[Eeglablist] Baseline

[Tarik S Bel-Bahar]

Hello To followup here are some examples of articles and reviews
related to filtering and/or baselining which you might find useful .
There is unfortunately not a well-developed literature on these
topics, either in terms of methods, or comparing the effects of
different approaches on results.

Digital filter design for electrophysiological data–a practical approach

On high-pass filter artifacts (they're real) and baseline correction
(it's a good idea) in ERP/ERMF analysis

High-pass filters and baseline correction in M/EEG analysis–continued discussion

Single-Trial Normalization for Event-Related Spectral Decomposition
Reduces Sensitivity to Noisy Trials


If you're doing connectivity with continuous EEG data the following can help:
Opportunities and methodological challenges in EEG and MEG resting
state functional brain network research






On Wed, Feb 3, 2016 at 9:51 PM, Tarik S Bel-Bahar
<tarikbelbahar at gmail.com> wrote:
> Hello Lucia, here are some notes below that may help. Cheers.
>
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> 1. If you haven't had a chance to yet, consider looking at the baselining
> tutorials and "defaults" for eeglab, fieldtrip, and other programs. You can
> also see what the usual baselines are in their tutorial data. Of course,
> just surveying 20 or 30 articles via Google Scholar from top journals in EEG
> using a protocol similar to yours would give you a good sense of the current
> norm.
> 2. Baselines usually range from -100 to -1000 ms before the period. It
> depends on how clean and stable they are. Some groups ask for a period of
> stillness or fixation on a cross in the second preceding the stimulus onset
> per trial, so as to maximize having a good baseline.
> 3. If you're averaging trials, you can look at your grand averages with and
> without baseline.It won't hurt to see for yourself what the difference is.
> You can also practice with shorter or longer baselines to see the effect on
> your grand averages.
> 4. Baselining is the norm if you are looking at post-stimulus event-related
> activity, including classic ERP's. Steve Luck's book on Intro to ERP
> technique (and slides related to the book) refer to baselining and it's
> effects, as well as other handbooks oriented towards ERP analyses.
> 5. There are various ways to baseline. See some recent articles via Google
> scholar about how to treat ERPs, single-trials, and issues in baselining
> (e.g., a recent article from  Delorme and colleagues that talked about
> taking the average baseline across the whole trial.
> 6. If you are doing pre-stimulus period analyses there are different
> considerations. Just google eeglablist or google-scholar for these articles.
> 7. Overall the baseline should be a relatively "neutral" prestimulus period
> that serves as an adequate and "valid" period against which to compare
> post-stimulus activity. Most classic ERPs and components "pop out" best in
> grand-averages when they are baselined.
> 8. You may also benefit from checking out the EEG Publication standards from
> Keil et al (2014) published in Psychophysiology
> 9. Last, there may be no true baseline or any period in brain activity that
> serves as a true neutral baseline. For example, resting with eyes closed but
> awake is never "just resting". In short there is always brain-mind activity
> going on. In traditional baseline period per trial in classic ERP paradigms,
> it's usually the case that the baseline period contains some mental activity
> related to preparing/expecting the next stimulus/trial/response.
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> On Wed, Feb 3, 2016 at 4:17 AM, Lucia Brini <brinilucia at gmail.com> wrote:
>>
>> Good morning,
>>
>> I’d like to ask you some questions about the baseline: how can I decide if
>> remove it or not? Are there precise criteria? Because I’m doing a study on
>> the five-box task and I can’t appreciate if I have to remove it or not.
>>
>> Thank for your attention.
>>
>>
>>
>> Lucia
>>
>>
>>
>> Inviato da Posta per Windows 10
>>
>>
>>
>>
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>
>