Readers may be interested in an earlier study by Susanne Jaeggi and Martin Buschkuehl in which they used brain imaging to study brain activation during the dual n-back task at n=2 and n=3.
“On how high performers keep cool brains in situations of cognitive overload.”
Jaeggi SM, Buschkuehl M, Etienne A, Ozdoba C, Perrig WJ, and Nirkko AC
Cognitive, affective & behavioral neuroscience 7(2):75 2007 Jun
The results indicate that at the most challenging task (n=3) the brains of the high performers showed more distinct activation patterns and less overall activation than the brains of the low performers.
There’s no definitive overall conclusion, but there’s a lot of interesting discussion and hypothesis.
Reading this study put me in mind of the comments made by Brett, a Brain Fitness Pro customer from New Jersey. Brett described a feeling of overall cool-headedness and self-awareness after he’d completed the first training period.