46 lines
1.8 KiB
TeX
46 lines
1.8 KiB
TeX
\documentclass[a4paper,12pt,pdftex]{exam}
|
|
|
|
\newcommand{\ptitle}{Steady-state f-I curve}
|
|
\input{../header.tex}
|
|
\firstpagefooter{Supervisor: Jan Grewe}{phone: 29 74588}%
|
|
{email: jan.grewe@uni-tuebingen.de}
|
|
|
|
\begin{document}
|
|
|
|
\input{../instructions.tex}
|
|
|
|
|
|
%%%%%%%%%%%%%% Questions %%%%%%%%%%%%%%%%%%%%%%%%%
|
|
\section*{Quantifying the responsiveness of a neuron using the F-I curve.}
|
|
The responsiveness of a neuron is often quantified using an F-I
|
|
curve. The F-I curve plots the \textbf{F}iring rate of the neuron as a function
|
|
of the stimulus \textbf{I}ntensity.
|
|
|
|
\begin{questions}
|
|
\question In the accompanying datasets you find the
|
|
\textit{spike\_times} of an P-unit electrorecptor of the weakly
|
|
electric fish \textit{Apteronotus leptorhynchus} to a stimulus of a
|
|
certain intensity, i.e. the \textit{contrast}. The contrast is also
|
|
part of the file name itself.
|
|
\begin{parts}
|
|
\part Estimate for each stimulus intensity the average response
|
|
(PSTH) and plot it. You will see that there are three parts. (i)
|
|
The first 200 ms is the baseline (no stimulus) activity. (ii) During
|
|
the next 1000 ms the stimulus was switched on. (iii) After stimulus
|
|
offset the neuronal activity was recorded for further 825 ms.
|
|
\part Extract the neuron's activity in the last 200 ms before
|
|
stimulus offset and plot it against the stimulus intensity or the
|
|
contrast, respectively.
|
|
\part Fit a Boltzmann function to the FI-curve. The Boltzmann function
|
|
is defined as:
|
|
\begin{equation}
|
|
y=\frac{\alpha-\beta}{1+e^{(x-x_0)/\Delta x}}+\beta,
|
|
\end{equation}
|
|
where $\alpha$ is the starting firing rate, $\beta$ the saturation
|
|
firing rate, $x$ the current stimulus intensity, $x_0$ starting
|
|
stimulus intensity, and $\Delta x$ a measure of the slope.
|
|
\end{parts}
|
|
\end{questions}
|
|
|
|
\end{document}
|