Who hasn’t done it? You’re driving your car, on the phone, and jotting down a name or number – all at the same time. You’re multi-tasking. And with two eyes, two ears, two hands and two feet, there are plenty of tools to work with – right? Yes, but, and it’s a big but, one brain is guiding them all, and therein lies the problem.
First the good news.
It is possible to multi-task – you are living proof, and doing it all the time. Thank your basal ganglia, pictured right.Nestled deep beneath the cortex, the basal ganglia is a complex set of subcorticol structures that store your life experiences and habits. Here you will find fail-safe programs that allow you to act on auto-pilot – no need to think too hard about changing the gears as you drive, the procedure for brushing your teeth or where the digits on your mobile phone are. These programs run themselves, and you are just along for the ride. The basal ganglia is like an enormous data warehouse of every skill you’ve ever acquired, every emotion you regularly experience and every habit, good or bad, you’ve ever established.
Even better news is that the basal ganglia is so good at running these programs, it will happily run several concurrently: yes you can eat your breakfast, make the kids school lunch, watch the TV weather forecast and empty the dishwasher – at the same time. In fact, the basal ganglia will want to step in and establish a program for anything you do or think about repeatedly – and automate it, so it’s easier next time around.
Now for the bad news.
It is the prefrontal cortex, and not the basal ganglia, that you require to hold current information in working memory,consciously process that information and deal with new or complex issues. There is no autopilot here. And where the basal ganglia operates with free association and can draw on almost unlimited capacity, the prefrontal cortex operates via serial processing, has limited daily capacity, and struggles constantly with what to prioritise and bring to conscious thought. So requiring a serial processor to multi-task is a tall order. Studies of dual task interference have shown that performance deteriorates significantly as soon as we attempt more than one cognitive task at a time. Recent studies targeting multi-tasking specifically show deficits in memory and learning when juggling cognitive load.
- Myth 1: multi-tasking makes you more productive. Each additional task you undertake concurrently with others reduces performance in them all.
- Myth 2: you can rebound quickly from distractions. There is a refractory period in the brain following a distraction in concentration that can take up to 15 minutes to restore.
Using your whole brain, and being aware of its strengths and limitations, can provide some strategies to improve our multi-tasking abilities.
- Transfer whatever you can to the basal ganglia. That requires repetition and reinforcement.
- Organize your daily activities so that you tackle one mentally taxing task at a time.
- Minimize the possibility of distraction when you need to complete a mental task.