More About Laughter

Every time someone laughs around us, our brains must interpret what it means. As German scientists have discovered, it is more complex than we thought.

A joyful belly laugh is interpreted by the brain in a completely different way from a scornful titter or the giggle from someone being tickled, a group of scientists from Tübingen in south west Germany have found.

In experiments designed to help patients with chronic anxiety disorders, they found that positive non-verbal communication, such as a joyful laugh was processed by a different part of the brain from a negative, scornful snicker.

Laughing is one of the oldest forms of non-verbal communication and is also seen in rats and apes. It could be key to helping patients with psychiatric disorders, who often are unable to correctly interpret non-verbal communication.

Humans have developed several different forms of laughter, each of which can have a complex series of meanings and intentions behind them. “Laughing is a very strong signal in social interaction. If you are laughed at with joy you feel accepted. If you are the victim of scornful laughter, you feel shut out of the group,“ said Dr. Dirk Wildgruber.

In their experiments, Wildgruber and his team played various types of recorded laughter and measured how the sounds were interpreted in the brain. They found that giggles generated when someone is being tickled stimulates areas of the brain responsible for interpreting complex acoustic signals. Happy or scornful laughter, on the other hand, stimulates completely separate brain regions usually tasked with guessing the intentions of others. From there, the laughter kick-starts connections with different parts of the brain depending on the tone - negative or positive.

The next step will be to look into how people with psychological disturbances react to different laughter signals to find out which areas of the brain could be artificially stimulated to help them, said Wildgruber.