Four-Channel or More Training

I’m not aware of any data comparing multi-channel with 2-channel options. In areas other than sum-channel options (synchrony, squashes, squishes, etc.) it becomes rather complicated to set up 4-channel protocols without ending up with a large number of inhibit and reward bands.

One of the benefits of 4-channel over 2-channel would be that you can cover a lot of real estate in the brain. For example, in a brain with excessive fast activity on the right hemisphere, instead of training F4 and C4 in one protocol and then repeating the protocol in T4 and P4, you could train pretty much the whole right hemisphere to do the same thing at the same time, saving training time and perhaps making the effect more powerful.

There is, in the brain-trainer package, a 4-channel synchrony design that uses coherence and phase difference values among multiple relationships in the 4 sites.