The brain cannot multitask

When it comes to paying attention, multitasking is a myth. Many of you might argue that at some level we can and do multitask. For example, we eat and talk on our phones at the same, the brain controls our breathing, our heart beats, processes all kinds of information coming from the various senses. All at the same time. 

There is a fundamental difference between the different activities just mentioned and say talking on the phone while driving. Driving and talking on the phone both require our attention. It is difficult to pay attention to the conversation on the phone while paying attention to the roads and traffic. Each requires a certain amount of brain power and fact of the matter is, when driving needs our attention, we focus on that (a context switch) which takes away from the phone conversation. Sometimes what happens is you are on the road while in an engaging topic, and then you later realize you missed your exit. You tell the person to hold on while you get back on track. This is a context switch. You have to focus on getting back on track and ignore the conversation. It's a natural reaction. 

Breathing and heart beats do not require our attention. It just happen automatically. Eating while talking on the phone is also automatic. You don;t have to think about picking up the food and putting in your mouth then chewing it. It happens automatically. You're attention can then be spent on the phone. 

To understand this better, lets take a look at what happens when we need to do the context switch. Let's use the example of driving and talking on the phone. You are about to start driving:

1) Shift alert. When you begin driving, blood quickly rushes to the part of the brain that works like a switchboard (the anterior prefrontal cortex for you brain nerds). This simply means the brain is being alerted about a shift in attention.

2) Rule activation for driving. In this step, two things happen:

• a search query in the brain occurs to find the neurons capable of driving (keeping track of the traffic, the directions, turn signals, etc).
• once the neruons for driving are found, they are then activated

The phone rings....

3) Disengagement. Your sensory systems hears the phone ring. Since the rules for talking on the phone are different from the rules for driving, the brain must disengage from driving (scary huh?) before the phone can be picked up. The switchboard is consulted as the shift alert step happens again.

4) Rule activation for talking on the phone. Just like in step 2, two things happen:

• search for the nuerons cablable for picking up and talking on the phone
• activate neurons. 

As you can probably see, the context switch is a time consuming process. It has to happen sequentially. This is why while driving and talking on the phone is bad!! This is why you can get lost, this is why terrible accidents happen daily on our roads. As John Medina puts it, if you are good at "multitasking" that just simple means you have a good working memory (which funny enough, many women seem to have; so am I just crazy?)

Needless to say, because of all the context switching, it takes longer to finish all the tasks you need to do. Even worse, you will make more mistakes in doing those tasks because you have to keep track of all the things going on. Given such inefficiencies, it makes you wonder why schools and business take pride and demand multitasking? Why take three to 5 different classes in one term? Why try to perform several multiple different tasks at work (answer email, phone calls, write reports, etc)? The simple answer: to get more done. The problem: it actually causes you to get LESS done. go figure.