Publications de Joao Emanuel Felipe Gerhard

On the stability and dynamics of stochastic spiking neuron models: Nonlinear Hawkes process and point process GLMs

Joao Emanuel Felipe Gerhard, Moritz Deger

Point process generalized linear models (PP-GLMs) provide an important statistical framework for modeling spiking activity in single-neurons and neuronal networks. Stochastic stability is essential when sampling from these models, as done in computational ...

Public Library of Science2017

Statistical models of effective connectivity in neural microcircuits

Joao Emanuel Felipe Gerhard

To appreciate how neural circuits in the brain control behaviors, we must identify how the neurons comprising the circuit are connected. Neuronal connectivity is difficult to determine experimentally, whereas neuronal activity can often be readily measured ...

EPFL2014

Inference of neuronal network spike dynamics and topology from calcium imaging data

Wulfram Gerstner, Friedemann Zenke, Joao Emanuel Felipe Gerhard

Two-photon calcium imaging enables functional analysis of neuronal circuits by inferring action potential (AP) occurrence ("spike trains") from cellular fluorescence signals. It remains unclear how experimental parameters such as signal-to-noise ratio (SNR ...

Frontiers Research Foundation2013

Successful Reconstruction of a Physiological Circuit with Known Connectivity from Spiking Activity Alone

Joao Emanuel Felipe Gerhard

Identifying the structure and dynamics of synaptic interactions between neurons is the first step to understanding neural network dynamics. The presence of synaptic connections is traditionally inferred through the use of targeted stimulation and paired re ...

Public Library of Science2013

Spline- and Wavelet-based Models of Neural Activity in Response to Natural Visual Stimulation

Joao Emanuel Felipe Gerhard, Luca Szegletes

We present a comparative study of the performance of different basis functions for the nonparametric modeling of neural activity in response to natural stimuli. Based on naturalistic video sequences, a generative model of neural activity was created using ...

Ieee2012

Extraction of network topology from multi-electrode recordings: is there a small-world effect?

Wulfram Gerstner, Joao Emanuel Felipe Gerhard

The simultaneous recording of the activity of many neurons poses challenges for multivariate data analysis. Here, we propose a general scheme of reconstruction of the functional network from spike train recordings. Effective, causal interactions are estima ...

Frontiers Research Foundation2011

Improved Similarity Measures for Small Sets of Spike Trains

Wulfram Gerstner, Richard Naud, Skander Mensi, Joao Emanuel Felipe Gerhard

Multiple measures have been developed to quantify the similarity between two spike trains. These measures have been used for the quantification of the mismatch between neuron models and experiments as well as for the classification of neuronal responses in ...

Massachusetts Institute of Technology Press2011

Applying the Multivariate Time-Rescaling Theorem to Neural Population Models

Joao Emanuel Felipe Gerhard

Statistical models of neural activity are integral to modern neuroscience. Recently interest has grown in modeling the spiking activity of populations of simultaneously recorded neurons to study the effects of correlations and functional connectivity on ne ...

Massachusetts Institute of Technology Press2011

Rescaling, thinning or complementing? On goodness-of-fit procedures for point process models and Generalized Linear Models

Wulfram Gerstner, Joao Emanuel Felipe Gerhard

Generalized Linear Models (GLMs) are an increasingly popular framework for modeling neural spike trains. They have been linked to the theory of stochastic point processes and researchers have used this relation to assess goodness-of-fit using methods from ...

Massachusetts Institute of Technology Press2010