From 1e928bc5c99906af47feaeb4e9397c9070018f0d Mon Sep 17 00:00:00 2001
From: Jan Grewe <jan.grewe@g-node.org>
Date: Sat, 19 Jan 2019 10:00:16 +0100
Subject: [PATCH] [project_sta] even more text

---
 .../stimulus_reconstruction.tex               | 33 +++++++++++--------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/projects/project_stimulus_reconstruction/stimulus_reconstruction.tex b/projects/project_stimulus_reconstruction/stimulus_reconstruction.tex
index c2c45be..24cb00a 100644
--- a/projects/project_stimulus_reconstruction/stimulus_reconstruction.tex
+++ b/projects/project_stimulus_reconstruction/stimulus_reconstruction.tex
@@ -11,28 +11,33 @@
 
 %%%%%%%%%%%%%% Questions %%%%%%%%%%%%%%%%%%%%%%%%%
 \section*{Reverse reconstruction of the stimulus that evoked a neuronal response.}
-To analyse encoding properties of a neuron one often calculates the
+To analyse the encoding properties of a neuron one often calculates the
 Spike-Triggered-Average (STA). The STA is the average stimulus that
 led to a spike in the neuron:
 \[ STA(\tau) = \frac{1}{n} \displaystyle\sum_{i=1}^{n}{s(t_i - \tau)} \]
 where $n$ is the number of spikes and $t_i$ is the time of the
 $i_{th}$ spike. $\tau$ is a temporal shift relative to the spike
 time. For the beginning let $\tau$ assume values in the range
-$\pm50$\,ms. It can be estimated by cutting out snippets form the
-stimulus centered on the respective spike time and averaging them. The
-Spike-Triggered-Average can be used to reconstruct the stimulus from
-the neuronal response. The reconstructed stimulus can then be compared
-to the original stimulus.
+$\pm50$\,ms. The STA can be estimated by cutting out snippets from the
+stimulus that are centered on the respective spike time and by
+subsequently averaging them. The STA can be used to reconstruct the
+stimulus from the neuronal response. The reconstructed stimulus can
+then be compared to the original stimulus and provides a good
+impression about the features that are encoded in the neuronal
+response.
 
 \begin{questions}
-  \question In the accompanying data files you find the spike responses of
-  a p-type electroreceptor afferent (P-unit) and a pyramidal neuron
-  recorded in the hindbrain of the weakly electric fish
-  \textit{Apteronotus leptorhynchus}. The respective stimuli are
-  stored in separate files. The data is sampled with 20\,kHz temporal
-  resolution and spike times are given in seconds. Start with the
-  P-unit and, in the end, apply the same analyzes/functions to the
-  responses from the pyramidal neuron.
+  \question In the accompanying data files you find the spike
+  responses of a p-type electroreceptor afferent (P-unit) and a
+  pyramidal neuron recorded in the hindbrain of the weakly electric
+  fish \textit{Apteronotus leptorhynchus}. The respective stimuli are
+  stored in separate files. The neron is stimulated with an amplitude
+  modulation of the fish's own electric field. The stored stimulus
+  trace is the modulator that is applied to the field and is
+  dimensionless, i.e. it has not unit. The data is sampled with
+  20\,kHz temporal resolution and spike times are given in
+  seconds. Start with the P-unit and, in the end, apply the same
+  analyzes/functions to the responses from the pyramidal neuron.
   \begin{parts}
     \part Estimate the STA and plot it. What does it tell?
     \part Implement a function that does the reverse reconstruction and uses the STA to reconstruct the stimulus.