Dear Martin,
If you don't want to change the actual data that you read but just the
time axis you can easily do that by using the timeonset method which
specifies the time of the first sample in PST (in sec). E.g.
D = spm_eeg_load;
D = timeonset(D, D.timeonset-0.023);
save(D);
Changing the third column of the trl will also have the same effect.
Vladimir
On 8 Feb 2012, at 17:32, Martin Dietz wrote:
> Dear M/EEG users,
>
> Delivery of auditory stimuli in our MSR is invariably delayed by 23
> ms relative to the triggers. What would be the best way to adjust
> the trial offset for epoching ?
>
> In the manual one suggestion is to use spm_eeg_definetrial and then
> adjust the first and last sample of trl, but wouldn't it make more
> sense to adjust the offset, in this case trl(:,3) = trl(:,3) +
> round(23*S.fsample/1e3) ?
>
> Best wishes
> Martin
>
> Martin Dietz
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