The long-running case of alleged “sonic attacks” conducted against US embassy personnel in Cuba has just developed a fresh twist.
New findings by a large team of American researchers seem set to guarantee that the matter, more evocative of old Cold War spy stories than modern-day cyber-snooping, will continue to attract attention for quite a while yet.
The story began in late 2016 when a few staff at the US and Canadian embassies in Cuba started reporting a range of chronic yet vague health problems.
Typically, those affected would report a sudden onset of symptoms, which centred around a loud grating noise – evocative of the sort of cavitation produced by driving a car with a window slightly open – sometimes accompanied by sensations of pressure and vibration.
For some of the people involved, the symptoms were unpleasant and debilitating. However, they were far from universal, with embassy staff members in neighbouring offices, pedestrians on the street outside, or residents of adjacent buildings reporting that they neither heard nor felt anything.
At least three of the US staff affected were CIA operatives. Intelligence agents are by their nature paranoid people and it was perhaps inevitable that because the cause of the grating noises remained unknown (and, in some ways, the noises themselves remained unconfirmed) a theory positing malevolent intent emerged.
By 2018 investigators – which included US, Canadian and, eventually, 2000 Cuban researchers – were no closer to an answer. Then the New Yorker magazine ran a feature about the travails of embassy workers in which the collection of putative symptoms was labelled “Havana Syndrome”.
Given that it sounded very much like the title of a thriller that should have been written by Graham Greene or Martin Cruz Smith, the name stuck.
Initial findings were vague, but US and Canadian authorities were quick to dismiss any implication that the distress of the embassy workers was the result of any kind of Cuban government subterfuge.
That message changed dramatically (although perhaps not unexpectedly) in late 2017, when US President Donald Trump declared that the Cubans were behind the “sonic attacks” against US personnel.
The president (again perhaps not unexpectedly) offered no evidence to back up his claim, nor any ideas as to how any such attacks were being carried out.
Several theories were suggested by researchers and pundits. Some mechanisms, such as the use of electromagnetic waves, were in principle testable. Others, such as mass hysteria, were unhelpfully recursive – if hysteria was responsible for the symptoms, what caused the hysteria?
Many people thought, or perhaps hoped, that the bizarre story had reached a natural, if farcical, end in 2018 when a team of scientists analysed an audio recording made by embassy personnel and concluded that the high-pitched drone it captured was made by crickets.
In particular, the researchers declared the god-awful racket was being made by a species called the Indies short-tailed cricket (Anurogryllus celerinictus), which was native to Cuba, rather short-lived and extremely loud.
And there, perhaps, the matter may have lain were it not for a team of doctors led by Ragini Verma, from the Diffusion and Connectomics in Precision Healthcare Research Lab in Pennsylvania, US.
Verma and colleagues decided to subject 40 former embassy employees – all of whom claimed to have experienced symptoms – to functional magnetic resonance imaging. They also performed the same procedure on 48 demographically similar but symptom-free non-diplomatic controls.
The results, published in the journal JAMA, reveal that the brains of embassy staff members were significantly different to those of the other participants.
In particular, the authors report, there were differences in “whole brain white matter volume, regional grey and white matter volumes, cerebellar tissue microstructural integrity, and functional connectivity in the auditory and visuospatial subnetworks of the brain”.
Other major parts of brain architecture, however, including whole-brain functionality, showed no difference between the two groups.
And while it is perhaps significant that the brains of people who all claimed to have been subjected to some form of sonic insult are different to those who have never holidayed in, much less spied upon, Havana, the results do not conclusively point to covert counterintelligence cleverness.
(And neither, by the same token, do they exculpate the crickets.)
Verma and colleagues acknowledge several limitations in their research design, including the impossibility of distinguishing whether specific individual brain architectures existed before any move to Cuba, and the fact that completely matching the test subjects with controls wasn’t feasible.
“The clinical importance of these differences is uncertain and may require further study,” the authors conclude.
Clearly, the world has not yet heard the last of Havana Syndrome.
Barry Keily is a science journalist based in Victoria, Australia.
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