FG Modellierung kognitiver Prozesse

10 Items

Recent Submissions
Memory replay in balanced recurrent networks

Chenkov, Nikolay ; Sprekeler, Henning ; Kempter, Richard (2017-01-30)

Complex patterns of neural activity appear during up-states in the neocortex and sharp waves in the hippocampus, including sequences that resemble those during prior behavioral experience. The mechanisms underlying this replay are not well understood. How can small synaptic footprints engraved by experience control large-scale network activity during memory retrieval and consolidation? We hypot...

Nonlinear Bayesian filtering and learning: a neuronal dynamics for perception

Kutschireiter, Anna ; Surace, Simone Carlo ; Sprekeler, Henning ; Pfister, Jean-Pascal (2017-08-18)

The robust estimation of dynamical hidden features, such as the position of prey, based on sensory inputs is one of the hallmarks of perception. This dynamical estimation can be rigorously formulated by nonlinear Bayesian filtering theory. Recent experimental and behavioral studies have shown that animals’ performance in many tasks is consistent with such a Bayesian statistical interpretation. ...

A local measure of symmetry and orientation for individual spikes of grid cells

Weber, Simon Nikolaus ; Sprekeler, Henning (2019-02-07)

Grid cells have attracted broad attention because of their highly symmetric hexagonal firing patterns. Recently, research has shifted its focus from the global symmetry of grid cell activity to local distortions both in space and time, such as drifts in orientation, local defects of the hexagonal symmetry, and the decay and reappearance of grid patterns after changes in lighting condition. Here...

Learning place cells, grid cells and invariances with excitatory and inhibitory plasticity

Weber, Simon Nikolaus ; Sprekeler, Henning (2018-02-21)

Neurons in the hippocampus and adjacent brain areas show a large diversity in their tuning to location and head direction, and the underlying circuit mechanisms are not yet resolved. In particular, it is unclear why certain cell types are selective to one spatial variable, but invariant to another. For example, place cells are typically invariant to head direction. We propose that all observed ...

Computational models of spatial representations

Weber, Simon Nikolaus (2019)

Our sense of location depends on a structure deep within the brain called the hippocampal formation, and on its neighbor, the parahippocampal region. Studies in rodents have shown that these brain areas contain different types of neurons that help the animal to work out where it is. The activity of those neurons is modulated by the trajectory of the animal, and this modulation varies among cell...

Low dimensional visualization and modelling of data using distance-based models

Grünhage, Gina (2018)

This thesis consists of two parts, which seek low-dimensional representations for visualization and analysis of data. Both parts use rather different types of models and inference methods. In both cases, however, the models show inherent invariances, which need to be coped with during the optimization procedures. The first part addresses a fundamental problem in machine learning, namely, the ch...

Burst-dependent bidirectional plasticity in the cerebellum Is driven by presynaptic NMDA receptors

Bouvier, Guy ; Higgins, David ; Spolidoro, Maria ; Carrel, Damien ; Mathieu, Benjamin ; Léna, Clément ; Dieudonné, Stéphane ; Barbour, Boris ; Brunel, Nicolas ; Casado, Mariano (2016-03-24)

Numerous studies have shown that cerebellar function is related to the plasticity at the synapses between parallel fibers and Purkinje cells. How specific input patterns determine plasticity outcomes, as well as the biophysics underlying plasticity of these synapses, remain unclear. Here, we characterize the patterns of activity that lead to postsynaptically expressed LTP using both in vivo and...

Functional consequences of inhibitory plasticity: homeostasis, the excitation-inhibition balance and beyond

Sprekeler, Henning (2017-05-10)

Computational neuroscience has a long-standing tradition of investigating the consequences of excitatory synaptic plasticity. In contrast, the functions of inhibitory plasticity are still largely nebulous, particularly given the bewildering diversity of interneurons in the brain. Here, we review recent computational advances that provide first suggestions for the functional roles of inhibitory ...

Linking appearance to neural activity through the study of the perception of lightness in naturalistic contexts

Maertens, Marianne ; Shapley, Robert (2013)

The present paper deals with the classical question how a psychological experience, in this case apparent lightness, is linked by intervening neural processing to physical variables. We address two methodological issues: (a) how does one know the appropriate physical variable (what is the right x ?) to look at, and (b) how can behavioral measurements be used to probe the internal transformation...

Exploitation of environmental constraints in human and robotic grasping

Eppner, Clemens ; Deimel, Raphael ; Álvarez-Ruiz, José ; Maertens, Marianne ; Brock, Oliver (2015)

We investigate the premise that robust grasping performance is enabled by exploiting constraints present in the environment. These constraints, leveraged through motion in contact, counteract uncertainty in state variables relevant to grasp success. Given this premise, grasping becomes a process of successive exploitation of environmental constraints, until a successful grasp has been establish...