I've been using these techniques,
but I never put the scientific name to the process.
A combination of:
Vagus reflex - Wikipedia, the free encyclopedia
The vagus nerve plays a role in (amongst other things) controlling the pulse.
The vagus reflex is a reaction which can reduce the pulse rate during
tachycardia (racing pulse). The following stimuli may produce the vagus
reflex:
tensing the lower abdomen (similar to straining at stool)
gentle pressure on the closed eyes
a gulp of ice-cold water
splashing ice-cold water on the face
immersing the arms in ice-cold water
finger stuck down the throat
the insertion of an IV needle
cough or sneeze (involuntary or autonomic works best)
holding breath (after exhaling) - see Valsalva manoeuvre
insertion of an object into the uterus such as an IUD
Valsalva maneuver - Wikipedia, the free encyclopedia
The Valsalva maneuver or Valsalva manoeuvre is performed by forcible
exhalation against a closed airway, usually done by closing one's mouth and
pinching one's nose shut. Variations of the maneuver can be used either in
medical examination as a test of cardiac function and autonomic nervous
control of the heart, or to "clear" the ears and sinuses (that is, to equalize
pressure between them) when ambient pressure changes, as in diving or
aviation.
Negative Resistance Training Tutorial Video ? 5min.com
Eccentric contraction involves the development of tension whilst the muscle is being lengthened
Muscle contraction - Wikipedia, the free encyclopedia
In eccentric contraction, the force generated is insufficient to overcome the
external load on the muscle and the muscle fibers lengthen as they contract.
An eccentric contraction is used as a means of decelerating a body part or
object, or
lowering a load gently rather than letting it drop.
(without weights)
And that's as far as I've gotten.