Direct manipulation of conscious visual perception by real-time fMRI multivoxel pattern decoded neurofeedback of frontoparietal brain activity

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dc.catalogadorpva
dc.contributor.advisorOssandón, Tomás
dc.contributor.advisorSitaram, Ranganatha
dc.contributor.authorAmaro Fuenzalida, Juan Ignacio
dc.contributor.otherPontificia Universidad Católica de Chile. Facultad de Medicina
dc.contributor.otherPontificia Universidad Católica de Chile. Facultad de Ciencias Biológicas
dc.contributor.otherPontificia Universidad Católica de Chile. Facultad de Ciencias Sociales
dc.contributor.otherPontificia Universidad Católica de Chile. Facultad de Química y Farmacia
dc.date.accessioned2025-11-06T14:34:37Z
dc.date.available2025-11-06T14:34:37Z
dc.date.issued2025
dc.date.updated2025-10-29T20:06:18Z
dc.descriptionTesis (PhD degree in Neuroscience)--Pontificia Universidad Católica de Chile, 2025
dc.description.abstractThe present study addresses the problem of consciousness from the perspective of its phenomenological content (awareness). It examines the main contemporary theories concerning the neural correlates of consciousness, focusing on the Global Neuronal Workspace Model (GNWM) and the Higher-Order Theory (HOT). While the GNWM proposes that conscious access arises from the propagation of sensory information toward frontoparietal networks—particularly the dorsolateral prefrontal cortex—HOT suggests that consciousness emerges when a sensory representation is meta-represented by a higher-order representation localized in frontal regions. The former explains conscious access as a process of amplification and global broadcasting of information, whereas the latter attributes to the frontal cortex a constitutively representational role, capable of generating a conscious version of sensory inputs.Building on these perspectives, the present work aims to examine whether frontoparietal neural representations maintain an identity relationship with the subjective experience of visual stimuli, following the Neural Identity Theory (NIT), which posits that mental states and neural patterns are coextensive—two descriptions of the same phenomenon. This hypothesis was evaluated experimentally through functional magnetic resonance imaging (fMRI) and multivoxel pattern analysis (MVPA) during a Directional Motion Detection Task (DMDT).The study tested two main hypotheses: (1) frontoparietal activity varies as a function of stimulus ambiguity, being modulated by signal strength (coherence); and (2) the decodability of frontoparietal patterns provides evidence of an identity relationship between subjective experience and neural representation.The results showed that frontal activity increased under ambiguous conditions, indicating that when the stimulus was difficult to discriminate, frontal regions actively contributed to the construction of conscious experience through attentional and metarepresentational mechanisms. This involvement included the dorsolateral prefrontal, orbitofrontal, anterior cingulate, and opercular cortices.Notably, MVPA results revealed that even during trials without conscious report, information about motion direction could be decoded from patterns in the orbitofrontal and temporal cortices. This suggests that the brain maintains representations of stimuli even in the absence of conscious access. When sensory information was insufficient, participants appeared to rely on reconstructive or inferential processes dependent on memory, integrating perceptual fragments with stored knowledge. This pattern suggests that conscious experience depends not only on stimulus features but also on previous experience and the history of interactions with the environment.Taken together, these findings support a representational and integrative view of consciousness, in which the frontal cortex not only facilitates access to information but also contributes to its construction.
dc.fechaingreso.objetodigital2025-10-29
dc.format.extent126 páginas
dc.fuente.origenAutoarchivo
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/106555
dc.information.autorucEscuela de Medicina; Ossandón, Tomás; 0000-0002-7306-7754; 1011810
dc.information.autorucEscuela de Medicina; Sitaram, Ranganatha; S/I; 1020541
dc.information.autorucEscuela de Medicina; Amaro Fuenzalida, Juan Ignacio; S/I; 1086271
dc.language.isoen
dc.nota.accesocontenido completo
dc.rightsacceso abierto
dc.rights.licenseAtribución-NoComercial-SinDerivadas 4.0 Internacional (CC BY-NC-ND 4.0)
dc.rights.urihttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.es
dc.subject.ddc610
dc.subject.deweyMedicina y saludes_ES
dc.subject.ods03 Good health and well-being
dc.subject.odspa03 Salud y bienestar
dc.tipo.dtdInvestigación comparativa / correlacional
dc.titleDirect manipulation of conscious visual perception by real-time fMRI multivoxel pattern decoded neurofeedback of frontoparietal brain activity
dc.typetesis doctoral
sipa.codpersvinculados1011810
sipa.codpersvinculados1020541
sipa.codpersvinculados1086271
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