A comparison of recording modalities of P300 event-related potentials (ERP) for brain-computer interface (BCI) paradigm

International audienceAims of the study A brain-Computer Interface aims at restoring communication and control in severely disabled people by identification and classification of EEG features such as Event Related Potentials (ERPs). The aim of this study is to compare different EEG recording modalities for extraction of ERPs. The first comparison evaluates the performance of six disc electrodes with that of the Emotiv headset, while the second evaluates three different electrode types (disc, needle, and large squared electrode). Material and methods Ten healthy volunteers gave informed consent and were randomized to try the traditional EEG system (6 disc electrodes with gel and skin preparation) or the Emotiv headset first. Together with the six disc electrodes, a needle and a square electrode of larger surface were simultaneously recording near lead Cz. Each modality was evaluated over three sessions of auditory P300 separated by one hour. Results No statically significant effect was found for the electrode type, nor was the interaction between electrode type and session number. There was no statistically significant difference of performance between the Emotiv and the six traditional EEG disc electrodes, although there was a trend showing worse performance of the Emotive headset. However, the Modality-Session interaction was highly significant (p<0.001) showing that, while the performance of the 6 disc electrodes stay constant over sessions, the performance of the Emotiv headset drops dramatically between 2 and 3 hours of use. Finally, the evaluation of comfort by participants revealed an increasing discomfort with the Emotiv headset starting with the second hour of use. Conclusion Our study does not recommend the use of one modality over another based on performance but suggests the choice should be made on more practical considerations such as the expected length of use, the availability of skilled labor for system setup and above all, the patient experience

Data-driving methods: More than merely trendy buzzwords?

SCOPUS: re.jinfo:eu-repo/semantics/publishe

Rapid degradation of azo-dye using Mn–Al powders produced by ball-milling

This study was conducted on the reduction reaction of the azo dye Reactive Black 5 by means of the Mn85Al15 particles prepared by melt-spinning and ball-milling processes. The morphology, the surface elementary composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The degradation efficiency of the ball milled powder was measured by using an ultraviolet-visible absorption spectrophotometer and the collected powder was analyzed by means of Fourier transform infrared spectroscopy technique to characterize the functional groups in the extract. The degradation of Reactive Black 5 and the analysis of the aromatic by-products were investigated by high performance liquid chromatography coupled with tandem mass spectrometry. The ball-milled powder shows higher degradation efficiency and the Reactive Black 5 solution was completely decolorized after 30 min. The degradation kinetics and the formation by-products depend on the pH and temperature of the solution. The analyses of the extracted product confirmed the cleavage of the (–N[double bond, length as m-dash]N–) bonds. Our findings are expected to pave the way for a new opportunity with regard to the functional applications of nanostructured metallic particle

Data-driving methods: More than merely trendy buzzwords?

SCOPUS: re.jinfo:eu-repo/semantics/publishe