Quite a coincidence, that you have the book. Scientist myself, but there is a lot not figured out yet.
(There is no such thing as coincidence?) I found the most important part to be about letting go of resentment.
No wonder forgiveness features high in prayer.
Zen people would say not to repress negative thoughts but to observe them, to say hello to them and
then let them go like clouds passing, then to come back into the present moment.
I like affirmations, its like focussing on something positive rather
than repeating negative thought records.
I am quite convinced that our emotions influence our chemistry, but also the other way round: when I feel well,
my brain thinks more positive thoughts.
Good luck in your experimenting. Glenna