Subject: Re: [AUDITORY] EEG purchase From: Amos Boasson <agboas@xxxxxxxx> Date: Thu, 18 Aug 2022 19:25:21 +0300--000000000000d5c4bb05e6866f33 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear Carlos, and list members: Carlos, keep in mind that in the Biosemi ActiveTwo system a not-so-widely-known problem exists, of the signal being contaminated by the dithering process in the Sigma-Delta ADC box, at frequency-multiples related to the sampling rate. This problem disturbs mainly if you are interested in spectrum analysis at higher frequencies, as for examples in studies of the Frequency Following Response (FFR), where presentation of the stimulus in alternate polarities leads you to look for a response at double the stimulus frequency. Because of the 1/f decrement, mechanical 'side-effects' infiltrating the signal, unremovable, are more and more disturbing. the higher your frequency region of interest. Biosemi intends to implement a whole different technology in their next model (ActiveThree?), which would eliminate this problem, but I have not seen it on their site yet. This problem may not disturb some kinds of analysis, but you may want to consider it. Good luck with your new lab! Sincerely, Amos Boasson =E2=80=AB=D7=91=D7=AA=D7=90=D7=A8=D7=99=D7=9A =D7=99=D7=95=D7=9D =D7=93=D7= =B3, 17 =D7=91=D7=90=D7=95=D7=92=D7=B3 2022 =D7=91-7:07 =D7=9E=D7=90=D7=AA = =E2=80=AAJan Schnupp=E2=80=AC=E2=80=8F <=E2=80=AA 000000e042a1ec30-dmarc-request@xxxxxxxx=E2=80=AC=E2=80=8F>:=E2=80=AC > I cannot recommend strongly enough AGAINST the EGI setup. I had inherited > one of their systems. It was terribly buggy. Lost parts of the signal. Lo= st > triggers. My PhD student lost many months trying to debug the device or > find work-arounds. Their customer service was unresponsive. It was simply > terrible. What rescued my student was that we were able to get an ANT EEG= o > system from a friend, which perhaps hasn't the greatest S/N but it was > quite adequate, and at least it was relatively straight-forward to get to > work as advertised and we got some nice studies done with it. ANT now als= o > offer a sponge cap for their EEGo system which can reduce prep time. We > ordered one but we haven't received it yet so I can't tell you whether th= e > S/N is adequate. > Under absolutely no circumstances would I ever again waste a single dolla= r > or minute of my time on anything EGI. > > Best wishes, > > Jan > > > --------------------------------------- > Prof Jan Schnupp > City University of Hong Kong > Dept. of Neuroscience > 31 To Yuen Street, > Kowloon Tong > Hong Kong > > https://auditoryneuroscience.com > http://jan.schnupp.net > > > On Mon, 15 Aug 2022 at 10:40, Petter Kallioinen < > 000001c5645d28b7-dmarc-request@xxxxxxxx> wrote: > >> Dear Carlos, >> I have used neuroscan a little and EGI a lot, but I do prefer Biosemi. >> The system is more simple and modular than EGI. I have done about 250 >> recordings with 4-6 year olds in pre-schools using Biosemi. While I do >> think it is possible to have good signal in EGI, it is easier to >> troubleshoot bad signals in Biosemi, usually a single or a few bad >> electrodes that can be fixed with more gel. In EGI problems are often mo= re >> vague and indirect. If you use Biosemi 64 channels with children, time o= f >> application can be an issue. Two well trained assistants could do it in >> 15-20 minutes, but is is still an issue. Depending on your research >> question 32 channels could be good enough and considerably faster. >> >> Customer support is fast but brief with Biosemi, and a lot of times I >> have solved things based on forum discussions rather than direct support= , I >> am still more satisfied with support from Biosemi compared to EGI. Biose= mi >> is more to the point and technical, whereas EGI has a slow and somewhat >> bureaucratic support. >> >> Signal quality should be better with Biosemi active electrodes compared >> to EGI, but I have actually not tested this thoroughly. When I have look= ed >> at amplitudes of MMN responses the effects have been quite similar betwe= en >> EGI and Biosemi. I was surprised by this but it could be a larger >> difference in paradigms with fewer events. >> >> Best wishes! >> /Petter Kallioinen, EEG technician at linguistics dept, Stockholm >> University >> >> On 12 Aug 2022, at 17:20 , Carlos Benitez-Barrera < >> 000001c4037ab8ae-dmarc-request@xxxxxxxx> wrote: >> >> Dear Auditory List, >> >> I am planning on purchasing an EEG system for my new lab at UW-Madison, >> USA. I have been in contact with several EEG providers, and I=E2=80=99m = still >> undecisive on which system would be best for my lab. I=E2=80=99m familia= r with >> Neuroscan and EGI, but I=E2=80=99m actually leaning towards Biosemi or B= rain >> Products (Brain and Vision in the US). I run simple auditory paradigms w= ith >> children (ages 3 to 14) and adults. The main characteristics that I=E2= =80=99m >> looking for are (not necessarily in order): >> >> - Ease of use >> - Prep cap time (important to minimize with children) >> - Customer support >> - Signal quality >> >> >> I=E2=80=99m shooting for a 64-channel system. Also, I=E2=80=99m still he= sitating between >> saline caps or gel caps. I heard that the Biosemi caps despite of being = gel >> based are very fast to get going. >> >> Anyway, I=E2=80=99m just looking for some advice from any of you working= with >> these systems. Any experiences or recommendations will help! >> >> Thank you in advance for your taking your time to reply! >> >> Sincerely, >> Carlos >> >> >> --000000000000d5c4bb05e6866f33 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"rtl"><div dir=3D"ltr">Dear Carlos, and list members:</div><div = dir=3D"ltr">Carlos, keep in mind that in the Biosemi ActiveTwo system a not= -so-widely-known problem exists, of the signal being contaminated by the di= thering process in the Sigma-Delta ADC box, at frequency-multiples related = to the sampling rate.</div><div dir=3D"ltr">This problem disturbs mainly if= you are interested in spectrum analysis at higher frequencies, as for exam= ples in studies of the Frequency Following Response (FFR), where presentati= on of the stimulus in alternate polarities leads you to look for a response= at double the stimulus frequency. Because of the 1/f decrement, mechanical= =C2=A0'side-effects' infiltrating the signal, unremovable, are more= and more disturbing. the higher your frequency region of interest.</div><d= iv dir=3D"ltr">Biosemi intends to implement a whole different technology in= their next model (ActiveThree?), which would eliminate this problem, but I= have not seen it on their site yet.</div><div dir=3D"ltr">This problem may= not disturb some kinds of analysis, but you may want to consider it.</div>= <div dir=3D"ltr">Good luck with your new lab!</div><div dir=3D"ltr">Sincere= ly, Amos Boasson</div></div><br><div class=3D"gmail_quote"><div dir=3D"rtl"= class=3D"gmail_attr">=E2=80=AB=D7=91=D7=AA=D7=90=D7=A8=D7=99=D7=9A =D7=99= =D7=95=D7=9D =D7=93=D7=B3, 17 =D7=91=D7=90=D7=95=D7=92=D7=B3 2022 =D7=91-7:= 07 =D7=9E=D7=90=D7=AA =E2=80=AAJan Schnupp=E2=80=AC=E2=80=8F <=E2=80=AA<= a href=3D"mailto:000000e042a1ec30-dmarc-request@xxxxxxxx">000000e042= a1ec30-dmarc-request@xxxxxxxx</a>=E2=80=AC=E2=80=8F>:=E2=80=AC<br= ></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;= border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr">I= cannot recommend strongly enough AGAINST the EGI setup. I had inherited on= e of their systems. It was terribly buggy. Lost parts of the signal. Lost t= riggers. My PhD student lost many months trying to debug the device or find= work-arounds. Their customer service was unresponsive. It was simply terri= ble. What rescued my student was that we were able to get an ANT EEGo syste= m from a friend, which perhaps hasn't the greatest S/N but it was quite= adequate, and at least it was relatively straight-forward to get to work a= s advertised and we got some nice studies done with it. ANT now also offer = a=C2=A0sponge cap for their EEGo system which can reduce prep time. We orde= red one but we=C2=A0haven't received it yet so I can't tell you whe= ther=C2=A0the S/N is adequate.=C2=A0<div>Under absolutely no circumstances = would I ever again waste a single dollar or minute of my time on anything E= GI.=C2=A0</div><div><br></div><div>Best wishes,</div><div><br></div><div>Ja= n<br><div><br clear=3D"all"><div><div dir=3D"ltr"><div dir=3D"ltr"><div><di= v dir=3D"ltr"><div><div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><div = dir=3D"ltr"><div style=3D"font-size:12.8px"><br></div><div style=3D"font-si= ze:12.8px">---------------------------------------</div><div style=3D"font-= size:12.8px">Prof Jan Schnupp<br>City University of Hong Kong<br>Dept. of N= euroscience</div><div><div style=3D"font-size:12.8px">31 To Yuen Street,=C2= =A0</div><div style=3D"font-size:12.8px"><span style=3D"font-size:12.8px">K= owloon Tong</span></div><div style=3D"font-size:12.8px">Hong Kong</div><div= style=3D"font-size:12.8px"><br></div><a href=3D"https://auditoryneuroscien= ce.com" target=3D"_blank">https://auditoryneuroscience.com</a></div><div><a= href=3D"http://jan.schnupp.net" target=3D"_blank">http://jan.schnupp.net</= a></div></div></div></div></div></div></div></div></div></div></div><br></d= iv></div></div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gma= il_attr">On Mon, 15 Aug 2022 at 10:40, Petter Kallioinen <<a href=3D"mai= lto:000001c5645d28b7-dmarc-request@xxxxxxxx" target=3D"_blank">00000= 1c5645d28b7-dmarc-request@xxxxxxxx</a>> wrote:<br></div><blockquo= te class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px = solid rgb(204,204,204);padding-left:1ex"> <div> Dear Carlos, <div>I have used neuroscan a little and EGI a lot, but I do prefer Biosemi.= The system is more simple and modular than EGI. I have done about 250 reco= rdings with 4-6 year olds in pre-schools using Biosemi. While I do think it= is possible to have good signal in EGI, it is easier to troubleshoot bad signals in Biosemi, usuall= y a single or a few bad electrodes that can be fixed with more gel. In EGI = problems are often more vague and indirect. If you use Biosemi 64 channels = with children, time of application can be an issue. Two well trained assistants could do it in 15-20 minutes,= but is is still an issue. Depending on your research question 32 channels = could be good enough and considerably faster.=C2=A0</div> <div><br> </div> <div>Customer support is fast but brief with Biosemi, and a lot of times I = have solved things based on forum discussions rather than direct support, I= am still more satisfied with support from Biosemi compared to EGI. Biosemi= is more to the point and technical, whereas EGI has a slow and somewhat bureaucratic support.</div> <div><br> </div> <div>Signal quality should be better with Biosemi active electrodes compare= d to EGI, but I have actually not tested this thoroughly. When I have looke= d at amplitudes of MMN responses the effects have been quite similar betwee= n EGI and Biosemi. I was surprised by this but it could be a larger difference in paradigms with fe= wer events.=C2=A0</div> <div><br> </div> <div>Best wishes!</div> <div>/Petter Kallioinen, EEG technician at linguistics dept, Stockholm Univ= ersity =C2=A0<br> <div><br> <blockquote type=3D"cite"> <div>On 12 Aug 2022, at 17:20 , Carlos Benitez-Barrera <<a href=3D"mailt= o:000001c4037ab8ae-dmarc-request@xxxxxxxx" target=3D"_blank">000001c= 4037ab8ae-dmarc-request@xxxxxxxx</a>> wrote:</div> <br> <div> <div style=3D"font-family:Helvetica;font-size:14px;font-style:normal;font-v= ariant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:star= t;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;t= ext-decoration:none"> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">Dear Auditory List,</span><span><u></u><u></= u></span></div> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">=C2=A0</span><span><u></u><u></u></span></di= v> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">I am planning on purchasing an EEG system fo= r my new lab at UW-Madison, USA. I have been in contact with several EEG pr= oviders, and I=E2=80=99m still undecisive on which system would be best for= my lab. I=E2=80=99m familiar with Neuroscan and EGI, but I=E2=80=99m actually leaning towards Biosemi or Brain Product= s (Brain and Vision in the US). I run simple auditory paradigms with childr= en (ages 3 to 14) and adults. The main characteristics that I=E2=80=99m loo= king for are (not necessarily in order):</span><span><u></u><u></u></span><= /div> <ul type=3D"disc" style=3D"margin-bottom:0in;margin-top:0in"> <li class=3D"MsoNormal" style=3D"margin:0in 0in 0.0001pt;font-size:12pt;fon= t-family:Calibri,sans-serif"> <span style=3D"font-size:11pt">Ease of use</span><u></u><u></u></li><li cla= ss=3D"MsoNormal" style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-famil= y:Calibri,sans-serif"> <span style=3D"font-size:11pt">Prep cap time (important to minimize with ch= ildren)</span><u></u><u></u></li><li class=3D"MsoNormal" style=3D"margin:0i= n 0in 0.0001pt;font-size:12pt;font-family:Calibri,sans-serif"> <span style=3D"font-size:11pt">Customer support</span><u></u><u></u></li><l= i class=3D"MsoNormal" style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-= family:Calibri,sans-serif"> <span style=3D"font-size:11pt">Signal quality</span><u></u><u></u></li></ul= > <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">=C2=A0</span><span><u></u><u></u></span></di= v> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">I=E2=80=99m shooting for a 64-channel system= . Also, I=E2=80=99m still hesitating between saline caps or gel caps. I hea= rd that the Biosemi caps despite of being gel based are very fast to get go= ing.=C2=A0</span><span><u></u><u></u></span></div> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">=C2=A0</span><span><u></u><u></u></span></di= v> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">Anyway, I=E2=80=99m just looking for some ad= vice from any of you working with these systems. Any experiences or recomme= ndations will help!</span><span><u></u><u></u></span></div> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">=C2=A0</span><span><u></u><u></u></span></di= v> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">Thank you in advance for your taking your ti= me to reply!</span><span><u></u><u></u></span></div> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">=C2=A0</span><span><u></u><u></u></span></di= v> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">Sincerely,</span><span><u></u><u></u></span>= </div> <div style=3D"margin:0in 0in 0.0001pt;font-size:12pt;font-family:Calibri,sa= ns-serif"> <span style=3D"font-size:11pt">Carlos</span></div> </div> </div> </blockquote> </div> <br> </div> </div> </blockquote></div> </blockquote></div> --000000000000d5c4bb05e6866f33--