Those who multitask a lot were compared to those who multitask much less.

Here is a link to a longer article that I summarize below:
"The huge finding is, the more media people use the worse they are at using any media. We were totally shocked"   Associated Press. Wednesday, August 26, 2009. Research conduced at Stanford University.
Published in the prestigious Proceedings of the National Academy of Science, August 25, 2009.

An older article: "Multi-tasking adversely affects brain's learning, UCLA psychologists report"
What's new is that even if you can learn while distracted, it changes how you learn"--making the learning "less efficient and useful."

The Stanford research showed:
In their                                                      multitaskers are

ability to ignore irrelevant information         much worse

ability to organize information                      worse

memory                                                          equal

ability to switch tasks rapidly                        worse    [A surprise! That's what they do a lot and they were worse at it!]

ability to focus on a task                                worse
                                        

    The Stanford research did not find anything multitaskers are better at.


What does this mean to you?  It means that if you also do other things while you study, you will not learn as well. Pay full attention to what you are doing (and don't do e-mail or phone or change music every few minutes).