Major powers are known to have engaged in extensive research into human and animal brains for military purposes for decades. Research in this field is known to go back to the Cold War. In 2018, researchers obtained a massive trove of documents
on MKULTRA, a secret CIA programme that engaged in mind control experiments on people and animals, revealing that among other things, the agency sought to create living machine remote control dogs and "electric fishes" fitted with electronic implants and to test experimental mind-control drugs on unwilling human test subjects such as prison inmates. The USSR was known to have engaged in similar research
, but to have focused on parapsychological experimentation and artificial mind control devices rather than the use of narcotics and brain implants.