P O V:
I'm surprised that I can't find any scientific studies on the subject (maybe I'm not looking hard enough). Wouldn't it be nice to have scientific "proof" of the different jhanas; that the jhanas can be linked to specific brain wave frequencies. It probably isn't that straight-forward but anyway it would be interesting to see "the brain on jhana".
You're right. It isn't that straightforward.
P O V:
The main reason I ask is that while I'm new to the jhana models I'm more familiar with brain waves. I can recognize when my mind switches to an Alpha state for example, so if I knew that this correlates to say access concentration it would help a lot.
So, what you're basically saying here is that you are searching for a way to be able to identify absorption states when they are occurring in your practice. That's always the first stumbling block that new practitioners have when attempting to practice the jhanas.
I was around when some of the first literature was being published in the 1960s about brain waves and the alpha state, so I am familiar with this.
The only problem with using brain waves to be able to identify these states is that they do not always line up with the way the Buddha has described, and so many of us have experienced, these states. For instance, the alpha state can veer off into dull mindedness, which is the polar opposite of mindful absorption. I've just given you a couple of hints right there.
If you're looking for a way to identify absorption when it occurs in your practice, you would do better to work using the model of
samadhi and how this can expand into full blown absorption. After all, the eighth step of the noble eightfold path is "right concentration" or
samma samadhi. And before "right concentration" can take place, "right mindfulness" (
samma sati) must be established in place. Now, the term
samadhi is used in a variety of ways in the Pali suttas. But, as it pertains to absorption and the jhanas, there are some very specific factors involved, and these would include
the development of concentration such that the "unification of the mind" on an object or subject takes place. As that unification becomes absorbed in that object or subject, one reaches the first jhana. So, the first step on the way to absorption is the cultivation and development of "concentration" (which also happens to be one of the definitions of
samadhi). From there, together with mindful alertness (
sati), the mind becomes unified around the object, which in turn establishes the first jhana.
One thing to keep in mind here is that this process (the process of achieving jhana or absorption) is not mystical or mysterious (an altered state). It is straightforwardly involved with the cultivation of enough concentration to allow the mind to become unified and absorbed in its target, be that an object or a subject.
So you see, attempting to equate the alpha state with the description given above is problematic, as it simply does not adequately begin to encompass all the factors involved in the achievement of absorption. It doesn't even address any of the factors involved in achieving so-called "access concentration," for the same reasons as given above (i.e. the mind can devolve into dull mindedness and therefore veer off the path of concentration necessary to achieve "access concentration").
I'll give you a rule of thumb to go by as far as the achievement of "access concentration" is concerned. It involves unbroken and undistracted awareness of an object for an extended period of time. For example, if you can maintain unbroken awareness or with broken awareness not passing by without notice of an object (like the breath, for instance) for a period of two minutes then you have the requisite amount of concentration necessary to attempt to enter the first jhana.