Biology subjects

Yellin, D.

Publications and source records attributed to Yellin, D..

3 recordsLinked to original sources

bioRxiv2026

A cortical gradient of distance to criticality governs large-scale resting-state fMRI dynamics

The cortex generates a remarkable diversity of regional dynamics despite relying on broadly shared principles of recurrent organization. Here, we identify distance to criticality (DTC) as a unifying axis along which these dynamics are spatially organized. Analyzing resting-state fMRI BOLD signals and leveraging simple network models of randomly connected recurrent units, we show that DTC robustly explains key dynamical features, in particular, local power spectra and functional connectivity, across the full set of 360 cortical areas. Our analysis shows that a rank-order distribution of DTC values is highly conserved across subjects. Moreover, the empirical analysis of cortical slow dynamics and its fitted network simulations demonstrate similar power-laws across hierarchies of the cortical sheet. These results suggest that recurrent neuronal networks, operating close to criticality, can generate a remarkably rich dynamical repertoire which fit the entire range of experimentally observed cortical slow-timescale dynamics. Our findings underscore the importance of DTC as a powerful, fundamental generator underlying the spectrum of diverse cortical dynamics. HighlightsO_LISpontaneous (resting-state) activity in the human cortex is shown to be organized along a conserved spatial gradient of distance from criticality (DTC), with regions exhibiting a stable cross-individual rank order along this axis. C_LIO_LIMulti-subject fMRI data of regional power spectra and functional connectivity can be fitted with a single parameter simulation model based on DTC. C_LIO_LIQuantitative estimation of the DTC across cortical regions can be achieved using a simple sparse recurrent neural network model. C_LIO_LIThe model fits the power spectra of low frequency fluctuations and the distribution of functional connectivity. C_LIO_LIShape collapse analysis of the power spectrum demonstrates a universal profile across the resting cortex depending only on the DTC. C_LI

neuroscience↗

bioRxiv2025

Pupillometry Reveals Autonomic Adjustments During Diving Reflex in Face Immersion Apnea

The human diving reflex is an innate cardiorespiratory adjustment triggered during apnea that concurrently activates both sympathetic and parasympathetic branches of the autonomic nervous system to maintain physiological stability under stress. Although pupil dilation and constriction are antagonistically regulated by these branches, the effect of the diving reflex on pupil diameter oscillations, known as hippus, remains unexplored. Here, we compared hippus in healthy participants during breathing or apnea either with (Wet) or without (Dry) facial immersion in cold water. In both apneic conditions, hippus exhibited reduced power in the low-frequency band (< 0.25 Hz). Notably, during Wet apnea, we observed a reallocation of power towards higher frequencies (> 0.25 Hz) and increased entropy of fluctuations, indicating a shift in autonomic balance and greater signal complexity during the diving reflex. This pilot study highlights pupil dynamics as a sensitive and non-invasive probe of autonomic adjustments underlying the human diving reflex.

physiology↗

bioRxiv2023

Modulation of proximity to criticality enhances slow activity fluctuations during free recall

Ultra-slow fluctuations are a hallmark of spontaneous cortical activity. We examine the hypothesis that these unique dynamics arise from recurrent neuronal networks operating near a phase transition, a state characterized by critical slowing down. A further prediction of such dynamics is that a small modulation towards the critical transition should lead to specific amplification of slow fluctuations. Here, we relate this phenomenon to experimental findings using a simulation of a simple random recurrent network. Importantly, the model aligns with direct intracranial electroencephalography recordings from human visual cortex during both rest and visual free-recall, specifically replicating the observed enhancement of slow fluctuations during free recall. These simulations illuminate a simple and powerful mechanism underlying slow spontaneous fluctuations, while enabling the rapid transition between different spontaneous states. They propose that modulation towards criticality might be a universal strategy employed by cortical networks to engage in a spontaneous generative mode.

neuroscience↗