Hi,
I'm new to the DhO and very much appreciate the members feedback from what i have skimmed. I started concentration meditation about a year and a half ago through a practice with a friend and went to a zen center later on on a school field trip. After the zen center I used breath as my primary object of concentration and practiced every day for a few hours. I felt i was going nowhere and I was a bit dogmatized to my own intellect at the time and kept chasing my own tail, not wanting to hear others advise. Anyways... Lately i've picked up again and during my practice about an half hour to an hour into it i start feeling the breath through my whole body with the whole of my mind and the sensation in the center of my forehead begins dividing, or splitting, into two pulsating sensations that traverse across my forehead and come to rest at my temples. The sensations on either side simultaneously grow stronger with each breath in and dim with the breath out. The sensation in the center of my head re-appears and pulses with the sensations at my temples and I feel a sense of unity and emptiness, like I am completely hollow. It's a very pleasant experience, just would like to know what it may be.

"the sensation in the center of my forehead begins dividing, or splitting, into two pulsating sensations that traverse across my forehead and come to rest at my temples."

Mason, I'm new here too. I do not have an answer for you, but I've had a very similar experience. In my case, it feels like my 3rd eye gets sucked in and then turns inside out. I imagine a rubber membrane folding in and flipping around--or something splitting and slaying. I asked a Sri Lanka monk/meditation teacher about this and other experiences. He said, "I can't help you. It's as if you are at a 2nd grade level and are seeking advice from a PhD student."

Sheesh, am I glad to have found Ingram's book and website!

Nice to meet you.

~CG

Two guesses based on the clues you provide:

The two sides of your body feeling different or distinct it a very 3rd ñana (Three Characteristics) type of description, but the marked pleasantness and mentions of pulses makes me think it has progressed to early A&P.

These are my impressions this morning. I hope they help and am glad you like the book,

Daniel