The opener will attempt to reverse a run of low scores when England begin the second test against West Indies in Grenada on Tuesday, having managed only 24 runs in the drawn first test.
"I did have a look back in early February, watched a little a bit and it has changed quite a lot," he told the BBC.
"It's evolutionary, if you tried to go back to exactly what you did it would probably be really unnatural. I'd like to think my game has improved over time, I definitely believe it has, it's just different," said Cook.
While the heat has been on Cook, he said the criticism does not worry him and he would continue to trust his methods.
"I have been lucky that I have had a very simple game plan on the mental side throughout my career and it definitely works," he said.
"I am a resilient guy who can try and play each ball on its merits for a long period of time, that is kind of what my success has been built on so that hasn't changed," Cook added.
Spinner James Tredwell, impressive in the first test, is a major injury worry after hurting his arm diving for a ball in Antigua. His place could go to all-rounder Moeen Ali.
West Indies have dropped spinner Sulieman Benn and have added quickie Shannon Gabriel to the squad.