[FieldTrip] equal number of trials across conditions

Vitória Magalhães Piai vitoria.piai at gmail.com
Sun May 20 11:53:58 CEST 2012

Hi everyone,

I'm working on a dataset (ERPs, but this is not that relevant for the 
question, I believe) for which one condition elicited more errors than 
the other.

I'd like to have both conditions with the same number of trials in the 
Ideally, I'd throw away the noisiest trials from one condition, instead 
of just start throwing away trials at random.

I was thinking of using z-scores for that but I was wondering if any of 
you has already done this before and how. What would be the best way to go?
Take the mean amplitude across all trials (collapsed over condition or 
not?) and calculate the z-score for each trial individually? Then take 
out the one with the largest scores? How does this approach sound?
Does FT keep information about the variance for each trial somewhere in 
the output of an artefact rejection function? Or would I have to compute 
that myself?

I'd appreciate any suggestions or feedback.

Cheers, Vitória

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