i'd have to disagree with that, surely there has been research that you can "practice to get better" BUT Ti isBeing able to understand and comprehend subjects that require logical thinking have nothing to do with T functions. Your functions are more how you interact with environments, either internal or external, not your ability to think and understand things.
"Ti seeks precision, such as the exact word to express an idea. It notices the minute distinctions that define the essence of things, then analyzes and classifies them. Ti examines all sides of an issue, looking to solve problems while minimizing effort and risk. It uses models to root out logical inconsistency. Ti is calm, articulate, and aware of the forces that bind reality together. As introverted thinkers, INTPs spend the majority of their time and energy ordering the interior, logical world of principles and generalizations in an effort to understand."
INTP - Wikipedia, the free encyclopedia
and as far as the MBTI says it is the ONLY function that allows us to do this.
being an INFP our Ti is very weak it's our 8th function in the shadow functions...... we don't even use it unless we are in stress......
what you are describing is most likely Te that you have harnessed and learned to use.
now surely there are genius INFP's ( there are ALWAYS exceptions in topics like these) however they will be an genius in most things that prob require Te .
stuff that requires Ti will still be hard on them.( yes exceptions exist for this too)
also, like what josh man said there is a reason why NT's score higher in the charts........
EDIT: i'd also like to add Dr dario's research.
his research says personality type is a LOT more than just preference of brain region. They use their brains in fundamentally different ways.