I think it's "neuro" here is more "psychological", meaning the ability to
automatically know
en masse the people. In the past we have had ads almost "for everyone", it was not much possible choose a specific cohort with a specific message, yes you can send some brochures in specific places normally frequented by a certain cohort of people, you can use friends, but it's still not much targeted.
Nowadays we are able to "know automatically" and separate specific cohort of people, let's say we want something pro-rail and we have some angry users waiting for a late train, a news arrive in their aggregator narrating another train delay somewhere else caused by a landslide, another one caused by a suicide, finally an article on the terrible current years of rails due to climate change and social unrest. The angry target probably remain a bit angry, but far less than before. Similarly in a campaign against rail another news can pops up just when someone look for a possible trip/to buy a ticket, about some horror story of passengers leaving at 40+℃ for some hours due to some malfunction and bad management plus another about an accident due to little maintenance and safety checks.
Nothing new under the Sun, but the ability to get the right news/ads at the right time makes the level of effectiveness something much, much bigger than ever and the ability to target users is still in very few hands. They can't "rule the society" but being able to steer they are kind of ruler anyway.