Along the lines of the movies "Limitless", or Scarlett Johansson's new movie "Lucy". Basic premise of the story is: Man escapes from US government facility after the treatments, his brain continuing to evolve. Teaches himself to manipulate the usual systems: financial markets, the internet etc. while evading the government.
Then he becomes aware that there's someone else out there like him. An earlier test subject, further along on the brain evolutionary path.
They face off at the end, battling with a slightly vague form of mental combat...
Our protagonist loses, due to his opponent triggering some sleeper logic bomb implanted in his subconscious some weeks earlier via some abstract visual pattern.
I found this on the internet a few years ago. Any suggestions?