While many of us rely on vision to interact with and experience the world, for people with damage or disease to the eye or visual cortex, experience through this modality is extremely limited. Brain and retinal stimulation devices show exciting promise for restoring vision, but little is understood about where and when vision percepts can be induced through stimulation. Using a non-invasive brain stimulation technique called transcranial magnetic stimulation (TMS), we characterized the spatial and temporal dynamics of perception induced through brain stimulation. In the first set of experiments, we explore the importance of higher visual and non-visual areas vs. early visual areas in generating perception. We demonstrate that stimulation of even non-visual areas can evoke percepts in some subjects, but that this perception is likely a consequence of direct or indirect stimulation of early visual regions. In the second set of experiments, we demonstrate that percepts evoked from stimulation of this non-visual area likely arise from excitation of the optic nerve, an early visual structure. This reinforces the importance of early visual areas, not later ones, in generating perception, and suggests that induction of perception must involve activity in early visual structures. In the last set of experiments, we investigated the temporal dynamics of percepts induced through non-invasive stimulation. We show that the latency and duration of percepts evoked through brain stimulation are highly variable across individuals. Furthermore, we demonstrate that perception of these percepts is not instantaneous, but rather requires additional feedback processing for conscious awareness. Together, our results bridge a fundamental gap in our understanding of the some of the most fundamental characteristics of perception induced through non-invasive brain stimulation.
","abstract_html":"<p>While many of us rely on vision to interact with and experience the world, for people with damage or disease to the eye or visual cortex, experience through this modality is extremely limited. Brain and retinal stimulation devices show exciting promise for restoring vision, but little is understood about where and when vision percepts can be induced through stimulation. Using a non-invasive brain stimulation technique called transcranial magnetic stimulation (TMS), we characterized the spatial and temporal dynamics of perception induced through brain stimulation. In the first set of experiments, we explore the importance of higher visual and non-visual areas vs. early visual areas in generating perception. We demonstrate that stimulation of even non-visual areas can evoke percepts in some subjects, but that this perception is likely a consequence of direct or indirect stimulation of early visual regions. In the second set of experiments, we demonstrate that percepts evoked from stimulation of this non-visual area likely arise from excitation of the optic nerve, an early visual structure. This reinforces the importance of early visual areas, not later ones, in generating perception, and suggests that induction of perception must involve activity in early visual structures. In the last set of experiments, we investigated the temporal dynamics of percepts induced through non-invasive stimulation. We show that the latency and duration of percepts evoked through brain stimulation are highly variable across individuals. Furthermore, we demonstrate that perception of these percepts is not instantaneous, but rather requires additional feedback processing for conscious awareness. Together, our results bridge a fundamental gap in our understanding of the some of the most fundamental characteristics of perception induced through non-invasive brain stimulation.</p>","abstract_has_math":false,"creators":["Webster, Kelly"],"institution":"The Graduate School and University Center of The City University of New York","degree_name":"Doctor of Philosophy","degree_level":"Doctoral","degree_discipline":"Psychology","degree_department":null,"school":null,"contributors":[],"advisors":["Tony Ro"],"committee_chairs":[],"committee_members":["Robert Duncan","Jay Edelman","Tatiana Emmanouil","Jonathan Levitt"],"year":2020,"date_issued":"2020-02-01T08:00:00Z","date_published":"2020-02-01T08:00:00Z","updated_at":"2026-07-24T01:59:05Z","subjects":["Cognition and Perception","Cognitive Neuroscience","transcranial magnetic stimulation","vision","visual perception","brain stimulation","phosphenes"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://academicworks.cuny.edu/gc_etds/3521","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Tony Ro"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Robert Duncan","Jay Edelman","Tatiana Emmanouil","Jonathan Levitt"]},{"key":"dc:creator","label":"Author","values":["Webster, Kelly"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2020-10-15T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Psychology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["The Graduate School and University Center of The City University of New York"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Cognition and Perception","Cognitive Neuroscience","transcranial magnetic stimulation","vision","visual perception","brain stimulation","phosphenes"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://academicworks.cuny.edu/gc_etds/3521"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["While many of us rely on vision to interact with and experience the world, for people with damage or disease to the eye or visual cortex, experience through this modality is extremely limited. Brain and retinal stimulation devices show exciting promise for restoring vision, but little is understood about where and when vision percepts can be induced through stimulation. Using a non-invasive brain stimulation technique called transcranial magnetic stimulation (TMS), we characterized the spatial and temporal dynamics of perception induced through brain stimulation. In the first set of experiments, we explore the importance of higher visual and non-visual areas vs. early visual areas in generating perception. We demonstrate that stimulation of even non-visual areas can evoke percepts in some subjects, but that this perception is likely a consequence of direct or indirect stimulation of early visual regions. In the second set of experiments, we demonstrate that percepts evoked from stimulation of this non-visual area likely arise from excitation of the optic nerve, an early visual structure. This reinforces the importance of early visual areas, not later ones, in generating perception, and suggests that induction of perception must involve activity in early visual structures. In the last set of experiments, we investigated the temporal dynamics of percepts induced through non-invasive stimulation. We show that the latency and duration of percepts evoked through brain stimulation are highly variable across individuals. Furthermore, we demonstrate that perception of these percepts is not instantaneous, but rather requires additional feedback processing for conscious awareness. Together, our results bridge a fundamental gap in our understanding of the some of the most fundamental characteristics of perception induced through non-invasive brain stimulation.
"]},{"key":"dc:title","label":"Title","values":["Mapping the Spatial and Temporal Dynamics of Visual Percepts Elicited by a Non-Invasive Brain Stimulation Technique"]}]}],"canonical_facts":{"dc:contributor.advisor":["Tony Ro"],"dc:contributor.committeemember":["Robert Duncan","Jay Edelman","Tatiana Emmanouil","Jonathan Levitt"],"dc:creator":["Webster, Kelly"],"dc:date.available":["2020-10-15T07:00:00Z"],"dc:description.abstract":["While many of us rely on vision to interact with and experience the world, for people with damage or disease to the eye or visual cortex, experience through this modality is extremely limited. Brain and retinal stimulation devices show exciting promise for restoring vision, but little is understood about where and when vision percepts can be induced through stimulation. Using a non-invasive brain stimulation technique called transcranial magnetic stimulation (TMS), we characterized the spatial and temporal dynamics of perception induced through brain stimulation. In the first set of experiments, we explore the importance of higher visual and non-visual areas vs. early visual areas in generating perception. We demonstrate that stimulation of even non-visual areas can evoke percepts in some subjects, but that this perception is likely a consequence of direct or indirect stimulation of early visual regions. In the second set of experiments, we demonstrate that percepts evoked from stimulation of this non-visual area likely arise from excitation of the optic nerve, an early visual structure. This reinforces the importance of early visual areas, not later ones, in generating perception, and suggests that induction of perception must involve activity in early visual structures. In the last set of experiments, we investigated the temporal dynamics of percepts induced through non-invasive stimulation. We show that the latency and duration of percepts evoked through brain stimulation are highly variable across individuals. Furthermore, we demonstrate that perception of these percepts is not instantaneous, but rather requires additional feedback processing for conscious awareness. Together, our results bridge a fundamental gap in our understanding of the some of the most fundamental characteristics of perception induced through non-invasive brain stimulation.
"],"dc:identifier":["https://academicworks.cuny.edu/gc_etds/3521"],"dc:subject":["Cognition and Perception","Cognitive Neuroscience","transcranial magnetic stimulation","vision","visual perception","brain stimulation","phosphenes"],"dc:title":["Mapping the Spatial and Temporal Dynamics of Visual Percepts Elicited by a Non-Invasive Brain Stimulation Technique"],"thesis:degree_discipline":["Psychology"],"thesis:degree_level":["Doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["The Graduate School and University Center of The City University of New York"]},"updated_at":"2026-07-24T01:59:05Z"}