It'll come as no surprise to anybody here that the human brain is pretty amazing, and I often wonder how far it can be pushed, or how much control you have over it (or your body by extension). I won't get into any metaphysical considerations here or anything like that, I'd just like to share something I do quite often and hope other people share too.
As far back as I can remember, I've been making up and playing mental games with myself. I didn't really do it consciously until I was maybe about 7 or 8, but as of today I still do pretty much all of them. They generally take no more than a few minutes and I think they're quite an interesting way of exercising your mind and figuring things about how you work.
I'm not sure whether this will come through as absolute lunacy or total stupidity on my part, but this isn't something I've ever seen discussed and I'm genuinely interested in it.
Here are some of my favorites:
this is probably the first one I can remember making up. You basically stare at any point in space (doesn't matter where as long as it's not empty), then gradually make objects disappear from the scene (not physically). It took me ages to do it at first, but if you concentrate hard enough it starts happening pretty quickly. I haven't been able to do it while moving my eyes, not sure whether it's even possible. I find it interesting to see that you can filter your own sight to an extent, and that your brain will even make up for the now-void spots. In my case, the larger the object, the harder it is to make it disappear (not enough RAM?), but small objects can be excluded pretty much instantaneously.
this is actually an extension of the one above, where instead of filtering objects out, you add ones in. This is pretty fun, and it actually comes in very handy, for instance if you're trying to see the finished result of what you're working on.
You can also do variations of the above two with other senses, such as singling out sounds or smells, but I personally find those much harder.
the simple and easy version of this game is to try and think about something completely different while talking to somebody. The more interesting version is to start a particular thread of thought about any subject. It's easier to stick to the same one and have enough to think about on this subject. Then you gradually start new threads, like for instance counting up, adding music, showing pictures on a particular subject, a moving pattern etc. while of course keeping the old threads "running". One thing that I find particularly interesting about this is that certain things are much harder to do together. For instance, talking out loud and having a different train of thought in your head is relatively easy, however entertaining two subjects at the same time in your head is nearly impossible (at least for me). In my case, I can stack up a lot of threads for stuff that I can project to my sight, however I find it much harder to stack up threads that require projected sound. For instance, if I count up by telling myself the numbers (thread #2), I start losing my train of thought (thread #1) pretty quickly. However, if I simply project the numbers as images then I have no problem. This game is also something you get better at overtime if you can figure out what things are easier to process together.
think of a muscle you wouldn't normally think of, one that you wouldn't normally be able to control consciously, and concentrate to the point where you can control it. It takes a lot of time, and I often find myself having to work through other muscles/tendons/skin before I can find the muscle in question. I don't manage to make it work all the time, but when I do it feels strangely rewarding.
this one is both amazing and dangerous, it's somewhere between pure simplicity and serious OCD. This is a game which for me quickly became a lot more than a game when I was a teenager and I would highly recommend not making it your lifestyle. The idea is to think through every single thing you tend to do without normally thinking too much. You then basically break down an activity to its most essential elements, clear the ones you don't need and re-arrange the other ones in a more effective order. This is interesting because you can become a lot more efficient at a lot of things, and you also realise that a lot of things you do are in fact a waste of time, so you can basically give yourself a lot more free time (at least in theory). The problem on the other hand is that if you make it your lifestyle, it can become really stressful and you start wanting to re-factor other people, which is really, really bad.
I'm sure plenty of other people must have similar games and I'm curious to know what they are.
Nice ideas! I realise i've tried a couple of these without thinking of them as exercises
The best "refactoring" I've experienced has been a simple shoelace trick - http://www.youtube.com/watch?v=TKWL1md7Dv4
A couple of people so far have spotted me doing and been confused :)
"Selective sight" might be partly physical too. I believe if you keep your eyes perfectly still (i.e. manually press them through your eyelids) your vision will slowly fade as the exact same image on your retina stops producing a response. A slight head movement will restore vision, as there has been some tiny shift again.
Then again, "physical" there probably means partly chemical on your retina, and partly your brain ignoring things that aren't moving.