Cardiac responses induced during thought-based control of a virtual environment.
Cardiac responses induced by motor imagery were investigated in 3 subjects in a series of experiments with a synchronous (cue-based) Brain-Computer Interface (BCI). The cue specified right hand vs. leg/foot motor imagery. After a number of BCI training sessions reaching a classification accuracy of at least 80%, the BCI experiments were carried out in an immersive virtual environment (VE), commonly referred as a "CAVE". In this VE, the subjects were able to move along a virtual street by motor imagery alone. The thought-based control of VE resulted in an acceleration of the heart rate in 2 subjects and a heart rate deceleration in the other subject. In control experiments in front of a PC, all 3 subjects displayed a significant heart rate deceleration of the order of about 3-5%. This heart rate decrease during motor imagery in a normal environment is similar to that observed during preparation for a voluntary movement. The heart rate acceleration in the VE is interpreted as effect of an increased mental effort to walk as far as possible in VE.
Pfurtscheller
G
G
Laboratory of Brain-Computer Interfaces, Institute for Knowledge Discovery, Graz University of Technology, Krenngasse 37, A-8010 Graz, Austria. pfurtscheller@tugraz.at
Leeb
R
R
Slater
M
M
D000328:Adult; D001921:Brain / Q000502:physiology*; D004562:Electrocardiography / Q000379:methods; D004569:Electroencephalography / Q000379:methods; D004777:Environment; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007092:Imagination / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D013997:Time Factors; D014584:User-Computer Interface