@INPROCEEDINGS{TanHoeSteSch12,
    AUTHOR = {Tangermann, Michael and H\"ohne, Johannes and Stecher, Heiko and Schreuder, Martijn},
    TITLE = "No Surprise --- Fixed Sequence Event-Related Potentials for Brain-Computer Interfaces",
    booktitle = "Engineering in Medicine and Biology Society (EMBC), 2012 Annual International Conference of the IEEE",
    pages = "2501--2504",
    YEAR = "2012",
    organization = "IEEE",
    folder = "BBCI",
    grant = "TOBI",
    pdf = "http://doc.ml.tu-berlin.de/bbci/publications/TanHoeSteSch12.pdf",
    ABSTRACT = "Introduction: In the field of Brain-Computer Interfaces (BCI), the original two-class oddball paradigm has been extended to multiple stimuli with balanced probabilities and random presentation sequences. Exploiting the differences between standard and deviant ERP responses, these multi-class paradigms are suitable for communication and control. Methods: The present study investigates the effect of giving up the randomness of stimulation sequences in favor of a repeated, predictable pattern. Data of healthy subjects (n=10) who performed a single session with a 6-class spatial auditory ERP paradigm were analyzed offline. Their auditory evoked potentials (AEP) resulting from the potentially simpler task (using fixed sequences) are compared with the AEP evoked by pseudo-randomized stimulation sequences. Results: Class-discriminative EEG responses between target and non-target stimuli were observed for both conditions. The binary classification error estimated for standard epochs of was comparable for both conditions (random: 24\\%, fixed: 25\\%). Expanding the standard epochs to include pre-stimulus intervals, we found that the regular structure of the fixed sequence can be exploited. Compared to the standard epoch, the MSE improves by 7\\%, while in the random condition an improvement could not be observed."
}