Commit 06927ada authored by Julius Welzel's avatar Julius Welzel
Browse files

Replace 3_results

parent fe4deb20
......@@ -2,11 +2,186 @@
\begin{document}
\subsection{Behavioural Differences}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%% EMG %%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\subsection{EMG-data}
To only analyse clean EEG data, distinguishing between movement and non-movement was substantial of the analyses. With the implemented ES, individual BP times and thresholds for every participant were determined to use for this differentiation. No significant differences between the two groups were evident in either BP times ( BP time: $M_{Old}: 1271 ms ± 329,\; M_{young}: 1361 ms ± 201, \; t_{32}=1.44,\; p=0.161$) or the threshold (Threshold: $M_{Old}: 1.58SD ± 0.26,\; M_{young}: 1.57SD ± 0.26, \; t_{32}=0.139,\; p=0.891$) used for movement/non-movement classification by the two-sampled t-test. \Cref{fig:EMG_params} shows boxplots of the results for the BP times and the threshold per group.
\subsection{ERD Dynamics}
\begin{figure}[ht]
\centering
\vspace{1em}
\begin{subfigure}{0.49\textwidth}
\includegraphics[width=0.95\textwidth]{images/3_results/BP_times.png}
\caption{BP times}
\label{fig:overview_BP_t}
\end{subfigure}
\hfill
\begin{subfigure}{0.49\textwidth}
\includegraphics[width=0.95\textwidth]{images/3_results/Thresh_SD.png}
\caption{SD thresh}
\label{fig:overview_threshSD}
\end{subfigure}
\caption{Overview of EMG parameters}
\label{fig:EMG_params}
\end{figure}
\subsection{Global Map Differences (GMD)}
A summary statistics for the epochs marked as movement in the MI blocks during the visuo-motor task and an example how the activity in non-movement and movement EMG epochs looks like is shown in \cref{fig:EMG_result}.
As the ES did only suggest how to process the MI-EMG epochs for a maximally number being classified as clean (under the restriction, that all ME-EMG epochs are marked as movement) additional visual inspection was done to ensure no misclassifications happened.
\begin{figure}[ht]
\centering
\vspace{1em}
\begin{subfigure}{0.49\textwidth}
\includegraphics[width=0.95\textwidth]{images/3_results/Movement_epoch_n.png}
%\caption{Movement epochs in MI blocks}
\label{fig:EMG_res_move}
\end{subfigure}
\hfill
\begin{subfigure}{0.49\textwidth}
\includegraphics[width=0.95\textwidth]{images/3_results/BP_emg_eg.png}
%\caption{Movement epochs in MI blocks}
\label{fig:n_ep_move}
\end{subfigure}
\caption{Descriptive results of EMG analysis including example. \textbf{A. }Movement epochs in MI blocks. \textbf{B. }Example of a non movement epoch (top) and movement epoch (bottom). The vertical line indicates the individual BP time.}
\label{fig:EMG_result}
\end{figure}
\end{document}
\ No newline at end of file
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%% ERD maps %%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\subsection{ERD maps}
In order to assess the ERD pattern of the MI epochs for the two groups, a grand average z-scored topography for each group was generated (\cref{fig:zERD_MI}). The z-scored map might be misleading and the attentive reader noticed, that only ERD values are included for the generation of the topographies. Accordingly a more positive z-score in the topographies is equivalent to a smaller ERD and a more negative z-score is equivalent to a stronger ERD. The ERD however is the relative power to a baseline period. Therefore the average to derive the topographies contains only ERD (negative relative power) values (see \cref{eeg_data_pro}. This approach was choosen, because ERD during task seem to reflect the age differences which are of interest in this study.
% Figure zERD per FB MI
\begin{figure}[!ht]
\vspace{1em}
\centering
\includegraphics[width=\textwidth]{images/3_results/rERD_MI_z_topo.pdf}
\caption{Average topographies for MI trials for three frequency bands. Broad-band $\equiv 8-30 [Hz]$, $\alpha$-band $\equiv 8-12 [Hz]$, $\beta$-band $\equiv 15-30 [Hz]$.}
\label{fig:zERD_MI}
\end{figure}
Across all frequency bands, the topographies show a bilateral ERD pattern over sensori-motor areas. A complex right hand task as was used for this study, would be expected cause a ERD not only to the left (contralateral) hemisphere, but to be present over the right (ipsilateral) hemisphere as well. For the younger participants, there seems to be a stronger lateralisation towards the left (contralateral) hemisphere. The more bilateral pattern in the older participants is in line with the literature.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%% Spatial pattern %%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\subsection{Spatial pattern}
To understand how much cortex contributes to the ERD pattern, 24 intersection areas of the average map of every participant were calculated. An example can be seen in \cref{fig:example_intersect}.
The distribution of the intersection areas would be expected to have parabolic shape. The distribution results from every map being intersected "horizontally" at 24 z-levels, from the highest to the lowest z-value. Accordingly, at the highest and lowest z-value no intersection area would be found. For around the middle of the map, the highest intersection areas would be expected. Underlying individual intersection areas making up a group did not differ in kurtosis (Broad-band: $t_{20}=1.610,\; p=0.123$; $\alpha$-band: $t_{18}=-0.218,\; p=0.830$; $\beta$-band: $t_{18}=0.170,\; p=0.867$) or skewness (Broad-band: $t_{20}=1.756,\; p=0.094$; $\alpha$-band: $t_{18}=-0.485,\; p=0.634$; $\beta$-band: $t_{18}=-1.335,\; p=0.199$) in either of the three frequency bands. This lead to believe, that underlying distribution are comapreable in terms of distribution parameters. Parameters of the 24 intersection areas for all three frequency bands are shown in more detail in the appendix (cf. \cref{fig:dist_inter_all}).
\begin{figure}[!ht]
\centering
\begin{subfigure}{\textwidth}
\includegraphics[width=0.99\textwidth,keepaspectratio]{images/3_results/surf_area_overview_broad.png}
\caption{Broad-band.}
\label{fig:fun_inter_bb}
\end{subfigure}
\begin{subfigure}{\textwidth}
\includegraphics[width=0.99\textwidth,keepaspectratio]{images/3_results/surf_area_overview_mue.png}
\caption{$\alpha$-band.}
\label{fig:fun_inter_mu}
\end{subfigure}
\begin{subfigure}{\textwidth}
\includegraphics[width=0.99\textwidth,keepaspectratio]{images/3_results/surf_area_overview_beta.png}
\caption{$\beta$-band.}
\label{fig:fun_inter_beta}
\end{subfigure}
\caption{Distribution intersection areas for all frequency bands on the left in each subplot. Group average 3D representations of the topographies on the right.}
\label{fig:dist_inter_all}
\end{figure}
For every distribution a anterior and lateral view of the underlying 3D maps provides an additional overview.
The dashed lines in the distribution plot indicate the $FWHM$ for the two groups. The intersection planes in the 3D topographies correspond the the $FWHM$ values and are given for illustrative purposes. The sum of the $FWHM$ levels of each group is used for the statistical comparison. The sum of the distributions over the $FWHM$ reflects, how much the ERD at a these z-values is spread over the brain. However, results have to be treated with great caution as there are some vague assumptions made in this approach. The results of the two-tailed t-test show no significant difference in intersection areas for the broad ($t_{32}=-1.731,\; p=0.931$) and for the $\alpha$ band ($t_{32}=0.141,\; p=0.890$). However a significant difference was revealed by the t-test for the $\beta$-band ($t_{32}=-4.965,\; p=0.003$).
\subsection{Realtion of ERD pattern and behavioural measures}
To give understand what the additional intersection areas of the ERD reflect, the areas were related to the absolute $\Delta$ between ME and MI trial times using a spearman correlation.
\begin{figure}[!ht]
\centering
\begin{subfigure}{0.45\textwidth}
\includegraphics[width=0.9\textwidth,keepaspectratio]{images/3_results/area_dRT_broad.png}
\label{fig:rela_inter_bb}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\includegraphics[width=0.9\textwidth,keepaspectratio]{images/3_results/area_dRT_mue.png}
\label{fig:rela_inter_mu}
\end{subfigure}
\begin{subfigure}{0.45\textwidth}
\includegraphics[width=0.9\textwidth,keepaspectratio]{images/3_results/area_dRT_broad.png}
\label{fig:rela_inter_beta}
\end{subfigure}
\caption{Relation between intersection area range and absolute $\Delta$ in trial times. $r\equiv correlation score$ in each group.}
\label{fig:area_times}
\end{figure}
\end{document}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ARCHIVE
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Table: EMG overview
% \begin{table}[!ht]
% \vspace*{1em} %add vertical space
% \centering
% \begin{threeparttable}
% \caption{Numer of clean epochs per block per group} % make sure caption is before lable
% \label{table: EMG results}
% \begin{tabular}{l l l l l l}
% \toprule
% \multicolumn{1}{l}{\textbf{Group} } & \multicolumn{5}{l}{{\textbf{Block}}} \\
% {} & {EX1} & {MI1} & {MI2} & {EX2} & \textit{Overall} \\ \hline
% Young & 100\% & 97.8\% & 97.0\% & 100.0\% & 98.7\% \\
% Old & 100\% & 93.2\% & 96.0\% & 100.0\% & 97.3\% \\ \hline
% \textit{Overall} & 100\% & 95.5\% & 96.5\% & 100.0\% & \textbf{98.0\%} \\
% \bottomrule
% \end{tabular}
% \end{threeparttable}
% \end{table}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%Behavioural%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% \subsection{Behavioural measures}
% The questionnaires completed by the participants were intended to give an overview of their MI ability (KVIQ) and cognitive function in the older participants (MoCA). The ANOVA of the KVIQ scores did not reveal a significant effect between the two groups.
% The results of the MoCA unveiled that none of the older participants showed signs of cognitive impairment (Cutoff < 23), all participants of this group were included. See \cref{table: questionnaires} for detailed score of full questionnaire assessment.
% % Table: Questionnaires
% \begin{table}[ht]
% \vspace*{1em} %add vertical space
% \centering
% \begin{threeparttable}
% \caption{Scores of questionnaires per group} % make sure caption is before lable
% \label{table: questionnaires}
% \begin{tabular}{l l l l l l l}
% \toprule
% \multicolumn{1}{l}{\textbf{Group} } & \multicolumn{6}{l}{{\textbf{Questionaires}}} \\
% \multicolumn{1}{c}{} & \multicolumn{2}{c}{\textit{EHI}} & \multicolumn{2}{c}{\textit{KVIQ}} & \multicolumn{2}{c}{\textit{MoCA}} \\
% {} & {M} & {SD} & {M} & {SD} & {M} & {SD} \\ \hline
% Old & 9.14 & $\pm{1.86}$ & 8.25 & $\pm{2.19}$ & 6.00 & $\pm{2.51}$\\
% Young & 9.84 & $\pm{0.96}$ & 7.45 & $\pm{3.09}$ & - & - \\ \hline
% Overall &9.49 & $\pm{1.41}$ & 7.85 & $\pm{2.64}$ & 6.00 & $\pm{2.51}$ \\
% \bottomrule
% \end{tabular}
% \begin{tablenotes}[para,flushleft]
% {\small
% \textbf{Note. } EHI $\equiv$ Edinburgh Handiness Inventory, KVIQ $\equiv$ Kinestetic-Visual-Imagery-Quality, MoCA $\equiv$ Montreal Cognitive Assessment
% }
% \end{tablenotes}
% \end{threeparttable}
% \end{table}
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment