Once again my memory fails me… I think in the MN (but not sure) there is a sutta which describes an advanced practice where one, just out of will-power and as a practice, turns a pleasant feeling into an unpleasant one, and vice versa.
And how are they a noble one with developed faculties? When a mendicant sees a sight with their eyes, liking, disliking, and both liking and disliking come up in them. If they wish: ‘May I meditate perceiving the unrepulsive in the repulsive,’ that’s what they do. If they wish: ‘May I meditate perceiving the repulsive in the unrepulsive,’ that’s what they do. If they wish: ‘May I meditate perceiving the unrepulsive in the repulsive and the unrepulsive,’ that’s what they do. If they wish: ‘May I meditate perceiving the repulsive in the unrepulsive and the repulsive,’ that’s what they do. If they wish: ‘May I meditate staying equanimous, mindful and aware, rejecting both the repulsive and the unrepulsive,’ that’s what they do.
I found the other suttas that contain this teaching, probably it comes from an SN transmission originally: SN 46.54, SN 52.1, SN 54.8, AN 5.144, DN 28.
Perception involves not only feeling, but importantly views:
“Gone astray with wrong views, beings
Mis-perceive with distorted minds.”
"Eventually such thought patterns can become habitual, and evolve into distortions of view (ditthi-vipallasa). We might become so convinced that there is a snake by the path that no amount of evidence to the contrary from our own eyes or reason, nor the advice of others, will shake our beliefs and assumptions. We are stuck in a mistaken view.
Furthermore, these three levels of distortion are cyclical — our perceptions are formed in the context of our views, which are strengthened by our thoughts, and all three work together to build the cognitive systems which make up our unique personality."—Olendzki, translator’s note AN 4.49.