Where exactely is the 'source of thoughts' and the 'feeling of self' located?

When I am meditating, most of the time the thoughts feel like arising from the heart center, and sometimes they feel like lingering in the head. Same with the 'feeling of self', most of the time it feels like 'I am' feeling is located somewhere around the heart. I need to know as I think being mindful in this region will help a lot to stop thoughts and to attain 'anatta.