This is Your Brain on a Test


This is a picture of a Quick-Cap, which measures electrical activity on the surface of the scalp. While it looks like something out of a futuristic movie about thought control, it’s actually quite comfortable and unobtrusive. While it’s not nearly as precise as a fMRI, electroencephalography (EEG) is much easier to use and drastically cheaper; the cap does a decent job of registering which regions of the brain are firing moment to moment.

Carol Dweck and Jennifer Mangels had Columbia undergraduates wear the cap while taking a computerized trivia test. The students worked through over 200 questions, covering topics from geography, religion, world and US history, math and science, literature, and art history. These questions were chosen because they’d ring a bell of familiarity – students felt like they should know the answer, but often weren’t quite able to recall it. Example: In what country is Kathmandu? The computer adjusted the level of difficulty just slightly, so that most students felt a little frustrated, getting about 60% of the answers wrong. If they were below that level, the computer might feed them an easier question – “Who was the Confederate General at the Battle of Gettysburg?” – but if they were above the level, they got “Who was the Union General at the Battle of Gettysburg?”

Students typed in their answer. A couple seconds later, they saw a green light or a red light to indicate if they were accurate. A few seconds after that, they were shown the correct answer (i.e., General Robert E Lee, or General Meade, respectively). This gave them a chance to learn from their mistakes.

But whether they wanted to learn was an entirely different question.

That was the purpose of the scalp cap. It measured activity in the brain’s attention systems – just how vigilantly were the students paying attention when they found out of their answer was correct or not? And were the students bothering to pay attention a moment later, when they saw the correct answer? Fundamentally, this study separated students who just wanted to do well on the test from students who really wanted to learn new material.

Before the testing, the students had filled out a questionnaire to assess their motivation personality. Based on their responses, Dweck and Mangels split them into two groups. One group was concerned, primarily, with being better than others. They agreed with statements like, “You have a certain amount of intelligence and you can’t do much to change it,” or “It’s important to me to be smarter than other students.” The other group disagreed with those statements, and instead agreed to comments like, “It’s very important to me that my coursework offer real challenges.” This latter group wasn’t into comparing themselves. Let’s call these two groups the Grade-Hungry and the Knowledge-Hungry.

These attitudes had a significant impact on the EEG readings – the students’ motivation personality was visible in the brain waves, on a millisecond to millisecond graph.

The Grade-Hungry students paid extremely close attention to the moment of green light/red light – they really were obsessed with whether they got the answer right or wrong. But immediately after, their attention systems took a break. They checked out, and they weren’t really paying much attention when the correct answer flashed by.

Respectively, the Knowledge-Hungry paid attention (but not quite as obsessively) to whether they were right or wrong, and they paid significantly more attention to the correct answers. They took advantage of the chance to learn. This contrast was most dramatic when each group got an answer wrong. The Knowledge-Hungry activated deep memory regions, indicating they were storing these new facts away for later. Such activity was not nearly as deep in the Grade-Hungry, suggesting a far more cursory interest; instead, their brains seemed to feel threatened by learning they’d gotten an answer wrong. Their brains indicated a far more emotional, fearful response. They clearly did not like being wrong, and they didn't care that Katmandu is in Nepal.

Not surprisingly, when the students were later surprised by a retest, consisting only of the questions they’d gotten wrong the first time around, the Knowledge-Hungry kids did far better.

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