<mods:mods xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-7.xsd"><mods:titleInfo><mods:title>An Investigation of Cortical Circuit Mechanisms Underlying Non-Invasive Brain Stimulation and their Causal Role in the Modulation of Somatosensory Perception</mods:title></mods:titleInfo><mods:typeOfResource authority="primo">dissertations</mods:typeOfResource><mods:name type="personal"><mods:namePart>Sliva, Danielle Dolores</mods:namePart><mods:role><mods:roleTerm type="text">creator</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Jones, Stephanie R.</mods:namePart><mods:role><mods:roleTerm type="text">Advisor</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Moore, Christopher I.</mods:namePart><mods:role><mods:roleTerm type="text">Reader</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Desrochers, Theresa</mods:namePart><mods:role><mods:roleTerm type="text">Reader</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Worden, Michael</mods:namePart><mods:role><mods:roleTerm type="text">Reader</mods:roleTerm></mods:role></mods:name><mods:name type="corporate"><mods:namePart>Brown University. Department of Neuroscience</mods:namePart><mods:role><mods:roleTerm type="text">sponsor</mods:roleTerm></mods:role></mods:name><mods:originInfo><mods:copyrightDate>2023</mods:copyrightDate></mods:originInfo><mods:physicalDescription><mods:extent>xxi, 295 p.</mods:extent><mods:digitalOrigin>born digital</mods:digitalOrigin></mods:physicalDescription><mods:note type="thesis">Thesis (Ph. D.)--Brown University, 2023</mods:note><mods:genre authority="aat">theses</mods:genre><mods:abstract>Low-frequency “brain rhythms” and stimulus-evoked response potentials (ERPs) are prominent electroencephalography (EEG) signatures of human cortical processing. Decades of work have shown that they are reliable markers of healthy and impaired brain function, yet whether they causally impact cortical processing or are merely epiphenomenal remains debated. Several non-invasive brain stimulation (NIBS) approaches address this debate by attempting to amplify or emulate these signals to causally impact behavior, with varying degrees of success. Biophysically principled neural modeling that links EEG signals to their underlying cell- and circuit-level generators is a powerful tool that can improve our understanding of NIBS effects on behavior by revealing their underlying neural mechanisms. This dissertation builds upon the Jones lab’s prior work using neural modeling to study the mechanisms and meaning of brain rhythms and ERPs in somatosensory perception and attention. I extend this work to causally manipulate human tactile perception by integrating NIBS with EEG and neural modeling. Here, I detail two experiments in which I attempted to emulate the perceptual effects of rhythmic somatosensory alpha- (8-12 Hz) and beta-frequency (15-29 Hz) activity using NIBS. First, I attempted to amplify alpha activity to causally inhibit tactile perception by applying transcranial alternating current stimulation (tACS) at participants’ endogenous frequency. I find that tACS does not change alpha power, and neural modeling provides an interpretation of tACS-induced ERP modulation that supports the alternative hypothesis that tACS inhibits tactile detection by enhancing synaptic plasticity. Second, I attempted to emulate the “event-like” nature of transient beta activity using single pulses of low-intensity TMS. Prior modeling work predicts that beta events generate excitation followed by slow inhibition, yet I find that TMS broadly enhances perception. Neural modeling of the TMS-evoked potential (TEP) suggests that TMS amplifies and synchronizes local cell spiking, facilitating  the relay of sensory information to enhance perception. I also show that cued somatic attention changes the TEP, and predict that it may help mitigate the peripheral somatic TMS-EEG confound. Overall, this work highlights a more principled approach to interpret NIBS effects using neural modeling, and facilitates the design of novel protocols to causally modulate human perception.</mods:abstract><mods:subject authority="fast" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/01005663"><mods:topic>Magnetic brain stimulation</mods:topic></mods:subject><mods:subject><mods:topic>computational neural modeling</mods:topic></mods:subject><mods:subject><mods:topic>Transcranial alternating current stimulation</mods:topic></mods:subject><mods:subject><mods:topic>Brain rhythms</mods:topic></mods:subject><mods:language><mods:languageTerm authority="iso639-2b">English</mods:languageTerm></mods:language><mods:recordInfo><mods:recordContentSource authority="marcorg">RPB</mods:recordContentSource><mods:recordCreationDate encoding="iso8601">20230602</mods:recordCreationDate></mods:recordInfo></mods:mods>