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Unveiling Hidden Neural Codes: SIMPL – A Scalable and Fast Approach for Optimizing Latent Variables and Tuning Curves in Neural Population Data

Dr. Rishabh Pathak
This research paper presents SIMPL (Scalable Iterative Maximization of Population-coded Latents), a novel, computationally efficient algorithm designed to refine the estimation of latent variables and tuning curves from neural population activity. Latent variables in neural data represent essential low-dimensional quantities encoding behavioral or cognitive states, which neuroscientists seek to identify to understand brain computations better. Background and Motivation Traditional approaches commonly assume the observed behavioral variable as the latent neural code. However, this assumption can lead to inaccuracies because neural activity sometimes encodes internal cognitive states differing subtly from observable behavior (e.g., anticipation, mental simulation). Existing latent variable models face challenges such as high computational cost, poor scalability to large datasets, limited expressiveness of tuning models, or difficulties interpreting complex neural network-based functio...
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The 3D biventricular electromechanical model in account for the interaction between the heart and the circulatory system.

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Dr. Rishabh Pathak


    The 3D biventricular electromechanical model described in the PDF file incorporates a detailed representation of the interaction between the heart and the circulatory system. This model couples the electromechanical behavior of the heart with a 0D closed-loop (lumped parameters) hemodynamical model of the entire cardiovascular system, including blood flow dynamics. By integrating these two components, the model can simulate the complex interplay between cardiac mechanics and circulatory dynamics.Specifically, the electromechanical aspect of the model accounts for processes such as cardiac electrophysiology, active contraction of cardiomyocytes, tissue mechanics, and blood circulation within the heart chambers. These core models capture the molecular, cellular, tissue, and organ-level processes involved in the heart's pumping function. The coupling between these electromechanical components and the closed-loop hemodynamical model is achieved through suitable interface conditions, such as volume conservation constraints.

     By considering the holistic interaction between the heart's electromechanical activity and the circulatory system's hemodynamics, the 3D biventricular electromechanical model provides a comprehensive framework for studying cardiac function in a physiological context. This integrated approach allows researchers to investigate how changes in cardiac mechanics affect blood flow dynamics and vice versa, providing valuable insights into the complex behavior of the cardiovascular system.

 

Piersanti, R., Regazzoni, F., Salvador, M., Corno, A. F., Dede', L., Vergara, C., & Quarteroni, A. (2021). 3D-0D closed-loop model for the simulation of cardiac biventricular electromechanics. *arXiv preprint arXiv:2108.01907*.

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