Researchers studied 152 adolescents who played video games for an average of 12.6 hours per week. They found that gaming correlated with increased thickness in the left dorsolateral prefrontal cortex and the left frontal eye field.
A study of people aged 60-85 years old published in Nature found that cognitive control is improved by playing a custom-designed, three-dimensional video game. That is, the participants enhanced their ability to multi-task, as well as their working memory and their ability to sustain attention.
This echoes a portion of the book Everything Bad is Good for You.