We are pleased to announce that we are now able to provide head caps for the ActiveTwo system with 128 positions derived from the expanded 5% Electrode System. These new caps incorporate positions that are a variation on the layout depicted on page 4, Figure 2 in:
Oostenveld and Praamstra. The five percent electrode system for high-resolution EEG and ERP measurements. Clinical Neurophysiology 112 (2001) 713-719.
The most important advantage of these expanded 128 channel head caps compared to standard 128 caps is the fact that 64 of the positions overlap exactly with the standard Biosemi 64 channel layout, which is based on the 10/20 system.
This overlay is particularly valuable for labs doing some studies with 64 channels and other studies with 128 channels. By sub-sampling the 128 channel data, recordings from the two different cap densities can be made 100% compatible.
These new 128 channel caps can be labeled with the unique names prescribed in the Oostenveld and Praamstra article, or they can be labeled as A1-D32. A1-D32 labeling has the advantage that it is possible to use the same A and B electrode sets for 128 and 64 channel recordings without any usability challenges.
A CFG file for ActiView with the 5% system electrode names is available from Cortech Solutions support.
These new 128 channel head caps will ultimately be available from Extra Small to Extra Large in size. To see the model numbers and descriptions of presently available 128 channel head caps, visit this link.