Scientists now believe that neuroweapons are the mostly likely cause for the mysterious attacks that left more than two dozen U.S. government officials stationed in Havana with symptoms including dizziness, hearing loss, and cognitive problems, according to a Monday report from Yahoo News. Four scientists, including the first doctor to evaluate the affected patients, expanded on their diagnoses during a Pentagon-sponsored conference call Friday, as part of the Pentagon’s larger effort to determine the person—and weapon—behind the attacks. But while neuroweapons are a likely culprit, scientists can’t yet agree on what kind of neuroweapon was used. Some, including Michael Hoffer at the University of Miami, believe the weapon targeted only the victims’ ear canals, while scientists at the University of Pennsylvania believe the patients suffered a minor traumatic brain injury instead. “If anything else, the Havana Event is a wakeup call for us, we really have to take a look at these kinds of gray area neuroweapons very carefully,” one University of Pittsburgh professor said. Others have questioned the validity of the entire investigation, arguing that top health experts at the Centers for Disease Control and Prevention were not included early enough in the process. And despite the neuroweapon determination, the motive, weapon, and parties responsible for the attacks remain unclear. “Somebody needs to get the bottom of it,” a DARPA official said.