[projects] updated lif and serial correlations

projects/project_lif/lif.tex

@@ -111,14 +111,10 @@ potentials $V_i$ for successive time points $t_i$ according to
     a sine wave $E(t)=A\sin(2\pi ft)$ with $A=2$\,mV and frequency
     $f=10$, 20, and 30\,Hz.
 
-    \part Compute the firing rate as a function of the frequency of
-    the stimulating sine wave ($A=2$\,mV and frequencies between 5 and
-    30\,Hz). For a spike train with $n$ spikes at times $t_k$ ($k=1,
-    2, \ldots n$) the firing rate is
-    \begin{equation}
-      \label{firingrate}
-      r = \frac{n-1}{t_n - t_1}
-    \end{equation}
+    \part Compute the firing rate (number of spikes per time) as a
+    function of the frequency of the stimulating sine wave ($A=2$\,mV
+    and frequencies between 5 and 30\,Hz).
+    
     What do you observe? Does the firing rate encode the frequency of
     the stimulus? Look at the spike trains in response to the sine
     waves to figure out what is going on.