Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 43 for “"Top-down control"”.
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Top-Down Control of Lateral Interactions in Visual Cortex
… features (Li et al. 2004). We hypothesized that top-down modulation of effective connectivity within V1 underlies the behaviorally dependent modulations of contextual interactions in V1. To test this idea, we used a chronically implanted multi-electrode array in awake primates and studied the …
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Effects of cannibalism, maternal age and varying fish selectivity in age structured models of deep water hake populations
… density-dependent cannibalism was included as a top-down control on a modeled population of M. paradoxus which used spawner biomass and maternal based recruitment. The ASM was used to evaluate the effects cannibalism had on age structure, recruitment and spawner biomass of the modeled population. …
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Effects of action video game training on spatial attention
… suggest that action video game play improves top-down attentional control. A current learning to learn theory proposes that probabilistic inference, the ability to identify statistical patterns and create task-relevant perceptual templates to efficiently orient endogenous attention, underlies …
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Separating Within-trial Activities in the Stop Signal Task Using fMRI
… rapidly unfolding within-trial activities in a stop signal task using fMRI. Current models of inhibitory control address processes that are engaged after the presentation of go- and stop-signals. The first study presented here separated warning- from response-phase activities in healthy adults …
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Visual Attention in Dynamic Environments and its Application to Playing Online Games
… of Cognitive Programs (CPs) - an executive controller built on top of Selective Tuning (ST) model of attention. CPs enable top-down control of visual system and interaction between the low-level vision and higher-level task demands. Abstract We implement a subset of CPs for playing online …
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Playing It by Eye: Stimulus Based Effects on Attention Patterns in Shopping
… also questioning deeply held assumptions about top down control during shopping. Theoretical implications for the feature congestion and statistical salience models are also discussed.
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Interneuron networks and cortical dynamics : emulated whisking drives SOM interneurons in the ketamine anesthetized mouse SI neocortex
… stimulation independent of volitional or other top-down control on the part of the animal. I also test and confirm the hypothesis that, based only on bottom-up sensory stimulation the activity of two major classes of interneurons (adapting Parvalbumin positive and facilitating Somatostatin …
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An alternative hypothesis for explaining anomalies in the fine scale distribution patterns of Colophospermum mopane : Are shrub and tree forms genetically distinct ?
Abiotic and top down control hypotheses do not adequately explain the fine scale distribution patterns of shrub and tree Colophospermum mopane (Caesalpinioideae). Genetic distinctiveness between growth forms is investigated as an alternative hypothesis. Tree and shrub C. mopane from the riparian …
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Changing consumer strength in a changing climate
… turf productivity as a result. Whilst strong top-down control of primary productivity is supported by metabolic theory of ecology (MTE), it assumes that consumption rates of herbivores keep pace with metabolism and mirror increased growth of producers. At moderate warming, both metabolic rates …
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Behavioral and neural bases of emotion regulation in childhood and adolescence
… to emotional events, or in the ability to exert top-down control over emotional responses. The present studies sought to address these gaps in the literature. Studies 1 and 2 compared the behavioral and neural correlates, respectively, of emotional reactivity to and regulation of emotional …
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Food web regulation under different forcing regimes in shallow lakes
… and potentially several levels of consumers on top of the producers. Feeding interactions can regulate communities either by severe grazing pressure or by shortage of resources or prey production, termed top-down and bottom-up control, respectively. The limitations of all communities …
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Aging and Cognitive Control: Hemispheric Differences and White Matter Integrity
"The ability to flexibly control cognitive processed declines with aging. Age-related changes in cognitive control have been associated with white matter as well as gray matter decline. Specifically, it has been established that anterior regions of the corpus callosum (aCC) decline with advanced …
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Systematic variability in stage-one processing as revealed by eye movements in efficient visual search
… we update our model to propose that (1) top-down control factors such as strategy and task instructions influence the time to stop evidence accumulation in stage one and (2) exhaustive processing occurs at a smaller spatial scale (i.e. not necessarily across the entire display) although …
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Process Depletion in Emotion Regulation
… trials. This shows a diminished capacity to downregulate emotions when reappraisal is preceded by Incongruent Stroop. Although not hypothesized, dampened activity was observed in emotion reactivity regions (cuneus, thalamus) for Look Negative trials (in the absence of instructions to …
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Negotiating the State: British Telegraphic Politics and Spaces, 1870-1912
… the inland network's expansion was not shaped by top-down control of the centralised state, but was rather a fragmented and negotiated process. As a result, the expansion of the inland telegraph network emerges as a deeply contested project. By focusing outside of the discipline and governance …
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An Investigation Into The Neural Nature Of Persecutory Ideation
… ideation, suggesting a role of weakened top-down control on subjective valuation. Moreover, we established this mechanism was associated with unique environmental influence in community monozygotic twins. In our second study we aimed to replicate the task-based finding in two …
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The ecological effects of grazing by the White Rhino (Ceratotherium simum simum) at a landscape scale
… thesis I generated hypotheses concerning the top down effect of grazing ungulates on grass communities and fire behavior from work done within grazing exclosures in Hluhluwe iMfolozi Park. White Rhino had a large influence in controlling grass biomass in Hluhluwe, a high rainfall mesic …
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Chalga To The Max! Musical Speech And Speech About Music On The Road Between Bulgaria And Modern Europe
… Regimenting modern popular music with top-down control points also to the political communication implicit in chalga. Cognizant of their inferior location vis-à-vis "real modern societies," ordinary Bulgarians seek paternalist leaders who can address them on an intimate level but are …
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Behind anemone lines: determining the environmental drivers influencing lagoonal benthic communities, with special reference to the anemone Nematostella vectensis.
… and macrozoobenthic fauna which suggests that top-down control of macrozoobenthic species is not significant enough to influence their distribution. Salinity and temperature were spatially homogenous but macrozoobenthic assemblages indicate longer term variability; the euryhaline annelid …
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Modeling for microbial communities with cross-feeding and predator-prey interactions
… the predation of viruses on microbes acts as a top-down control of microbial abundances. When viruses infect migrating bacteria, whether the bacterial abundance is limited by nutrient capacity (nutrient-limited regime) or the viral predation (virus-limited regime) is not explored. To …
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