Updated/made figure captions up to Fig. 7.

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j-hartling
2026-05-03 19:55:26 +02:00
parent 9c5811d97c
commit 69f172ff2c
8 changed files with 1299 additions and 1223 deletions

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main.tex
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@@ -67,12 +67,12 @@
\newcommand{\thp}{T_{\text{HP}}} % Highpass filter adaptation interval
% Math shorthands - Early representations:
\newcommand{\raw}{x} % Placeholder input signal
\newcommand{\filt}{\raw_{\text{filt}}} % Bandpass-filtered signal
\newcommand{\env}{\raw_{\text{env}}} % Signal envelope
\newcommand{\db}{\raw_{\text{log}}} % Logarithmically scaled signal
\newcommand{\dbref}{\raw_{\text{ref}}} % Decibel reference intensity
\newcommand{\adapt}{\raw_{\text{adapt}}} % Adapted signal
\newcommand{\raw}{x_{\text{raw}}} % Placeholder input signal
\newcommand{\filt}{x_{\text{filt}}} % Bandpass filtered signal
\newcommand{\env}{x_{\text{env}}} % Signal envelope
\newcommand{\db}{x_{\text{log}}} % Logarithmically scaled signal
\newcommand{\dbref}{x_{\text{ref}}} % Decibel reference intensity
\newcommand{\adapt}{x_{\text{adapt}}} % Adapted signal
% Math shorthands - Kernel parameters:
\newcommand{\kw}{\sigma} % Unspecific Gabor kernel width
@@ -354,9 +354,8 @@ outlined in the following sections.
\begin{figure}[!ht]
\centering
\includegraphics[width=\textwidth]{figures/fig_auditory_pathway.pdf}
\caption{\textbf{Schematic organisation of the song recognition pathway in
grasshoppers compared to the structure of the functional
model pathway.}
\caption{\textbf{Schematic organisation of the grasshopper song recognition
pathway and structure of the functional model pathway.}
\textbf{a}:~Simplified course of the pathway in the
grasshopper, from the tympanal membrane over receptor
neurons, local interneurons, and ascending neurons further
@@ -365,12 +364,12 @@ outlined in the following sections.
the three neuronal populations within the metathoracic
ganglion.
\textbf{c}:~Network representation of neuronal connectivity.
\textbf{d}:~Flow diagram of the different signal
representations and transformations along the model
pathway. All representations are time-varying. 1st half:
Preprocessing stage (one-dimensional). 2nd half: Feature
extraction stage (high-dimensional).
}
\textbf{d}:~Flow diagram of consecutive signal
representations~(boxes) and transformations~(arrows) along
the model pathway. All representations are time-varying.
1st half: Preprocessing stage~(one-dimensional
representation). 2nd half: Feature extraction
stage~(high-dimensional representation). }
\label{fig:pathway}
\end{figure}
@@ -428,12 +427,12 @@ following feature extraction stage.
\includegraphics[width=\textwidth]{figures/fig_pre_stages.pdf}
\caption{\textbf{Representations of a song of \textit{O. rufipes} during
the preprocessing stage.}
\textbf{a}:~Bandpass-filtered tympanal signal.
\textbf{b}:~Signal envelope.
\textbf{c}:~Logarithmically scaled envelope.
\textbf{d}:~Intensity-adapted envelope.
\textbf{a}:~Bandpass filtered tympanal signal $\filt(t)$.
\textbf{b}:~Signal envelope $\env(t)$.
\textbf{c}:~Logarithmically compressed envelope $\db(t)$.
\textbf{d}:~Intensity-adapted envelope $\adapt(t)$.
}
\label{fig:pre}
\label{fig:stages_pre}
\end{figure}
\FloatBarrier
@@ -543,14 +542,15 @@ can be read out by a simple linear classifier.
\includegraphics[width=\textwidth]{figures/fig_feat_stages.pdf}
\caption{\textbf{Representations of a song of \textit{O. rufipes} during
the feature extraction stage.}
Different colors indicate Gabor kernels with different
lobe number $\kn$ and sign, with lighter colors for higher
$\kn$~($1\,\leq\,\kn\,\leq\,4$; both $+$ and $-$ per $\kn$;
two kernel widths $\kw$ of $4\,$ms and $32\,$ms per sign).
\textbf{a}:~Kernel-specific filter responses.
\textbf{b}:~Binary responses.
\textbf{c}:~Finalized features.
}
Different color shades indicate different types of Gabor
kernels with specific lobe number $\kn$ and either $+$ or
$-$ sign, sorted (dark to light) first by increasing $\kn$
and then by sign~($1\,\leq\,\kn\,\leq\,4$; first $+$, then
$-$ for each $\kn$; two kernel widths $\kw$ of $4\,$ms and
$32\,$ms per type; 8 types, 16 kernels in total).
\textbf{a}:~Kernel-specific filter responses $c_i(t)$.
\textbf{b}:~Binary responses $b_i(t)$.
\textbf{c}:~Finalized features $f_i(t)$.}
\label{fig:stages_feat}
\end{figure}
\FloatBarrier
@@ -576,29 +576,30 @@ specific operations involved, as outlined in the following sections.
\begin{figure}[!ht]
\centering
\includegraphics[width=\textwidth]{figures/fig_invariance_rect_lp.pdf}
\caption{\textbf{Intensity invariance by logarithmic compression and
adaptation is restricted by the noise floor.}
Synthetic input $\filt(t)$ consists of song component
$\soc(t)$ scaled by $\sca$ with (\figc{} and \figd) or
without (\figa{} and \figb) additive noise component
$\noc(t)$. Input $\filt(t)$ is transformed into envelope
$\env(t)$, logarithmically compressed envelope $\db(t)$,
and intensity-adapted envelope $\adapt(t)$.
\textbf{Left}:~$\env(t)$, $\db(t)$, and $\adapt(t)$ for
different scales $\sca$.
\textbf{Right}:~Ratios of the standard deviation of
$\env(t)$, $\db(t)$, and $\adapt(t)$ relative to the
respective reference standard deviation $\sigma_{\eta}$
for input $\filt(t)=\noc(t)$.
\figa{} and \figb:~Ideally, if $\filt(t)=\sca\cdot\soc(t)$, then
$\adapt(t)$ is intensity-invariant across all $\sca$.
\figc{} and \figd:~In practice, if
$\filt(t)=\sca\cdot\soc(t)+\noc(t)$, the intensity
invariance of $\adapt(t)$ is limited to sufficiently large
$\sca$. Shaded area indicates saturation of $\adapt(t)$ at
$95\,\%$ curve span.
}
\label{fig:inv_rect-lp}
\caption{\textbf{Rectification and lowpass filtering improves SNR
but does not contribute to intensity invariance.}
Input $\raw(t)$ consists of song component $\soc(t)$ scaled by
$\sca$ with optional noise component $\noc(t)$ and is
successively transformed into tympanal signal $\filt(t)$ and
envelope $\env(t)$. Different line styles indicate different
cutoff frequencies $\fc$ of the lowpass filter extracting
$\env(t)$.
\textbf{Top}:~Example representations of $\filt(t)$ and
$\env(t)$ for different $\sca$.
\textbf{a}:~Noiseless case.
\textbf{b}:~Noisy case.
\textbf{Bottom}:~Intensity metrics over a range of $\sca$.
\textbf{c}:~Noiseless case: Standard deviations $\sigma_x$ of
$\filt(t)$ and $\env(t)$.
\textbf{d}:~Noisy case: Ratios of $\sigma_x$ of $\filt(t)$ and
$\env(t)$ to the respective reference standard deviation
$\sigma_{\eta}$ for input $\raw(t)=\noc(t)$.
\textbf{e}:~Ratios of $\sigma_x$ to $\sigma_{\eta}$ of
$\env(t)$ as in \textbf{d} for different species (averaged
over songs and recordings, see appendix
Fig.\,\ref{fig:app_rect-lp}).
}
\label{fig:rect-lp}
\end{figure}
\FloatBarrier
@@ -634,7 +635,7 @@ space into an additive term, or offset, in logarithmic space
\end{equation}
which allows for its separation from $\soc(t)$ but introduces a scaling of
$\noc(t)$ by the inverse of $\sca$. The subsequent
highpass-filtering~(Eq.\,\ref{eq:highpass}) of $\db(t)$ can then be
highpass filtering~(Eq.\,\ref{eq:highpass}) of $\db(t)$ can then be
approximated as a subtraction of the local offset within a suitable time
interval $0 \ll \thp < \frac{1}{\fc}$:
% \begin{equation}
@@ -675,29 +676,34 @@ the signal for reliable song recognition.
\begin{figure}[!ht]
\centering
\includegraphics[width=\textwidth]{figures/fig_invariance_log_hp.pdf}
\caption{\textbf{Intensity invariance by logarithmic compression and
adaptation is restricted by the noise floor.}
Synthetic input $\filt(t)$ consists of song component
$\soc(t)$ scaled by $\sca$ with (\figc{} and \figd) or
without (\figa{} and \figb) additive noise component
$\noc(t)$. Input $\filt(t)$ is transformed into envelope
$\env(t)$, logarithmically compressed envelope $\db(t)$,
and intensity-adapted envelope $\adapt(t)$.
\textbf{Left}:~$\env(t)$, $\db(t)$, and $\adapt(t)$ for
different scales $\sca$.
\textbf{Right}:~Ratios of the standard deviation of
$\env(t)$, $\db(t)$, and $\adapt(t)$ relative to the
respective reference standard deviation $\sigma_{\eta}$
for input $\filt(t)=\noc(t)$.
\figa{} and \figb:~Ideally, if $\filt(t)=\sca\cdot\soc(t)$, then
$\adapt(t)$ is intensity-invariant across all $\sca$.
\figc{} and \figd:~In practice, if
$\filt(t)=\sca\cdot\soc(t)+\noc(t)$, the intensity
invariance of $\adapt(t)$ is limited to sufficiently large
$\sca$. Shaded area indicates saturation of $\adapt(t)$ at
$95\,\%$ curve span.
\caption{\textbf{Intensity invariance through logarithmic compression and
adaptation is restricted by the noise floor and decreases
SNR.}
Input $\filt(t)$ consists of song component $\soc(t)$
scaled by $\sca$ with optional noise component $\noc(t)$
and is successively transformed into envelope $\env(t)$,
logarithmically compressed envelope $\db(t)$, and
intensity-adapted envelope $\adapt(t)$.
\textbf{Top}:~Example representations of $\env(t)$,
$\db(t)$, and $\adapt(t)$ for different $\sca$.
\textbf{a}:~Noiseless case.
\textbf{b}:~Noisy case.
\textbf{Bottom}:~Intensity metrics over a range of $\sca$.
\textbf{c}:~Noiseless case: Standard deviations $\sigma_x$
of $\env(t)$, $\db(t)$, and $\adapt(t)$.
\textbf{d}:~Noisy case: Ratios of $\sigma_x$ of $\env(t)$,
$\db(t)$, and $\adapt(t)$ to the respective reference
standard deviation $\sigma_{\eta}$ for input
$\filt(t)=\noc(t)$. Shaded areas indicate $5\,\%$ (dark
grey) and $95\,\%$ (light grey) curve span for
$\adapt(t)$.
\textbf{e}:~Ratios of $\sigma_x$ to $\sigma_{\eta}$ of
$\adapt(t)$ as in \textbf{d} for different species
(averaged over songs and recordings, see appendix
Fig\,\ref{fig:app_log-hp_curves}). Dots indicate $95\,\%$
curve span per species.
}
\label{fig:inv_log-hp}
\label{fig:log-hp}
\end{figure}
\FloatBarrier
@@ -706,40 +712,93 @@ the signal for reliable song recognition.
\begin{figure}[!ht]
\centering
\includegraphics[width=\textwidth]{figures/fig_invariance_thresh_lp_single.pdf}
\caption{\textbf{Intensity invariance by thresholding and temporal
averaging depends on both the threshold value and the
noise floor.}
Synthetic input $\adapt(t)$ consists of song component
$\soc(t)$ scaled by $\sca$ with additive noise component
$\noc(t)$. Input $\adapt(t)$ is transformed into kernel
response $c_i(t)$, binary response $b_i(t)$, and feature
$f_i(t)$. Threshold value $\thr$ is set to multiples of
the reference standard deviation $\sigma_{\eta}$ of $c_i(t)$ for input
$\adapt(t)=\noc(t)$. Darker colors correspond to higher
$\thr$.
\textbf{Left}:~$\adapt(t)$, $c_i(t)$, $b_i(t)$, and
$f_i(t)$ for different scales $\sca$ and threshold values
$\thr$. Left-most column is is the pure-noise reference.
\textbf{Right}:~Average value of $f_i(t)$ during the song
for the different $\thr$.
\figa:~Input $\adapt(t)$.
\figb-\figd:~$c_i(t)$, $b_i(t)$, and $f_i(t)$ for the
different $\thr$ based on the same $\adapt(t)$ from
\figa{}.
\fige:~Average value of $f_i(t)$ during the song for
the different $\thr$ in \figb{}-\figd.
\caption{\textbf{Intensity invariance through thresholding and temporal
averaging is mediated by the interaction of threshold
value and noise floor.}
Input $\adapt(t)$ consists of song component $\soc(t)$
scaled by $\sca$ with optional noise component $\noc(t)$
and is transformed into single kernel response $c(t)$,
binary response $b(t)$, and feature $f(t)$. Different
color shades indicate different threshold values $\Theta$
(multiples of reference standard deviation $\sigma_{\eta}$
of $c(t)$ for input $\adapt(t)=\noc(t)$, with darker
colors for higher $\Theta$).
\textbf{Left}:~Noisy case: Example representations of
$\adapt(t)$ as well as $c(t)$, $b(t)$, and $f(t)$ for
different $\sca$.
\textbf{a}:~$\adapt(t)$ with kernel $k(t)$ in black.
\textbf{b\,-\,d}: $c(t)$, $b(t)$, and $f(t)$ based on the
same $\adapt(t)$ from \textbf{a} but with different
$\Theta$.
\textbf{Right}:~Average value $\mu_f$ of $f(t)$ for each
$\Theta$ from \textbf{b\,-\,d}, once for the noisy case
(solid lines) and once for the noiseless case (dotted
lines). Dots indicate $95\,\%$ curve span (noisy case).
\textbf{e}:~$\mu_f$ over a range of $\sca$.
\textbf{f}:~$\mu_f$ over the standard deviation of noisy
input $\adapt$ corresponding to the values of $\sca$ shown
in \textbf{e}.
% Why plot noiseless case over SD of noisy input? Omit?
}
\label{fig:inv_thresh-lp_single}
\label{fig:thresh-lp_single}
\end{figure}
\FloatBarrier
% \caption{\textbf{Rectification and lowpass filtering improves SNR
% but does not contribute to intensity invariance.}
% Input $\raw(t)$ consists of song component $\soc(t)$ scaled by
% $\sca$ with optional noise component $\noc(t)$ and is
% successively transformed into tympanal signal $\filt(t)$ and
% envelope $\env(t)$. Different line styles indicate different
% cutoff frequencies $\fc$ of the lowpass filter extracting
% $\env(t)$.
% \textbf{Top}:~Example representations of $\filt(t)$ and
% $\env(t)$ for different $\sca$.
% \textbf{a}:~Noiseless case.
% \textbf{b}:~Noisy case.
% \textbf{Bottom}:~Intensity metrics over a range of $\sca$.
% \textbf{c}:~Noiseless case: Standard deviations of $\filt(t)$
% and $\env(t)$.
% \textbf{d}:~Noisy case: Ratios of standard deviations of
% $\filt(t)$ and $\env(t)$ to the respective reference standard
% deviation for input $\raw(t)=\noc(t)$.
% \textbf{e}:~Ratios of standard deviations of $\env(t)$ as in
% \textbf{b} for different species (averaged over songs and
% recordings, see appendix Fig.\,\ref{fig:app_rect-lp}).
% }
\begin{figure}[!ht]
\centering
\includegraphics[width=\textwidth]{figures/fig_invariance_thresh_lp_species.pdf}
\caption{\textbf{Feature representation of different species-specific songs
saturates at different points in feature space.}
Same input and processing as in
Fig.\,\ref{fig:thresh-lp_single} but with three different
kernels $k_i$, each with a single kernel-specific
threshold value $\thr=0.5\cdot\sigma_{\eta_i}$.
\textbf{a}:~Examples of species-specific grasshopper
songs.
\textbf{Middle}:~Average value $\mu_{f_i}$ of each feature
$f_i(t)$ over $\sca$ per species (averaged over songs and
recordings, see appendix
Figs.\,\ref{fig:app_thresh-lp_pure} and
\ref{fig:app_thresh-lp_noise}). Different color shades
indicate different kernels $k_i$. Dots indicate $95\,\%$
curve span per $k_i$.
\textbf{b}:~Noiseless case.
\textbf{c}:~Noisy case.
\textbf{Bottom}:~2D feature spaces spanned by each pair of
$f_i(t)$. Each trajectory corresponds to a
species-specific combination of $\mu_{f_i}$ that develops
with $\sca$ (colorbars). Horizontal dashes in the colorbar
indicate $5\,\%$ (dark grey) and $95\,\%$ (light grey)
curve span of the norm across all three $\mu_{f_i}$ per
species.
\textbf{d}:~Noiseless case.
\textbf{e}:~Noisy case. Shaded areas
}
\label{fig:inv_thresh-lp_species}
\label{fig:thresh-lp_species}
\end{figure}
\FloatBarrier
@@ -749,7 +808,7 @@ the signal for reliable song recognition.
\caption{\textbf{Step-wise emergence of intensity invariant song
representation along the model pathway.}
}
\label{fig:inv_full}
\label{fig:pipeline_full}
\end{figure}
\FloatBarrier
@@ -759,7 +818,7 @@ the signal for reliable song recognition.
\caption{\textbf{Step-wise emergence of intensity invariant song
representation along the model pathway.}
}
\label{fig:inv_short}
\label{fig:pipeline_short}
\end{figure}
\FloatBarrier
@@ -768,7 +827,7 @@ the signal for reliable song recognition.
\includegraphics[width=\textwidth]{figures/fig_features_cross_species.pdf}
\caption{\textbf{Inter- and intraspecific feature variability.}
}
\label{fig:cross_species}
\label{fig:feat_cross_species}
\end{figure}
\FloatBarrier
@@ -778,7 +837,7 @@ the signal for reliable song recognition.
\caption{\textbf{Step-wise emergence of intensity invariant song
representation along the model pathway.}
}
\label{fig:inv_field}
\label{fig:pipeline_field}
\end{figure}
\FloatBarrier
@@ -936,7 +995,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_noise_env_sd_conversion_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_env-sd}
\end{figure}
\FloatBarrier
@@ -945,7 +1004,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_invariance_rect-lp_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_rect-lp}
\end{figure}
\FloatBarrier
@@ -954,7 +1013,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_invariance_log-hp_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_log-hp_curves}
\end{figure}
\FloatBarrier
@@ -963,7 +1022,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_saturation_log-hp_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_log-hp_saturation}
\end{figure}
\FloatBarrier
@@ -972,7 +1031,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_invariance_thresh-lp_pure_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_thresh-lp_pure}
\end{figure}
\FloatBarrier
@@ -981,7 +1040,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_invariance_thresh-lp_noise_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_thresh-lp_noise}
\end{figure}
\FloatBarrier
@@ -990,7 +1049,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_kernel_sd_perc_thresh_lp_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_thresh-lp_kern-sd}
\end{figure}
\FloatBarrier
@@ -999,7 +1058,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_kernel_sd_perc_full_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_full_kern-sd}
\end{figure}
\FloatBarrier
@@ -1008,7 +1067,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_kernel_sd_perc_short_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_short_kern-sd}
\end{figure}
\FloatBarrier
@@ -1017,7 +1076,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_kernel_sd_perc_field_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_field_kern-sd}
\end{figure}
\FloatBarrier
@@ -1027,7 +1086,7 @@ initiation of one behavior over another is categorical (e.g. approach/stay)
\includegraphics[width=\textwidth]{figures/fig_invariance_cross_species_thresh_appendix.pdf}
\caption{\textbf{}
}
\label{}
\label{fig:app_cross_species_thresh}
\end{figure}
\FloatBarrier