This is not any kind of bioassay being done. It is simply a phenomenon that is done that is created in order to make an impression on you. It is a form of intimidation they are using to remind you it is they who are in control, not you. If you look beyond this manipulation and see it simply as acts of a bully wanting to intimidate their victim, to keep them complacent and obedient, you can rise above this and claim your sovereignty even under a seemingly forbidding situation such as this, where the extraterrestrials do have a large measure of control of things in a physical sense. But that is a narrow margin of superiority that is of practical significance to some degree but ultimately is a technical victory only. They cannot control your soul and your soul’s desires, nor what you do in service to the soul. That will be forever beyond their grasp. So this is something simply to be ignored, like the many other troubling sensations you experience of the same sort, meant to be reminders of their ability to interfere with you.