Brand new studies by British researchers show that engagement with technology has different effects on working memory, the type of memory that allows you to remember and use information. Spending time on Facebook appears to have about the same effect as working Sudoku puzzles, but spending time on Twitter and YouTube were likely to weaken memory.
It also appears that video games that involve strategy and planning also succeed in improving working memory. At the core of the results is the fact that activities that require you to keep track of information and actions and then planning your next actions train the working memory. To the contrary, instant information sources like twitter or YouTube are just about absorbing continous streams of short information negatively impacting memory. (see previous blog on the Ibrain)