This thesis attempted to further understanding of various aspects of the competitive state anxiety response. The specific questions that were addressed in the five studies reponed involve investigations into antecedents of competitive anxiety, temporal patterning, additional dimensions to the anxiety response and relationships with performance. Competitive anxiety was assessed in all of the studies by the Competitive State Anxiety Inventory-2 (CSAI-2) which measures cognitive anxiety, somatic anxiety and self-confidence. The first two studies employed a purely quantitative approach whilst the final three studies incorporated both quantitative and qualitative methodologies. The first study investigated situational factors which predict the CSAI-2 components in the specific / population of middle-distance runners. Cognitive anxiety· was predicted by three factors, 'Perceived Readiness', 'Attitude Towards Previous Performance' and 'Position Goal', whilst self-confidence was predicted by 'Perceived Readiness' and 'External Environment'. None of the factors predicted somatic anxiety. These results suggested that cognitive anxiety and self-confidence share some common antecedents but that there are also factors unique to each. The second study examined the temporal patteming of the CSAI-2 components in the period leading up to competition as a function of gender. Gender has previously been shown to mediate patteming of responses so that antecedents were also examined in an attempt to explain such findings. Results showed that males and females reported differential temporal patteming for cognitive anxiety and self-confidence and that different antecedents predicted these variables. Significant predictors of cognitive anxiety and self-confidence were associated with personal goals and standards in females and interpersonal comparison and winning in males. The third and fourth studies investigated the importance of additional dimensions to the competitive state anxiety response in furthering understanding of the construct. These studies examined the frequency and direction dimensions of anxiety and findings suggested that the intensity alone approach currently employed is restrictive and that important information can be gained from considering these other dimensions. The fifth study focused on the dimensions of intensity and direction of anxiety and their specific relationship with sports performance. Findings revealed that a direction dimension was a better predictor of basketball performance than any of the intensity variables, further suggesting that future anxiety research should measure this dimension.

The large numbers of neurons that comprise the adult brain display an immense diversity. Repeated divisions of a relatively small pool of neural stem cells generate this neuronal diversity during development. To increase progress towards medical treatments for neurodegenerative diseases, it is of interest to understand both how neural stem cells generate the assortment of neurons and how these neurons come together to form a functional brain. Brain assembly occurs sequentially across time with early events laying the foundation for later events. Drosophila neural stem cells, neuroblasts (NBs), are an excellent model for investigating how neural diversity is generated and what roles early and late born neurons have in shaping the stereotypical adult brain structure. Generation of neural diversity, begins with specifying the diverse population of stem cells, called spatial patterning, and continues with diversifying neurons made from the diverse stem cells, called temporal patterning. Drosophila NBs exhibit both spatial and temporal patterning. Drosophila NBs have three types of division modes: type 0, type I and type II. Type II NBs expand the number of neurons made with progeny that exhibit a transit-amplifying division pattern, similar to that of mammalian outer subventricular zone (OSVZ) progenitors. Additionally, type II NBs exhibit temporal patterning across both the NB and their progeny to generate a large diversity of neurons that populate a conserved region of the brain responsible for many sensory and motor functions, called the central complex. Type II NBs have only been identified and studied during later stages in development, with nothing known about their origin or early divisions. In this dissertation, I describe the early lineages of the type II NBs within the Drosophila embryo. I show that type II NBs and lineages originate early in development, exhibit temporal patterning across both the NB and transit-amplifying progeny, and produce neurons that survive into the adult brain to innervate and potentially serve as a foundation within the adult central complex. Additionally, I explain how live imaging of the developing Drosophila brain can answer questions not easily addressed through other methods.

The central nervous system (CNS) has an astonishing diversity of neurons and glia. The diversity of cell types in the CNS has greatly increased throughout evolution and underlies our unique cognitive abilities. The diverse neurons and glia in the CNS are made from a relatively small pool of neural stem cells and progenitors. Understanding the developmental mechanisms that generate diverse cell types from neural progenitors will provide insight into the complexity of the mammalian CNS and guide stem cell based therapies for brain repair. Temporal patterning, during which individual neural progenitors change over time to make different neurons and a glia, is essential for the generation of neural diversity. However, the regulation of temporal patterning is poorly understood. Human outer subventricular zone (OSVZ) neural stem cells and Drosophila type II neural stem cells (called neuroblasts) both generate transit-amplifying intermediate neural progenitors (INPs). INPs undergo additional rounds of cell division to increase the number of neurons and glia generated in neural stem cell lineages. However, it is unknown whether INPs simply expand the numbers of a particular cell type or make diverse neural progeny. In this dissertation, I show that type II neuroblast lineages give rise to extraordinary neural diversity in the Drosophila adult brain and contribute diverse neurons to a major brain structure, the central complex. I find that INPs undergo temporal patterning to expand neural diversity in type II lineages. I show that INPs sequentially generate distinct neural subtypes; that INPs sequentially express Dichaete, Grainyhead, and Eyeless transcription factors; and that these transcription factors are required for the production of distinct neural subtypes. Moreover, I find that parental type II neuroblasts also sequentially express transcription factors and generate different neuronal/glial progeny over time, providing a second temporal identity axis. I conclude that neuroblast and INP temporal patterning axes act combinatorially to specify diverse neural cell types within adult central complex; OSVZ neural stem cells may use similar mechanisms to increase neural diversity in the human brain. This dissertation includes previously published co-authored material.

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