[Eeglablist] Neuroscan files and scale distortion

[Isabella Bower]

Hi EEGLAB list,

Would anyone have any advice or experience with importing files recorded using Neuroscan/Curry – but finding very low amplitude/scale distortion occurring? We thought this may be due to either some sort of autoscale adjustment from having a trigger and unused chans, but channel removal doesn’t resolve this. This low amplitude seems to be at the imported data stage (pop_loadcurry) as we tried plotting the ERP’s across all steps to ensure it wasn’t introduced in preprocessing. The plotted ERP’s seem to be fine in waveform, but just a very low amplitude appearing for visual ERP’s to validated tasks (less than +/- 1 µV). Unsure if there could be a setting responsible in the Curry interface that may have caused this (will try to get access to the program for checking) and/or whether anything more can be done in EEGLAB to identify the cause and resolve.

Thank you in advance,

Bella