bdf import, 16 bits events

Clemens Maidhof clemens.maidhof at HELSINKI.FI
Tue Jan 19 17:31:56 CET 2010

Dear Fieldtrip users,

we are using 16 Bits for coding events in BDF data (i.e., all 16 pins
for trigger input of the BioSemi connector used; 8 Bits for Presentation
and 8 Bits for another device). However, when importing the bdf-file
with Fieldtrip into EEGLAB (v7.2.8.18b, Matlab 7.0.8), all event codes
with a value higher than 28 (from Bits 9-16) seem to be incorrect: these
triggers are recognized, but their value is the sum of an addition of
the actual value with a value from the first 8 bits.
During recording, the BioSemi software shows the correct events in the
acquisition software, and also when imported into BESA all correct event
codes are there. So we thought this has probably to do with the
import-function in fieldtrip.

Has anybody encountered the same problem or maybe even better, knows a
solution ;-) ?

Thanks a lot in advance for any hints and tips!

Clemens Maidhof
Cognitive Brain Research Unit, Department of Psychology, University of
Helsinki & Finnish Centre of Excellence in Interdisciplinary Music
Research, University of Jyväskylä, Finland
clemens.maidhof at

The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also and
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the fieldtrip mailing list