Almost everybody's had the experience: On your day off, you pull out of the driveway —and without thinking — turn the car as if you were headed off to work. Or those times when you drop your car keys in the regular spot at home — and then not remember doing it.
Those moments of absentminded action involve a kind of memory that allows us to do things out of habit, without consciously choosing to do them. This automatic processing frees up the rest of the brain to think about more important topics. If we had to consciously think through all the things we do out through habitual memory, there'd be little brain space left over.
A specific region of the brain is involved when automatic memory fires up and sends your body and brain off to do a task unconsciously. With a series of experiments, New York University researchers have pinpointed the region as the striatum, according to a recent study in the journal Neuron.
“The amount of mental space we have to do purposeful actions is very small,” says study coauthor Elizabeth Phelps, a professor of psychology and neuroscience at NYU. “Other actions, like walking or driving a car, are done in a sort of auto-drive. When you’re driving you can’t be paying to every little detail of how you steer the car and where the brake pedal is, if you are also going to be paying attention to signs, traffic signals and pedestrians.”
Phelps and her colleagues asked volunteers to scrutinize a computer screen, searching for the letter T, which was oriented in various directions. All around the T were other distracting shapes. The volunteers were told to push a button when they spotted the T and note the orientation of the letter.
Sometimes all the figures on the screen were in blue and sometimes they were in pink. Most of the time when they were in pink, the letter would appear in a specific quandrant. After repeating the process several times, a volunteer unconsciously learned that when the letters were pink, she should look for the T in the lower left quadrant, for example. As she turned her eyes in that direction, the striatum sparked into action. The brain region never lit up when the letters were in blue.
When the volunteers were asked later if they knew why they had gotten faster at finding the T, they were completely unaware of the association their brains had made between the color pink and the probable location of the letter, said study coauthor Elizabeth Goldfarb, a researcher at NYU.
We think we're conscious of what our brains are doing, but actually, we're not.
“It can be a little scary especially if you’re thinking about something and realize that for the last five minutes you’ve been driving along," says Marc Coutanche, an assistant professor of psychology and a research scientist at the Learning Research and Development Center at the University of Pittsburgh.
The upside — our brains can focus quickly: "If something changes dramatically, like a dog running out in front of your car, you’ll snap out of it," says Coutanche.
“An awful lot of our behavior is driven by habit and associations we’ve made by doing the same thing every day when we’re in the same type of situation,” said Susan Courtney, a professor at Johns Hopkins University and chair of the department of psychological and brain sciences. “And most of the time it works very well.”
But there are times when the brain’s penchant for going into auto mode can be problematic, said Courtney, who is unaffiliated with the new research.
For example, Courtney said, “you have a habitual path you take home from work every day, but today you have to stop at the grocery store. You have to keep that activity in mind or you’re going to go straight home and then realize you haven’t gotten the milk you were planning to buy and then have to go back.”
Courtney studies how the brain toggles back and forth between automatic and conscious memory. She suggests ways to snap your brain back to attention:
Leave a post-it note reminder where you can see it, on the steering wheel, for example.
Set your phone so that it beeps when you need to pop out of autopilot.
- Avoid distractions when you're trying to keep something in your head. If you're driving turn off the radio.
- Try to think of something related to what you want to remember. For example, you might keep thinking about your grocery list and whether you’ve forgotten to put something on your list.