[FieldTrip] problem with reading .edf+ files

[Schönherr, Margit]

Hello,

I want to analyze invasive EEG data and I have problems reading the data correctly. The data are continuous and I used BESA to convert them to .edf format. When I read them into matlab, however, the data are not continuous anymore, but segmented into very short trials. For example, a data set of 1 hour is split into 8229 trials of 0.43 s length. Even more confusing, the trial length differs across subjects.

What is the difference between .edf and .edf+? BESA Research produces the latter, could this be the reason for the issue?
I also tried to track down the place where the segmentation into trials is done, but I ended up at line 111 of read_edf.m (EDF.Dur = str2num(H1(245:252))  % 8 Byte  # duration of data record in sec).

I would be very glad if someone could tell me, how to read the data correctly with fieldtrip. Thanks!

Best,
Margit