Most of our measures of a key cognitive process do not agree

The amygdala is a structure located deep in the brain that tends to be active when people react emotionally to events (as well as a wide variety of additional circumstances). So it makes sense to expect it to be less active if people tried to dampen their emotions. But to know if this is actually accurate, we need to look at brain activity. Here, the team relied on 40 functional MRI datasets, providing a large enough data set to tease out even relatively small effects.

Which is a good thing, because the effects were really hard to detect. “The effect size was relatively small: to detect this effect size with 80% statistical power, a single study would need to test 1,105 participants,” the researchers note, adding that very few fMRI studies have access to this many subjects.

But even bigger problems arose when differences between individuals in the MRI data were compared to their differences in questionnaires or in task-based assessments. Almost no variance in the different measures was correlated with each other. We could go over the numbers, but one figure published in the newspaper makes the problem very clear.

A question of timing?

Other problems arose when researchers began studying the activity of areas of the brain responsible for high-level decision-making. If people were truly leveraging their ability to reappraise emotional triggers, these areas would likely need to be active, as they are necessary to fuel the reappraisal process.

But that’s not what the fMRI data shows. Instead, there was a correlation between the response in the amygdala and the response elsewhere in the brain. In other words, if the amygdala was very active, implying a stronger emotional response, then the activity in the decision-making areas of the brain was also higher. If the emotional response seemed muted, then activity in the reasoning centers was also lower.