“The brain is like a muscle. The more you use it, the stronger it becomes.” While not false in other contexts, those words aren’t referring to using brain training apps.
With honeyed declarations of enhancing memory, focus, and critical thinking, Lumosity, Peak, and Elevate are amongst the top education mobile applications. Much like your (hopefully) regular gym sessions, “brain training” apps have long maintained that users can improve various domains of cognitive abilities with daily practice. Past studies tell us that, indeed, the brain can be trained for specific types of tasks (e.g., working memory, spatial memory, etc.), but how strong are these effects and for how long do they last? More importantly, the critical issue is not whether brain training can improve performance on whichever puzzle the app gives you, but whether those benefits transfer to real life applications or lead to general improvement in level of cognitive functioning.
An additional oversight is that all of these apps are being marketed to the general, non-patient population when they’ve really only been used in patients. A massive 6-week study trained 11,430 healthy participants on cognitive tasks aimed at improving reasoning, memory, planning, visual skills, and attention. Although enhanced performance was observed in every one of the cognitive tasks in which subjects were trained, researchers found no evidence that this had any effect on untrained tasks, even when tasks were cognitively closely related. Another study that used Lumosity in 128 healthy young adults concluded that there appear to be no benefits of the app, compared to those gained from playing standard online video games.
Brain training apps are certainly effective for drilling you on one type of thing, like memorizing word lists or improving visual accuracy, but have not yet been proven to aid in overall cognitive ability. Nevertheless, these types of apps could still be helpful for patients at risk of cognitive decline, recovering from stroke, or living with disabilities. As always, solid scientific empirical evidence should be necessary before something goes on the market.