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This video was recorded at BBCI Workshop: Advances in Neurotechnologies, Berlin 2012. Each method for imaging brain activity has technical or physiological limits. Thus, combinations of neuroimaging modalities that can alleviate these limitations such as simultaneous recordings of neurophysiological and hemodynamic activity have become increasingly popular. Multimodal imaging setups can take advantage of complementary views on neural activity and enhance our understanding about how neural information processing is reflected in each modality. However, dedicated analysis methods are needed to exploit the potential of multimodal methods. The talk will first spend some time on the multimodal data fusion problem from the Machine Learning point of view and introduce useful algorithms. Then I will discuss a hybrid noninvasive Brain Computer Interface (BCI) that combines electroencephalography (EEG) and near-infrared spectroscopy (NIRS). In particular I will show that near-infrared spectroscopy (NIRS) can be used to enhance the EEG-BCI approach. In our study both methods were applied simultaneously in a real-time Sensory Motor Rhythm (SMR)-based BCI paradigm, involving executed movements as well as motor imagery. We tested how the classification of NIRS data can complement ongoing real-time EEG classification. Our results show that simultaneous measurements of NIRS and EEG can significantly improve the classification accuracy of motor imagery in over 90% of considered subjects and increases performance by 5% on average. However, the long time delay of the hemodynamic response may hinder an overall increase of bit-rates. Furthermore we find that EEG and NIRS complement each other in terms of information content and are thus a viable multimodal imaging technique, suitable for BCI.

Disciplines:

• Science and Technology

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