We've conducted the same experimental condition using a BioSemi and a Neuroscan system, and noticed that the ERP amplitudes came out much higher when recorded with BioSemi.
Has anyone else noticed anything similar? Can anyone suggest why this might happen (other than simply different participants)?
Bandwidth limiting or trigger jitter on the Neuroscan setup. This does not necessarily mean that there is anything wrong with the Neuroscan, it can well be an operator error or a problem with the stimulus setup.