Your Brain Knows What You Like Better Than You Do
Brain imaging reveals hidden consumer preferences.
Posted Jan 02, 2019
A song comes through your earbuds: good rhythm, clever lyrics, pleasing melody. You know whether you like the song, right?
Maybe not. A series of studies using brain imaging raise the possibility that sometimes we think we like or dislike things, but our brains know better.
I will explain what I mean, by describing one of the studies. In it, teenagers listened to songs while researchers measured their brain activity using fMRI machines. Basically, an fMRI shows how much blood is flowing to various regions of the brain over time; when a pleasurable song pipes into kids' ears, for example, the pleasure centers of their brains light up. After playing music and scanning people's brains, the researchers and participants went their own separate ways. Two years later, the researchers looked at how the songs they played for the teenagers that day fared in the ensuing time. Surprisingly, the teenagers’ readings of the songs – of how much they liked or disliked – did not predict subsequent downloads. Their expressed opinions about the songs were like faulty political polls, failing to predict how they actually felt about the music.
Even more surprisingly, the number of times any song was downloaded over those two years did correlate with whether those songs lit up the pleasure centers of their brains at the time of the study. A student might have said a song was “so-so,” but if her fMRI image suggested that the song was pleasurable, it would be that image that predicted future song sales, not her stated opinions.
Skeptical? You should be. Maybe the teenagers didn't want to admit how much they liked the Justin Bieber songs they were exposed to (even though early Bieber had some solid tuneage). But before dismissing this finding, you should know that other studies revealed a similar disparity between what people said they liked and what they actually liked.
For example, one study showed people information about microloans they could potentially take out. The results of fMRI imaging were better at predicting the actual success of various loan products than were the hypothetical choices people made during the experiment. In another study, the success of crowdfunding campaigns was better predicted by fMRI scans than by people's ratings of each campaign.
So is the verdict in? Does the brain know more about what we like than we do?
The jury is still out and needs more evidence before it can make a decision. For starters, most research on this topic has involved only a small number of participants – from as few as 18 to a whopping 47. You see, fMRI studies are quite expensive, making it difficult to enroll hundreds or thousands of participants. With such small studies, we have to be concerned that a few outliers are biasing the results.
Second, there are probably researchers who have studied this question, found that fMRI ratings are no better than other measures of predicting subsequent behavior, and then decided the finding was too boring to publish: "We only had 25 fMRI readings, so our negative finding isn't worth reporting." This kind of publication bias means surprising, maybe even unrepeatable results are more likely to get published than less surprising, and more accurate, results.
While we need to be cautious about interpreting these early studies, it is notable that the verdict is undecided on this topic. A dozen years ago, few of us decision-making researchers would have guessed that fMRI scans could predict people's choices better than many attitudinal measures we had developed. Now we have to be open to that possibility.
You might think Drake's latest release leaves you cold, but your nucleus accumbens may know better.
Previously published in Forbes.