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</o:shapelayout></xml><![endif]--></head><body lang=NL-BE link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal>Dear all<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-US>If we reject some artefacts in eeg recordings by zeroing their components and then reconstruct the “original” EEG by multiplying the rest of the components matrix with the inverted unmixing matrix, the time points of the “reconstructed” eeg are a weighted linear interpolation and hence there will be changes in phase angle between channels.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>This is a topic that is rarely mentioned in ICA literature although some simulation studies have been done (Montefusco at al) <a href="http://ieeexplore.ieee.org/xpl/abstractAuthors.jsp?arnumber=6696198">http://ieeexplore.ieee.org/xpl/abstractAuthors.jsp?arnumber=6696198</a> showing that the phase distortion is largest at the origin of the artefact (due to weighting coefficients) and within its frequency range , yet the effect is not stationary.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Is there a way, a strategy, a method , when using ICA for rejecting EEG artefacts , to avoid this phase distortion problem ?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Sincerely<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Georges<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> <o:p></o:p></span></p></div></body></html>