[galdosdi]

Because sexual response is controlled by the brain.

If I imagine myself in a calming forest, I can feel calmer and my heart rate may go down. Does that mean I magically transported my soul to a forest or some other such superstition?

[openfuture]

Yes.

Or at least some cultures { think of it / use language } in that way

[nsouth]

It's nothing to do with reducing your arousal, but redirecting the nervous energy away from the genitals.