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scientificComputing/projects/project_noiseficurves/noiseficurves.tex
2015-11-02 09:36:45 +01:00

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\documentclass[addpoints,11pt]{exam}
\usepackage{url}
\usepackage{color}
\usepackage{hyperref}
\pagestyle{headandfoot}
\runningheadrule
\firstpageheadrule
\firstpageheader{Scientific Computing}{Project Assignment}{11/02/2014
-- 11/05/2014}
%\runningheader{Homework 01}{Page \thepage\ of \numpages}{23. October 2014}
\firstpagefooter{}{}{{\bf Supervisor:} Jan Benda}
\runningfooter{}{}{}
\pointsinmargin
\bracketedpoints
%\printanswers
%\shadedsolutions
%%%%% listings %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage{listings}
\lstset{
basicstyle=\ttfamily,
numbers=left,
showstringspaces=false,
language=Matlab,
breaklines=true,
breakautoindent=true,
columns=flexible,
frame=single,
% captionpos=t,
xleftmargin=2em,
xrightmargin=1em,
% aboveskip=11pt,
%title=\lstname,
% title={\protect\filename@parse{\lstname}\protect\filename@base.\protect\filename@ext}
}
\begin{document}
%%%%%%%%%%%%%%%%%%%%% Submission instructions %%%%%%%%%%%%%%%%%%%%%%%%%
\sffamily
% \begin{flushright}
% \gradetable[h][questions]
% \end{flushright}
\begin{center}
\input{../disclaimer.tex}
\end{center}
%%%%%%%%%%%%%% Questions %%%%%%%%%%%%%%%%%%%%%%%%%
\begin{questions}
\question You are recording the activity of a neuron in response to
constant stimuli of intensity $I$ (think of that, for example,
as a current $I$ injected via a patch-electrode into the neuron).
Measure the tuning curve (also called the intensity-response curve) of the
neuron. That is, what is the firing rate of the neuron's response
as a function of the input $I$. How does this depend on the level of
the intrinsic noise of the neuron?
The neuron is implemented in the file \texttt{lifspikes.m}. Call it
with the following parameters:
\begin{lstlisting}
trials = 10;
tmax = 50.0;
input = 10.0; % the input I
Dnoise = 1.0; % noise strength
spikes = lifspikes( trials, input, tmax, Dnoise );
\end{lstlisting}
The returned \texttt{spikes} is a cell array with \texttt{trials} elements, each being a vector
of spike times (in seconds) computed for a duration of \texttt{tmax} seconds.
The input is set via the \texttt{input} variable, the noise strength via \texttt{Dnoise}.
\begin{parts}
\part First set the noise \texttt{Dnoise=0} (no noise). Compute and plot the firing rate
as a function of the input for inputs ranging from 0 to 20.
\part Do the same for various noise strength \texttt{Dnoise}. Use $D_{noise} = 1e-3$,
1e-2, and 1e-1. How does the intrinsic noise influence the response curve?
\part Show some interspike interval histograms for some
interesting values of the input and the noise strength.
\part How does the coefficient of variation $CV_{isi}$ (standard
deviation divided by mean) of the interspike intervalls depend on
the input and the noise level?
\end{parts}
\end{questions}
\end{document}