Paper List
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STAR-GO: Improving Protein Function Prediction by Learning to Hierarchically Integrate Ontology-Informed Semantic Embeddings
This paper addresses the core challenge of generalizing protein function prediction to unseen or newly introduced Gene Ontology (GO) terms by overcomi...
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Incorporating indel channels into average-case analysis of seed-chain-extend
This paper addresses the core pain point of bridging the theoretical gap for the widely used seed-chain-extend heuristic by providing the first rigoro...
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Competition, stability, and functionality in excitatory-inhibitory neural circuits
This paper addresses the core challenge of extending interpretable energy-based frameworks to biologically realistic asymmetric neural networks, where...
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Enhancing Clinical Note Generation with ICD-10, Clinical Ontology Knowledge Graphs, and Chain-of-Thought Prompting Using GPT-4
This paper addresses the core challenge of generating accurate and clinically relevant patient notes from sparse inputs (ICD codes and basic demograph...
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Hypothesis-Based Particle Detection for Accurate Nanoparticle Counting and Digital Diagnostics
This paper addresses the core challenge of achieving accurate, interpretable, and training-free nanoparticle counting in digital diagnostic assays, wh...
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MCP-AI: Protocol-Driven Intelligence Framework for Autonomous Reasoning in Healthcare
This paper addresses the critical gap in healthcare AI systems that lack contextual reasoning, long-term state management, and verifiable workflows by...
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Model Gateway: Model Management Platform for Model-Driven Drug Discovery
This paper addresses the critical bottleneck of fragmented, ad-hoc model management in pharmaceutical research by providing a centralized, scalable ML...
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Tree Thinking in the Genomic Era: Unifying Models Across Cells, Populations, and Species
This paper addresses the fragmentation of tree-based inference methods across biological scales by identifying shared algorithmic principles and stati...
Emergent Spatiotemporal Dynamics in Large-Scale Brain Networks with Next Generation Neural Mass Models
Universitat de les Illes Balears, Spain | Universitat Politècnica de Catalunya, Barcelona, Spain | Institut de Matemàtiques de la UPC - Barcelona Tech (IMTech), Barcelona, Spain | Centre de Recerca Matemàtica, Barcelona, Spain
The 30-Second View
IN SHORT: This work addresses the core challenge of understanding how complex, brain-wide spatiotemporal patterns emerge from the interaction of biophysically detailed local dynamics and empirical anatomical connectivity.
Innovation (TL;DR)
- Methodology Introduces a next-generation neural mass model (NG-NMM) into a large-scale brain network framework, providing a more biophysically grounded and analytically tractable description of population-level gamma oscillations via the PING mechanism.
- Methodology Applies the Master Stability Function (MSF) formalism and Floquet theory to systematically analyze transverse instabilities of homogeneous states (both fixed points and limit cycles) in a high-dimensional (90-node) network, linking instability modes to emergent spatiotemporal patterns.
- Biology Demonstrates that the network coupling in NG-NMMs enables cross-frequency coupling (CFC), specifically generating gamma oscillations whose amplitude is modulated by slower rhythms—a phenomenon not possible in isolated nodes and highly relevant for cognitive functions like memory.
Key conclusions
- NG-NMMs exhibit a broader dynamical repertoire than classical models, including regions of bistability, period-doubling cascades, and deterministic chaos within the homogeneous manifold (e.g., positive Lyapunov exponents for I_ext^E ~10-10.5 at ε=12).
- Anatomical connectivity is crucial for inducing cross-frequency coupling, allowing the emergence of gamma oscillations (27-170 Hz) with amplitude modulated by slower rhythms, a key feature of brain dynamics.
- The system's rich spatiotemporal patterns (traveling waves, high-dimensional chaos) arise from transverse instabilities of homogeneous solutions, analytically predicted by the MSF and confirmed via Lyapunov exponent and frequency spectrum analysis.
Abstract: Understanding the dynamics of large-scale brain models remains a central challenge due to the inherent complexity of these systems. In this work, we explore the emergence of complex spatiotemporal patterns in a large scale-brain model composed of 90 interconnected brain regions coupled through empirically derived anatomical connectivity. An important aspect of our formulation is that the local dynamics of each brain region are described by a next-generation neural mass model, which explicitly captures the macroscopic gamma activity of coupled excitatory and inhibitory neural populations (PING mechanism). We first identify the system’s homogeneous states—both resting and oscillatory—and analyze their stability under uniform perturbations. Then, we determine the stability against non-uniform perturbations by obtaining dispersion relations for the perturbation growth rate. This analysis enables us to link unstable directions of the homogeneous solutions to the emergence of rich spatiotemporal patterns, that we characterize by means of Lyapunov exponents and frequency spectrum analysis. Our results show that, compared to previous studies with classical neural mass models, next-generation neural mass models provide a broader dynamical repertoire, both within homogeneous states and in the heterogeneous regime. Additionally, we identify a key role for anatomical connectivity in cross-frequency coupling, allowing for the emergence of gamma oscillations with amplitude modulated by slower rhythms. These findings suggest that such models are not only more biophysically grounded but also particularly well-suited to capture the full complexity of large-scale brain dynamics. Overall, our study advances the analytical understanding of emerging spatiotemporal patterns in whole-brain models.