Yogic dhyana originates in back brain, based on past experience.
Yoga Sutras
Pranayama — Source of Dhyana (Meditation)
Yogic dhyana commences with pranayama. Pranayama to samadhi is a single continuous process.
Pranayama—Desha Kala Samkhya Regulation
Pranayama regulates breath by desha (region), kala (duration), samkhya (cycles).
Pranayama (Part 3)
Breath and mind: two sides of the same coin. Breath assists comprehension.
Pranayama (Part 2)
Pranayama uses vehicle of the breath. Breath & mind must benefit from asana.