Here you find some articles and resources that may be of value to you at this point.
Meditation and Yoga can Modulate Brain Mechanisms that affect Behavior and Anxiety-A Modern Scientific Perspective
Here is an article on engaging the Vegas nerve which was even published in Forbes.
Effects of Yoga Respiratory Practice (Bhastrika pranayama) on Anxiety, Affect, and Brain Functional Connectivity and Activity: A Randomized Controlled Trial
Here is an article on the polyvagal theory which is what I was telling you about by Dr. Stephen Porghes . The poly vagal theory address is getting someone out of a sympathetic into a parasympathetic state he also explains being in a ventral state which is more in a sympathetic state. That is the ideal state where people can connect socially and be effectively in the prefrontal cortex.