6 months ago I met a monk. I did a 10 day meditation retreat with him. 

We were exploring around 5 meditation techniques in total. They were all showing different kinds of things and designed for different kind of purposes. 

One of them was "noting". The goal of it - to note more than 6 things/sensations per second. As soon as your brain starts doing that - it starts breaking, as if getting short-circuit. 

After around 4 days I started noting 6 - 10 things, depending on a session. 

I've had out-of-body experience, DMT-like experiences, kundalini awakening and many others. 

Can't imagine what would happen if I went above 10+.