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