of stimuli are not noticed by the visual system. The model provides a link from neural dynamics, to neural mechanism and finally to behavior, and thus offers a testable comprehensive framework of visual stability.

Thesis (M. Arch.)--University of Tennessee, Knoxville, 2009. / Title from title page screen (viewed on Mar. 11, 2010). Thesis advisor: William Rudd. Vita. Bailey appendix II.pdf (18364 KB) link located at bottom of [Article summary page]. Includes bibliographical references.

This study sought to determine whether the DG, CA3, and CA1 regions contain uniformly excitable populations and test the hypothesis that rapid addition of new, more excitable, granule cells in prepubescence results in a low activation probability (P1) in the DG. The immediate-early gene Homer1a was used as a neural activity marker to quantify activation in juvenile (P28) and adult (~5 mo) rats during track running. The main finding was that P1 in juveniles was substantially lower not only the DG, but also CA3 and CA1. The P1 for a DG granule cell was close to 0 in juveniles, versus 0.58 in adults. The low P1 in juveniles indicates that sparse, but non-overlapping, subpopulations participate in encoding events. Since sparse, orthogonal coding enhances a network’s ability to decorrelate input patterns (Marr, 1971; McNaughton & Morris, 1987), the findings suggest that juveniles likely possess greatly enhanced pattern separation ability. / ix, 51 leaves : ill. ; 29 cm

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

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Through an exploration of both sculptural and thought processes undertaken in making my Masters exhibition, ‘Hippocampus’, I unpack some possibilities, instabilities, and limitations inherent in representation and visual perception. This thesis explores the Hippocampus as image (seahorse) and concept (brain-structure involved in cognitive mapping of space). Looking at Gilles Deleuze’s writings on representation, I will expand on the notion of the map as being that which does not define and fix a structure or meaning, but rather is open, extendable and experimental. I explore the becoming, rather than the being, of image and concept. The emphasis here is on process, non-representation, and fluidity of meaning. This is supportive of my personal affirmation of the practice and process of art-making as research. I will refer to the graphic prints of Maurits Cornelis Escher as a means to elucidate a visual contextualization of my practical work, particularly with regard to the play with two- and three-dimensional space perception. Through precisely calculated ‘experiments’ that show up the partiality of our visual perception of space, Escher alludes to things that either cannot actually exist as spatial objects or do exist, but resist representation. Similarly I will explore how my own sculptures, although existing in space resist a fixed representation and suggest ideas of other spaces, non-spaces; an in-between space that does not pin itself down and become fixed to any particular image, idea, objector representation.

L'homme ne perçoit pas l'espace de manière homogène : le cerveau code l'espace proche du corps différemment de l'espace lointain. Cette distinction joue un rôle primordial notre comportement social : l'espace proche du corps, appelé espace péripersonnel (EPP), serait une zone de protection du corps, où la présence d'un individu est perçue comme une menace. L'EPP a été initialement décrit par la psychologie sociale et l'anthropologie, comme un facteur de la communication humaine. L'EPP a été plus tard décrit chez le singe par des études de neurophysiologie comme un espace codé par des neurones multisensoriels. Ces neurones déchargent uniquement en réponse à des évènements sensoriels situés à une distance limitée du corps du singe (qu'ils soient tactiles, visuels ou auditifs). L'ensemble de ces neurones multisensoriels code ainsi l'EPP tout autour du corps. Ce codage exclusif de l'EPP est crucial pour interagir avec le monde extérieur, car c'est dans cet espace que sont réalisées les actions visant à protéger le corps ou visant à atteindre des objets autour de soi. Le codage mutlisensoriel de l'EPP pendant des interactions sociales est à ce jour peu étudié. Dans ce travail de recherche, nous avons réalisé plusieurs études en vu d'identifier des facteurs contribuant à la perméabilité de l'EPP et ses aspects adaptatifs. Une première étude a examiné les frontières latérales de l'EPP chez des individus seuls, en mesurant l'interaction d'une source sonore dynamique s'approchant du corps avec le temps de détection de stimulations tactiles. Cette étude a montré des différences dans la taille de l'EPP entre les deux hémi-espaces, qui seraient liées à la latéralité manuelle. Une seconde étude a exploré les modulations de l'EPP dans des contextes sociaux. Elle a montré que l'EPP est modifié lorsque des individus réalisent une tâche en collaboration. La troisième étude est une recherche méthodologique qui vise à dépasser les limitations des paradigmes comportementaux utilisés actuellement pour mesurer l'EPP. Elle propose de nouvelles pistes pour évaluer comment les stimuli approchant le corps sont intégrés en fonction de leur distance et du contexte multisensoriel dans lequel ils sont traités. L'ensemble de ces travaux montre l'intérêt d'étudier l'intégration multisensorielle autour du corps dans l'espace 3D pour comprendre pleinement l'EPP, et les impacts potentiels de facteurs sociaux sur les processus multisensoriels de bas-niveaux. De plus, ces études soulignent l'importance pour les neurosciences sociales de développer des protocoles expérimentaux réellement sociaux, à plusieurs participants. / The space near the body, called peripersonal space (PPS), was originally studied in social psychology and anthropology as an important factor in interpersonal communication. It was later described by neurophysiological studies in monkeys as a space mapped with multisensory neurons. Those neurons discharge only when events are occurring near the body (be it tactile, visual or audio information), delineating the space that people consider as belonging to them. The human brain also codes events that are near the body differently from those that are farther away. This dedicated brain function is critical to interact satisfactorily with the external world, be it for defending oneself or to reach objects of interest. However, little is known about how this function is impacted by real social interactions. In this work, we have conducted several studies aiming at understanding the factors that contribute to the permeability and adaptive aspects of PPS. A first study examined lateral PPS for individuals in isolation, by measuring reaction time to tactile stimuli when an irrelevant sound is looming towards the body of the individual. It revealed an anisotropy of reaction time across hemispaces, that we could link to handedness. A second study explored the modulations of PPS in social contexts. It was found that minimal social instructions could influence the shape of peripersonal space, with a complex modification of behaviors in collaborative tasks that outreaches the handedness effect. The third study is a methodological investigation attempting to go beyond the limitations of the behavioral methods measuring PPS, and proposing a new direction to assess how stimuli coming towards the body are integrated according to their distance and the multisensory context in which they are processed. Taken together, our work emphasizes the importance of investigating multisensory integration in 3D space around the body to fully capture PPS mechanisms, and the potential impacts of social factors on low-level multisensory processes. Moreover, this research provides evidence that neurocognitive social investigations, in particular on space perception, benefit from going beyond the traditional isolated individual protocols towards actual live social interactive paradigms.

The implication of space in film is worth exploring in detail particularly with regard to the films of Alfred Hitchcock, since he is, perhaps more than any other filmmaker, concerned with the dynamics of proximity. Possibly because of his experience as a set designer on Graham Cutt’s silent films Woman to Woman (1922), The White Shadow (1923), The Passionate Adventure (1924), The Blackguard, and The Prude’s Fall (both 1925), Hitchcock very early in his career was faced with the task of expressing himself - without words - through setting, set shape, and room size. In Francois Truffaut's book, Hitchcock, the Master relates an important (since he remembers his) childhood episode in which his father arranged for the chief of police to lock him in a jail cell for five or ten minutes, admonishing that, “This is what we do to naughty boys.” Consequently, we see in Hitchcock’s films (which were all visually designed by him in the storyboard process) a persuasive aura of claustrophobia which involves a certain amount of connotes guilt and fear. As I intend to explain, this claustrophobia has far-reaching implications in five hermeneutic contexts, proving to be an important key to his moral-aesthetic universe.

The question that forms the foundation of this project is quite simple: how can space help us discuss literature and vice versa? The chapters of this dissertation explore the writing of Francesco Dall’Ongaro, Italo Svevo, Pier Antonio Quarantotti Gambini, and Marisa Madieri, each of whom addresses spatial concepts in their textual representations of the northern Adriatic region. Utilizing the related yet distinct approaches of spatial literary studies and geocriticism, paired with intellectual history, I find that the northern Adriatic region can be construed as a literary creation comprised of distinct, resistant narratives. The four texts under discussion promote a particular narrative of the region, revealing different strategies for its literary construction. Furthermore, this project aims to demonstrate that the spatially-attentive critic, no matter the discipline, has a vital role in deconstructing the process by which spaces enter the imaginary through cultural production.

Internal consistency reliability and validity were established for a new 31 item Imagery Manipulation Scale. Previous attempts to correlate subjectively rated control of visual imagery with tests of spatial ability have been unsuccessful. However, no attempt to construct a subjectively rated control of imagery scale was located which tried to establish internal consistency reliability and both content and construct validity. Further, no research was located in which subjects were requested to rate their imagery ability utilized during the performance of the actual spatial tasks used to try to establish validity. A new scale of subjectively rated control of imagery was devised in which subjects were requested to rate their imagery while solving spatial tasks which involved visualizing the manipulation of geometric forms. Content validity was established by analyzing the transformation involved while solving the spatial problems. Internal consistency reliability for the 31 item scale was established across two samples. Validity was established with the second sample (100 university students: 26 male and 74 female). The task utilized to provide validity could be objectively scored, and was made up of four spatial subtests, which were adapted from the Vandenberg and Kuse Mental Rotations Test, the Kosslyn Directions Test, performed in both the forward and backward direction, and a block task utilized by Snyder. A convergent and discriminant validity analysis established construct validity. Further, the hypotheses of three investigators, Kosslyn, Shepard and his colleagues, and Snyder, were supported by the results of the present investigation, thus substantiating the conclusion that reported control of imagery processing can be operationalized with performance scores on spatial ability tasks.