How to activate the vagus nerve

What's the vagus nerve? 

It transmits information from the brain to other tissues in the body, and plays a key role in mental health.

Because of its size, it regulates many  internal organ functions, such as digestion, heart rate, and respiratory rate.

HERE ARE A FEW WAYS TO ACTIVATE THE VAGUS NERVE 

LAUGHING

SINGING OR HUMMING

gargling water

HOLDING AN ICE PACK ON YOUR CHEST FOR 15 MINUTES