EEGLAB time frequency question

I would like to hear an explanation of the function of the no baseline checkbox in EEGLAB's time frequency analysis. First of all, I am new to EEGLAB. I would like to know the effect of applying the no baseline checkbox during data analysis. When the no baseline checkbox was applied, the frequency decibel line on the left side of the graph was not activated as a straight line. Conversely, when the no baseline checkbox was not applied, the decibel line was activated. When the no baseline checkbox is applied, a neat graph shape can be obtained, so it is preferred, but I do not know why the decibel line on the left is disabled. I would like to know if the no baseline is effective in removing noise and what it does.

[Walter Roberson]

This is not a matlab question. You should be asking in a support resource for that third party program.

Answer 1

[Angelo Yeo]

First of all, like @Walter Roberson said this is not a EEGLAB forum. Please ask such questions in EEGLAB forums. Also, you can find more information by googling "baseline correction for ERSP". I believe that is the terminology that most neuroscientists use. Below are my comments based on stuff I learned in my graduate school when researching on EEG.

1) The reason why ERSP result without baseline correction look "NEAT" is because they are not post-processed by subtracting and dividing by baseline-period averaged power.

2) Whether to correct baseline depends on the purpose of your analysis, but many EEG researches make use of baseline correction not only because they are not interested in brain activities that are not related to experiment but also it's easier to compare results with relative powers. Main purpose of baseline correction is to make it easy to figure out what happened after the event at 0 sec. However do not forget that this does depend on the purpose of your analysis.