Abstract
Customizing the parameter values of brain interface (BI) systems by a human expert has the advantage of being fast and computationally efficient. However, as the number of users and EEG channels grows, this process becomes increasingly time consuming and exhausting. Manual customization also introduces inaccuracies in the estimation of the parameter values. In this paper, the performance of a self-paced BI system whose design parameter values were automatically user customized using a genetic algorithm (GA) is studied. The GA automatically estimates the shapes of movement-related potentials (MRPs), whose features are then extracted to drive the BI. Offline analysis of the data of eight subjects revealed that automatic user customization improved the true positive (TP) rate of the system by an average of 6.68% over that whose customization was carried out by a human expert, i.e., by visually inspecting the MRP templates. On average, the best improvement in the TP rate (an average of 9.82%) was achieved for four individuals with spinal cord injury. In this case, the visual estimation of the parameter values of the MRP templates was very difficult because of the highly noisy nature of the EEG signals. For four able-bodied subjects, for which the MRP templates were less noisy, the automatic user customization led to an average improvement of 3.58% in the TP rate. The results also show that the inter-subject variability of the TP rate is also reduced compared to the case when user customization is carried out by a human expert. These findings provide some primary evidence that automatic user customization leads to beneficial results in the design of a self-paced BI for individuals with spinal cord injury.
Similar content being viewed by others
References
Babiloni C, Carducci F, Cincotti F, Rossini PM, Neuper C et al (1999) Human movement-related potentials vs desynchronization of EEG alpha rhythm: a high-resolution EEG study. Neuroimage 10(6):658–665
Back T, Fogel DB, Michalewicz T (2000) Evolutionary computation. Institute of Physics Publishing, Bristol and Philadelphia
Bashashati A, Fatourechi M, Ward RK, Birch GE (2006) User customization of the feature generator of an asynchronous brain interface. Ann Biomed Eng 34(6):1051–1060
Birch GE, Lawrence PD, Hare RD (1993) Single-trial processing of event-related potentials using outlier information. IEEE Trans Biomed Eng 40(1):59–73
Birch GE, Bozorgzadeh Z, Mason SG (2002) Initial on-line evaluations of the LF-ASD brain-computer interface with able-bodied and spinal-cord subjects using imagined voluntary motor potentials. IEEE Trans Neural Syst Rehabil Eng 10(4):219–224
Blanchard G, Blankertz B (2004) BCI competition 2003—data set IIa: spatial patterns of self-controlled brain rhythm modulations. IEEE Trans Biomed Eng 51(6):1062–1066
Blankertz B, SchÃfer C, Dornhege G, Curio G (2002) Single trial detection of EEG error potentials: a tool for increasing BCI transmission rates. In: Proceedings of the international conference on artificial neural networks (ICANN2002), pp 1137–1143
Borisoff JF, Mason SG, Bashashati A, Birch GE (2004) Brain-computer interface design for asynchronous control applications: improvements to the LF-ASD asynchronous brain switch. IEEE Trans Biomed Eng 51(6):985–992
Borisoff JF, Mason SG, Birch GE (2006) Brain interface research for asynchronous control applications. IEEE Trans Neural Syst Rehabil Eng 14(2):160–164
Brownlee KA (1965) Statistical theory and methodology in science and engineering. A Wiley Publication in Applied Statistics, 2nd edn. Wiley, New York
Burke DP, Kelly SP, de Chazal P, Reilly RB, Finucane C (2005) A parametric feature extraction and classification strategy for brain-computer interfacing. IEEE Trans Neural Syst Rehabil Eng 13(1):12–17
Cui RQ, Deecke L (1999) High resolution DC-EEG analysis of the bereitschaftspotential and post movement onset potentials accompanying uni- or bilateral voluntary finger movements. Brain Topogr 11(3):233–249
Deecke L, Grozinger B, Kornhuber HH (1976) Voluntary finger movement in man: Cerebral potentials and theory. Biol Cybern 23(2):99–119
Fatourechi M, Bashashati A, Ward RK, Birch GE (2005) A hybrid genetic algorithm approach for improving the performance of the LF-ASD brain computer interface. In: Proceedings of the IEEE international conference on acoustics, speech, and signal processing (ICASSP ‘05), vol 5, pp v/345–v/348
Francis JT, Chapin JK (2006) Neural ensemble activity from multiple brain regions predicts kinematic and dynamic variables in a multiple force field reaching task. IEEE Trans Neural Syst Rehabil Eng 14(2):172–174
Glassman EL (2005) A wavelet-like filter based on neuron action potentials for analysis of human scalp electroencephalographs. IEEE Trans Biomed Eng 52(11):1851–1862
Goldberg DE (1989) Genetic algorithms in search, optimization and machine learning. Addison-Wesley Publishing Company, Reading, MA
Hallett M (1994) Movement-related cortical potentials. Electromyogr Clin Neurophysiol 34(1):5–13
Hochberg LR, Serruya MD, Friehs GM, Mukand JA, Saleh M et al (2006) Neuronal ensemble control of prosthetic devices by a human with tetraplegia. Nature 442(7099):164–171
Jayant NS, Noll P (1984) Digital coding of waveforms. Prentice Hall, Englewood Cliffs
Krauledat M, Dornhege G, Blankertz B, Losch F, Curio G et al (2004) Improving speed and accuracy of brain-computer interfaces using readiness potential features. In: Proceedngs of the 26th IEEE annual international conference of the engineering in medicine and biology society (EMBC 2004), vol 2, pp 4511–4515
Lal TN, Schroder M, Hinterberger T, Weston J, Bogdan M et al (2004) Support vector channel selection in BCI. IEEE Trans Biomed Eng 51(6):1003–1010
Levine SP, Huggins JE, BeMent SL, Kushwaha RK, Schuh LA et al (2000) A direct brain interface based on event-related potentials. IEEE Trans Rehabil Eng 8(2):180–185
Mason SG, Bohringer R, Borisoff JF, Birch GE (2004) Real-time control of a video game with a direct brain computer interface. J Clin Neurophysiol 21(6):404–408
Mason SG, Bashashati A, Fatourechi M, Navarro KF, Birch GE (2006) A comprehensive survey of brain interface technology designs. Ann Biomed Eng (in press)
Mason SG, Birch GE (2000) A brain-controlled switch for asynchronous control applications. IEEE Trans Biomed Eng 47(10):1297–1307
Mason SG, Birch GE (2005) Temporal control paradigms for direct brain interfaces—rethinking the definition of asynchronous and synchronous. In: Proceedings of HCI international conference, Las Vegas, USA
Millan Jdel R, Mourino J (2003) Asynchronous BCI and local neural classifiers: An overview of the adaptive brain interface project. IEEE Trans Neural Syst Rehabil Eng 11(2):159–161
Pfurtscheller G, Muller-Putz GR, Schlogl A, Graimann B, Scherer R et al (2006) 15 years of BCI research at graz university of technology: current projects. IEEE Trans Neural Syst Rehabil Eng 14(2):205–210
Pregenzer M, Pfurtscheller G (1999) Frequency component selection for an EEG-based brain to computer interface. IEEE Trans Rehabil Eng 7(4):413–419
Scherer R, Muller GR, Neuper C, Graimann B, Pfurtscheller G (2004) An asynchronously controlled EEG-based virtual keyboard: Improvement of the spelling rate. IEEE Trans Biomed Eng 51(6):979–984
Townsend G, Graimann B, Pfurtscheller G (2004) Continuous EEG classification during motor imagery-simulation of an asynchronous BCI. IEEE Trans Neural Syst Rehabil Eng 12(2):258–265
Wenjie X, Cuntain G, Chng Eng S, Ranganatha S, Thulasidas M et al (2004) High accuracy classification of EEG signal. In: Proceedings of the 17th international conference on pattern recognition (ICPR 2004), vol 2, pp 391–394
Yom-Tov E, Inbar GF (2003) Detection of movement-related potentials from the electro-encephalogram for possible use in a brain-computer interface. Med Biol Eng Comput 41(1):85–93
Yoon H, Yang K, Shahabi C (2005) Feature subset selection and feature ranking for multivariate time series. IEEE Trans Knowl Data Eng 17(9):1186–1198
Yu Z, Mason SG, Birch GE (2002) Enhancing the performance of the LF-ASD brain-computer interface. In: Proceedings of the 2nd joint EMBS-BMES Conference, vol 3, pp 2443–2444, Houston, USA
Yu Z, Mason SG, Birch GE (2003) Impact of an energy normalization transform on the performance of the LF-ASD brain computer interface. In: Proceedings of the advances in neural information processing systems (NIPS2003), pp 725–732
Acknowledgments
This work was supported in part by the NSERC under Grant 90278-06 and the CIHR under Grant MOP-72711. The authors also would like to thank Mr. Craig Wilson for his valuable comments on this paper.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Fatourechi, M., Bashashati, A., Birch, G.E. et al. Automatic user customization for improving the performance of a self-paced brain interface system. Med Bio Eng Comput 44, 1093–1104 (2006). https://doi.org/10.1007/s11517-006-0125-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11517-006-0125-2