As the kundalini rises it begins to change the vibration of your being, both expanding and accelerating your awareness. As it illuminates the chakras, the chakras begin to switch on and vibrate, sending powerful surges of energy and vibrations up the spinal column into the brain.
These vibrations stimulate the brain which operates with increasingly greater efficiency. The brains ability to detect subtle phenomena expands. Like a very compressed program of evolution, the brain operates in increasingly powerful ways, experiencing reality at increasingly subtle levels. Rather than observing the surface of things that is the report of the senses, you begin to experience reality at its vibrational essence.
What we call yoga, spiritual life, is the experience of the kundalini rising and stimulating the brain, causing it to evolve in its operations. Meditation is the essence of yoga and calibrates this process