# What Brain Neurons Tell Us about the 'Hipster Effect' when Everything Ends Up Looking the Same

Jonathan Touboul is a mathematician and a neuroscientist. He holds a PhD in math from France’s prestigious École Polytechnique, where he won a prize for his thesis on how to simulate neurons in the brain. He publishes papers with titles like “Pulsatile localized dynamics in delayed neural-field equations in arbitrary dimension” and “The propagation of chaos in neural fields.”

Recently, though, Touboul has been thinking about hipsters. Specifically, why hipsters all seem to dress alike. In his line of work, there are neurons that also behave like hipsters. They fire when every neuron around them is quiet; or they fall silent when every neuron around them is chattering.

Because he is a mathematician, Touboul began to look for a way to explore this idea using equations. In other words, he constructed a mathematical model. His key insight is that people (and neurons) do not instantly perceive what is mainstream. There’s a delay. And in situations where the delay is large enough, the contrarians can inadvertently synchronize with each other.

“In wanting to oppose the trends, there actually emerges some sort of hipster loop,” Touboul said.

A day before Halloween, Touboul put a draft of his paper on the arXiv, calling it “The hipster effect: When anticonformists all look the same.”

The paper was catnip, of course, for the hipster blogosphere, which loves all objets highbrow/lowbrow, the more meta the better. But this is a whimsical analogy for a serious topic. Widespread synchronicity in the brain is considered harmful, Touboul noted. It’s a feature of epileptic seizures, which can occur when groups of neurons fire together in abnormal ways.

To help us better understand his mathematical argument, Touboul walked us through parts of his paper, which he is submitting to a physics journal.

Trying to unpack one of these models can be like describing a work of Cubism: The art is lost. To his credit, Touboul keeps the math in his paper light and graceful. A background in nonlinear dynamics certainly helps, but with a sprinkle of imagination, anyone can grasp the story that his equations tell.

Touboul begins by envisioning a world where people choose between just two styles: Call them punk or normcore. There are two kinds of people in this world: those who like to go with the flow, and those who do the opposite — hipsters, in other words. Over time, people perceive what the mainstream trend is, and either align themselves with it or oppose it.

Here are some examples with a population of three conformists and one hipster. How the world evolves over time depends on who starts off in the majority and who starts off in the minority. Take white to be normcore, and black to be punk (obviously).