You are talking about fMRI I think. Whilst this can be useful in tracking dementias and seizure disorder. Its use in understanding brain activity for given tasks is controversial as studies in a given individual are very inconsistent.
This is a good revue from Duke University.
Interesting.
This group had the same task, buying groceries. Some used one side of brain 100% of time for the task, others used another side of brain, a 100% for the same purchasing decisions.
Just an interesting outcome. No idea if other tasks would show same results or not.
