Polarity of ERP signal
I am using a cyton board with a daisy board attachment (see pictures in the end). This is for an ERP based study.
The processing steps involve band pass filtering the signal to stay
between 0.05 - 50 Hz using an FIR filter, followed by averaging of CP channels,
baseline correction and detrending. The resulting ERP signal for neutral visual
stimuli (see below) looks reversed.
I was looking at a previous forum post about the polarity of the signals recorded (https://openbci.com/index.php/forum/#/discussion/comment/9867).
I was wondering if this is because of the
reversed polarity due to attaching the electrodes in the negative pins (see
attached) and we should simply flip the signal