Hello, sorry for the late (and long) reply. I haven't been able to be very active on the forum lately.
In the first video you mention, between seconds 7 and 8, the man panics (regret or survival instinct) and tries to save himself (grabbing the rope with his hands and trying to brace his feet against the wall to stop the compression on his neck).
At 20 seconds he loses all muscle strength, and that is his death sentence; it is now impossible for him to save himself. Then he loses consciousness and the characteristic
involuntary body movements are observed (signs of severe brain damage).
It's a normal amount of time (seconds); it's not a hard and fast rule that consciousness is lost after 15 seconds, but rather an average. Some people lose consciousness much sooner. On the first page of this thread, I attached
two PDFs studies with charts analyzing each phase of the death mechanism in hanging, which show that the time it takes to lose consciousness varies from person to person. (In those cases presented, the longest time was 18 seconds and the shortest was 8 seconds) The different videos posted here also show that the number of seconds of consciousness (and agonal sequence) can vary in each case.
Regarding the other video you mentioned
(please, add the link next time; that way it's easier for everyone to access the material):
[Hidden content]
It was a bad choice to put the knot on the side of her neck. We have
two carotid arteries, one on each side of the neck (both carry oxygenated blood to the brain and irrigate it), and both need to be compressed, so that consciousness occurs as quickly as possible.
For this reason, the knot of the ligature should be placed behind the neck in the center, so that the pressure and penetration of the rope are concentrated on the front and both sides of the neck. The area behind the neck where the knot rests will be the area with the least pressure.
Using a self-tightening knot (Arbor Knot) for the ligature helps in the compression process, because it closes itself to the maximum (when the body is suspended applying weight), exerting continuous and uninterrupted pressure.
She presents the decerebrate rigidity posture (indicates severe brain damage occurring) within seconds of losing consciousness. The blood flow (supplying oxygen and nutrients) is insufficient (cerebral hypoxia) and neurons begin to die.
You can also observe all the
seizure phases (in this case, they are also signs of brain lesions):
• Tonic phase: muscles suddenly get stiff (arms, legs, and trunk); extension of the back (arched in the shape of a C), neck, and limbs.
• Clonic phase: muscles go into rhythmic contractions; bending and relaxing at the elbows, hips, and knees. The arms and legs often jerk. They alternately flex and relax.
(All these movements are involuntary)
At 4:49 she regains consciousness and makes an attempt to get back onto the ladder by putting her foot on it, making it move even further away.. now without any chance of salvation.
I believe that somehow her body responded in the face of imminent death with its last energies (allowing some functions) in an attempt to preserve itself.
Perhaps it's something like the sudden "surge of energy" that people who are close to death exhibit.
Even if only one carotid artery is blocked (it's a medical emergency after all), the sudden and violent trauma inflicted on the body (a suicide attempt) is incompatible with life.
The brain is the most energy demanding organ, neurons require constant oxygen for glucose metabolism to sustain their activity/functions. If this resource becomes insufficient or blocked, damage begins to occur. Neurons depend on continuous and adequate oxygen delivery via blood flow.
Poor technique and understanding of the method prolonged the entire process too much. Both carotid arteries must be properly blocked/compressed.