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Theofanis I. Panagiotaropoulos

3 papers in the library · 15 citations · publishing 2020-2023

Papers

Bistability of prefrontal states gates access to consciousness

bioRxiv Preprint Server January 29, 2020 Abhilash Dwarakanath, Vishal Kapoor, Joachim Werner et al. 15 citations preprint

Access of sensory information to consciousness depends on neural activity crossing a threshold in the prefrontal cortex (PFC), yet how brain state fluctuations interact with conscious content is unclear. Using multielectrode recordings during a no-report binocular rivalry task in animals, two distinct prefrontal states were identified: low-frequency (1-9 Hz) bursts that precede spontaneous switches in conscious perception (perceptual update), and beta-band (20-40 Hz) bursts correlated with stable perception. Beta bursts synchronize neural ensembles coding the perceived stimulus. Similar fluctuations occur during rest, suggesting they are endogenous. The findings indicate that global cortical states, not selective spiking, drive internal switches in conscious perception.

An adversarial collaboration to critically evaluate theories of consciousness

bioRxiv Preprint Server June 23, 2023 Oscar Ferrante, Urszula Gorska-Klimowska, Simon Henin et al. preprint

An open science adversarial collaboration directly juxtaposed Integrated Information Theory (IIT) and Global Neuronal Workspace Theory (GNWT) by investigating neural correlates of visual experience. 256 human subjects viewed suprathreshold stimuli for variable durations while neural activity was measured with fMRI, MEG, and ECoG. Information about conscious content was found in visual, ventro-temporal, and inferior frontal cortex, with sustained responses in occipital and lateral temporal cortex reflecting stimulus duration, and content-specific synchronization between frontal and early visual areas.

Decoding the contents of consciousness from prefrontal ensembles

bioRxiv Preprint Server January 28, 2020 Vishal Kapoor, Abhilash Dwarakanath, Shervin Safavi et al. preprint

The prefrontal cortex can represent the contents of conscious perception even when no overt report is required. Recordings from macaque monkeys during binocular rivalry—where perception alternates between two conflicting images—showed that neural ensemble activity in the prefrontal cortex decoded which image the animal was seeing as accurately as when images were presented without competition. This decoding remained significant even when eye movements were suppressed, indicating that the signals were not solely due to oculomotor confounds. The findings suggest that prefrontal population dynamics reflect internally driven changes in conscious perception during multistable vision.