He simply observed it, trying to get a better feel for it.
('It doesn't feel like it's conscious in the same way my brain is.') He mused.
Even its mental takeover was not something that the Symbiote was consciously doing, but rather something that was part of its biological programming. This matched the information that he had learned about it.
As time passed, the dormant brain began showing more and more activity. He felt excited at the prospect of mastering the extra brain capacity. However, that was not something that could be done quickly. The symbiote had grade-ten difficulty for a reason, and that reason wasn't purely due to the risk of being mentally taken over by the symbiote.
Currently, the brain was an empty slate. Neurons alone weren't enough for them to be of immediate use. It was like a computer without an operating system. There were training techniques that he would need to undergo, and planned to undergo in this training session.