Читать книгу Sort Your Brain Out - Джек Льюис, Адриан Вебстер - Страница 33

Not that long ago it was rare for people to watch TV while simultaneously surfing the internet. Now such “dual‐screening” is commonplace. Studies investigating this behaviour revealed that people switch their attention between screens on average about 120 times during a 30‐minute viewing period. That's about four times per minute or once every 15 seconds! Could this herald a brave new era of prolific multitasking, enabling us to squeeze yet more efficiency out of our busy, information overloaded lives?

The first thing to get to grips with is that there is no such thing as true multitasking. Yes, we can walk down the street while talking on the phone, but that's partly because our walking expertise is so innate that we can do it entirely without thinking and partly because it's governed by its own dedicated brain resources. But our brains haven't yet evolved the capacity to simultaneously perform two completely different tasks that require the same cognitive resources. The truth is that most mental tasks that feel like they are being done in parallel actually involve rapid switching between the two. And, anytime a human brain switches from one task to another, there is an associated cost. You don't pick up where you left off straight away when your mind returns to the “other” task. There is always a slight delay – known as a “switch cost” – in remembering exactly where you were so you can continue with the original task.

While women may be famous for their multitasking skills, the idea that all those tasks are actually happening in parallel is an illusion. Women who seem to have a superior ability in this regard, compared to most men, are usually better at minimizing the inevitable switch cost. While some people, through regular, intense and consistent training, have become extremely adept at making this process as efficient as possible, there is nonetheless always a small, unavoidable time penalty associated with each switch between tasks. In men the switch cost tends to be larger than in women, but there is always a measurable negative consequence of switching between multiple cognitive tasks in both, as compared to simply focusing on one task at a time.