User Tutorial:BCI2000 Tour
This page is intended to get you started, and make you comfortable using BCI2000. It shows you how to use BCI2000 in a simulation mode, so it should work on any computer, without an EEG amplifier attached.
Starting up BCI2000
BCI2000 consists of four executables (modules) which need to be started up in a certain order. This can be done using the script (batch) files in the batch directory. Alternatively, there is a BCI2000Launcher program that allows you to manage BCI2000 module startup from a graphical user interface.
We will begin the BCI2000 tour by double-clicking the file batch/CursorTask_SignalGenerator.bat. This will launch the modules required for a simulation of a Mu rhythm BCI session.
When the main operator window appears, choose BCI2000 Help from the Help menu. The operator module's help page will be opened in a web browser window. On the left side of the help page, a navigation menu provides access to the entire BCI2000 documentation.
The BCI2000 help is a local copy of the BCI2000 online documentation wiki, providing a snapshot that corresponds to your version of the BCI2000 executables.
Loading a Parameter File
BCI2000 configuration is stored in parameter files. Before performing an experiment, you will typically load a parameter file that contains subject-specific as well as general configuration information.
In the main operator window, click the Config button. A configuration window appears. There, click the Load Parameters button, which will open up a file chooser dialog. Open parms/MuTutorial/MuFeedback.prm.
Entering a Subject ID
BCI2000 stores data files in directories with names that are constructed from subject ID and session number.
In the configuration dialog, go to the Storage tab, and identify the DataDirectory parameter. This parameter determines the path to the top level data directory, i.e. the directory below which session directories will be created. By default, this parameter is set to ../data, a relative path that points to your BCI2000 installation's data directory.
Go to the SubjectName parameter, and enter an ID such as TEST, or your own initials.
Close the configuration dialog by using its close button (top right). This will accept your parameter changes (there is no "Cancel" option). In the main operator window, click Set Config. This will prompt the operator module to send configuration parameters to the remaining BCI2000 modules, which will perform some sanity checks on them, configure themselves accordingly, and report back to the operator module.
Once you clicked the Set Config button, a signal source window will appear, displaying a simulated EEG. In a real BCI session, you will use this window to assess signal quality. When moving the mouse, you should notice a change in the simulated EEG signal. This is the signal that will later control the feedback cursor.
Right-clicking the EEG window will bring up a context menu with display options such as increasing/decreasing the number of channels displayed, choosing display colors, applying filters to the signal. (Details are described on the Operator Module's reference page.)
Performing a Session
Once Set Config has been clicket, the Start button will be active. Click it to start a simulated feedback session. During the session, you will see a cursor moving from the left to the right by itself, and one of two targets highlighted on the right. Your task will be to move the cursor up or down, such that it hits the highlighted target. In simulation mode, you can move the feedback cursor by moving the mouse cursor up and down.
The period during which the cursor moves from left to right is called a Trial. During operation, a number of trials will follow each other, making up a Run. After a few minutes, BCI2000 will stop operation by itself, and the Start button will change to Resume. This means that a run has been finished, corresponding to a single data file. Clicking Resume each time, you may add as many runs to the current Session as you like. All runs belonging to a session will be stored in that session's data directory.
BCI2000 contains a component that adapts itself to the brain signal's mean value and its amount of variation. This component needs to observe the signal for a while before it can operate properly. This means that initially you will not feel a correspondence between your actions and the cursor; just stick with it for a few trials, and you will note how control gets more accurate over time. Also, it is important that you place the mouse cursor in a center position at the beginning of each trial, to give you enough space to move into the required direction.
When you have acquired one or more runs, you may quit BCI2000.
Opening Data Files in BCI2000Viewer
Use the Windows Explorer to display the contents of data/<SubjectName>001, which is the session directory corresponding to your recorded session (in place of <SubjectName>, enter the ID that you used for the SubjectName parameter). In the session directory, single runs correspond to .dat files carrying the session's name, appended with a run number.
To view the content of a data file, open it in the BCI2000Viewer program provided in tools/BCI2000Viewer. It is recommendable that you double-click the .dat file in question, and then use "Choose application" to permanently associate BCI2000Viewer with the .dat extension.
Alternatively, drag a .dat file onto the BCI2000Viewer icon, a link thereto, or BCI2000Viewer's application window to display the file's contents.
Viewing State Information
Once you opened a file in BCI2000Viewer, check the "TargetCode", "ResultCode", and "Feedback" checkboxes displayed in its top right.
Above the signal, values of these so-called state variables will be displayed. Whenever TargetCode changes from 0, a target has been displayed during the recording. Whenever ResultCode changes from 0, a target has been hit by the cursor. A Feedback value of 1 indicates that the feedback cursor was visible. In data analysis, this state information allows to determine trial structure and data labels.