FG Neuronale Informationsverarbeitung

7 Items

Recent Submissions
Optimizing the depth and the direction of prospective planning using information values

Sezener, Can Eren ; Dezfouli, Amir ; Keramati, Mehdi (2019-03-12)

Evaluating the future consequences of actions is achievable by simulating a mental search tree into the future. Expanding deep trees, however, is computationally taxing. Therefore, machines and humans use a plan-until-habit scheme that simulates the environment up to a limited depth and then exploits habitual values as proxies for consequences that may arise in the future. Two outstanding quest...

Computational modeling of glutamate-induced calcium signal generation and propagation in astrocytes

Oschmann, Franziska (2018)

Since the 1990s researchers have shown that astrocytes generate calcium oscillations in response to neuronal activity and propagate them as intercellular calcium waves over long distances. Moreover, astrocytes release transmitters in a calcium-dependent manner and by that signal to neurons. These discoveries have made astrocytes and especially calcium signal generation and propagation in astroc...

Investigating the effects of weak extracellular fields on single neurons: a modelling approach

Aspart, Florian (2018)

In the past decades, the rise of transcranial current stimulation (tCS) has sparkled an increasing interest in the effects of weak extracellular electric fields on neural activity. These fields, such as induced during tCS, have been shown to polarize the neuronal membrane and, consequently, to modulate the spiking activity. In this thesis, I follow a modelling approach to investigate how single...

Dorsolateral prefrontal cortex contributes to the impaired behavioral adaptation in alcohol dependence

Beylergil, Sinem Balta ; Beck, Anne ; Deserno, Lorenz ; Lorenz, Robert C. ; Rapp, Michael A. ; Schlagenhauf, Florian ; Heinz, Andreas ; Obermayer, Klaus (2017-04-17)

Substance-dependent individuals often lack the ability to adjust decisions flexibly in response to the changes in reward contingencies. Prediction errors (PEs) are thought to mediate flexible decision-making by updating the reward values associated with available actions. In this study, we explored whether the neurobiological correlates of PEs are altered in alcohol dependence. Behavioral, and ...

Low-dimensional spike rate models derived from networks of adaptive integrate-and-fire neurons

Augustin, Moritz ; Ladenbauer, Josef ; Baumann, Fabian ; Obermayer, Klaus (2017)

The spiking activity of single neurons can be well described by a nonlinear integrate-and-fire model that includes somatic adaptation. When exposed to fluctuating inputs sparsely coupled populations of these model neurons exhibit stochastic collective dynamics that can be effectively characterized using the Fokker-Planck equation. This approach, however, leads to a model with an infinite-dimens...

How adaptation currents change threshold, gain, and variability of neuronal spiking

Ladenbauer, Josef ; Augustin, Moritz ; Obermayer, Klaus (2014)

Many types of neurons exhibit spike rate adaptation, mediated by intrinsic slow K+ currents, which effectively inhibit neuronal responses. How these adaptation currents change the relationship between in vivo like fluctuating synaptic input, spike rate output, and the spike train statistics, however, is not well understood. In this computational study we show that an adaptation current that pri...

How adaptation shapes spike rate oscillations in recurrent neuronal networks

Augustin, Moritz ; Ladenbauer, Josef ; Obermayer, Klaus (2013)

Neural mass signals from in-vivo recordings often show oscillations with frequencies ranging from <1 to 100 Hz. Fast rhythmic activity in the beta and gamma range can be generated by network-based mechanisms such as recurrent synaptic excitation-inhibition loops. Slower oscillations might instead depend on neuronal adaptation currents whose timescales range from tens of milliseconds to seconds....