Why Do We Turn Down the Radio When We're Lost?

Turning down the radio instead of looking at a map when you find yourself lost or driving on unfamiliar roads may seem like a strange thing to do, but as it turns out, it's not strange at all. It's your brain's natural reaction to the circumstances.

In order to understand why you turn down the radio when you're lost, you have to understand a few things about how the human brain works. The human brain has three parts: the cerebrum, the largest part of the brain, and the part that controls your higher cognitive functions such as language and emotions; the cerebellum, which controls your muscle movements and balance; and the brainstem, which controls all the body's automatic functions, such as breathing, as well as acting as the relay station between the spinal cord and the cerebrum and cerebellum.

As you go through your day, you collect information about your environment through your five primary sensory systems: taste, hearing, smell, touch and vision. Each sensory system has its own sensory neurons, and each tells the central nervous system about changes in your environment. The brain, which is part of the central nervous system, combines all this information and decides how to proceed. That process is called encoding. The brain is constantly evaluating what should be its primary task — the chief task the brain focuses on — and its secondary task, the concurrent task that gets less focus.

The brain's ability to switch back and forth between its tasks is called attention switching, and it comes with a price: When the brain switches its focus and attention from one task to another it's fast, but it's not instantaneous. Those fractions of a second spent attention toggling may slow down your performance, including minor delays in your reaction times. And when you're lost, that could mean the difference between seeing or not seeing the street sign you need to spot.

People often turn down the radio when driving in crowded urban areas, looking for a specific address, or driving in dangerous conditions (such as torrential rain or during a snowstorm) because those activities require more concentration than during a typical drive. Turning the radio down or off eliminates a task from the brain's to-do list, shifting its focus to the most important task: finding the way.

At work, 11 percent of us write our to-do lists during meetings, and more than half of us check email while we're on a phone call. Many of us like to think of ourselves as expert multitaskers — and we consider performing two or more tasks at the same time, performing two or more tasks quickly back to back, or switching rapidly between two tasks to be the norm. Yet what you might not realize is that such alleged productivity isn't all it's cracked up to be. Although many of us are proud of our multitasking abilities, and despite our fondness for juggling multiple cognitive tasks simultaneously, the brain isn't actually built to multitask [source: Faw, Sollisch].

Give the brain one task, and it's no problem. Two tasks, and the brain divides and conquers them. More than two tasks, though, and things change. With divided focus and attention, the brain begins to perform less effectively, and is prone to making more errors.

The human brain, it turns out, doesn't have infinite resources, and it handles tasks sequentially — yet it's able to switch from task to task so rapidly we think we're multitasking. And because we have a limited capacity when it comes to focus and attention, especially when we're concentrating hard, the brain has to choose what information gets processed and encoded. For example, your brain can handle either visual driving-related tasks (looking for an address) or rocking out. Not only is the brain incapable of multitasking, when we try to multitask each goal competes for the brain's available resources. Multitasking creates a traffic jam, and in the end we perform poorly on each task as a result. We overlook important information, we make errors, and we end up remembering less information overall. When the brain is forced to switch rapidly from task to task it doesn't perform as well as it does when it can focus on one thing at a time. Multitasking increases our error rate by as much as 50 percent. And it doesn't speed things up, either — trying to multitask doubles the amount of time it takes to perform each of the tasks at hand [source: Parrish].

When you introduce a third task, the brain's prefrontal cortex, which makes executive decisions, will discard the one it considers the least important [source: Telis]. It's got to do with the limits of our sensory system; we tune out what our brain determines to be of lesser importance. When we're lost or when we have to perform a driving task that we don't do very often, such as parallel parking, we edit our environment. We stop listening to passenger conversation, our field of vision shrinks, and we turn down the radio's volume (or we turn it off) in an effort to throw all of our focus into vision or spatial relationships, respectively.