The Brain Fart — What Causes It?

You walk into the grocery store, and that list of three things you didn’t write down (but instead repeated to yourself several times so you wouldn’t forget) evaporates. You walk up the stairs on an errand only to find that you’ve completely forgotten why you came. You miss your exit on the drive home from work, even though you’ve driven it hundreds of times.

The brain fart — that shifty thief has long been accused of random lapses of thought that give us pause (literally) — while we try to remember or retrace our paths.

Brain farts are part of normal brain function

“Having brain farts is just part of being human,” suggests an article for Discover magazine. Studies indicate that our brains conserve energy when we’re doing something repetitive.

Although brain research is still in its infancy, studies point to the default mode network (DMN) brain region as the culprit. This part of the brain is responsible for inward-focused thinking, such as daydreaming. But, believe it or not, this type of thinking is not passive and uses a lot of energy.

So, when you need to carry out a task that requires focused attention, your brain must inhibit the DMN.

But the DMN — appropriately named — is the default setting of your brain, so you will probably revert to it while performing many tasks throughout your daily routine. Your brain perceives familiar or monotonous tasks as patterns (They’re activities you’ve done many times before.) so your brain may take a quick timeout to preserve energy.

“As much as 30 seconds before test subjects in one study made a mistake, blood flow started to decrease in the part of the brain associated with maintaining focus,” summarizes Robbie Gonzalez of Dr. Tom Eichele’s 2007 research. “Autopilot would be a better metaphor,” explains Dr. Stefan Debener, collaborator on the study.

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Your brain is taking a quick timeout to conserve a little energy

It’s during this idle state of mind, when your brain is shutting down some of its processing systems it believes you don’t need in that moment, that brain farts are likely to occur. Your walk up the stairs or into your neighborhood grocery store, your drive home — these are things your brain recognizes as repetitive and sees as opportunities for a quick timeout — back to default mode — leading to the mental lapse.

Scientists assure us that DMN blips are typically short-lived, and once you realize you’ve made an error your brain will likely kick into overdrive to try and correct the mistake.

Since brain farts are part of being human, it’s unlikely you can eliminate them. But increasing brain function through learning or games helps build memory skills.