Can I run an EEG protocol using mixed electrode types (Dry, Gel, and Foretrodes)?
Yes. It is possible to perform an EEG recording using a combination of Drytrodes, Geltrodes, and/or Foretrodes within the same protocol. This flexibility allows you to adapt the montage to your specific research or clinical needs.
What should you keep in mind?
With newer-generation devices and the latest NIC versions, the system automatically performs an impedance check before starting the recording.
The acceptance thresholds for impedance depend on the electrode type selected in the software.
For this reason, it is important to:
Correctly assign the electrode type (Dry/Foretrode or Gel) in NIC before running the impedance check. The Drytrodes will have higher impedance values acceptance.
Ensure that each electrode is properly prepared and positioned.
Will mixing electrode types affect signal amplitude?
There should not be inherent amplitude differences simply due to mixing electrode types.
However, higher electrode–skin impedance can result in increased channel noise.
For example, dry electrodes will show higher impedance than gel-based electrodes, those channels may present a higher noise level.
This does not necessarily mean the signal is invalid, but it may affect overall signal quality depending on your study requirements.
Best practice recommendations
Perform appropriate skin preparation when required (especially for gel-based electrodes).
Verify impedance values before starting the recording.
If noise levels are higher than expected, consider re-adjusting the electrode or improving contact or using only one type of electrodes.
If you are unsure whether your impedance values or signal quality are acceptable, feel free to contact our Support team and share impedance screenshots or sample recordings. We will be happy to assist you.