{"id":{"repo_id":"calgary","oai_identifier":"oai:ucalgary.scholaris.ca:1880/122373"},"canonical_url":"https://search.dev.ndltd.org/etd/calgary/oai:ucalgary.scholaris.ca:1880/122373","repository":{"repo_id":"calgary","name":"University of Calgary","base_url":"https://ucalgary.scholaris.ca/server/oai/request"},"display":{"title":"Physiological High-Frequency Oscillations in Scalp EEGs Change During Brain Maturation","abstract":"High-frequency oscillations (HFOs), occurring between 80-1000 Hz, were first identified only three decades ago. Since then, physiological HFOs have been implicated in learning, memory and motor function, while epileptic HFOs have been associated with epileptogenic tissue. Many studies have shown that HFO activity correlates with seizure frequency, severity, and surgical outcomes. However, distinguishing physiological from epileptic HFOs remains challenging due to their overlapping frequency ranges and similar morphologies. Little is known about how physiological HFOs change throughout typical brain development. Without a clear understanding of normal developmental patterns, it is difficult to determine which HFOs are truly physiological and which may be pathological. This thesis aims to characterize normative developmental changes in physiological HFOs across age, brain region and sex. Using a dataset of 244 scalp EEG recordings from developmentally typical children, we found that HFOs follow a structured developmental trajectory, differ by sex and vary regionally across different stages of maturation. These findings were used to generate a reference atlas describing typical HFO occurrence rates per minute. This atlas serves as a foundational tool for understanding physiological brain development and for distinguishing normal HFO activity from epileptic patterns. Moreover, this work also highlights the feasibility of automated HFO detection from scalp EEGs. The use of non-invasive methods opens the door to larger-scale studies and broader applications beyond epilepsy.","abstract_html":"High-frequency oscillations (HFOs), occurring between 80-1000 Hz, were first identified only three decades ago. Since then, physiological HFOs have been implicated in learning, memory and motor function, while epileptic HFOs have been associated with epileptogenic tissue. Many studies have shown that HFO activity correlates with seizure frequency, severity, and surgical outcomes. However, distinguishing physiological from epileptic HFOs remains challenging due to their overlapping frequency ranges and similar morphologies. Little is known about how physiological HFOs change throughout typical brain development. Without a clear understanding of normal developmental patterns, it is difficult to determine which HFOs are truly physiological and which may be pathological. This thesis aims to characterize normative developmental changes in physiological HFOs across age, brain region and sex. Using a dataset of 244 scalp EEG recordings from developmentally typical children, we found that HFOs follow a structured developmental trajectory, differ by sex and vary regionally across different stages of maturation. These findings were used to generate a reference atlas describing typical HFO occurrence rates per minute. This atlas serves as a foundational tool for understanding physiological brain development and for distinguishing normal HFO activity from epileptic patterns. Moreover, this work also highlights the feasibility of automated HFO detection from scalp EEGs. 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This atlas serves as a foundational tool for understanding physiological brain development and for distinguishing normal HFO activity from epileptic patterns. Moreover, this work also highlights the feasibility of automated HFO detection from scalp EEGs. The use of non-invasive methods opens the door to larger-scale studies and broader applications beyond epilepsy."]},{"key":"dc:title","label":"Title","values":["Physiological High-Frequency Oscillations in Scalp EEGs Change During Brain Maturation"]}]}],"canonical_facts":{"dc:contributor.advisor":["Jacobs-LeVan, Julia","Teskey, Gordon Campbell"],"dc:contributor.committeemember":["Serena Orr, Julia Kam"],"dc:creator":["Chabrotra, Riddhi"],"dc:date":["2025-11"],"dc:date.accessioned":["2025-08-06T16:21:45Z"],"dc:date.available":["2025-08-06T16:21:45Z"],"dc:date.issued":["2025-07-27"],"dc:description.abstract":["High-frequency oscillations (HFOs), occurring between 80-1000 Hz, were first identified only three decades ago. 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