Thesis (D. Min.)--Biblical Theological Seminary, 2008. / Abstract. Includes bibliographical references (leaves 122-132).

Thesis (Ph. D.)--Rutgers University, 2010. / "Graduate Program in Integrative Neuroscience." Includes bibliographical references (p. 111-123).

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 149-165). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (B.A. (Hons.)) - University of Queensland, 2004. / Includes bibliography.

Thesis (Ph.D. in Pharmacology) -- University of Colorado, 2006. / Typescript. Includes bibliographical references (leaves 125-149). Free to UCDHSC affiliates. Online version available via ProQuest Digital Dissertations;

Despite a central role for morphological knowledge in supporting linguistic generalisation, the neural representations supporting its learning remain largely unexplored. This thesis addressed this gap by exploring the role of memory consolidation in morphological learning and generalisation. In three experiments, adult participants learned an artificial language in which stems (e.g. gleet, shiln) combined with plural affixes (e.g. –aff, -opp; gleetaff, shilnopp) to refer to the occupation of multiple male and female characters. Mimicking properties of morphological systems in natural languages, the plurals varied in their phonological consistency/ambiguity and type/token frequency. Two sets of plurals, distinguished by gender, were trained on two successive days. Experiment 1 revealed that generalisation to novel phonologically ambiguous forms measured on the second day showed a greater influence of token frequency for plurals trained on the previous day, suggesting overnight changes in their underlying representations. Experiment 2 examined this effect further by using fMRI to compare the neural representations underlying plurals learned on the day of scanning or on the previous day. Representational Similarity Analysis revealed increased similarity structure among high type frequency plurals and reduced similarity structure among high token frequency plurals following overnight consolidation in the left superior temporal gyrus (STG). These results are consistent with a Complementary Learning Systems (CLS) model in which overnight consolidation supports the development of overlapping representations among several items sharing the same feature (here, an affix; type frequency) and strengthens item-specific representations for frequently occurring items (token frequency). Additionally, connectivity analyses showed that the functional coupling between the left STG and the left dorsolateral prefrontal cortex was weaker for high type frequency plurals and stronger for high token frequency plurals following overnight consolidation. These results suggest that the engagement of prefrontal control processes in retrieving the newly-learned plurals is subject to overnight consolidation and sensitive to the similarity structure underlying the plurals to be retrieved. However, the overnight changes in similarity structure and functional networks observed in Experiment 2 were not mirrored by changes in generalisation to novel forms as were observed in Experiment 1. Experiment 3 aimed to address the discrepancy in consolidation-related changes in generalisation behaviour between the first two experiments. Type/token frequencies were manipulated to bias learning, consolidation, and generalisation towards high token frequency plurals. Despite this manipulation, no consolidation-related changes in generalisation were observed. Findings from all three experiments are interpreted in the context of the CLS model and a role for overnight consolidation in morphological learning and generalisation is discussed.

The successful reduction of fear is the aim of clinicians treating people with anxiety disorders such as post-traumatic stress disorder or phobias. Existing treatments for these conditions, however, require many treatment sessions and are prone to relapse. A new technique, first demonstrated in rats by Monfils, Cowansage, Klann, & LeDoux (2009) and later shown to be effective in humans (Schiller et al., 2010), provides a method of efficiently reducing fear in a manner which is resistant to various known triggers of relapse. This procedure involves a single presentation of the fear-inducing stimulus one hour prior to extinction training. This procedure produces extinction learning that is resistant to the return of fear resulting from a change of context, the passage of time, exposure to the unconditioned stimulus, and even further conditioning of the stimulus with an aversive stimulus. This dissertation focuses on one particular property of this procedure: that a stimulus extinguished using this procedure is resistant to subsequent retraining of the fear association. The first four experiments presented here are aimed at replicating this phenomenon and determining whether prediction error at retrieval is necessary for the effect to occur. Following on from these studies, the next chapter presents three experiments which investigate whether trial spacing effects could explain the enhanced extinction and highlights conditions under which the effect is weakened, or possibly reversed. The next three experiments compare the properties of a stimulus extinguished under these conditions with a stimulus extinguished under normal conditions. These studies focus on explanations involving inhibition, inattention and the disruption of stimulus representations. In the final three experiments, the possibility of reversing the effect is investigated. These studies look at the effect of memory retrieval prior to retraining of the stimulus to determine the conditions under which the stimulus can again come to elicit a fear response.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2002. / Bibliography: leaves 78-89.

<strong>Background:</strong> Our ability to consolidate what we learn changes with age. However, little is known about the neurophysiological underpinnings of consolidation of motor learning in ageing. This is largely because studies have repeatedly demonstrated a deficit in sleep-dependent consolidation of motor learning in older adults. This thesis aims to reassess commonly held assumptions about consolidation in ageing, as well as to examine the neurophysiological and neurochemical mechanisms that support the learning and consolidation processes. <strong>Methods:</strong> Most of the studies in this thesis are based on the design of a novel whole-hand task for use in older adults, which reduces dependency on fine motor skill. This thesis adopts a number of converging measures to examine learning and memory including electroencephalograhy (EEG), magnetic resonance spectroscopy (MRS), actigraphy recordings, as well as behavioural and self-reported measures of sleep. <strong>Results:</strong> Findings show significant improvements in learning with the adapted motor task in older adults. Importantly, this task reveals significant sleep- dependent enhancements in older adults, which are comparable to those seen in younger controls. Functional changes in sleep architecture with ageing show overall decline in slow wave sleep. Sleep-dependent improvements were specifically associated with activity in stage 3 slow wave sleep and increased hemispheric differences regardless of age. Changes in GABA concentrations with learning on a visuomotor tracking task showed marked variability across participants, and no clear associations were found between GABA and consolidation. <strong>Conclusion:</strong> The evidence presented in this thesis highlight the complex dynamics underlying sleep consolidation, and challenges a commonly held assumption about consolidation in older adults. Specifically, the studies presented here show that observed declines in motor consolidation with ageing may be contaminated by age-related deficits fine motor skill. By removing such kinematic constraints, it was possible to detect marked improvements in motor performance also in older adults despite age-related changes in sleep architecture.