<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi All,</div><div><br></div><div>Now I try to read BIOSEMI data (.bdf format, 64ch) by using "ft_preprocessing", but I have one trouble.</div><div>Baseline of each data much differ depending on channels. So, now I use cfg.demean as below script.</div><div><br></div><div><font class="Apple-style-span" face="Courier"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; ">cfg.trialdef.prestim = 0.5; <span style="color: #00a300">% in seconds</span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; ">cfg.trialdef.poststim = 1; <span style="color: #00a300">% in seconds</span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; ">cfg = ft_definetrial(cfg);</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; ">cfg.demean=<span style="color: #c900fe">'yes'</span>;</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; ">cfg.baselinewindow = [-0.1 0];</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; color: rgb(201, 0, 254); "><span style="color: #000000">cfg.channel = {</span>'Fp1'<span style="color: #000000"> </span>'AF7'<span style="color: #000000"> </span>'AF3'<span style="color: #000000"> </span>'F1'<span style="color: #000000"> </span>'F3'<span style="color: #000000"> </span>'F5'<span style="color: #000000"> </span>'F7'<span style="color: #000000"> </span>'FT9'<span style="color: #000000"> </span>'FT7'<span style="color: #000000"> </span>'FC5'<span style="color: #000000"> </span>'FC3'<span style="color: #000000"> </span>'FC1'<span style="color: #000000"> </span>'C1'<span style="color: #000000"> </span>'C3'<span style="color: #000000"> </span>'C5'<span style="color: #000000"> </span>'T7'<span style="color: #000000"> </span>'TP7'<span style="color: #2b00ff">...</span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; color: rgb(201, 0, 254); "><span style="color: #000000"> </span>'CP5'<span style="color: #000000"> </span>'CP3'<span style="color: #000000"> </span>'CP1'<span style="color: #000000"> </span>'P1'<span style="color: #000000"> </span>'P3'<span style="color: #000000"> </span>'P5'<span style="color: #000000"> </span>'P7'<span style="color: #000000"> </span>'P9'<span style="color: #000000"> </span>'PO7'<span style="color: #000000"> </span>'PO3'<span style="color: #000000"> </span>'O1'<span style="color: #000000"> </span>'Iz'<span style="color: #000000"> </span>'Oz'<span style="color: #000000"> </span>'POz'<span style="color: #000000"> </span>'Pz'<span style="color: #000000"> </span>'Fp2'<span style="color: #000000"> </span>'AF8'<span style="color: #000000"> </span>'AF4'<span style="color: #000000"> </span>'Fz'<span style="color: #000000"> </span>'F2'<span style="color: #2b00ff">...</span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; color: rgb(201, 0, 254); "><span style="color: #000000"> </span>'F4'<span style="color: #000000"> </span>'F6'<span style="color: #000000"> </span>'F8'<span style="color: #000000"> </span>'FT10'<span style="color: #000000"> </span>'FT8'<span style="color: #000000"> </span>'FC6'<span style="color: #000000"> </span>'FC4'<span style="color: #000000"> </span>'FC2'<span style="color: #000000"> </span>'FCz'<span style="color: #000000"> </span>'Cz'<span style="color: #000000"> </span>'C2'<span style="color: #000000"> </span>'C4'<span style="color: #000000"> </span>'C6'<span style="color: #000000"> </span>'T8'<span style="color: #000000"> </span>'TP8'<span style="color: #000000"> </span>'CP6'<span style="color: #000000"> </span>'CP4'<span style="color: #000000"> </span>'CP2'<span style="color: #000000"> </span>'CPz'<span style="color: #000000"> </span>'P2'<span style="color: #2b00ff">...</span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; color: rgb(201, 0, 254); "><span style="color: #000000"> </span>'P4'<span style="color: #000000"> </span>'P6'<span style="color: #000000"> </span>'P8'<span style="color: #000000"> </span>'P10'<span style="color: #000000"> </span>'PO8'<span style="color: #000000"> </span>'PO4'<span style="color: #000000"> </span>'O2'<span style="color: #000000"> </span>'PO9'<span style="color: #000000"> </span>'PO10'<span style="color: #000000"> };</span></div></font><span class="Apple-style-span" style="font-family: Courier; font-size: 12px; ">cfd.reref=(<span style="color: #c900fe">'yes'</span>);</span><font class="Apple-style-span" face="Courier"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Courier; ">cfg.refchannel=(<span style="color: #c900fe">'all'</span>);</div></font><span class="Apple-style-span" style="font-family: Courier; font-size: 12px; ">data = ft_preprocessing(cfg);</span></div><div><br></div><div>But, I now focused on DC shift(Slow cortical potential <0.5Hz), so, I can't use cfg.demean and I'm looking for another method to solve this problem.</div><div>Additionally, is this trouble( Baseline of each data much differ depending on channels.) common with BIOSEMI data format ?</div><div>or is it due to our recording device?</div><div><br></div><div>I woud appreciate if someone could advise or comment on how bests to go about this issue.</div><div><br></div><div>Thanks.</div><div>Itta Nakamura M.D.</div><div>Kyushu-University Neuropsychiatry Department, Japan. </div><br></body></html>