updated data overview

nonlinearbaseline.tex

@@ -553,7 +553,7 @@ Overall, observing \nli{} values greater than at least 1.6, even for a number of
 
 \begin{figure*}[tp]
   \includegraphics[width=\columnwidth]{dataoverview}
-  \caption{\label{fig:dataoverview} Nonlinear responses in P-units and ampullary afferents. The second-order susceptibility is condensed into the susceptibility index, SI($r$) \eqnref{eq:nli_equation}, that quantifies the relative amplitude of the ridge where the two stimulus frequencies add up to the cell's baseline firing rate (see \subfigrefb{fig:punit}{G}). The SI($r$) is plotted against the cells' CV of its baseline interspike intervals (left column), the response modulation (the standard deviation of firing rate evoked by the band-limited white-noise stimulus) --- a measure of effective stimulus strenght (center column), and the CV of the interspike intervals during stimulation with the white-noise stimulus (right column). Pearson's correlation coefficient $R$ and the number of data points $n$ are indicated; all correlations are significant at a level below $p=0.0002$. Kernel-density estimates of the distributions of the displayed quantities are plotted on top and right. Data points are color coded by a third quantity as indicated by the color bars. The horizontal dashed line marks a threshold for SI($r$) values at 1.8 and the percentages to the right denote the fractions above and below this threshold. \figitem{A} The SI($r$) of all 39 model P-units (table~\ref{modelparams}) measured at contrasts of 1, 3, and 10\,\% of RAM stimuli with a cutoff frequency of 300\,Hz. The SI($r$) was estimated based on 100 FFT segments. The black square marks the cell from \subfigrefb{fig:noisesplit}{C}, the circles the four cells shown in \subfigref{fig:modelsusceptcontrasts}{A--D}, and the triangle the cell from \subfigref{fig:modelsusceptlown}{A--B}. \figitem{B} Electrophysiological data from 159 P-units. Each cell contributes on average with 2 (min. 1, max. 10) RAM stimulus presentations to the $n=382$ data points. The RAMs with cutoff frequency of 300\,Hz were presented at contrasts ranging from 0.1\,\% to 20\,\% (median 5\,\%). The number of available FFT segements ranged from 105 to 2560 (median 235). The two black triangles mark the responses of the example P-unit from \subfigrefb{fig:punit}{E,F}, the circles the other four examples from \subfigrefb{fig:punit}{H}, and the triangle the unit from \subfigrefb{fig:noisesplit}{A}. \figitem{C} Recordings from 30 ampullary afferents, each contributing on average 3 RAM stimulus presentations to $n=89$ data points. Stimuli had a cutoff frequency of 150\,Hz and their contrasts ranged from 2.5\,\% to 20\,\% (median 5\,\%). 105 to 3648 FFT segements were available per stimulus (median 722).  The two black triangles mark the responses of the example ampullary afferent from \subfigrefb{fig:ampullary}{E,F}, and the circles the other four examples from \subfigrefb{fig:ampullary}{H}.}
+  \caption{\label{fig:dataoverview} Nonlinear responses in P-units and ampullary afferents. The second-order susceptibility is condensed into the susceptibility index, SI($r$) \eqnref{eq:nli_equation}, that quantifies the relative amplitude of the ridge where the two stimulus frequencies add up to the cell's baseline firing rate $r$ (see \subfigrefb{fig:punit}{G}). The SI($r$) is plotted against the cells' CV of its baseline interspike intervals (left column), the response modulation (the standard deviation of firing rate evoked by the band-limited white-noise stimulus) --- a measure of effective stimulus strength (center column), and the CV of the interspike intervals during stimulation with the white-noise stimulus (right column). Pearson's correlation coefficient $R$ and the number of data points $n$ are indicated; all correlations are significant at a level below $p=0.0002$. Kernel-density estimates of the distributions of the displayed quantities are plotted on top and right. Data points are color coded by CV$_{\text{base}}$ or response modulation as indicated by the color bars. The horizontal dashed line marks a threshold for SI($r$) values at 1.8 and the percentages to the right denote the fractions above and below this threshold. \figitem{A} The SI($r$) of all 39 model P-units (table~\ref{modelparams}) measured at contrasts of 1, 3, and 10\,\% of RAM stimuli with a cutoff frequency of 300\,Hz. The SI($r$) was estimated based on 100 FFT segments. The black square marks the cell from \subfigrefb{fig:noisesplit}{C}, the circles the four cells shown in \subfigref{fig:modelsusceptcontrasts}{A--D}, and the triangle the cell from \subfigref{fig:modelsusceptlown}{A--B}. \figitem{B} Electrophysiological data from 159 P-units. Each cell contributes on average with 2 (min. 1, max. 6) RAM stimulus presentations to the $n=329$ data points. The RAMs with cutoff frequency of 300\,Hz were presented at contrasts ranging from 2.5\,\% to 20\,\% (average 8\,\%). The number of available FFT segements ranged from 105 to 1520 (median 301). The two black triangles mark the responses of the example P-unit from \subfigrefb{fig:punit}{E,F}, the circles the other four examples from \subfigrefb{fig:punit}{H}, and the triangle the unit from \subfigrefb{fig:noisesplit}{A}. \figitem{C} Recordings from 30 ampullary afferents, each contributing on average 3 RAM stimulus presentations to $n=89$ data points. Stimuli had a cutoff frequency of 150\,Hz and their contrasts ranged from 2.5\,\% to 20\,\% (average 7\,\%). 105 to 3648 FFT segements were available per stimulus (median 722).  The two black triangles mark the responses of the example ampullary afferent from \subfigrefb{fig:ampullary}{E,F}, and the circles the other four examples from \subfigrefb{fig:ampullary}{H}.}
 \end{figure*}
 
 \subsection{Low CVs and weak stimuli are associated with distinct nonlinearity in recorded electroreceptive neurons}