You know the material. You’ve memorized diagrams, walked through the practice problems, can explain the concepts out loud the night before.

You sit, open the test, read the first question

and suddenly your mind is totally blank. Your facts have inexplicably become fuzzy, like the filing cabinet in your brain has been dumped out while you were walking through the door.

The inner monologue is immediately cruel and familiar: I didn’t study enough. I’m awful at this. I’m choking.

That diagnosis seems intuitive, but it’s almost certainly wrong. The problem when it comes to high stakes testing is rarely about storage, but it’s about bandwidth.

The Competition for Working Memory

Your brain allocates precious space in working memory to juggling and manipulating information in the present moment. Unlike long term memory, which has essentially infinite storage space, working memory is small and fragile.

And in the landmark work on performance under pressure, Sian Beilock and her colleagues set out to understand why people “choke”, by asking why the pressure of an impending test often leads to worse performance.

What they found out was fascinating: high pressure situations may not destroy what you know

but the pressure itself provokes worries about performance, consequences, and potential failure. Worst of all, those worries consume working memory, with similar bandwidth requirements as the math problem you’re trying to solve.

You don’t freeze because the memory of the Pythagorean theorem has vanished, but because calculating it suddenly seems impossible when you’ve got an earful of judgment in your head.

The Useful Distinction: Knowledge vs. Retrieval Capacity

The useful distinction, when it comes to understanding mental freezes, is between knowledge and retrieval capacity.

A problem with knowledge requires more study, better note-taking, and more frequent reviews.

A problem with retrieval is one where you need to free up the working memory space for the calculation.

When you’re under the impression that a brain freeze is a knowledge issue, you’ll tend to try harder to retrieve the information in the first place. This often has the opposite effect: when you strain your mental power to try and recall the answer right away, you increase the feeling of threat, prompting the intrusion of more distracting worries.

A Small Experiment: The Offload

In a study published in Science , Gerardo Ramirez and Sian Beilock tested out an incredibly simple behavioral intervention: expressive writing.

Students who spent ten minutes just before an exam free writing their worries about the upcoming test did significantly better than students who didn’t write anything at all. This was particularly true for test takers who typically experienced high levels of test anxiety.

While worrying out loud won’t give you the answer to a math problem, it will offload those intrusive thoughts onto paper, so that they won’t secretly consume the working memory right when you need it most.

The Next Time You Face a High-Stakes Exam, Try This Two-Part Sequence

The Pre-Test Dump: Spend five minutes before the exam begins writing down any worries that you might have on scrap paper. Acknowledge the stakes directly: ______or “I feel nervous about the third section” before tucking the paper away or throwing it away entirely.

The 30-Second Skip: If you find yourself frozen on a blank question, resist the impulse right away. Straining to retrieve the answer is the cue that will signal to your brain that there’s a threat of some sort, increasing the likelihood of additional intrusive thought. Circle the question, take your eyes off the page for three breaths to reset your working memory, and move on to the next, lower stakes question. This gives your retrieval network a chance to clear out the interference.

A Caveat On Preparation

Freeing up working memory only works if the information was encoded in the first place. Offloader worry can’t retrieve concepts that were never learned or practiced, and the objective of managing pressure is to make sure that anxiety doesn’t consume the effort that went into your preparation.

The Shift

Brain freeze is not an indictment of a weak intellect, nor is it a sign that you weren’t properly prepared.

It’s an overloaded processing system trying to solve two demanding problems at once, passing the test and coping with the fear of not doing well.

Once you accept that brain freezes are typically a bandwidth issue, rather than a content issue, you can begin to clear the lane and let the preparation take effect.

The research

Beilock, S. L., & Carr, T. H. (2005). When high chefs fall: Working memory and choking under pressure in mathematical problem solving. Journal of Experimental Psychology: General, 134 (1), 101-119. DOI: 10.1037/0096-3445.134.1.101

Ramirez, G., & Beilock, S. L. (2011). Writing about testing worries boosts exam performance in the classroom. Science, 331 (6014), 211-213. DOI: 10.1126/science.1199427