Analysis - GeorgeGiannopoulos/StimuliXpert GitHub Wiki

analysis main window

Table of contents

Analysis Main Menu File Tools First Panel Second Panel Third Panel

Analysis

The StimuliXpert contains a variety of tools which can assist in processing the recorded EEG data. These tools are gathered into a new window which can be accessed by clicking the Analysis button. Analysis enables the user to analyze the total EEG signals or to analyze each stimulus file separately. Once the user has selected the experiment file(s) to be processed, he/she can choose:

  • 14 Channels analysis
  • per Channels analysis
  • correlation coefficients analysis

Main Menu

Button Action
File Choose a new recorded file or Export results to text or png format
Tools Copy Plot to Clipboard

File

Button Action
New The user can initialize the data displayed by selecting a new log file
Export Plot to PNG (1920x1080) Exports the charts displayed on the right side of the window and stores them in a 1920x1080 PNG file
Export Plot to PNG Custom Resolution Exports the charts displayed on the right side of the window and stores them in a custom resolution PNG file
Save correlation coefficients to csv Save the correlation coefficients to a .csv file
Save correlation coefficients to txt Save the correlation coefficients to a .csv file
Exit Exit the application

Tools

Button Action
Copy Plot to Clipboard (1920x1080) Copies the charts to Clipboard using 1920x1080 resolution
Copy Plot to Clipboard Custom Resolution Copies the charts to Clipboard using custom resolution

Note: The maximum supported resolution is 8K (7680 × 4320)

custom resolution


First Panel

analysis main window

In the first tab, the user can select the channels that he/she wants to review and then from the drop-down menu he/she can choose between time or frequency analysis. For frequency analysis, the user can select one of five frequency bands. When the user selects a frequency band, then the signal passes through a filter in order to produce the waveform for that particular band.

The bands are five and split the 1Hz - 40Hz band spectrum into five:

Band Name Band Frequency
Delta 1Hz - 4Hz
Theta 4Hz - 8Hz
Alpha 8Hz - 13Hz
Beta 13Hz - 30Hz
Gamma 30Hz - 48Hz

Second Panel

analysis second panel

In the second tab, the user can view the analysis results for a channel by selecting this channel from the drop-down menu. The diagrams show waveforms in time analysis (as recorded by Emotiv EPOC) and in frequency analysis on the five bands as described above.

Third Panel

analysis third panel

In the last tab, the user can select the desired channel in which he/she wants to review the correlation coefficients of that channel series with the emotional Valence or Arousal as described by the subject during the experiment (using a keyboard, a mouse or a digitizer).

Note: The image shown on this tab illustrates two rows with data and five columns. The rows represent valence and arousal, while the columns correspond to the frequency bands. The colors of the coefficients have been calculated by a process called color map, where the blue color corresponds to values of correlation coefficients close to -1 while the red at values close to 1. The green color indicates almost zero values for the corresponding coefficient correlation.

ColorMap scale