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Forty-eight rat pups were handled and isolated from postnatal days 3 through 13 in order to determine whether this manipulation would alter the postnatal development of the hippocampus. Half of these animals were then reared in enriched environments from weaning until maturity to determine whether enrichment would ameliorate the expected deficits in learning ability. Beginning at 90 days of age, all animals were tested on a T-maze, rotating bar and both place and cued versions of a water maze task. The study failed to find gross deficits in learning as a result of the handling/isolation procedure, although emotional differences between groups was evident, as were sex differences. Apparently more questions have been raised than answered by this study, and possible directions for future research are discussed.

published_or_final_version / Biological Sciences / Master / Master of Philosophy

Individual differences in learning with a focus on neuropsychologic anomalies underlying learning strategies has been receiving attention in recent years. As a result, interest has increased in quantifying and analyzing cognitive behavior more directly. One of the tools that measures brain activity directly is the evoked potential (EP). This study investigated the EP recorded from the brainstem region, often referred to as brainstem auditory evoked response (BAER). The importance of BAERs in detecting pathology in the brainstem has been well documented. BAERs have also been advocated as an important tool in the electrophysiological assessment of children's brainstem function relative to learning disorders. BAER latencies were recorded, therefore, from a small group of average children and studied in relation to the BAER stability overtime. Intra-individual differences were compared to between-subject differences. So little BAER research has been performed with children that more studies are needed just to clarify normal variability of BAER parameters. The present investigation studied intra-individual differences in the stability of BAER latencies over time in young subjects with normal hearing, for comparing with and contrasting to previous results from a study using an adult sample. BAER latencies were recorded for left, right, and binaural ear presentations. A coefficient of stability (CS) was calculated for each peak, for each ear over time. ANOVA results showed significance for peak and peak by ear interaction. Several BAER parameters were examined within-subjects that may not be revealed in studies between-subjects. Profiles for intra-aural differences over time showed individual differences in the stability of the BAER. Although there appeared to be a trend toward inter-ear differences the differences did not reach significance. The profiles indicated considerable intra-aural pattern replicability, and a trend toward increase in stability over time. The results supported a need for future research on laterality studies, more age specific normative data and correlational studies in relation to individual cognitive differences.

Coccidioidomycosis is a fungal infection endemic to the southwestern United States. Hematogenous dissemination of the etiologic agent produces a chronic basilar meningitis in a small percentage of children. While new and aggressive therapy has decreased mortality, children with coccidioidal meningitis (CM) continue to suffer significant morbidity. A comprehensive investigation of intellectual, achievement, and behavioral outcomes in a series of 9 children who were diagnosed and treated for CM at the Arizona Health Sciences Center between 1977 and 1988 was conducted. Nearest-age siblings were also evaluated. Findings revealed compromised cognitive abilities and an increased incidence of academic and behavioral difficulties in the patient group as compared to normative expectations and the performance of siblings. Results support the need for timely educational interventions to assist such patients in maximizing their potential in the academic environment.

This dissertation studies the neural basis of song, a universal human behavior. The relationship of words and melodies in the perception of song at phonological, semantic, melodic, and rhythmic levels of processing was investigated using the fine temporal resolution of Electroencephalography (EEG). The observations reported here may shed light on a ubiquitous human experience and also inform the discussion of whether language and music share neural resources or recruit domain-specific neural mechanisms. Experiment 1 was designed to determine whether words and melody in song are processed interactively or independently. Participants listened to sung words in which the melodies and/or the words were similar or different, and performed a same/different task while attending to the linguistic and musical dimensions in separate blocks of trials. Event-Related Potentials and behavioral data converged in showing interactive processing between the linguistic and musical dimensions of sung words, regardless of the direction of attention. In particular, the N400 component, a well-established marker of semantic processing, was modulated by musical melody. The observation that variations in musical features affect lexico-semantic processing in sung language was a novel finding with implications for shared neural resources between language and music. Experiment 2 was designed to explore the idea that well-aligned text-settings, in which the strong syllables occur on strong beats, capture listeners' attention and help them understand song lyrics. EEG was recorded while participants listened to sung sentences whose linguistic stress patterns were well-aligned, misaligned, or had variable alignment with the musical meter, and performed a lexical decision task on subsequently presented visual targets. / Results showed that induced beta and evoked gamma power were modulated differently for well-aligned and misaligned syllables, and that task performance was adversely affected when visual targets followed misaligned and varied sentences. These findings suggest that alignment of linguistic stress and musical meter in song enhance beat tracking and linguistic segmentation by entraining periodic fluctuations in high frequency brain activity to the stimuli. A series of follow-up studies has been outlined to further investigate the relationship between rhythmic attending in speech and music, and the influence of metrical alignment in songs on childhood language acquisition. / by Reyna Leigh Gordon. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Number perception, its neural basis and its relationship to how numerical stimuli are presented have been challenging research topics in cognitive neuroscience for many years. A primary question that has been addressed is whether the perception of the quantity of a visually presented number stimulus is dissociable from its early visual perception. The present study examined the possible influence of visual quality judgment on quantity judgments of numbers. To address this issue, volunteer adult subjects performed a mental number comparison task in which two-digit stimulus numbers (Arabic number format), among the numbers between 31 and 99 were mentally compared to a memorized reference number, 65. Reaction times (RTs) and neurophysiological (i.e. electroencephalographic (EEG) data) responses were acquired simultaneously during performance of the two-digit number comparison task. In this particular quantity comparison task, the number stimuli were classified into three distance factors. That is, numbers were a close, medium or far distance from the reference number (i.e., 65). In order to evaluate the relationship between numerical stimulus quantity and quality, the number stimuli were embedded in varying degrees of a typical visual noise form, known as "salt and pepper noise" (e.g., the visual noise one perceives when viewing a photograph taken with a dusty camera lens). In this manner, the visual noise permitted visual quality to be manipulated across three levels: no noise, medium noise (approximately 60% degraded visual quality from nonoise), and dense noise (75% degraded visual quality from no-noise). / The RTs provided the information about the overt responses; however, the temporal relationship of visual quality (starts earlier than quantity perception) and quantity were examined using eventrelated potentials (ERPs) extracted from continuous EEG recordings. The analysis of the RTs revealed that the judgment of number quantity is dependent upon visual number quality. In addition, the same effect was observed over the ERP components occurring between 100 ms and 300 ms after stimulus onset time over the posterior electrodes. Principal components analysis (PCA) and independent component analysis (ICA) methods were used to further analyze the ERP data. The consistent results of the PCA and ICA were used to represent the spatial brain dynamics, as well as to obtain temporal dynamics. The overall conclusion of the present study is that ERPs, ICs and PCs along with RTs suggested a strategy of quantitative perception (i.e., number comparison) based on the qualitative attributes of the stimuli highlighting the importance of the design of the task and the methodology / by Meltem Ballan. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

<p>The study aims to understand the challenges facing the Itinerant Learning Support Educators in an Inclusive Education framework. At the onset of the study there were very limited research studies and literature available on the challenges facing Itinerant Learning Support Educators hence literature in the study drew on the development and history of Special Education towards a global shift with regard to Inclusive Education policy development. As such the literature was utilized to understand how global phenomena and policies in developed countries impact on local policy transformation and contexts. The study followed a qualitative research approach to explore the challenges facing Itinerant Learning Support Educators in performing their functions. To gain an in depth understanding of their perceptions a case study method was followed and data collection techniques included focus group interviews. The sample in this study comprised of 14 Itinerant Learning Support Educators. The data was analyzed using a thematic approach. The findings of this study highlighted that despite a shift towards Inclusive Education in South Africa, Itinerant Learning Support Educators found themselves challenged by a range of contextual issues that impacted on the effective delivery of inclusive principles and practices. The study recommends that the Department of Education should take cognisance of these challenges, review the job description of Itinerant Learning Support Educators and put clear guidelines and support structures in place to support them in functioning optimally within an Inclusive Education paradigm.</p>

Understanding the process of associative learning between environmental stimuli and cocaine is essential for the prevention of drug-use relapse and long-term treatment of cocaine dependence. Based on contemporary learning theories, empirical studies using natural rewards have shown that cognitive factors, such as uncertainty and prediction errors, play an important role in the process of reward associative learning. Uncertainty is the lack of an accurate predictor for reward while prediction error is defined as the discrepancy between expected and received reward. In this dissertation, we focused on the role of uncertainty and prediction error in cocaine-associative learning. Olfactory and visual cues during self-administration/conditioning sessions were used to induce cocainereward expectation and uncertainty in operant trained catheterized Sprague Dawley rats. The influence of cue-induced uncertainty and prediction error on nucleus accumbens dopamine (NAcc DA) following self-administration of cocaine and saline in these conditioned animals was then measured using in-vivo microdialysis. Results showed that cocaine-stimulated NAcc DA was enhanced in the presence of cues signaling cocaine reward uncertainty (Uncertainty) as compared to animals expecting to get cocaine (Certainty). Also omission of expected cocaine reward (Prediction Error) resulted in a significant depression of NAcc DA levels below baseline. Recently diazepam (a positive GABAA modulator) has been shown to disrupt cocaine-induced LTP and it has been suggested that this disruption can block the acquisition of drug-associated memories. We therefore hypothesized that diazepam-pretreatment during conditioning sessions would disrupt the learned responses to cocaine and saline in the presence of cue-induced uncertainty and prediction error. Our results show that diazepam pretreatment duringconditioning sessions, blocked the differential cocaine-stimulated NAcc DA response to cue-induced certainty and uncertainty. Moreover, on omission of expected cocaine reward (Prediction Error) there was no significant depression of NAcc DA below baseline. The findings of this dissertation thus highlight the importance of cognitive factors (uncertainty and prediction errors) in the process of cocaine-associative learning. They also provide a platform to further explore the influence of these factors on other neuroadaptations during cocaine-associative learning, which will help us develop effective behavioral and pharmacological therapies to prevent drug-use relapse.

This series of experiments used the multiple learning and memory systems hypothesis of the mammalian nervous system to investigate the possibility that the amygdala, dorsal striatum, and hippocampal systems might, in certain situations, interact to produce behavior in the normal animal. Using variations of the conditioned-cue preference (CCP) task, evidence is presented showing that context-specific information acquired by the hippocampus interferes with acquisition of amygdala-based stimulus-reward learning. It was also demonstrated that there are amygdala-, dorsal striatum-, and hippocampus-based forms of place learning and that cue ambiguity and movement are important factors determining which of these learning and memory systems gain behavioral control in place learning situations. These findings provide evidence for interactions among learning and memory systems and implicate the amygdala and dorsal striatum in some types of non-hippocampal based place learning using distal cues.