diff --git a/text/thesis/02MaterialsAndMethods.tex b/text/thesis/02MaterialsAndMethods.tex index 8627811..10fb37b 100644 --- a/text/thesis/02MaterialsAndMethods.tex +++ b/text/thesis/02MaterialsAndMethods.tex @@ -246,6 +246,8 @@ One session consists of 5 runs with 40 trials each. The trials were separated by resting phases of varying length (2-3s, randomly assigned). Each trial began with an auditory cue specifying the random but equally distributed target for this trial. This leads to 50 reaches to the same target each session. After the cue the participants should \qq{perform the movement and return to the starting position at a comfortable pace but within 4 seconds}\footnote{\cite{Shiman15}}\\ For each subject there were 4 to 6 sessions, each recorded on a different day. All in all there were 255 runs in 51 sessions. Each session was analyzed independently as one continuous trial. + \subsection{Environment for evaluation} + The calculations were done on Ubuntu \texttt{14.04 / 3.19.0-39} with \matlab{} \texttt{R2016a (9.0.0.341360) 64-bit (glnxa64) February 11, 2016}. \section{Data Acquisition} \subsection{Loading of data} The data recorded with BCI2000 (\cite{Schalk04}) can be loaded into \matlab{} with a specific \texttt{.mex} file. The according \texttt{.mex}-Files for some platforms (Windows, MAC, Linux) are available from BCI2000 precompiled.\\ diff --git a/text/thesis/03Results.tex b/text/thesis/03Results.tex index 98e22fb..903b4e5 100644 --- a/text/thesis/03Results.tex +++ b/text/thesis/03Results.tex @@ -190,7 +190,7 @@ \label{res:offsetEEG} Offset makes no significant difference when predicting Synergies\footnote{Autoencoder: $p\approx0.81$, PCA: $p\approx0.77$, NMF: $p\approx0.60$} or velocities ($p\approx0.99$) or positions ($p\approx0.98$). \subsubsection{Pause} - Whether there is a pause of 1s or only 0.5s doesn't make a significant difference for Autoencoder ($p\approx0.13$), PCA ($p\approx0.29$), NMF ($p\approx0.05$) or Velocities ($p\approx0.95$). + Whether there is a pause of 1s or only 0.5s doesn't make a significant difference for Autoencoder ($p\approx0.13$), PCA ($p\approx0.29$), NMF ($p\approx0.15$) or Velocities ($p\approx0.95$). \subsubsection{EMG} We also predict EMG from EEG. The results are shown in figure \ref{fig:EEGemg}. There are no significant differences between the channels ($p\approx0.29$). \begin{figure} @@ -236,6 +236,13 @@ \caption{Correlations for predicting velocities and positions from Autoencoder data} \label{tab:corrAutoenc} \end{table} + \subsubsection{Comparison with EMG} + When compared to the original 6D EMG data as a predictor a 3D autoencoder is only significantly worse when predicting positions ($p<0.05$), not for velocities ($p\approx0.23$). + \begin{figure} + \includegraphics[width=\textwidth]{pictures/results/EMGautoencPos.png} + \caption{Predicting positions from EMG or Autoencoder} + \label{fig:EMGautoencPos} + \end{figure} \subsection{Cross-validation of Ridge Parameter} %TODO \section{Topographical plots} diff --git a/text/thesis/04Discussion.tex b/text/thesis/04Discussion.tex index dde1106..63fe232 100644 --- a/text/thesis/04Discussion.tex +++ b/text/thesis/04Discussion.tex @@ -30,17 +30,26 @@ \section{Velocities and Positions} \label{dis:velPos} We expected better performance when predicting velocities instead of absolute positions. Our findings however show the opposite. The performance is quite a lot better when predicting positions directly.\\ - This might mean that both EMG and EEG data carry more information about the actual configuration and less about the mere change. + This might mean that both EMG and EEG data carry more information about the actual configuration and not only about the change. %TODO: reason? \section{Pause} \label{dis:pause} - + The use of a 1 second pause before movement onset only shows significant differences for classification of EMG and predicting Synergies from low frequencies. + \subsection{Classification from EMG} + When doing classification from EMG data there is an great improvement when leaving the whole second before movement onset out. This results from the way we did the classification. Since we decided on when the movement starts based on the EMG data.\\ + What this finding shows is that the threshold is chosen well to classify the movements. + \subsection{Synergies from Low Frequencies} + There is a significant improvement for predicting Synergies from low frequency data. This shows again what \cite{Lew14} proposed; in low frequency features we find mainly pre-movement activation. Activity while moving is probably mostly occluded by motor commands. \section{Offset} \label{dis:offset} - + Applying an offset when using EEG-data or not does not make a significant difference. This is probably due to our configuration with EEG windows as large as 1 second. If smaller windows were used an offset could help, here there is no difference. \section{Synergies} \label{dis:synergies} \subsection{Autoencoder} \subsection{Principal Component Analysis} \subsection{Non-negative Matrix Factorization} \subsection{Prediction via Synergies} + + \subsection{Comparison with EMG} + The results show that the dimensionality reduction from 6 dimensional EMG to 3 dimensional Synergies (here via autoencoder) does not cost much information when predicting velocities and positions.\\ + For velocities there is no significant difference and even for positions the mean only differs about $0.03$ (EMG: $0.23$, Autoencoder: $0.20$). diff --git a/text/thesis/05Future.tex b/text/thesis/05Future.tex index 10600d3..5db1ab7 100644 --- a/text/thesis/05Future.tex +++ b/text/thesis/05Future.tex @@ -1,3 +1,6 @@ \chapter{Future Work} \section{new Data set} Are the results different because of the new classification? + \section{Offset} + There is no significant effect of an offset in our configuration. When using smaller EEG windows however there might be one. This could be tried in further analyses with small EEG windows.\\ + These small windows however will probably bring other problems as e.g. unstable transformation into Fourier space. So maybe it is necessary to use large windows, then an offset is unnecessary. diff --git a/text/thesis/Acd.tex b/text/thesis/Acd.tex new file mode 100644 index 0000000..53ad7ee --- /dev/null +++ b/text/thesis/Acd.tex @@ -0,0 +1 @@ +\chapter{Contents on CD} diff --git a/text/thesis/Aenvironment.tex b/text/thesis/Aenvironment.tex deleted file mode 100644 index 59e6f57..0000000 --- a/text/thesis/Aenvironment.tex +++ /dev/null @@ -1,4 +0,0 @@ -\chapter{Environment} -Ubuntu 14.04 / 3.19.0-39 - -\matlab{} R2016a (9.0.0.341360) 64-bit (glnxa64) February 11, 2016 diff --git a/text/thesis/pictures/results/EEGemg.png b/text/thesis/pictures/results/EEGemg.png index 4afe22f..7446d63 100644 --- a/text/thesis/pictures/results/EEGemg.png +++ b/text/thesis/pictures/results/EEGemg.png Binary files differ diff --git a/text/thesis/pictures/results/EMGautoencPos.png b/text/thesis/pictures/results/EMGautoencPos.png new file mode 100644 index 0000000..343f5a3 --- /dev/null +++ b/text/thesis/pictures/results/EMGautoencPos.png Binary files differ diff --git a/text/thesis/thesis.tex b/text/thesis/thesis.tex index b27bdf7..cc94eb2 100644 --- a/text/thesis/thesis.tex +++ b/text/thesis/thesis.tex @@ -239,7 +239,7 @@ %%Appendix \appendix -\input{Aenvironment} +\input{Acd} \cleardoublepage \input{Bfunctions} diff --git a/usedMcode/evaluationCorrelations.m b/usedMcode/evaluationCorrelations.m index 7f04870..60fcaf3 100644 --- a/usedMcode/evaluationCorrelations.m +++ b/usedMcode/evaluationCorrelations.m @@ -117,4 +117,16 @@ anova1(correlations.EEG.emg.Default,EMGChannels) title('EMG from EEG') -mySaveFigure(gcf,strcat(figureSavePath,'EEGemg')) \ No newline at end of file +mySaveFigure(gcf,strcat(figureSavePath,'EEGemg')) + +%% compare EMG with synergies +anova1([correlations.EMG.pos.Default,correlations.Autoenc.pos.Default],{'EMG','EMG','EMG','Autoenc','Autoenc','Autoenc'}) + +title('Predict Positions from EMG or Synergies') +mySaveFigure(gcf,strcat(figureSavePath,'EMGautoencPos')) + + +anova1([correlations.EMG.kin.Default,correlations.Autoenc.kin.Default],{'EMG','EMG','EMG','Autoenc','Autoenc','Autoenc'}) + +title('Predict Velocities from EMG or Synergies') +mySaveFigure(gcf,strcat(figureSavePath,'EMGautoenc')) \ No newline at end of file