Educational Computing Research, Vol. 45 (2) 183-201, 2011
Authors: Lin Lin, Jennifer Lee, Tip Robertson

Main point:

Experiment (n=130, 90% female 23.9 y/o). Two multitasking environments: background video+reading and video+reading (testing both video and reading content afterwards). Background condition resulted better reading scores, test condition better video scores. Different video contents – comedy (positive) and news (negative) had different effects on reading.

Participants achieved better overall results in the background video condition. That is – when one tries to share attention between two sources of information then he actually can store less.

Read: Lin, Robertson, Lee (2009) Reading performances between novices and experts in different media multitasking environments