Previous research has investigated how the perirhinal cortex (PRC), hippocampus (HC) and temporal pole (TP) are involved in complex visual discrimination using a variety of stimuli. Results from these studies have shown that the PRC activates to a greater extent for object stimuli relative to scene stimuli and that familiar stimuli elicit greater activation than do novel stimuli. In contrast, the HC shows greater activation for scene stimuli relative to objects and has also been reported to show greater activation for familiar relative to novel stimuli. To our knowledge, however, no studies in humans have replicated the stimulus specificity findings reported for PRC and HC. Additionally, no studies have used a combination of perceptual difficulty and familiarity/novelty to investigate how varying these factors affects activation in PRC, HC and TP during visual discrimination tasks. Chapter 2 describes an fMRI study performed to investigate the PRC's and HC's involvement in object and scene visual discrimination. The results of this study showed that the PRC was activated similarly by scenes and objects and that the HC was activated similarly for objects and scenes. Chapter 3 describes an fMRI experiment that manipulated both familiarity and difficulty, measuring how this affected PRC, HC and TP activation. In PRC the results showed a significant interaction between novelty and level of difficulty, such that novel objects with high levels of overlapping features showed greater activation compared to all other conditions. In contrast, the HC only showed a main effect of difficulty, indicating that the stimuli with high, relative to low, levels of difficulty elicited greater activation regardless of familiarity. Cumulatively, the evidence above suggests that the involvement of the PRC and HC in visual discrimination is complex. We propose that PRC is engaged whenever visual discrimination is required for any stimuli with overlapping features not just objects, and is activated to a greater extent when stimuli are novel, while HC appears to respond to stimuli with overlapping features, regardless of familiarity.

It has been shown that infants build representations of their visual world by forming relations among its parts. However little is known about how they select the parts to relate. One possibility is that while constructing their visual world part by part they are also decomposing it, using finer and finer parts. One way to test this theory is to simply control the parts infants see. This easiest way to do this is to filter real life objects of their high and low spatial frequencies. High spatial frequencies provide information about the smaller parts where as low spatial frequencies provide information about the larger ones. By removing high or low spatial frequency we can control the coarseness of their representation and ultimately determine the level at which they function best. The present study examined infants’ ability to use high and low spatial frequencies to discriminate between objects. Infants were habituated and tested using a combination of high and low spatial frequency images. Only infants experiencing a consistent spatial frequency across habituation and test were able to discriminate between objects. Infants were also better at discriminating between objects containing high spatial frequencies. In a second study designed to be more true to life, infants were habituated to broadband images and tested using high or low spatial frequencies. This time infants did not discriminate between objects but they did look longer at low spatial frequency information than at the high. From these findings we can conclude that infants use both high and low spatial frequency information when discriminating objects, and that in certain cases one frequency may become more important than the other. The spatial frequency they use may be dependent on the context of the task. Numerous studies have shown that adults prioritize high and low spatial frequency information depending on how fast they want to process the object, the amount of detail they require, and whether they used high or low spatial frequency information during previous experiences. Infants may be similar. At times they may emphasize low spatial frequency information and the big picture. At other times they may emphasize high spatial frequency information and the detail. More studies examining how infants select information for processing are necessary and spatial frequency will likely to be an important tool in the investigation. / text

Conflict Event theory has the potential to change how archaeologists investigate battlefield sites. As a theoretical paradigm, eventful archaeology allows us to give agency to social-structure changing events, going beyond collect artifacts after the battle is over. Coupled with site formation processes, this model allows us to project battle elements to re-create the historical events that occurred at conflict sites. Within this theoretical framework, we can begin to understand why the conflict unfolded in a particular manner. Two site of the Texian Revolution are particularly appropriate to this new theoretical model: the San Jacinto Battleground (SJB), the location of the last battle of the Texian Revolution, and Washington-on-the-Brazos (WOB), the location of the signing of the Texas Declaration of Independence. Merging this theoretical model with an investigation of site formation processes (understanding the matrix in which the artifacts lie) and pulse-domain electromagnetic surveying allows for a much more robust approach to Battlefield Archaeology. Pulse-induction allows for the detection of discrete artifacts in the soil, and is a much more reliable method than the more commonly used magnetometry. Analyzing characteristics of the soil surrounding the artifacts then gives us a third line of inquiry as to why artifacts are in certain locations in the archaeological record, allowing for an explanation as to their quality and quantity. La teoría del Acontecimiento del conflicto tiene el potencial para cambiar cómo arqueólogos investigan sitios de campo de batalla. Como un paradigma teórico, la arqueología llena de acontecimientos nos permite dar agencia a la social-estructura que cambia acontecimientos, yendo más allá de reúne artefactos después de que la batalla esté sobre. Asociado con procesos de formación de sitio, este modelo nos permite proyectar batalla elementos para recrear los acontecimientos históricos que ocurrieron en sitios de conflicto. Dentro de esta armazón teórica, nosotros podemos comenzar a comprender por qué el conflicto desplegó en una manera particular. Dos sitio de la Revolución de Texian es especialmente apropiado a este nuevo modelo teórico: el San Campo de batalla de Jacinto (SJB), la ubicación de la última batalla de la Revolución de Texian, y de Washington en el Brazos (WOB), la ubicación del firmar de la Declaración de Tejas de Independencia. Unir este modelo teórico con una investigación de sitúa procesos de formación (comprendiendo la matriz en la que los artefactos están) y el pulso-dominio inspeccionar electromagnético tiene en cuenta un enfoque mucho más robusto a la Arqueología del Campo de batalla. La pulso-inducción tiene en cuenta el descubrimiento de artefactos distintos en la tierra, y es un método mucho más seguro que el magnetometry más comúnmente utilizado. Analizar características de la tierra que rodea los artefactos entonces nos dan una tercera línea de indagación en cuanto a por qué artefactos están en ciertas ubicaciones en el registro arqueológico, teniendo en cuenta una explicación en cuanto a su calidad y la cantidad.