If you watch a lot of soft porn, you may want more extreme stuff in the future. Porn, suggests a new study, influences the structure of your brain: in fact, it might even make your brain shrink.

Men who watch large amounts of sexually explicit material have brains with smaller reward systems, a study finds.

“That could mean that regular consumption of pornography more or less wears out your reward system,” says Simone Kühn, psychologist at the Max Planck Institute for Human Development in Berlin and lead author of the study, published in the “JAMA Psychiatry” journal.

Your reward system is a collection of neural structures in the brain that regulate and control behavior by inducing pleasure.

The researchers scanned the brains of 64 men aged between 21 and 45 with a MRI machine.

Those probands – or study subjects – who watched porn often had a smaller striatum, which is an important part of the reward system and also involved in sexual arousal.

The study also found that the reward systems of porn-experienced men were less active when they watched sexually arousing pictures inside the MRI machine.

“We assume that probands with a high porn consumption need increasing stimulation to receive the same amount of reward,” Simone Kühn says.

Consequence or precondition?

But were men with smaller striatum seeking more porn because they needed more external stimulation, or did the higher consumption of porn make this part of the brain smaller?

The researchers admit both could be true. But they say the latter is more likely.

Kühn says existing psychological, scientific literature suggests consumers of porn will seek material with novel and more extreme sex games.

“That would fit perfectly the hypothesis that their reward systems need growing stimulation.”