Some examples of what can hurt or harm working memory include things like Twitter. When you’re receiving an endless stream of information when you’re a ‘tweeter’, it’s also very succinct, so there’s no need to process or manipulate that information, it’s not a dialogue unlike something like Facebook where you might be updating your status and so on.
Fortunately, Mark Henderson at Times Online puts things in the right place:
Most people I know who use Twitter see it as an interactive tool for conversing with wide groups, and for drawing like-minded people’s attention to information that might interest them. It’s interactive, full of links, and information-rich. It’s a misconception that the 140-character limit makes depth impossible. In fact, to me, Twitter seems to build social networks just as effectively as Facebook, which Alloway thinks might improve working memory.
Mark is right, and I have a few examples that can explain why I think so: