A few weeks ago, I awoke in the middle of the night, not from a nightmare or indigestion, but from an idea that I wanted to share with a friend. At 3am, I booted the computer and started drafting an email.
The last time you sent your friend a link to a video, did you think about why? You probably looked at many stories that day, so what made that one worth sharing?
Philosophers have been grappling with similar questions for millennia. Aristotle suggested persuasive ideas shared three traits: they must be credible, elicit emotion and make sense. More recently, marketers and psychologists have looked to the internet to study why certain videos and articles get passed on while others get passed over. Aristotle probably wouldn’t have been surprised to learn that articles that excite a reader and have a positive message are more likely to reach the New York Times’ most-emailed list.
Only in the past few years, however, have we had the chance to glimpse the neural underpinnings that drive us to share silly cat videos. At a talk recently, Stanford neuroeconomist Brian Knutson mentioned a study that examined whether brain activity can offer clues to how popular something is likely to become. The study, by fellow PT blogger and Emory neuroeconomist Gregory Berns, suggests it can.
In his study, 32 teenagers, aged 12-17, completed a functional MRI scan during which they listened to 15-second song clips. Berns asked them if they liked the song and how familiar it sounded. He then followed the songs 3 years later to see which became hits.
First, Berns found that subjective liking was associated with greater brain activation in three regions, the ventral striatum, the ventromedial prefrontal cortex (vmPFC) and the cuneus. These regions have been shown in previous studies to encode value in the brain. People have a greater ventral striatum response to the possibility of winning $5 rather than $1. Similarly, they have more activation in the vmPFC when receiving $5 compared to $1. So it makes sense that these regions would have more activation when someone reports liking a song.
When he looked at sales of music, he found no relationship between subjective liking of a song and copies sold. How much the teenagers reported liking the music turned out to be a poor predictor of sales.
When Berns looked at brain activity, however, a different pattern emerged. Activity in 32 teen brains while listening to songs was linked to how many people bought that music over the next three years. The songs that elicited more activity in the ventral striatum racked up more sales.
As exciting as that relationship is, there are several reasons to interpret the results with caution. Berns didn’t use a robust prediction model or out-of-sample data. Using out-of-sample data would help validate the relation between brain activity and music sales. A recent paper suggests failure to use out-of-sample data leads neuroimaging studies to generate overly optimistic models. It is unclear how well the pattern reported in the study will generalize to other groups.
Further, we don’t know if brain activity represents unique predictive information. It could simply be a biological sign of something we already know predicts popularity, like how much the song elicits emotion. Future studies should address this.
Nonetheless, these results give reason for enthusiasm. A number of recent studies have examined what makes music or videos go viral, but this is the first to explore the brain’s role. The results provide initial evidence that ventral striatum activity from a few people when listening to a song could be a telltale for whether other people will buy it.
The idea that woke me germinated a few days prior when Brian Knutson told me about Berns’ study. I wonder what happened in my brain when I first heard about the study and if it would indicate that I’d later want to pass the finding along to a friend.
So how likely are you to share this post? If you just had a spike of ventral striatum activity, chances may be good.
Image credit: ElizaC3
Thanks to Julie Rodriguez for suggestions and to Phil Collins for ideas. Thanks to Greg Berns for sending me a copy of his paper and to Brian Knutson for telling me about it.