The choking game or blackout challenge is the act of intentionally cutting off oxygen to the brain with the goal of inducing temporary loss of consciousness and euphoria. Reasons for practice Limited research has been conducted regarding motivations for practicing the fainting game, although thrill seeking has been identified as a risk factor, as has the perception that it is a low-risk activity. Anecdotal reasons stated include: Peer pressure, a challenge or dare, a rite of passage into a social group or amusement over erratic behavior. Curiosity in experiencing an altered state of consciousness, the experience of a greyout, or an imagined approximation to a near-death experience. A belief that it can induce a brief sense of euphoria (a rushing sensation or high). The prospect of intoxication, albeit brief, at no financial cost. Reasons for practice are distinct from erotic asphyxiation. Steve Field, chairman of the Royal College of General Practitioners in London, claims that the fainting game is pursued primarily by children and teens "to get a high without taking drugs." Children "aren't playing this game for sexual gratification." It is frequently confused with erotic asphyxiation, which is oxygen deprivation for sexual arousal. Unlike erotic asphyxiation, practice of the fainting game appears to be uncommon in adulthood. Mechanisms of effect There are two main mechanisms behind many variations of this practice, both resulting in cerebral hypoxia (oxygen deprivation to the brain). The two mechanisms tend to be confused with each other or treated as one but are quite dissimilar although both have the potential to cause permanent brain damage or death. The two mechanisms are strangulation and self-induced hypocapnia and work as follows: Strangulation A ligature such as a belt or rope around the neck, or hands or arm pressure on the neck compresses the internal carotid artery. Apart from the direct restriction of blood to the brain there are two other significant responses produced by pressing on the neck: Pressing on the carotid arteries also presses on baroreceptors. These bodies then cause vasodilatation in the brain leading to insufficient blood to perfuse the brain with oxygen and maintain consciousness. A message is also sent via the vagus nerve to the main pacemaker of the heart to decrease the rate and volume of the heartbeat, typically by a third. In some cases there is evidence that this may escalate into asystole, a form of cardiac arrest that is difficult