The actual test, in any case:
> In each of their tests, the researchers split their subjects into two groups: those who regularly do a lot of media multitasking and those who don't.
> In one experiment, the groups were shown sets of two red rectangles alone or surrounded by two, four or six blue rectangles. Each configuration was flashed twice, and the participants had to determine whether the two red rectangles in the second frame were in a different position than in the first frame.
> They were told to ignore the blue rectangles, and the low multitaskers had no problem doing that. But the high multitaskers were constantly distracted by the irrelevant blue images. Their performance was horrible.
> Because the high multitaskers showed they couldn't ignore things, the researchers figured they were better at storing and organizing information. Maybe they had better memories.
> The second test proved that theory wrong. After being shown sequences of alphabetical letters, the high multitaskers did a lousy job at remembering when a letter was making a repeat appearance.
> "The low multitaskers did great," Ophir said. "The high multitaskers were doing worse and worse the further they went along because they kept seeing more letters and had difficulty keeping them sorted in their brains."
So the usual soft science dreck of investigating vague, ill-defined umbrella terms such as “multitasking” by investigating a highly constructed, specific scenario that never occurs in real life that falls under it, and then extrapolating this result to all of real life, not to mention inferring causation from correlation.
Logic of the form of “Eating is bad, because we fed our test subjects objects human beings normally never eat, and we concluded it was very averse to their health to eat marbles, shards of glass, and mercury.”