[FieldTrip] Spike artifacts 7-12Hz

Blume Christine christine.blume at sbg.ac.at
Thu Nov 29 21:56:27 CET 2018


Dear Matthias,


I would guess that if the ICA nicely removes this component that might be the best approach, it is also commonly used to remove eye blinks or ECG artefacts from data. You can also try to design your own filter if the artefact is really centered around 9 Hz,  although filtering is an issue on its own.


Hope this helps!

Christine


________________________________
Von: fieldtrip <fieldtrip-bounces at science.ru.nl> im Auftrag von "Matthias Möller" <MatthiasCMoeller at gmx.de>
Gesendet: Donnerstag, 29. November 2018 16:55:26
An: fieldtrip at science.ru.nl
Betreff: Re: [FieldTrip] Spike artifacts 7-12Hz

Dear all,

thanks a lot for your prompt answers, that is really supportive, thank you!


Testing is already done, so I can't test for devices anymore whether they produce artifacts or not.

To be honest I'm running out of ideas which devices might have been responsible. I used bluetooth headphones where the frequency is a lot higher, and in some sets I don't have the artifacts although subjects were stimulated using the same headphones. It's not in all recordings but in some. If it's in the recording, then it is throughout the whole one.
It's not influenced by referencing or filtering.

Deep brain stimulation seems to be to high in frequency as well.

For now the only thing I can do is to remove the respective components indeed.
Does anyone else maybe have an idea about how to filter out/get rid of those artifacts?

Best,

Matthias

Gesendet: Donnerstag, 29. November 2018 um 10:08 Uhr
Von: fieldtrip-request at science.ru.nl
An: fieldtrip at science.ru.nl
Betreff: fieldtrip Digest, Vol 96, Issue 22
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Today's Topics:

1. Re: Spike artifacts in EEG, 7-12Hz (Blume Christine)
2. Re: Spike artifacts in EEG, 7-12Hz (Marcin Koculak)
3. Re: Spike artifacts in EEG, 7-12Hz (anne Hauswald)
4. 15 PhD positions in Marie Slodowskwa-Curie Innovative
Training Network “INFANS" (Uwe Graichen)


----------------------------------------------------------------------

Message: 1
Date: Wed, 28 Nov 2018 15:04:32 +0000
From: Blume Christine <christine.blume at sbg.ac.at>
To: "fieldtrip at science.ru.nl" <fieldtrip at science.ru.nl>
Subject: Re: [FieldTrip] Spike artifacts in EEG, 7-12Hz
Message-ID: <07979b73a31a4cb5bd02398211e36ec6 at sbg.ac.at>
Content-Type: text/plain; charset="utf-8"

Dear Matthias,

Admittedly, I do not know what this could be. While the first step should of course be to find the source and eliminate this (any devices in the EEG lab, artefact from the acoustic stimulation/headphones, …), in case you are unable to find it, you could remove the component(s) that correspond to the artefact. But as I said, the first goal should always be to record clean data…

Best,
Christine


Von: fieldtrip <fieldtrip-bounces at science.ru.nl> Im Auftrag von "Matthias Möller"
Gesendet: Mittwoch, 28. November 2018 15:16
An: fieldtrip at science.ru.nl
Betreff: [FieldTrip] Spike artifacts in EEG, 7-12Hz

Dear all,

my name is Matthias and I am relatively new to the field of EEG analysis. I'm currently carrying out a study on the effects of natural sounds on the quantitative EEG in patients with Parkinson's disease at the universities of Vanvouver and Marburg.

Right now I'm experiencing these weird artifacts as seen in the screenshot. It's sharp spikes, looking similar to ECG artifacts, but in frequencies of 7-12Hz.
They are also showing up in the independent components after ICA as well.

The recording was done at a sampling rate of 500 Hz, I've applied a Band-Pass filter from 1-249Hz and two notch filters, 60 and 120 Hz (recording took place in Canada).

Has anyone seem similar artifacts before and maybe even knows how to get rid of them?

Many thanks in advance and all the best,

Matthias
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Message: 2
Date: Thu, 29 Nov 2018 00:19:13 +0100
From: Marcin Koculak <koculak.marcin at gmail.com>
To: fieldtrip at science.ru.nl
Subject: Re: [FieldTrip] Spike artifacts in EEG, 7-12Hz
Message-ID:
<CAJDQ6z46sUQacPVrWxWiNf8Hf25QeE=Hf4S92_kG--xnkdjjaQ at mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Dear Matthias,
I have never seen such artifacts, but if you are working with patients with
Parkinson's, have you checked if they have deep brain stimulation devices?
Maybe that is causing the artifacts in the data?
best,
Marcin

śr., 28 lis 2018 o 16:11 Blume Christine <christine.blume at sbg.ac.at>
napisał(a):

> Dear Matthias,
>
>
>
> Admittedly, I do not know what this could be. While the first step should
> of course be to find the source and eliminate this (any devices in the EEG
> lab, artefact from the acoustic stimulation/headphones, …), in case you are
> unable to find it, you could remove the component(s) that correspond to the
> artefact. But as I said, the first goal should always be to record clean
> data…
>
>
>
> Best,
>
> Christine
>
>
>
>
>
> *Von:* fieldtrip <fieldtrip-bounces at science.ru.nl> *Im Auftrag von *"Matthias
> Möller"
> *Gesendet:* Mittwoch, 28. November 2018 15:16
> *An:* fieldtrip at science.ru.nl
> *Betreff:* [FieldTrip] Spike artifacts in EEG, 7-12Hz
>
>
>
> Dear all,
>
>
>
> my name is Matthias and I am relatively new to the field of EEG analysis.
> I'm currently carrying out a study on the effects of natural sounds on the
> quantitative EEG in patients with Parkinson's disease at the universities
> of Vanvouver and Marburg.
>
>
>
> Right now I'm experiencing these weird artifacts as seen in the
> screenshot. It's sharp spikes, looking similar to ECG artifacts, but in
> frequencies of 7-12Hz.
>
> They are also showing up in the independent components after ICA as well.
>
>
>
> The recording was done at a sampling rate of 500 Hz, I've applied a
> Band-Pass filter from 1-249Hz and two notch filters, 60 and 120 Hz
> (recording took place in Canada).
>
>
>
> Has anyone seem similar artifacts before and maybe even knows how to get
> rid of them?
>
>
>
> Many thanks in advance and all the best,
>
>
>
> Matthias
> _______________________________________________
> fieldtrip mailing list
> https://mailman.science.ru.nl/mailman/listinfo/fieldtrip
> https://doi.org/10.1371/journal.pcbi.1002202
>
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Message: 3
Date: Thu, 29 Nov 2018 09:26:20 +0100
From: anne Hauswald <anne.hauswald at me.com>
To: FieldTrip discussion list <fieldtrip at science.ru.nl>
Subject: Re: [FieldTrip] Spike artifacts in EEG, 7-12Hz
Message-ID: <CFB17262-B923-4234-AE1B-AD2BBDE6F50B at me.com>
Content-Type: text/plain; charset="utf-8"

Dear Matthias,

I don’t know where your artifacts come from, but I have some suggestions that might help you getting close to the source.
- is it transient or do you find it throughout the whole recording?
- do you find it in more than one recording?
- does your choice of reference or filtering influence it?

Not sure it will lead to something, but at least you will have a better understanding of this artifact.

Best Anne


> Am 28.11.2018 um 15:15 schrieb Matthias Möller <MatthiasCMoeller at gmx.de>:
>
> Dear all,
>
> my name is Matthias and I am relatively new to the field of EEG analysis. I'm currently carrying out a study on the effects of natural sounds on the quantitative EEG in patients with Parkinson's disease at the universities of Vanvouver and Marburg.
>
> Right now I'm experiencing these weird artifacts as seen in the screenshot. It's sharp spikes, looking similar to ECG artifacts, but in frequencies of 7-12Hz.
> They are also showing up in the independent components after ICA as well.
>
> The recording was done at a sampling rate of 500 Hz, I've applied a Band-Pass filter from 1-249Hz and two notch filters, 60 and 120 Hz (recording took place in Canada).
>
> Has anyone seem similar artifacts before and maybe even knows how to get rid of them?
>
> Many thanks in advance and all the best,
>
> Matthias
> <9 Hz Artefact.JPG>_______________________________________________
> fieldtrip mailing list
> https://mailman.science.ru.nl/mailman/listinfo/fieldtrip
> https://doi.org/10.1371/journal.pcbi.1002202

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Message: 4
Date: Thu, 29 Nov 2018 10:08:29 +0100
From: Uwe Graichen <uwe.graichen at tu-ilmenau.de>
To: fieldtrip at science.ru.nl
Subject: [FieldTrip] 15 PhD positions in Marie Slodowskwa-Curie
Innovative Training Network “INFANS"
Message-ID: <fced2ce4-7d01-71bb-6134-1df7d0423293 at tu-ilmenau.de>
Content-Type: text/plain; charset="utf-8"

As part of the Marie Skłodowska-Curie Innovative Training Network
“INFANS - INtegrating Functional Assessment measures for Neonatal
Safeguard" http://www.infansproject.eu , funded by the European Union’s
Horizon 2020 Research and Innovation Programme, we advertise 15 PhD
positions.

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designed to overcome the severe shortage of clinically viable means to
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programme in biomedical engineering, signal processing and clinical
procedures to train a new generation of creative and entrepreneurial
young researchers.

The individual research projects of the early stage researchers (ESR)
encompass the topics: technological innovation, industrial development,
clinical validation, identification of neonatal healthcare needs. As
part of their research the INFANS ESRs will develop a novel platform for
high quality, clinically-viable EEG-NIRS monitoring accessible
worldwide. Well-targeted visits and secondments, soft skills and dynamic
training activities, an Open Science strategy, extensive involvement of
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mobility that will complement local doctoral training. The INFANS ESRs
will become independent researchers with improved career prospects in
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capacity for innovation in biomedical engineering.

The institution and the place where the different ESR projects will be
carried out, the scientific supervisor(s), individual research project
titles, and contact person for each available position can be found
specified in the attached document.

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