Nice recommendations, thanks.
Going from dual 2-back to dual 3-back was pretty hard! I had to (1) completely ignore audio, master 3-back with visuals only, (2) completely ignore visuals, master 3-back with audio only, then (3) try to combine them.
14[anonymous]
In case it is of help to anyone, I wrote a summary of Kaufman's book.
A lot of my significant personal improvement happened as a result of highly measurable progress and tight feedback loops. For example: