Biology subjects

Orsenigo, D.

Publications and source records attributed to Orsenigo, D..

3 recordsLinked to original sources

bioRxiv2026

Preserved brain hierarchy supports residual vision without awareness after visual cortex damage

Damage to the primary visual cortex causes loss of conscious vision, yet some patients retain the ability to respond to stimuli despite reporting no visual experience. Why similar lesions produce such different behavioral phenotypes remains unclear. While research to date has focused primarily on spared pathways that bypass V1, here we asked whether these divergent outcomes are also linked to the brain's intrinsic functional architecture. In the largest resting-state fMRI cohort of patients with unilateral V1 damage reported to date, we quantified information sharing between regions across cortical and subcortical parcels in blindsight-positive and blindsight-negative patients, as well as in age-matched healthy controls. Despite comparable lesions, the two patient groups displayed distinct hierarchical patterns on the cortex: B+ patients preserved a sensory-to-association organization as in healthy controls, whereas B- patients exhibited a marked flattening of this hierarchy. The effect was driven by abnormally low shared-information coupling within unimodal cortices and scaled continuously with single-subject behavioral blind-field detection performance. A thalamic region consistent with the pulvinar, linking the contralesional visual cortex and the frontal eye field, discriminated B+ from B- patients. These findings highlight the system-level consequences of V1 damage supporting blindsight, suggesting that the unimodal-transmodal axis might track not only global states of consciousness, but also whether sensory information can guide behavior without awareness.

neuroscience↗

bioRxiv2025

Beyond Pairwise Interactions: Charting Higher-Order Models of Brain Function

Traditional models of brain connectivity have primarily focused on pairwise interactions, over-looking the rich dynamics that emerge from simultaneous interactions among multiple brain regions. Although a plethora of higher-order interaction (HOI) metrics have been proposed, a systematic evaluation of their comparative properties and utility is missing. Here, we present the first large-scale analysis of information-theoretic and topological HOI metrics, applied to both resting-state and task fMRI data from 100 unrelated subjects of the Human Connectome Project. We identify a clear taxonomy of HOI metrics -- redundant, synergistic, and topological--, with the latter acting as bridges along the redundancy-synergy continuum. Despite methodological differences, all HOI metrics align with the brains overarching unimodal-to-transmodal functional hierarchy. However, certain metrics show specific associations with the neurotransmitter receptor architecture. HOI metrics outperform traditional pairwise models in brain fingerprinting and perform comparably in task decoding, underscoring their value for characterizing individual functional profiles. Finally, multivariate analysis reveals that -- among all HOI metrics -- topological descriptors are key to linking brain function with behavioral variability, positioning them as valuable tools for linking neural architecture and cognitive function. Overall, our findings establish HOIs as a powerful framework for capturing the brains multidimensional dynamics, providing a conceptual map to guide their application across cognitive and clinical neuroscience.

neuroscience↗

bioRxiv2025

Beyond Reorganization: Intrinsic cortical hierarchies constrain experience-dependent plasticity in sensory-deprived humans

Innate cortical organisation and postnatal sensory experience interact dynamically to shape the functional architecture of the human brain. Using naturalistic stimulation, functional gradient analyses, and comparative approaches in congenitally blind, congenitally deaf, and typically developed individuals, we investigated how intrinsic hierarchical structures and sensory experiences influence cortical organisation. Our findings demonstrate that the principal functional gradients spanning from unimodal sensory to transmodal association cortices are consistently preserved across all groups, suggesting a robust genetically determined cortical scaffold. Nonetheless, congenital sensory deprivation selectively reshapes the geometry of modality-specific gradients, characterised by reduced functional differentiation within sensory-deprived cortical regions. These geometric contractions promote experience-driven plastic reorganization, enabling deprived sensory areas to establish enhanced functional connectivity with transmodal and non-deprived sensory cortices. Critically, this reorganisation aligns systematically with pre-existing cortical gradients, highlighting intrinsic hierarchical constraints that guide experience-dependent plasticity. Moreover, sensory-deprived regions exhibiting heightened connectivity actively engage in processing structured perceptual information from intact modalities, reflecting specific feature-driven cross-modal adaptations. Collectively, these results underscore a fundamental duality in cortical organisation: innate hierarchical principles impose constraints on cortical architecture, while sensory experience drives adaptive refinement, demonstrating the brains intrinsic capacity for flexible functional reconfiguration in response to sensory deprivation.

neuroscience↗