I don't know where the articles source is but this linked study says there are no improved affects with with dual n back training. https://www.ncbi.nlm.nih.go

I don't know where the articles source is but this linked study says there are no improved affects with with dual n back training. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4820261/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4820261/ This meta analysis says there's a small affect https://link.springer.com/article/10.3758/s13423-014-0699-x https://link.springer.com/article/10.3758/s13423-014-0699-x