No, you CAN'T multitask

Not really. Not even if you're a woman. It looks like the human brain, using its bilateral division, assigns two tasks to different hemispheres and does something similar to computer buffering as needed.

"The human prefrontal function seems to be built to control two tasks simultaneously. It means in everyday behaviour we can readily switch between two tasks but not between three. With three tasks the division is limited to only two hemispheres, so there is a problem," Dr. Etienne Koechlin said.

What does that mean if you're doing more than two things at once, or trying to? Pretty simple:

The study suggests that this basic division of the brain into two halves may explain why human beings tend to prefer a simple choice between two options rather than three or more.

The story author then tries to extrapolate to British politics, and perhaps goes too far:

It might even explain why the Liberal Democrats, as the third political party, find it hard to get a look in at general elections.

Nope, not an explanation. Look at Germany, for example. Rather, the British, like the Americans, have a "first past the post" election system which makes it tougher on third parties.

Beyond that misconjecture, though, the full story is worth a read.