[Eeglablist] Brain PSD thresholds by frequency band

[Makoto Miyakoshi]

Dear Alberto,

> I get a lot of ICs that are very difficult to label so I also take in
account PSD.

If the spectra curve is not very smooth or does not follow 1/f, your ICA
decomposition may have a problem.

> However I still dont know if there are any thresholds which I could use
as a reference to evaluate if the IC could be EEG or not.

You cannot apply a simple threshold on one band to call something EEG or
noise. Particularly, the low frequency band has a very high power and
standard deviation as well.

Try my plugin to evaluate spectral fluctuation and cross-frequency
correlations if you are interested in.
https://sccn.ucsd.edu/wiki/CrossFreqPowerSpec

Makoto



On Thu, Jan 26, 2017 at 5:03 AM, Alberto Sainz <albertosainzc at gmail.com>
wrote:

> Dear Makoto and EEGLAB list,
>
> Yes, I mean uV^2/Hz. I get a lot of ICs that are very difficult to label
> so I also take in account PSD. However I still dont know if there are any
> thresholds which I could use as a reference to evaluate if the IC could be
> EEG or not.
>
> Thanks
>
> 2017-01-25 0:45 GMT+01:00 Makoto Miyakoshi <mmiyakoshi at ucsd.edu>:
>
>> Dear Alberto,
>>
>> After performing ICA, you evaluate each IC not only by their PSD but also
>> their spatial location etc. If an IC shows unmistakable EEG characteristics
>> in spatial and time domain, I would take it a brain EEG even if delta power
>> is 0-20 (??? what is 0-20 anyway? uV^2/Hz?)
>>
>> Makoto
>>
>> On Wed, Jan 18, 2017 at 10:32 PM, Alberto Sainz <albertosainzc at gmail.com>
>> wrote:
>>
>>> Hello,
>>>
>>> I am struggling a bit with ICA rejection when measuring PSD. I am not
>>> sure if i am prunning too much data when i look at some results. For
>>> example, I saw references of delta power between 0-6 and others between
>>> 0-20. I am not sure when high delta power (20?) is an artifact or brain
>>> activity.
>>> For alpha band right now i dont get power values larger than 1.
>>>
>>> Do we have any reference for (EEG-measured) PSD thresholds by frequency
>>> band? Also any for typical PSD artifacts like eye blinks?
>>>
>>> I hope I explained it correctly.
>>>
>>> Thanks
>>>
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>>
>>
>>
>> --
>> Makoto Miyakoshi
>> Swartz Center for Computational Neuroscience
>> Institute for Neural Computation, University of California San Diego
>>
>
>


-- 
Makoto Miyakoshi
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego
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