Though we have an understanding of what the Vagus nerve does, and I think this article misses that it is involved in both calming and stimulating the para-sympa

Though we have an understanding of what the Vagus nerve does, and I think this article misses that it is involved in both calming and stimulating the para-sympathic nervous system (someone correct me if I'm wrong), but the challenge with any of the "therapies" that apparently stimulate the vagus never is that we can't measure the vagus never directly, and are therefore making assumptions that this is the pathway these therapies are taking. I had built a "vagus nerve stimulation app" a while back which used vibration to enhance calm. I did some measurements comparing this vibrating stimulation to neurofeedback with a Muse device, and the results seemed positive, but because we couldn't say specifically which mechanism was being triggered, and that it wasn't more than just "listening to calm music", we didn't pursue it.