-
Article
Recurrent host mobility in spatial epidemics: beyond reaction-diffusion
Human mobility is a key factor in spatial disease dynamics and related phenomena. In computational models host mobility is typically modeled by diffusion in space or on metapolulation networks. Alternatively,...
-
Article
Decay of a Bose-Einstein condensate in a dissipative lattice – the mean-field approximation and beyond
The dynamical evolution of a Bose-Einstein condensate in an open optical lattice is studied. Based on the Bose-Hubbard model we rederive the mean-field limit for the case of an environmental coupling includin...
-
Article
Dynamical synapses causing self-organized criticality in neural networks
Self-organized criticality1 is one of the key concepts to describe the emergence of complexity in natural systems. The concept asserts that a system self-organizes into a critical state where system observables a...
-
Article
The scaling laws of human travel
The website wheresgeorge.com invites its users to enter the serial numbers of their US dollar bills and track them across America and beyond. Why? “For fun and because it had not been done yet”, they say. But ...
-
Article
Action Potential Onset Dynamics and the Response Speed of Neuronal Populations
The result of computational operations performed at the single cell level are coded into sequences of action potentials (APs). In the cerebral cortex, due to its columnar organization, large number of neurons ...
-
Chapter and Conference Paper
Pattern formation in the develo** visual cortex: Topological defects, their generation, motion, and annihilation
The pinwheel-like arrangement of iso-orientation domains around orientation centers is a ubiquitous structural element of orientation preference maps in primary visual cortex. We show that activity-dependent s...
-
Article
Spontaneous pinwheel annihilation during visual development
Neurons in the visual cortex respond preferentially to edge-like stimuli of a particular orientation1. It is a long-standing hypothesis that orientation selectivity arises during development through the activity-...
-
Chapter and Conference Paper
A Cortical Interpretation of ASSOMs
Self-organizing maps have been successfully used to model map formation in the visual cortex of mammals. When applying natural images as stimuli, properties of the maps obtained for low-dimensional input manif...
-
Chapter and Conference Paper
Analysing the Context Dependence of Receptive Fields in Visual Cortex
Stimuli outside the classical receptive field of orientation-selective cells in the visual cortex can strongly modulate the response properties of these cells. Normally, stimuli with orientation contrasts lead...
-
Chapter
Reorganization of Ocular Dominance Columns
Formation of ocular dominance columns in many models can be analyzed in terms of the spectra of eigenvalues of the linearized dynamics. Depending on the noise level and on boundary conditions, the correspondin...
-
Chapter
Identifying Oscillatory and Stochastic Neuronal Behavior with High Temporal Precision in Macaque Monkey Visual Cortex
We characterize the network dynamics underlying multi-unit activities from area MT of macaque monkey in terms of a hidden markov model (HMM) and compare our results to those previously obtained from cat visual...
-
Chapter
Activity-Dependent Self-Organization of Orientation Preference Predicts a Transient Overproduction of Pinwheels during Visual Development
The pinwheel-like arrangement of iso-orientation domains around orientation centers is a ubiquitous structural element of orientation preference maps in primary visual cortex. Here we investigate how activity-...
-
Chapter and Conference Paper
SOM-Model for the development of oriented receptive fields and orientation maps from non-oriented ON-center OFF-center inputs
We investigate the development of oriented receptive fields and an orientation map in a SOM-model which is driven by rotationally symmetric stimuli in ON-center and OFF-center input layers. To this end we use ...
-
Chapter and Conference Paper
Geometry of orientation preference map determines nonclassical receptive field properties
We propose a simple mechanism for the nonclassical receptive field property of orientation contrast sensitivity. Our model includes the long-range lateral connections linking cell populations of similar orient...
-
Article
Analyzing phase transitions in high-dimensional self-organizing maps
The self-organizing map (SOM), a widely used algorithm for the unsupervised learning of neural maps, can be formulated in a low-dimensional ‘feature map’ variant which requires prespecified parameters (‘featur...
-
Article
Organization of the visual cortex
-
Chapter and Conference Paper
Precise restoration of cortical orientation maps explained by hebbian dynamics of geniculocortical connections
It is widely assumed that experience dependence and variability of the individual layout of cortical columns are the hallmarks of activity-dependent self-organization during development. Recent optical imaging...
-
Chapter and Conference Paper
Linear and Nonlinear Dynamics in the Development of Orientation Preference Maps
The formation of feature-maps in the develo** visual cortex has become a central system for the study of cooperative phenomena in large neural networks, both theoretically[1, 2] and experimentally [3, 4]. Wi...
-
Chapter and Conference Paper
Lévy walks in chaotic systems: Useful formulas and recent applications
-
Article
Uncovering the synchronization dynamics from correlated neuronal activity quantifies assembly formation
Synchronous network excitation is believed to play an outstanding role in neuronal information processing. Due to the stochastic nature of the contributing neurons, however, those synchronized states are diffi...
