Yes! i have read the book "stealing fire" and it talks about this and also Nuns that go into deep prayer and lose their sense of self. Not sure if the compassion meditation is the same- i think the compassion is a gamma wave type, but the Nun related loss of self is linked to decreased activity in the right temporal lobe (don't quote me but i think thats the area)
I'm currently working on something that can allow me to see the different states - i.e. gamma, delta, alpha so that i can understand meditation more.
Dan Winter is working on an app http://www.flameinmind.com
that uses binaural beats, but its not coming out till may 2017.