[Eeglablist] eeglablist Digest, Vol 144, Issue 14

[James Jones-Rounds]

Hi Vishal, Makoto, and all,

I have also had a similar issue with running ASR. I tried several parameter
combinations for the Burst Criterion (values of 3 and 5), and Window
Criterion (values of 0.1 and 0.25), and each combination of these. It
frequently led to seemingly highly-correlated channel time-series data.
Then the resulting ICA patterns were not very interpretable: ironically,
every component seemed to basically represent a single electrode, with a
very focal peak in the topo map, and very little neural activity in the ERP
image.

For some datasets, however, the ASR pre-ICA cleaning step really cleared up
the data and revealed a number of neural components that manual cleaning
did not reveal. I haven't determined yet what the critical difference is
that affects the ASR performance..

James

On Thu, Oct 20, 2016 at 3:00 PM, <eeglablist-request at sccn.ucsd.edu> wrote:

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> Today's Topics:
>
>    1. Re: Highly Correlated channels after applying ASR
>       (Makoto Miyakoshi)
>    2. Re: Interpreting Brodmann Area and Anatomical location of
>       Domain in MPT analysis (Makoto Miyakoshi)
>    3. Re: Simultaneous recording of EEG and Robot motion
>       (Makoto Miyakoshi)
>
>
> ---------- Forwarded message ----------
> From: Makoto Miyakoshi <mmiyakoshi at ucsd.edu>
> To: Vishal Vijayakumar <vijay059 at umn.edu>
> Cc: EEGLAB List <eeglablist at sccn.ucsd.edu>
> Date: Wed, 19 Oct 2016 20:00:22 -0700
> Subject: Re: [Eeglablist] Highly Correlated channels after applying ASR
> Dear Vishal,
>
> What do you see when you perform average reference? How many channels do
> you have by the way? Also, what types of cap are you using? If EGI, check
> if they were bridged by any chance...
>
> Makoto
>
> On Mon, Oct 17, 2016 at 3:08 PM, Vishal Vijayakumar <vijay059 at umn.edu>
> wrote:
>
>> Hello,
>>
>> Apologies if you've answered this question already, but I observe that
>> data across my channels look highly correlated after applying ASR to the
>> filtered EEG data. My project involves analyzing tonic thermal pain, so I
>> apply ASR to 4 minute segments of the data. Because of the high
>> correlation, my ICA sphering matrix is quite large in magnitude (minimum
>> value of 1800) for many subjects. I also disable any channel-based
>> rejection because I'd like to concatenate data across subjects for group
>> ICA. My current problem persists even during single subject analysis.
>>
>>
>> I'm not sure if I'm doing something wrong, and I'd appreciate any insight
>> you can provide!
>>
>> Thanks,
>> Vishal
>>
>> _______________________________________________
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>
>
>
> --
> Makoto Miyakoshi
> Swartz Center for Computational Neuroscience
> Institute for Neural Computation, University of California San Diego
>
>
> ---------- Forwarded message ----------
> From: Makoto Miyakoshi <mmiyakoshi at ucsd.edu>
> To: Mohammed Jarjees <m.jarjees.1 at research.gla.ac.uk>
> Cc: "eeglablist at sccn.ucsd.edu" <eeglablist at sccn.ucsd.edu>
> Date: Wed, 19 Oct 2016 20:15:49 -0700
> Subject: Re: [Eeglablist] Interpreting Brodmann Area and Anatomical
> location of Domain in MPT analysis
> Dear Mohammed,
>
> Sorry for belated response.
> I asked the question to Nima and obtained the following response.
>
> 1. The data come from two different atlases.
> 2. Any area less than 0.5 contribution is not shown (wihch is why they
> don't sum up to 1).
> 3. For Brodmann area (in Talairach), it uses the closest cortical voxel.
> Basal ganglia is removed from this.
>
> Probably 1 and 2 explains the difference.
>
> Makoto
>
> On Sun, Sep 18, 2016 at 1:57 AM, Mohammed Jarjees <
> m.jarjees.1 at research.gla.ac.uk> wrote:
>
>> Dear all,
>>
>> I have used Measure Projection Toolbox (MPT) to analyse  motor imagery
>> EEG data.  In some domains I get Brodmann areas contributing and
>> corresponding anatomical areas which are not covering these Brodmann areas
>> at all (example below). If they are complementary, then why BA adds up to
>> 91% and anatomical areas up to  83%?
>>
>>
>>
>> *Brodmann areas*
>>
>> *Probability*
>>
>> BA 25
>>
>> BA 23
>>
>> BA 34
>>
>> BA 29
>>
>> BA 28
>>
>> 0.47
>>
>> 0.16
>>
>> 0.16
>>
>> 0.06
>>
>> 0.06
>>
>>
>>
>> *Total Probability*
>>
>> *0.91*
>>
>>
>>
>> *Anatomical areas*
>>
>> *Probabilities*
>>
>> L Caudate
>>
>> Brainstem
>>
>> R Caudate
>>
>> L Putamen
>>
>>
>>
>> *Total Probability*
>>
>>
>>
>> 0.29
>>
>> 0.23
>>
>> 0.17
>>
>> 0.14
>>
>>
>>
>> *0.83*
>>
>>
>>
>>
>>
>> I understand that anatomical areas can be wider than BAs, but shouldn't
>> it anatomical areas cover BAs?
>>
>> How should I interpret this?
>>
>>
>>
>> Best Regards
>>
>> Mohammed
>>
>>
>>
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>
>
>
> --
> Makoto Miyakoshi
> Swartz Center for Computational Neuroscience
> Institute for Neural Computation, University of California San Diego
>
>
> ---------- Forwarded message ----------
> From: Makoto Miyakoshi <mmiyakoshi at ucsd.edu>
> To: Sanjaya Vipula <sanjayavipula at gmail.com>
> Cc: EEGLAB List <eeglablist at sccn.ucsd.edu>
> Date: Wed, 19 Oct 2016 20:45:54 -0700
> Subject: Re: [Eeglablist] Simultaneous recording of EEG and Robot motion
> Dear Sanjaya,
>
> Right, maybe post-hoc signal processing can treat it well. At least, you
> can optimize the hardware so that the noise can be easier to be handled
> with.
>
> Makoto
>
> On Tue, Oct 18, 2016 at 11:15 PM, Sanjaya Vipula <sanjayavipula at gmail.com>
> wrote:
>
>> Dear Makoto,
>>
>> Exactly as you anticipated, the behavior is really different depending on
>> the conductivity.
>>
>> However the major problem is when the motor is operating the noise level
>> is too high. I am going to try to identify a exact noise band related to
>> the motor movement and to filter it as some of the members have suggested.
>>
>> Thank you for your comment.
>>
>> regards,
>>
>> Sanjaya
>>
>> On 18 October 2016 at 16:56, Makoto Miyakoshi <mmiyakoshi at ucsd.edu>
>> wrote:
>>
>>> Dear Sanjaya,
>>>
>>> Hmm that's a difficult question.
>>> Probably you can test it step by step. For example, while touching the
>>> robot with a rubber hand vs. bare hand, or using wood stick vs. rubber
>>> stick vs. conductive stick, or touch, close but no touch, no touch far,
>>> etc. I'm sure the artifact level is highest when subject's body touches the
>>> robot. Could there be any non-conductive material between a subject and and
>>> the robot to prevent the artifact from contaminating EEG?
>>>
>>> Makoto
>>>
>>> On Tue, Oct 11, 2016 at 12:29 AM, Sanjaya Vipula <
>>> sanjayavipula at gmail.com> wrote:
>>>
>>>> Dear All,
>>>>
>>>> I need some advice on a problem I face during EEG recording.
>>>>
>>>> I am trying to record EEG simultaneously with an exoskeleton movement.
>>>> The subject wear the exoskeleton during the experiments.
>>>>
>>>> When the exoskeleton is not operating normal EEG signals can be
>>>> observed from subject. However when the exoskeleton is operating a huge
>>>> noise can observed in the EEG recordings.
>>>>
>>>> I tried separating the power source of the EEG amplifier and the robot.
>>>> The noise is probably due to the motor operation. How the effect from the
>>>> motor operation can be suppressed in the EEG signal?
>>>>
>>>> Thank you very much in advance for any comments and tips.
>>>>
>>>> regards,
>>>>
>>>> Sanjaya
>>>>
>>>> --
>>>> <sanjayavipula at gmail.com>Sanjaya Vipula Bandara,
>>>> B.Sc. Mech.Eng.(SL), MPhil.Biorobotics(SL), AMIESL
>>>> PhD Student,
>>>> Department of Mechanical Engineering,
>>>> Kyushu University,
>>>> Fukuoka,
>>>> Japan
>>>>
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>>>
>>>
>>>
>>> --
>>> Makoto Miyakoshi
>>> Swartz Center for Computational Neuroscience
>>> Institute for Neural Computation, University of California San Diego
>>>
>>
>>
>>
>> --
>> <sanjayavipula at gmail.com>Sanjaya Vipula Bandara,
>> B.Sc. Mech.Eng.(SL), MPhil.Biorobotics(SL), AMIESL
>> PhD Student,
>> Department of Mechanical Engineering,
>> Kyushu University,
>> Fukuoka,
>> Japan
>>
>
>
>
> --
> Makoto Miyakoshi
> Swartz Center for Computational Neuroscience
> Institute for Neural Computation, University of California San Diego
>
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-- 
James Jones-Rounds
Laboratory Manager
Human Development EEG and Psychophysiology (HEP) Laboratory,
Department of Human Development,
--------------------------------------------
Cornell University | Ithaca, NY
607-255-9883
eeg at cornell.edu
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