A conceptual model of visual perception has been developed using a multidisciplinary approach which combines both top-down and bottom-up descriptions of vision. Top-down psychological theories of visual perception have been investigated resulting in the development of a theory of perception which combines the best of existing accounts. Perception is defined in terms of a combination of "data driven" and "concept driven" explanations. Bottom-up neurophysiological descriptions have also been investigated to provide possible descriptions of structure and function for the development of a conceptual model based upon the theory. An attempt is made to provide a "complete" account of visual perception through the development of both the theory and conceptual model. Further it is envisaged that the development of such a model will provide new insight into the development of artificial vision systems and new algorithms for perceptual function in such systems.

Linking brain regions or neural circuits to specific affective symptoms could help elucidate the neural mechanisms of affective states as well as antidepressant treatment effects. Much research has implicated the anterior cingulate cortex (ACC), mid-dorsolateral frontal cortex (MDLFC), and a "frontocingulate" (i.e., MDLFC-ACC) circuit in sad affect and depression as well as the mood response to antidepressant treatment, including 10-Hz repetitive transcranial magnetic stimulation (rTMS) applied over the MDLFC. While the empirical support for a direct role of the MDLFC in affect is unclear, a wealth of research supports the ACC as an interface between action and emotion (Paus, 2001). In a series of experiments using behavioural, brain imaging and brain stimulation techniques we investigated the involvement of the ACC and an MDLFC-ACC (i.e., frontocingulate) circuit in an "action and emotion" relevant behaviour, namely, paralinguistic aspects of speech production. (e.g., speech pitch and loudness). In Experiment 1, we examined the relationship between affect and paralinguistic aspects of speech and in Experiment 2 we investigated the role of the ACC in mediating this phenomenon. Next, applying our knowledge of the role of the ACC in affect-relevant behaviour, we combined rTMS with a speech task (Experiment 3) and with PET (Experiment 4) in order investigate further the possibility that influencing brain activity in a frontocingulate circuit may contribute to the known mood effects of rTMS applied over the MDLFC. Taken together, our results demonstrated a role for the ACC in pitch variation during affective states and suggested that changes in affect and pitch variation following 10-Hz rTMS applied over the left MDLFC may involve changes in neural activity in a network of brain regions widely implicated in affect, including a frontocingulate circuit. The findings of this collection of studies take us a step further toward understanding the r

Thesis (Ph. D.)--University of Hawaii at Manoa, 1982. / Bibliography: leaves [101]-105. / Microfiche. / viii, 105 leaves, bound ill. 29 cm

Craniosynostosis is a common developmental disorder characterised by premature, pathological fusion of one or more of the fibrous connections, or sutures, that normally separate the bony plates of the skull during early development. Premature sutural fusion, typically occurring in utero, results in anomalous skull growth, and may have consequences for the developing brain. Most cases of single-suture craniosynostosis (SSC) require surgery, preferentially performed within the first year of life, to release the fused suture and reshape the deformed skull and improve brain growth potential. The exact mechanisms by which brain development is disrupted in SSC are uncertain. Research suggests that children with all forms of SSC are at heightened risk for neuropsychological problems; however, the nature, extent and risk factors (e.g., genetic, environmental, severity of skull deformity) for these disturbances, are yet to be established. The aim of this study was to examine the impact that SSC may have on neurodevelopmental skills during infancy and to use a theory-driven approach to explore the possible contributory factors to developmental progression during infancy. / Participants included 30 infants with SSC (16 metopic, 14 sagittal). Participants were assessed on the Bayley Scales of Infant and Toddler Development – Third Edition (BSID-III) during early infancy when they were between 5 and 15 months of age. Fifty-three percent (n=16) of these infants were also assessed in late infancy when they were between 17 and 33 months of age and at least six months post-surgical intervention. During both early and late infancy, children with craniosynostosis demonstrated significantly poorer gross motor skills compared to the normative sample, but other skills were in line with normal population expectations. Factors including subtype of craniosynostosis, severity of deformity, social risk and age at surgery, were not shown to be significantly associated with developmental level during early or late infancy. The impact of genetic variables on early development was unclear in the current sample. / This study has provided important insights into the functional significance of disruption to typical brain growth in infants with SSC. Findings indicate that SSC is a condition associated with developmental delay during early infancy prior to surgical intervention, with developmental concerns remaining evident post-surgically in late infancy. Findings support recommendations for the close monitoring of the development of these children during early life.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed Mar. 27, 2008). PDF text: 86 p. : ill. (some col.) ; 303 K. UMI publication number: AAT 3278160. Includes bibliographical references. Also available in microfilm and microfiche formats.

Dissertation (PhD)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (Ph. D.)--UCLA, 2007. / Vita. Includes bibliographical references (leaves 156).

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (M.S.)--Auburn University, 2008. / Abstract. Includes bibliographical references (p. 121-132).

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 164-173). Available also in a digital version from Dissertation Abstracts.