Activation Paradigms for Mental Tasks based BCI

[sumits]

There are several papers which build BCI systems that use mental tasks as activation procedures. These include the following:

Geometric Figure Rotation:-The subject was given 30 seconds to see a complex three dimensional object, after which the object was removed. The subject was instructed to visualize the object being rotated about an axis.
Arithmetic Task:-The subject was asked to perform trivial and nontrivial multiplication. An example of a trivial calculation is to multiply 2 by 3 and nontrivial task is to multiply 49 by 78. The subject was instructed not to vocalize or make movements while solving the problem.
Arithmetic calculation (math): Participants were instructed to imagine solving a series of one by one digit multiplication.
Letter composing (letter): Participants were asked to mentally compose a simple letter in mind without vocalizing through their mouth.
Rubik’s cube rolling (cube) : Participants were asked to imagine a figure of Rubik’s cube being rolled forward.
Visual counting (count): Participants performed mentally counting number from one to nine repeatedly by visualizing the number appearing and disappearing on a blackboard in their mind.

What could be the possible training stimulus for such paradigms? Also, which channels should be used in such cases? Does BCI2000 have any modules which help in this case?

[mellinger]

For training, this is just a stimulus presentation paradigm like the standard mu rhythm training setup, except that you would want to use movie files rather than images/sound files as stimuli.

Currently, there is no movie support in the StimulusPresentationTask. The reason for this was mainly to avoid bloating the BCI2000 SVN repository with Qt's phonon multimedia framework. In the meantime, precompiled Qt has been moved out of the SVN repository, so this is not a concern any more, so sooner or later movie support will become available as well.

In the meantime, it should be straightforward to add movie support by yourself, starting out with a copy of the ImageStimulus base class, and modifying it to display movies rather than static images.

Regarding on-line classification, I'm not aware of any solid prior information that would be helpful in choosing features for classification of mental tasks. You will need to decide for one of those papers, and use the features suggested there, which may or may be not available in BCI2000 by default.

Regards,
Juergen