Some of you may not have heard the expression concentration phenomena. I'll give you a very simple one, and then we'll talk about meditation. In grade school, chalkboards, the teacher's on the board writing, and all of the sudden the chalk makes that scratching sound. What did it feel like? If you were a typical person like me, there a shiver up the spine, but did the teacher come and do anything to us? Did the teacher come and run a stick up our spine? We heard a sound, and all of the sudden we had a sensation up our spine. Weird. This is what's called a concentration phenomena, it's a very simply phenomena which virtually every kid gets, some adults, too, if they hear chalk scratching a chalkboard.
Now what's happening? We heard a sound, but something triggered off the feeling in the body. There's something strange happening. A sound is just a sound, why should it affect an energy element in the body? When the mind concentrates on something in an unbalanced way, it gets phenomena. The phenomena may have nothing at all to do with the actual concentration work itself. For some reason hearing that chalk ignites a similar phenomena in so many people, that I tend to think that it must be connected in some way with how people died in other existences, but that's just a little extra theory.
Regarding phenomena in meditation. Some people experience the body being really big, ten feet tall, whatever. Some people actually experience the head looking the wrong way, it's all twisted around, but it's not really happening. Some people experience being small, some people experience a sensation like rain drops on the body. Some people experience spider webs across the face. Some are pleasant and some are absolutely not pleasant. It's all phenomena, a misperception in the mind.
So if you experience any concentration phenomena in the meditation practice, what do we do then? Just note it, note it as a phenomena, try not to get attached to it, try not to hate it, try to see it just as an energy movement. Just like the chalk, it's the energy element in the body moving. Just try to note it for what it is. If you're in any way worried about it, perhaps you really think one of those phenomena is true, like the head twisted backwards, just open the eyes, look and see that everything is okay, "No it's okay it's just a phenomena".
Now a problem with a lot of people with concentration phenomena is that they put a different story to it, they put another misperception onto the phenomena. This is often what happens with religions that have prayer. A lot of people when they pray, they will get phenomena. They're so concentrated they will often get a very nice phenomena, in Buddhist terms it's called, "piti," which can be like pleasant raindrops in the body, but it's only a natural cause and effect phenomena. However, when a person doesn't know that it's simply a phenomena coming from concentration, they may put a story around the phenomena thinking they are in touch with God.
Unfortunately, then, as we know from history, people can do all sorts of crazy things. They actually believe they are a unique person in touch with God only because of a phenomena.
One unwise teacher once claimed in a talk that 86% of all Americans are first level enlightened, just because they have had a spiritual concentration phenomena. This teacher didn't know it was just a phenomena, so they believed 86% of all Americans were partly enlightened. This was an example of someone who totally doesn't understand what concentration phenomena is, and most religions don't, because they're not doing meditation as a scientific practice. They don't understand such occurrences.
This is a problem with many people, and what you want to do in your practice is with any phenomena that you have, just note it for what it is, see it as just another impermanent experience. Try to go back to your meditation subject and try not to get attached to it. The minute a person is attached to it, is that two things will happen. One is that it comes more, it'll come again and it'll come again, and for a while the person will be very happy, "Ah I've got it again, I've got it again." Until eventually, if a person gets a good teacher, they get told what it is, and then they go "Oh", and then they try not to have it. But it won't work, it'll keep coming, the person's stuck with it because they've built up so much conditioning of attachment to it that it keeps coming. Then their pleasant liking of it turns into hating it, wanting it to go away. So it's a big problem if a person gets attached on the liking side.
And it's also a problem if you start hating the phenomena, as I often say with my example of holding the fire. There's negative attachments, and if we start hating the phenomena, thinking, "I don't want that, I don't want that", it often keeps coming as well. So just to treat it neutrally, as just another impermanent experience, note it as phenomena and go back to what you're doing.