Baseline power accumulation in event/task-related EEG data?

Hello everyone,

i have a question regarding event/task-related EEG data. Are there any indications that baseline power increases from trial to trial? For example, in the case of a fine motor task (e.g. finger movement), that baseline power slowly accumulates from trial to trial through the task (baseline power trial 1 < trial 100)?

I am aware that the time between trials should be such that there is a return to baseline. However, if the power increases slowly, could it be that an effect is only seen after 70-80 trials?

Does anyone have experience or know of studies that can provide guidance on this issue?



Huh, interesting. That could happen if there is a fatigue effect or learning/adaptation effects. The way to test for it would be to extract the baseline power per trial, and then do a linear fit of power by trial number. You could run that as a simple regression or just a correlation.

Off-hand I don’t know if there’s literature on this in motor tasks. There is a literature on posterior alpha power fluctuations predicting perception, although that’s usually trial-to-trial fluctuations and not task-wise the way you’re talking about it.

Thanks for your quick reply Mike!

I mainly work with resting-state EEG recordings and examine the mean power spectrum of different frequency bands before and after an intervention (5min pre EEG → Intervention [e.g. 10min meditation, dance, whatever] → 5min post EEG). For example, I observe higher alpha and beta power from pre to post. I’m a bit stuck at the moment as I’m wondering if it makes sense to use event/task-related EEG findings (TF, ERD, ERS, … analyses) for interpretation.

I’m a bit undecided…and very skeptical :slight_smile: First of all, it’s of course a different methodology and with event/task-related EEG recordings one assumes that the response to the task/event is only observed for a short time and then falls back to the baseline. So there is no sustained change in “brain/mind state” e.g. due to higher alpha and beta power in the baseline (hence my initial question). On the other hand, my pre-intervention-post resting state design also represents some kind of event/task (a big one :D), just on a different timescale.

This all came to mind when I was thinking about using the short-term effects of the event/task-related EEG to interpret longer-term/persistent changes in the resting state. I hope it is not too confusing and you can understand my “problem” :smile:

lol, I wouldn’t call it a “problem” – it’s a challenge :slight_smile:

I don’t know what’s best in your case, but perhaps you can refer to this video for some inspiration. In particular, starting at around minute 13 where I talk about the possibility of differences in baseline power across conditions.

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Hi Niko,

Interesting challenge :slight_smile:
Not sure if this help, but maybe see this: Temporal Dynamics of Reactive Cognitive Control as Revealed by Event-related Brain Potentials
Is rather conflict adaptation. I find it interesting because they model how the effects change across trials,

Maybe it can give you some ideas,
Good luck in your research!


Hi Jose,

thank you very much for your advice! I will have a closer look at this paper.