- In 2016, diplomats from the US and Canada in Cuba reported hearing strange sounds that resulted in mysterious health consequences, including balance and vision problems.
- Some people wondered whether the sounds were “sonic attacks” or microwave weapons, though a study published earlier this year suggested they may simply have come from crickets.
- Now, brain scans of 40 US diplomats who were in Cuba at the time suggest something sinister may indeed have taken place, since their brains don’t look like others.
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At the time, diplomats reported hearing strange, high-pitched noises that they described as humming, buzzing, grinding metal, or a piercing squeal (though a few described more low-pitched sounds). Some of the same diplomats and their families later reported having trouble balancing, speaking, and hearing, with some saying they felt “mentally foggy.”
This led some US lawmakers to wonder whether the sounds were “sonic attacks” from some never-before-seen type of weapon.
Whatever the cause, new scans of 40 US diplomats’ brains suggest that the sounds weren’t good for their health.
A study released Tuesday in the journal JAMA compared brain scans from the diplomats (all of whom were stationed in Cuba at the time of the strange sounds) against scans of 48 other healthy adults who were not exposed. The findings suggest the mysterious noises may have altered the diplomats’ brains in disturbing ways: Their brain volume, tissue, and connectivity all appear different now.
The researchers behind the new study caution that more research is needed, however.
The sounds may have had an effect on the diplomats’ brains, especially on the amount of white matter
In 2016, some – but not all – US and Canadian diplomats stationed in Cuba started reporting hearing the strange noises, which some people described as a “loud ringing or a high-pitch chirping, similar to crickets,” according to the Associated Press. One diplomat reported that a “blaring, grinding noise” woke him up, while others said they could walk in and out of the noises, since they were audible only in specific spots.
The US State Department eventually concluded that the incidents were “specific attacks” and cut its Cuban embassy staff by 60%. Cuba fervently denied any foul play.
“Cuba has never, nor would it ever, allow that the Cuban territory be used for any action against accredited diplomatic agents or their families, without exception,” the Cuban government previously said in a statement.
After the diplomats returned to the US, the State Department sent some of them (along with their family members) to the University of Pennsylvania to get checked out. Results of an initial investigation, published in March 2018, suggested that among 21 of the retuned diplomats, a majority still had balance problems, vision issues, hearing problems, and headaches. In January 2019, however, researchers posited that the sounds may have been nothing more than chirping Caribbean crickets.
Now, a study of even more of those diplomats suggests that they may have less white matter in their brains than other people. White matter is located in the deep tissues of the brain, and it protects the nerve fibres that strengthen the speed of electrical signals in the brain. Specifically, the 40 diplomats studied had, on average, about 542 cubic centimeters of white matter in their brains, while a control group of “healthy” study participants had around 570 cubic centimeters – a significant difference.
The diplomats also demonstrated lower connectivity in their visuospatial and auditory brain networks. That makes sense given how they reported feeling after the attacks, the study authors said.
“It’s hard to tell where the problem started; the brain differences observed could be an immediate effect of the brain injury, or it could a compensatory effect of the recovery process,” lead author Ragini Verma, a professor of radiology at Penn, said in a release. “The important thing is that we did see differences at the group level.”
The finding held true even after government personnel with previous brain injuries (like concussions) were left out of the study results.
But no big conclusions can be drawn at this point
It’s still tough to determine what this study really reveals, given that the researchers weren’t able to look at the diplomats’ brains before they heard those mysterious sounds. No control group can ever be a perfect match for another.
“It’s good work, but there’s just not enough here to come to any conclusion,” Dr. Mark Rasenick, a neuroscientist at the University of Illinois Chicago School of Medicine, told the New York Times.
Part of the problem is that there’s still no agreement on what the sound was or where it came from.
“We know that the complex connections of the brain are highly vulnerable to changes in a person’s environment,” Christoph Anacker, an assistant professor of neurobiology at Columbia University, told Business Insider in an email. “Understanding the source of the audible and sensory phenomena that these patients were exposed to would be important to improve our understanding of which factors can change the way different brain structures work.”
If you’re curious about what diplomats may have heard on the ground in Cuba, here’s an original recording of some of the sound, from the AP:
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