The research on Lumosity has been completed recently. It showed the improvements are specific to the task. There is not a global improvement. I have done some of the free Lumosity exercises, BrainFit, and have a full copy of the Posit Science brain training. I noticed this early on in all three programs.

If someone needs remediation in an area that the Lumosity programs focuses on, it can be worthwhile. Think of it as similar to relearning to walk after a coma. The brain needs to have a basic capability for Lumosity to effect an improvement.