A Unified Theory for the Origin of Grid Cells Through the Lens of Pattern
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Grid Cells Are Ubiquitous in Neural Networks
Grid Cells Are Ubiquitous in Neural Networks Songlin Li1†, Yangdong Deng2*†, Zhihua Wang1 1 Department of Microelectronics and Nanoelectronics, Tsinghua University 2 School of Software, Tsinghua University * Corresponding author: Email [email protected] † The two authors contributed equally to this work. Abstract: Grid cells are believed to play an important role in both spatial and non-spatial cognition tasks. A recent study observed the emergence of grid cells in an LSTM for path integration. The connection between biological and artificial neural networks underlying the seemingly similarity, as well as the application domain of grid cells in deep neural networks (DNNs), expect further exploration. This work demonstrated that grid cells could be replicated in either pure vision based or vision guided path integration DNNs for navigation under a proper setting of training parameters. We also show that grid-like behaviors arise in feedforward DNNs for non-spatial tasks. Our findings support that the grid coding is an effective representation for both biological and artificial networks. Introduction: It has been long hypothesized that animals use a “cognitive map”1, namely, an internal knowledge representation to support intelligent behaviors. This proposal was later proved by neuroscience experiments on both spatial2,3 and non-spatial4,5 cognition tasks. Grid cells, which exhibit a spatial periodic firing pattern and thus constitute the hexagonal spatial representation as Fyhn et al has observed2, were discovered in the medial entorhinal cortex (MEC) of rodents2,3. Subsequent studies proposed models to characterize the behavior of grid cells in terms of spike-timing correlations6-8. The discovery of grid cells as well as the fact that different grid cells forms a multi-scale representation inspired the theory of vector-based navigation9. -
Self-Organization Principles of Intracellular Pattern Formation
Self-organization principles of intracellular pattern formation J. Halatek. F. Brauns, and E. Frey∗ Arnold{Sommerfeld{Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universit¨atM¨unchen, Theresienstraße 37, D-80333 M¨unchen,Germany (Dated: February 21, 2018) Abstract Dynamic patterning of specific proteins is essential for the spatiotemporal regulation of many important intracellular processes in procaryotes, eucaryotes, and multicellular organisms. The emergence of patterns generated by interactions of diffusing proteins is a paradigmatic example for self-organization. In this article we review quantitative models for intracellular Min protein patterns in E. coli, Cdc42 polarization in S. cerevisiae, and the bipolar PAR protein patterns found in C. elegans. By analyzing the molecular processes driving these systems we derive a theoretical perspective on general principles underlying self-organized pattern formation. We argue that intracellular pattern formation is not captured by concepts such as \activators", \inhibitors", or \substrate-depletion". Instead, intracellular pattern formation is based on the redistribution of proteins by cytosolic diffusion, and the cycling of proteins between distinct conformational states. Therefore, mass-conserving reaction-diffusion equations provide the most appropriate framework to study intracellular pattern formation. We conclude that directed transport, e.g. cytosolic diffusion along an actively maintained cytosolic gradient, is the key process underlying pattern formation. Thus the basic principle of self-organization is the establishment and maintenance of directed transport by intracellular protein dynamics. Keywords: self-organization; pattern formation; intracellular patterns; reaction-diffusion; cell polarity; arXiv:1802.07169v1 [physics.bio-ph] 20 Feb 2018 NTPases 1 INTRODUCTION In biological systems self-organization refers to the emergence of spatial and temporal structure. -
Marine Vehicles Localization Using Grid Cells for Path Integration
Marine Vehicles Localization Using Grid Cells for Path Integration Ignacio Carluchoa, Manuel F. Baileya, Mariano De Paulab, Corina Barbalataa [email protected], [email protected], mariano.depaula@fio.unicen.edu.ar, [email protected] a Department of Mechanical Engineering, Louisiana State University, Baton Rouge, USA b INTELYMEC Group, Centro de Investigaciones en F´ısica e Ingenier´ıa del Centro CIFICEN – UNICEN – CICpBA – CONICET, 7400 Olavarr´ıa, Argentina Abstract—Autonomous Underwater Vehicles (AUVs) are plat- forms used for research and exploration of marine environments. However, these types of vehicles face many challenges that hinder their widespread use in the industry. One of the main limitations is obtaining accurate position estimation, due to the lack of GPS signal underwater. This estimation is usually done with Kalman filters. However, new developments in the neuroscience field have shed light on the mechanisms by which mammals are able to obtain a reliable estimation of their current position based on external and internal motion cues. A new type of neuron, called Grid cells, has been shown to be part of path integration system in the brain. In this article, we show how grid cells can be used for obtaining a position estimation of underwater vehicles. The model of grid cells used requires only the linear velocities together with heading orientation and provides a reliable estimation of the vehicle’s position. We provide simulation results for an AUV which show the feasibility of our proposed methodology. Index Terms—Grid cells, Navigation, Neuro inspired agents, Autonomous underwater vehicles Fig. 1. A modified BlueROV2 used for experiments I. INTRODUCTION In recent years, the interest in exploring our oceans has that strongly correlates with the animal position in space [5]. -
Guiding Self-Organized Pattern Formation in Cell Polarity Establishment
ARTICLES https://doi.org/10.1038/s41567-018-0358-7 Guiding self-organized pattern formation in cell polarity establishment Peter Gross1,2,3,8, K. Vijay Kumar" "3,4,8, Nathan W. Goehring" "5,6, Justin S. Bois" "7, Carsten Hoege2, Frank Jülicher3 and Stephan W. Grill" "1,2,3* Spontaneous pattern formation in Turing systems relies on feedback. But patterns in cells and tissues seldom form spontane- ously—instead they are controlled by regulatory biochemical interactions that provide molecular guiding cues. The relationship between these guiding cues and feedback in controlled biological pattern formation remains unclear. Here, we explore this relationship during cell-polarity establishment in the one-cell-stage Caenorhabditis elegans embryo. We quantify the strength of two feedback systems that operate during polarity establishment: feedback between polarity proteins and the actomyosin cortex, and mutual antagonism among polarity proteins. We characterize how these feedback systems are modulated by guid- ing cues from the centrosome, an organelle regulating cell cycle progression. By coupling a mass-conserved Turing-like reac- tion–diffusion system for polarity proteins to an active-gel description of the actomyosin cortex, we reveal a transition point beyond which feedback ensures self-organized polarization, even when cues are removed. Notably, the system switches from a guide-dominated to a feedback-dominated regime well beyond this transition point, which ensures robustness. Together, these results reveal a general criterion for controlling biological pattern-forming systems: feedback remains subcritical to avoid unstable behaviour, and molecular guiding cues drive the system beyond a transition point for pattern formation. ell polarity establishment in Caenorhabditis elegans zygotes phase where myosin appears to reach a steady state (Supplementary is a prototypical example for cellular pattern formation that Fig. -
Emergence of Grid-Like Representations by Training
Published as a conference paper at ICLR 2018 EMERGENCE OF GRID-LIKE REPRESENTATIONS BY TRAINING RECURRENT NEURAL NETWORKS TO PERFORM SPATIAL LOCALIZATION Christopher J. Cueva,∗ Xue-Xin Wei∗ Columbia University New York, NY 10027, USA fccueva,[email protected] ABSTRACT Decades of research on the neural code underlying spatial navigation have re- vealed a diverse set of neural response properties. The Entorhinal Cortex (EC) of the mammalian brain contains a rich set of spatial correlates, including grid cells which encode space using tessellating patterns. However, the mechanisms and functional significance of these spatial representations remain largely mysterious. As a new way to understand these neural representations, we trained recurrent neural networks (RNNs) to perform navigation tasks in 2D arenas based on veloc- ity inputs. Surprisingly, we find that grid-like spatial response patterns emerge in trained networks, along with units that exhibit other spatial correlates, including border cells and band-like cells. All these different functional types of neurons have been observed experimentally. The order of the emergence of grid-like and border cells is also consistent with observations from developmental studies. To- gether, our results suggest that grid cells, border cells and others as observed in EC may be a natural solution for representing space efficiently given the predominant recurrent connections in the neural circuits. 1 INTRODUCTION Understanding the neural code in the brain has long been driven by studying feed-forward -
Models of Grid Cells and Theta Oscillations
BRIEF COMMUNICATIONS ARISING Models of grid cells and theta oscillations ARISING FROM M. M.Yartsev, M. P. Witter & N. Ulanovsky Nature 479, 103–107 (2011) Grid cells recorded in the medial entorhinal cortex (MEC) of freely and in putative velocity-controlled oscillatory inputs identified as inter- moving rodents show a markedly regular spatial firing pattern whose neurons within the septohippocampal circuit7. underlying mechanism has been the subject of intense interest. Yartsev et al.1 recorded the firing of grid cells from bats trained to Yartsev et al.1 report that the firing of grid cells in crawling bats does crawl within the recording environment, a behaviour that they per- not show theta rhythmicity ‘‘causally disproving a major class of form very slowly (a mean speed of 3.7 cm s21 versus 17.6 cm s21 in computational models’’ of grid cell firing that rely on oscillatory our rat data), often stopping entirely (supplementary figure 11 in interference2–7. However, their data may be consistent with these ref. 1). The authors found grid cells with very low firing rates (a mean models, with the apparent lack of theta rhythmicity reflecting slow peak rate of 0.56 Hz versus 5.14 Hz in our data) and little significant movement speeds and low firing rates. Thus, the conclusion of theta modulation. However, matching movement speed is important Yartsev et al. is not supported by their data. for comparisons involving theta. At low speeds movement-related In oscillatory interference models, path integration is performed by theta rhythmicity is strongly attenuated12 and the need for path velocity-dependent variation in the frequencies of theta-band oscilla- integration is reduced. -
Resonating Neurons Stabilize Heterogeneous Grid-Cell Networks
bioRxiv preprint doi: https://doi.org/10.1101/2020.12.10.419200; this version posted December 11, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Resonating neurons stabilize heterogeneous grid-cell networks 2 3 Divyansh Mittal and Rishikesh Narayanan* 4 5 Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of 6 Science, Bangalore, India. 7 8 *Corresponding Author 9 10 Rishikesh Narayanan, Ph.D. 11 Molecular Biophysics Unit 12 Indian Institute of Science 13 Bangalore 560 012, India. 14 15 e-mail: [email protected] 16 Phone: +91-80-22933372 17 Fax: +91-80-23600535 18 Number of words: 250 (abstract), 120 (significance statement) 19 20 Abbreviated title: Resonating neurons stabilize heterogeneous networks 21 22 Keywords: grid cells, entorhinal cortex, continuous attractor network, resonance, 23 heterogeneities 24 25 Author contributions 26 D. M. and R. N. designed experiments; D. M. performed experiments and carried out data 27 analysis; D. M. and R. N. co-wrote the paper. 28 29 Competing financial interests 30 The authors declare no conflict of interest. 31 32 Acknowledgments 33 This work was supported by the Wellcome Trust-DBT India Alliance (Senior fellowship to 34 RN; IA/S/16/2/502727), Human Frontier Science Program (HFSP) Organization (RN), the 35 Department of Biotechnology through the DBT-IISc partnership program (RN), the Revati 36 and Satya Nadham Atluri Chair Professorship (RN), and the Ministry of Human Resource 37 Development (RN & DM). The authors thank Dr. Poonam Mishra, Dr. -
Pattern Formation, Social Forces, and Diffusion Instability in Games
EPJ manuscript No. (will be inserted by the editor) Pattern Formation, Social Forces, and Diffusion Instability in Games with Success-Driven Motion Dirk Helbing ETH Zurich, UNO D11, Universit¨atstr.41, 8092 Zurich, Switzerland Received: date / Revised version: date Abstract. A local agglomeration of cooperators can support the survival or spreading of cooperation, even when cooperation is predicted to die out according to the replicator equation, which is often used in evolutionary game theory to study the spreading and disappearance of strategies. In this paper, it is shown that success-driven motion can trigger such local agglomeration and may, therefore, be used to supplement other mechanisms supporting cooperation, like reputation or punishment. Success-driven motion is formulated here as a function of the game-theoretical payoffs. It can change the outcome and dynamics of spatial games dramatically, in particular as it causes attractive or repulsive interaction forces. These forces act when the spatial distributions of strategies are inhomogeneous. However, even when starting with homogeneous initial conditions, small perturbations can trigger large inhomogeneities by a pattern-formation instability, when certain conditions are fulfilled. Here, these instability conditions are studied for the prisoner's dilemma and the snowdrift game. Furthermore, it is demonstrated that asymmetrical diffusion can drive social, economic, and biological systems into the unstable regime, if these would be stable without diffusion. PACS. 02.50.Le Decision theory and game theory { 87.23.Ge Dynamics of social systems { 82.40.Ck Pattern formation in reactions with diffusion, flow and heat transfer { 87.23.Cc Population dynamics and ecological pattern formation 1 Introduction tions [17,18], which agree with replicator equations for the fitness-dependent reproduction of individuals in biology Game theory is a well-established theory of individual [19,20,21]. -
Models of Grid Cells and Theta Oscillations
Publisher: NPG; Journal: Nature: Nature; Article Type: BCA DOI: 10.1038/nature11276 Models of grid cells and theta oscillations ARISING FROM M. M.Yartsev, M. P. Witter & N. Ulanovsky Nature 479, 103–107 (2011) Grid cells recorded in the medial entorhinal cortex (MEC) of freely moving rodents show a strikingly regular spatial firing pattern whose underlying mechanism has been the subject of intense interest. Yartsev et al.1 report that the firing of grid cells in crawling bats does not show theta rhythmicity “causally disproving a major class of computational models” of grid cell firing that rely on oscillatory interference2–7. However, their data may be consistent with these models, with the apparent lack of theta rhythmicity reflecting slow movement speeds and low firing rates. Thus, Yartsev et al.’s conclusion is not supported by their data. In oscillatory interference models, path integration is performed by velocity- dependent variation in the frequencies of theta-band oscillations, which combine to generate the grid-cell pattern2–4,6,7. In addition, learned associations to environmental sensory inputs (possibly mediated by place cells) ensure that grids are spatially stable over time and are sufficient to maintain firing in familiar environments2,3,8. In rats, the majority of grid cells show theta-modulated firing9,10, and the model predicts specific relationships between modulation frequency, running velocity and grid scale4, which have been verified in grid cells11 and in putative velocity-controlled oscillatory inputs identified as interneurons within the septohippocampal circuit7. Yartsev et al.1 recorded the firing of grid cells from bats trained to crawl within the recording environment, a behaviour that they perform very slowly (a mean speed of 3.7 cm s−1 versus 17.6 cm s−1 in our rat data), often stopping entirely (supplementary figure 11 in ref. -
May-Britt Moser Norwegian University of Science and Technology (NTNU), Trondheim, Norway
Grid Cells, Place Cells and Memory Nobel Lecture, 7 December 2014 by May-Britt Moser Norwegian University of Science and Technology (NTNU), Trondheim, Norway. n 7 December 2014 I gave the most prestigious lecture I have given in O my life—the Nobel Prize Lecture in Medicine or Physiology. Afer lectures by my former mentor John O’Keefe and my close colleague of more than 30 years, Edvard Moser, the audience was still completely engaged, wonderful and responsive. I was so excited to walk out on the stage, and proud to present new and exciting data from our lab. Te title of my talk was: “Grid cells, place cells and memory.” Te long-term vision of my lab is to understand how higher cognitive func- tions are generated by neural activity. At frst glance, this seems like an over- ambitious goal. President Barack Obama expressed our current lack of knowl- edge about the workings of the brain when he announced the Brain Initiative last year. He said: “As humans, we can identify galaxies light years away; we can study particles smaller than an atom. But we still haven’t unlocked the mystery of the three pounds of matter that sits between our ears.” Will these mysteries remain secrets forever, or can we unlock them? What did Obama say when he was elected President? “Yes, we can!” To illustrate that the impossible is possible, I started my lecture by showing a movie with a cute mouse that struggled to bring a biscuit over an edge and home to its nest. Te biscuit was almost bigger than the mouse itself. -
Using Neural Networks for Pattern Association for the Online Purchase
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by AIS Electronic Library (AISeL) Association for Information Systems AIS Electronic Library (AISeL) All Sprouts Content Sprouts 7-26-2009 Using Neural Networks for Pattern Association for the Online Purchase of Products Arpan Kumar Kar XLRI School of Business & Human Resources, [email protected] Supriyo Kumar De XLRI School of Business & Human Resources, [email protected] Follow this and additional works at: http://aisel.aisnet.org/sprouts_all Recommended Citation Kar, Arpan Kumar and De, Supriyo Kumar, " Using Neural Networks for Pattern Association for the Online Purchase of Products" (2009). All Sprouts Content. 281. http://aisel.aisnet.org/sprouts_all/281 This material is brought to you by the Sprouts at AIS Electronic Library (AISeL). It has been accepted for inclusion in All Sprouts Content by an authorized administrator of AIS Electronic Library (AISeL). For more information, please contact [email protected]. Working Papers on Information Systems ISSN 1535-6078 Using Neural Networks for Pattern Association for the Online Purchase of Products Arpan Kumar Kar XLRI School of Business & Human Resources, India Supriyo Kumar De XLRI School of Business & Human Resources, India Abstract Abstract: Today, a huge percentage of all the business transactions that take place in the domain of e-commerce are dominated by online shopping after the "virtual market" conceptualization of the business. This paper focuses on how pattern association rules may be obtained from the dynamic databases generated during purchases in an e-Store to maximize the profit of the marketer. -
Evolutionary Game Theory: Theoretical Concepts and Applications To
Physica A 389 (2010) 4265–4298 Contents lists available at ScienceDirect Physica A journal homepage: www.elsevier.com/locate/physa Evolutionary game theory: Theoretical concepts and applications to microbial communities Erwin Frey ∗ Ludwig-Maximilians-Universität München, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Theresienstrasse 37, D-80333 Munich, Germany article info a b s t r a c t Article history: Ecological systems are complex assemblies of large numbers of individuals, interacting Received 30 January 2010 competitively under multifaceted environmental conditions. Recent studies using Available online 4 March 2010 microbial laboratory communities have revealed some of the self-organization principles underneath the complexity of these systems. A major role of the inherent stochasticity of its Keywords: dynamics and the spatial segregation of different interacting species into distinct patterns Population dynamics has thereby been established. It ensures the viability of microbial colonies by allowing for Game theory species diversity, cooperative behavior and other kinds of ``social'' behavior. Evolution Stochastic processes A synthesis of evolutionary game theory, nonlinear dynamics, and the theory of Nonlinear dynamics stochastic processes provides the mathematical tools and a conceptual framework for a Pattern formation deeper understanding of these ecological systems. We give an introduction into the modern formulation of these theories and illustrate their effectiveness focussing on selected examples of microbial systems. Intrinsic fluctuations, stemming from the discreteness of individuals, are ubiquitous, and can have an important impact on the stability of ecosystems. In the absence of speciation, extinction of species is unavoidable. It may, however, take very long times. We provide a general concept for defining survival and extinction on ecological time-scales.