Brain researcher Katarina Gospic: It is unlikely that the Havana syndrome is mass hysteria

Up to 200 Americans who have been employed at the CIA, Pentagon or the country's embassies have suffered from what is known as the Havana Syndrome - a collection of symptoms with everything from visual disturbances and loud noises that do not disappear to depression.

The symptoms have occurred in staff around the world and there is no explanation for what caused them, but a common theory has been mass hysteria.

Brain researcher Katarina Gospic says that the spread of the cases means that mass hysteria is probably not what is behind it.

- That many in different places in the world would only be affected by mass hysteria in that way, I think is unlikely, she says.

Can be a combination

Another explanation discussed is microwaves.

Katarina Gospic believes that in that case it may have been used together with something else.

- You can not hear microwaves.

It is on the same spectrum as light.

We can not hear the color red.

However, microwaves can help create phenomena that you could hear.

It is not the wave itself.

But that you can influence people without them knowing if it has been determined, says Katarina Gospic.

- We can influence thoughts, feelings and behaviors and it is a powerful tool.

An example is how people are affected before elections.

- If I'm unsure and should go and vote, you can of course strengthen my insecurity which means that I stay on the couch, and then a type of candidate will benefit from my behavior.

Hard to know for ordinary researchers

But for an ordinary mortal, it can be an impossible task to try to find out what is behind phenomena such as the Havana syndrome, she explains.

Conventional researchers are not allowed to take part in intelligence research.

- I think we will not know the right answer.

If I worked with intelligence and came to the conclusion that it was then I would not reveal it, says Katarina Gospic.

Click on the clip to hear brain researcher Katarina Gospic talk about the syndrome and see more about the Havana syndrome in the Foreign Office: The Havana syndrome on SVT Play.