This video shows medical students performing the fainting lark to induce syncope. The video was made by Lempert et al. to study the clinical features of “transient cerebral hypoxia”. Ethical committee approval was obtained. The students perform the “fainting lark” (hyperventilating while squatting, quickly standing up, whilst straining) to lose consciousness. 

Do not try this at home. 

First, the fainting lark is shown, followed by: falls (0:36),  akinetic syncope (1:04), myoclonus (1:24),  other movements (2:41) and eye movements (3:58).

Reference: Lempert, T. , Bauer, M. and Schmidt, D. (1994), Syncope: A videometric analysis of 56 episodes of transient cerebral hypoxia. Ann Neurol., 36: 233-237. doi:10.1002/ana.410360217