I mean if then belief has a strong effect on cognition then theoretically it may be possible to dull or even eliminate pain with your mind. Think of it like this, belief based cognitive bias could build over time, meaning that you could stack the cognitive effect of it. You add one layer and the pain becomes slightly dulled and then add layers over following time, each coming to represent a new layer of cognitive bias stacked on top of each other.

----> belief in greater effect ---> cognitive bias ---> bias stack ----> repeat

I have tried this myself and it seems to have some merit from what I was able to perceive. I wonder what you may think. Does this in fact work? Could we train people to block out pain?