Re: Why don't we practice chokes?
It is unfortunate that the method of applying the Vascular Neck Restraint was not described in the abstract (only so much you can say in 250 words!). I would love to read the full-text of the paper.
It would be great to re-run the experiment with the VNR applied by an expert in shime-waza. Perhaps the tell-tale signs of vasovagal syncope associated with the carotid sinus baroreceptor reflex (bradycardia, decrease in mean arterial pressure) would be observed.