[wineeg] Mitsar question

  • From: "Vernon, David" <d.vernon@xxxxxxxxxxxxxx>
  • To: "'Juri D. Kropotov'" <kropotov@xxxxxxxxxx>
  • Date: Mon, 7 Jul 2003 16:04:29 +0100


i am going through an EEG file that i recorded using the Mitsar and after
completing the automatic EOG correction i wanted to go through the raw trace
myself and cut out any very noisy sections. I Managed to do this using the
mouse and the scissors symbol on the tool bar. When i do this a bold blue
line appears at the bottom of the raw EEG file.

However, when i then run the analysis it gives exactly the same output as a
raw EEG that i have not gone through and removed the additional artefacts.
Thus i must be missing something out. I have checked the manual but can find
no reference to manual artefact rejection using the cut tool. Can you help
me please, what do i have to do to make sure that the sections i have cut
are not included in the analysis?



David J Vernon PhD
Dept. of Cognitive Neuroscience & Behaviour
Imperial College London
St Dunstan's Road
W6 8RP

Tel:    44 (0) 208 383 0584
Fax:   44 (0) 208 846 1670

-----Original Message-----
From: Juri D. Kropotov [mailto:kropotov@xxxxxxxxxx]
Sent: 03 July 2003 16:05
To: Vernon, David
Subject: Re[2]: data issues

OK, David.
I'll check it and ask my server to enlarge my mail-box.

VD> Hi Juri,

VD> i cannot send you the data files, as everytime i have tried they just
VD> back undelivered. I checked with out technical people and they say its
VD> because your mailbox is to small to accept a 3.5mb file. I checked this
VD> by sending the file to Annie and she received it. I tried again to send
VD> to you and again it was returned. Do you know if your mailbox can accept
VD> files as large as 3.5mb if not the only way i can see of getting you the
VD> data will be to send it over on a cd, not ideal but i would really value
VD> your input

VD> david

VD> David J Vernon PhD
VD> Dept. of Cognitive Neuroscience & Behaviour
VD> Imperial College London
VD> St Dunstan's Road
VD> London
VD> W6 8RP

VD> Tel:    44 (0) 208 383 0584
VD> Fax:   44 (0) 208 846 1670

VD> -----Original Message-----
VD> From: Juri D. Kropotov [mailto:kropotov@xxxxxxxxxx]
VD> Sent: 02 July 2003 16:53
VD> To: Frick, Ann
VD> Cc: 'Megan Kelley (E-mail)'; Vernon, David
VD> Subject: Re: data issues

VD> Dear Annie,
VD> I've not got any EEG files from David and I am waiting to get it from
VD> you.

VD> You mentioned TOVA for ERPs.  Please use the animal GO/NOGO task I
VD> gave to you. We have 250 children data base for this task.

VD> As far as September concerns, I am going to Houston at iSNR conference
VD> and afraid that it will be exactly the third week of September.  Let
VD> us think about other dates.

VD> All the best, Juri

FA>> Dear Juri--I have been trying to send you the following email and
FA>> data files.  This hasn't been working.  So here is the original
VD> email--files
FA>> to follow as soon as I can figure out how.

FA>> Dear Juri,
FA>> I believe David sent you two files for a boy, TG, dob 12/10/1990.  I
VD> think
FA>> he is clearly in the 10% group that Chabot and Serfontein talk about.
VD> He
FA>> does have high frontal beta.  In fact, during recording, I was
VD> if
FA>> it wasn't a very high alpha, but it doesn't attentuate with eyes open.

FA>> However, all the children we've recorded show a pattern that is
VD> consistent
FA>> and puzzling.  They all have extremely high amplitude EEGs relative to
VD> the
FA>> database.  We are getting extremes in z-scores for both absolute and
FA>> relative power.  Absolute readings are very high magnitude across
VD> locations
FA>> in almost all frequency bands (>3sd) (least in alpha and theta).
VD> Relative
FA>> power scores are extremely low across most all frequency bands (>-3sd).

FA>> According to the database, these children are so extremely abnormal is
VD> these
FA>> regards, yet normal in the criteria for our study (theta/beta ratios).
VD> And
FA>> the results are consistent for all 4 of the children we have recorded
VD> the
FA>> children's center.  However, the adults we have recorded in our lab
VD> rooms
FA>> look as we would expect them to.

FA>> We get these same results whether we EOG correct and save as a .dat
VD> or
FA>> import the Mitsar file into NeuroGuide and use auto-select.  We have
FA>> manually artefacted these files at all. 

FA>> These data are so peculiar that I am concerned that we are doing
VD> something
FA>> wrong.  On a more positive note, the ERPs for the TOVA are running
FA>> have yet to sort out audio for the oddball task, but that should go
VD> easily.

FA>> We are interviewing for David's position right now.  It is quite a blow
VD> to
FA>> us that he is leaving.  I am planning to work through the rest of the
VD> time
FA>> he is here and until after a replacement starts in. Would the 3rd week
VD> in
FA>> Sept be a reasonable time to visit St. Petersburg.  I have friends from
VD> home
FA>> who want to go.  I'd love to see St P and stop by the Institute as

FA>> Thanks for any help.

FA>> All the best,
FA>> annie

FA>> Ann Frick
FA>> Imperial College London
FA>> Dept of Cognitive Neuroscience and Behaviour
FA>> Charing Cross Campus
FA>> St Dunstan's Road
FA>> London W6 8RP
FA>> phone 0208-846-7281
FA>> fax   0208-846-1670 

Best regards,
 Juri                            mailto:kropotov@xxxxxxxxxx

Other related posts: