It is a new age myth that the crown chakra has to do with mental operations. You don't become more intellectual once the crown chakra opens. Intellectualism and mind-
First step is an opening the size of a large coin on the top of the head. With this opening you begin to get somewhat access to temporary ecstatic and trans-
Second step is when the upper half of the brain opens up, so to speak. That is all the way down to the top of the ears and it feels like a small helmet of glowing light has be put onto your head. Or like a cap. When this happens you live in lovebliss and you glide in and out of sahaja samadhi on a daily basis. It is tempting to think this is a fully opened crown chakra, but it is only halfway there.
Third step is when the entire underside of the brain opens up. A fully opened crown chakra is a complete ball of radiating white light. At one and the same time you sense energy radiating up into the brain from the spine, and at the same time you sense energy radiating down from the brain. It radiates from the brain in all directions at once. Up, to the sides and down, like a small sun. Once this happens you are in sahaja samadhi of constant oneness with the Self and utter detachment from all identifications. You will begin to see a faint golden light in everything around you. This light is undoubtedly a recognition of the Self in everything, but there could be other aspects to it as well. Funnily enough, the lovebliss will abate somewhat and turn into a silent, unmoving joy and love. All traces of ecstasy have gone.
Each step will open up in a matter of seconds. It is not that you move from step one to step two by having the coin-
Meditation on the crown chakra is very important and the basic practice of bringing energy up the spine and into the brain, and radiating it from the brain in all directions, will help in this.