I'm having some trouble with understanding Reaction Time (RT) method.
I have a hypothesis that M occurs at B where M is a mental activity and B is a location in the brain. To verify it, I want to use either method subtraction method or mental chronometric (here I say RT). Using fMRI and subtraction method, I think it can be done. For example, suppose that sequence of metal activities A-N-M occurs. Then, by using fMRI, where M occurs and subtract places which are activated when A and N occur.
But designing experiment using the RT, How can I do that where M occurs in brain?