<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Farquhar, Jason</style></author><author><style face="normal" font="default" size="100%">Jeremy Jeremy Hill</style></author><author><style face="normal" font="default" size="100%">Schölkopf, B</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Optimizing Spatial Filters for BCI: Margin- and Evidence-Maximization Approaches.</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Brain Computer Interfaces</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">11/2006</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.researchgate.net/publication/237615110_Optimizing_Spatial_Filters_for_BCI</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;We present easy-to-use alternatives to the often-used two-stage Common Spatial Pattern + classifier approach for spatial filtering and classification of Event-Related Desynchronization signals in BCI. We report two algorithms that aim to optimize the spatial filters according to a criterion more directly related to the ability of the algorithms to generalize to unseen data. Both are based upon the idea of treating the spatial filter coefficients as hyperparameters of a kernel or covariance function. We then optimize these hyper-parameters directly along side the normal classifier parameters with respect to our chosen learning objective function. The two objectives considered are margin maximization as used in Support-Vector Machines and the evidence maximization framework used in Gaussian Processes. Our experiments assessed generalization error as a function of the number of training points used, on 9 BCI competition data sets and 5 offline motor imagery data sets measured in Tubingen. Both our approaches sho w consistent improvements relative to the commonly used CSP+linear classifier combination. Strikingly, the improvement is most significant in the higher noise cases, when either few trails are used for training, or with the most poorly performing subjects. This a reversal of the usual &quot;rich get richer&quot; effect in the development of CSP extensions, which tend to perform best when the signal is strong enough to accurately find their additional parameters. This makes our approach particularly suitable for clinical application where high levels of noise are to be expected.&lt;/p&gt;</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Lal, T.N</style></author><author><style face="normal" font="default" size="100%">Hinterberger, T.</style></author><author><style face="normal" font="default" size="100%">Widman, Guido</style></author><author><style face="normal" font="default" size="100%">Schroeder, Michael</style></author><author><style face="normal" font="default" size="100%">Jeremy Jeremy Hill</style></author><author><style face="normal" font="default" size="100%">Rosenstiel, W.</style></author><author><style face="normal" font="default" size="100%">Elger, Christian</style></author><author><style face="normal" font="default" size="100%">Schölkopf, B</style></author><author><style face="normal" font="default" size="100%">Niels Birbaumer</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Methods Towards Invasive Human Brain Computer Interfaces.</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Brain Computer Interfaces</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.64.8486</style></url></web-urls></urls><isbn><style face="normal" font="default" size="100%">0-262-19534-8</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;div class=&quot;page&quot; title=&quot;Page 1&quot;&gt;
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&lt;p&gt;&lt;span style=&quot;font-size: 10.000000pt; font-family: 'Times';&quot;&gt;During the last ten years there has been growing interest in the develop- ment of Brain Computer Interfaces (BCIs). The field has mainly been driven by the needs of completely paralyzed patients to communicate. With a few exceptions, most human BCIs are based on extracranial elec- troencephalography (EEG). However, reported bit rates are still low. One reason for this is the low signal-to-noise ratio of the EEG [16]. We are currently investigating if BCIs based on electrocorticography (ECoG) are a viable alternative. In this paper we present the method and examples of intracranial EEG recordings of three epilepsy patients with electrode grids placed on the motor cortex. The patients were asked to repeat- edly imagine movements of two kinds, e.g., tongue or finger movements. We analyze the classifiability of the data using Support Vector Machines (SVMs) [18, 21] and Recursive Channel Elimination (RCE) [11].&amp;nbsp;&lt;/span&gt;&lt;/p&gt;
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&lt;/div&gt;</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jeremy Jeremy Hill</style></author><author><style face="normal" font="default" size="100%">Lal, T.N</style></author><author><style face="normal" font="default" size="100%">Bierig, K.</style></author><author><style face="normal" font="default" size="100%">Niels Birbaumer</style></author><author><style face="normal" font="default" size="100%">Schölkopf, B</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">An Auditory Paradigm for Brain–Computer Interfaces.</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Brain Computer Interfaces</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://papers.nips.cc/paper/2551-an-auditory-paradigm-for-brain-computer-interfaces</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&amp;nbsp;&lt;/p&gt;
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&lt;p&gt;&lt;span style=&quot;font-size: 10.000000pt; font-family: 'CMR10';&quot;&gt;Motivated by the particular problems involved in communicating with “locked-in” paralysed patients, we aim to develop a brain- computer interface that uses auditory stimuli. We describe a paradigm that allows a user to make a binary decision by focusing attention on one of two concurrent auditory stimulus sequences. Using Support Vector Machine classification and Recursive Chan- nel Elimination on the independent components of averaged event- related potentials, we show that an untrained user’s EEG data can be classified with an encouragingly high level of accuracy. This suggests that it is possible for users to modulate EEG signals in a single trial by the conscious direction of attention, well enough to be useful in BCI.&amp;nbsp;&lt;/span&gt;&lt;/p&gt;
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